The Impact of Indian Ocean Variability on High Temperature Extremes across the Southern Yangtze
海洋对潜艇的影响英语作文
海洋对潜艇的影响英语作文The ocean can have a significant impact on submarines. The pressure at great depths can put a strain on the hull of the submarine, and the saltwater can cause corrosion. Additionally, the ocean's currents and tides can affect the movement and stability of the submarine, making it more challenging to navigate.The ocean also provides a unique acoustic environment for submarines. Sound travels much faster and farther in water than in air, allowing submarines to detect and communicate with each other over long distances. However, the ocean's natural sounds, such as waves, marine life, and geological activities, can also create background noisethat makes it harder for submarines to remain undetected.Furthermore, the ocean's temperature and salinity can affect the performance of a submarine's sonar and other electronic systems. Variations in these factors can lead to changes in the speed of sound in water, which in turn canimpact the accuracy of sonar readings and the effectiveness of communication systems.In addition, the ocean's vast size and depth provide both opportunities and challenges for submarines. On one hand, the ocean's expanse allows submarines to operate covertly and remain hidden from adversaries. On the other hand, the deep and dark waters can make it difficult for submarines to navigate and maintain situational awareness, especially in unfamiliar or hostile environments.Finally, the ocean's marine life and ecosystems can also impact submarines. Submarines must take care to avoid colliding with whales, dolphins, and other marine animals, and they must also be mindful of the environmental impact of their operations on the ocean and its inhabitants.。
The Indian Ocean Dipole and its Impact on the Surr
The Indian Ocean Dipole: a Physical EntityToshio Yamagata1, 2, Swadhin K. Behera2, Suryachandra A. Rao2, Zhaoyong Guan2,Karumuri Ashok2 and Hameed N. Saji21Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan2Climate Variations Research Program, Institute for Global Change Research, Frontier Research System for Global Change, Yokohama 236-0001, Japan1. IntroductionThe El Niño/Southern Oscillation (ENSO) phenomenon has been discussed for more than a century and is now recognized, after the active TOGA decade, as the most important tropical ocean-atmosphere coupled phenomenon. Recently, the Indian Ocean Dipole (IOD) phenomenon has been catalogued as another important manifestation of the tropical air-sea interaction (Saji et al., 1999; Webster et al., 1999; Behera et al., 1999; Vinayachandran et al., 1999; Murtugudde et al., 2000; Rao et al., 2002; Vinayachandran et al., 2002). It has also turned out that the impact of the IOD is not limited to the equatorial Indian Ocean; it influences the Southern Oscillation (Behera and Yamagata, 2002), the Indian summer monsoon rainfall and even the summer climate condition in Asia（Ashok et al., 2001; Saji and Yamagata, 2002）. The robust nature of the IOD as an ocean-atmopshere coupled phenomenon is simulated successfully using high-resolution coupled GCMs that also resolve ENSO in the Pacific (Iizuka et al., 2000; Cai et al., 2002 (personal communication)). However, because of its inevitable short history of research, several interesting issues related to its existence/nonexistence and dependence/independence of ENSO have been raised by some researchers (e.g., Allan et al., 2001; Dommenget and Latif, 2002;Baquero-Bernal and Latif, 2002).In this study, using multiple datasets such as GISST 2.3b (Rayner et al., 1996), sea surface height from SODA (Carton et al., 2000), rainfall (Xie and Arkin, 1996) and atmospheric data derived from NCEP-NCAR reanalysis (Kalnay et al., 1996), we demonstrate that the Indian Ocean Dipole (IOD) is a physical mode involving dynamics of the tropical Indian Ocean, and not an artifact as claimed recently based on statistical fallacies only using the sea surface temperature data. We believe that the concept of IOD has raised a new question, and a new possibility to regard the old problems such as the relation between the Indian summer monsoon rainfall and El Niño from a new angle, and to make a real advance in the predictability of climate variations originated in thetropics.2.IOD as a physical entityAs noted by previous studies using the EOF analysis, a basin-wide SST anomaly induced by the ENSO appears statistically as the most dominant interannual mode in the Indian Ocean (Cadet, 1985; Klien et al., 1999; Wallace et al., 1998; Venzke et al., 2000). The zonal dipole structure appears as the second mode. However, the dipole mode shows up as the dominant signal in some years. For example, it was the case during May through November in 1994. Behera et al. (1999) showed that a remarkable dipole in OLR anomalies also overlies the SST dipole (Fig. 1a). In contrast to the 1994 event where the dipole is prominent only in the Indian Ocean, a similar phenomenon in 1997 was accompanied by another dipole pattern in the Pacific due to simultaneous occurrence of the well-known El Niño event (Fig. 1b).The IOD phenomenon is not confined only to these two events. According to the GISST data, SST anomalies show opposite polarities in the eastern and western Indian Ocean during 178 months in total 504 months from 1958 to 1999. The opposite polarity in SST anomalies is associated with corresponding opposite anomalies in the zonal winds in central equatorial Indian Ocean. In response to the anomalous winds, the sea level was depressed (raised) in the eastern (western) Indian Ocean during the positive (negative) dipole events. The IOD indices derived from all these oceanic and atmospheric variables are shown in Fig. 2. All those indices are remarkably consistent with each other. Interestingly, one of the poles in the sea level anomalies capture the dipole mode very well as the dipole is the dominant mode of variability in the subsurface layer (Rao et al., 2002). This establishes the physical existence of the IOD beyond any doubt.In contrast to the above observation, Dommenget and Latif (2002) (hereafter referred to as DL) have questioned the existence of the IOD by only analyzing the SST data statistically despite the fact that the IOD is introduced as a physical mode based on various oceanic and atmospheric variables as discussed above. Since the fallacy of the DL’s argument is demonstrated in Behera et al (2002) (hereafter referred to as BRSY), we here discuss briefly the pitfall DL encountered and vindicate the physical existence of the IOD. DL believe that the existence of the dipole mode should necessarily lead to an anti-correlation between the two poles. As demonstrated in BRSY using a synthetic example, just like that in DL, the correlation reflects the dominant mode of variability (cf. Jolliffe 1987), which is the basin-wide monopole mode in the present case in a statistical sense. Therefore, an anticorrelation between the two poles can beachieved only when the basin-wide mode is filtered out. BRSY have reconstructed the SST anomalies by removing the dominant EOF mode. Since dipole is now the dominant mode in the reduced data, a linear regression succeeds in reproducing the anti-correlation between the two poles (Fig. 3). Interestingly, the V ARIMAX method also succeeds in identifying the dipole mode in contrast to DL because the basin-wide mode does not co-occupy the dipole mode. The spatial patterns thus obtained correspond very well with the composite maps shown in Saji et al (1999). The time series of the EOF and V ARIMAX modes are also in excellent agreement with the DMI (Saji et. al. 1999) (Fig. 2).3. IOD as a coupled mode inherent in the Indian OceanSince we have demonstrated that the IOD really exists in the Indian Ocean, the next interesting question is whether IOD events in the Indian Ocean is independent of ENSO events in the Pacific. This is a natural question when we have two oscillators somehow related to each other under the global atmospheric bridge. Owing to the non-orthogonality between the two time series, the simultaneous correlation coefficient between DMI and Niño-3 indices is 0.37. The correlation coefficient increases in the seasonally stratified data, reaching up to 0.54 for September through November. Therefore, we are apt to conclude that IOD events occur as a part of ENSO events (Allan et al., 2001; Baquero-Bernal and Latif, 2002). However, the non-orthogonality of two time series does not necessarily mean that the two phenomena are always connected in a physical space. It is also important to note in general that the apparently high correlation of 0.54 explains only about 30% of total variance in terms of possible ENSO influence; we still have 70% variance unexplained by this external influence.To understand the physical nature of the possible connection, we investigate the Walker circulation that may connect the Indian Ocean with the Pacific through the atmospheric bridge. Here the Walker circulation is diagnosed from the zonal mass flux formulation as described by Newell et al.(1974) and Bergman and Hendon (2000). In order to distinguish the nature of the zonal cell in response to all IOD events and pure IOD events, we made two different composites. A positive (negative) IOD event is considered as a pure event when it is not accompanied simultaneously by El Niño (La Niña) (see Table I). The presence of the anomalous Walker cell in the Indian Ocean is clearly seen in both plots (Figs 4a and 4b). However, the composite for the pure IOD events (Fig. 4a) clearly shows an anomalous cell operating only in the Indian Ocean, thereby confirming the independent occurrence of the pure IOD. To escape frommisunderstanding, we repeat that this analysis does not exclude the possibility that some IODs may be physically linked with some ENSO events.The point of the matter is further clarified when we make similar composites for SST and sea surface height (Figs. 5 and 6). The SST composites (Fig. 5a and 5b) for all IOD events show dipole patterns in both the Indian Ocean and the Pacific Ocean. The warm anomaly pattern seen in eastern Pacific (Fig. 5a), however, disappears in the composite map of pure IOD events (Fig. 5b). Those are consistent with the composites of the Walker circulation shown in Fig. 4. In contrast, the pure ENSO composite (see Table I) does not show any basin-wide dipole pattern in the Indian Ocean, as expected. Cold SST anomalies are, however, seen along the coast of Australia and near the Indonesian throughflow region in the pure ENSO composite (Fig. 5d). Fig. 6d shows negative sea surface height anomalies associated with this coastal phenomenon without the basin-wide scale. This phenomenon is due to intrusion of the western Pacific signal during the mature phase of El Niño through the Indonesian passage and the subsequent spreading of water mass along the Australian coast by coastal Kelvin waves. It is discussed by Clarke and Liu (1994) theoretically and confirmed by Meyers (1996) using XBT data; we prefer to call this as the Clarke-Meyers effect.Although the above coastal phenomenon explains partly the high correlation between DMI and Niño-3 particularly during the boreal fall, it should not be confused with the basin-wide phenomenon of IOD (Fig. 5d). Both the pure and all IOD composites show clearly that the lower sea surface height anomaly in the eastern Indian Ocean is accompanied by the higher anomaly in the central Indian Ocean (Fig 6a and 6b). However, such a pattern is completely missing in the pure ENSO composites. The fact that sea surface height do not show any significant east-west slope in case of the pure ENSO suggests that basin-wide ocean dynamics do not play a major role in the development of SST anomalies associated with the pure ENSO; this has been demonstrated by Rao et al. (2002).4. IOD influence on the surrounding climateSince the indices of ENSO and the IOD are non-orthogonal, it is reasonable to raise a counter issue that the Pacific ENSO itself may be affected by the IOD. Using partial correlation analysis, Behera and Yamagata (2002) are successful in revealing such an inverse influence on the Southern Oscillation Index. It is found that the DMI has a peak correlation coefficient of 0.4 with the Darwin pressure index when the former leads the latter by one month. When the Darwin index leads by 3 months, thecorrelation coefficient (0.2) drops below the significant level. The pressure index of the central-west Pacific region shows a peak correlation of about 0.3 when DMI leads the central-west Pacific index by 4-5 months. This suggests that some IOD events precede some ENSO events. In Fig. 2, we find that three of the major warm ENSO events (i.e., those in 1972, 1982, 1997) are associated with positive IOD events. In contrast, three of the major positive IOD events (i.e., those in 1961, 1967 and 1994) were not accompanied by the warm ENSO events. This again suggests the likelihood of the Pacific phenomenon being influenced by the phenomenon originated in the Indian Ocean.The above relationship undergoes decadal modulation with a good correlation during three sub-periods of 1958-67, 1968-76 and 1988-97. The correlation, however, is significantly reduced during the decade of 1977 through 1987. Less frequent occurrence of IOD in the decade explain the reduction in the correlation. Similar decadal modulation of the IOD impact on the Indian summer monsoon rainfall has been recently discussed by Ashok et al., (2001).The influence of the IOD is not just confined to the tropical region, but reaching far to the whole globe (Saji and Yamagata, 2002). Owing to the non-orthogonality of the IOD and ENSO indices, however, the vast IOD influences have not been appreciated so far. In a series of articles, Saji and Yamagata (2002), using a partial correlation analysis, have demonstrated that the enhancement of the East African rain is dominated by the positive IOD rather than El Niño. Interestingly, the positive IOD and the warm episode of ENSO have opposite influences in the Far East including in Japan and Korea; positive (negative) IOD events give rise to warm and dry (cold and wet) summer owing to enhancement of downdraft in the troposphere. This was clearly recorded during the IOD events in 1961, 67, 1994, as compared to the simultaneous occurrence of the positive IOD and the El Niño during 1997. The Indian summer monsoon rainfall (ISMR) is enhanced (decreased) during positive (negative) IOD events; the recent weakening of ENSO-ISMR relation may be interpreted in terms of frequent occurrence of the positive IOD in the recent decade (Ashok et al., 2001). In the Southern Hemisphere, the IOD impact is remarkable in the southwestern Australia and Brazil because of propagation of planetary waves in the winter hemisphere; positive (negative) IOD events cause warm and dry (cold and wet) conditions. The mechanism for these global teleconnection certainly needs further investigation. We get busy.5.Summary and discussionThe brief report presented here from our recent work has shown various interesting aspects of the climate variation in the Indian Ocean simply because we obtain a novel viewpoint so far neglected.The IOD appears as the second dominant mode in the EOF analysis of SST anomalies, as compared to the gravest basin-wide mode related to ENSO events. We should note that the statistical dominance does not necessarily mean physical dominance (e.g. Figs.1 and 2). This is because less frequent occurrence explains the lower position in statistics. Actually, the IOD signal in the Indian Ocean is clearly seen even in the raw SST data in 1961, 1967, 1972, 1982, 1994, 1997 (e.g. Meyers 1996; Saji et al 1999, Behera et al. 1999). This also confirms the physical existence of the IOD in the simplest way despite that recent statistical analyses by several authors (Baquero-Bernal and Latif, 2002; Allan et al., 2001) have claimed that the IOD is a statistical artifact.We have shown results from the composite analysis of the Walker circulation, SST and sea surface height anomalies in order to check whether IOD events in the Indian Ocean are just slaves to the Pacific ENSO events. It is found that an independent Walker cell may operate within the Indian Ocean during pure IOD events. The intrinsic property is further reflected in the SST composites. During pure IOD events, the composite plot does not show any significant SST anomalies in the Pacific. Interestingly, the composite pictures of SST and sea surface height revealed that, during mature stage of pure ENSO events, those anomalous fields are only evident near the western coast of Australia. The mature ENSO signal passes through the Indonesian throughflow and spreads along the Australian coast through the oceanic process of the Clarke-Meyers effect. This explains the high correlation between DMI and the Nino-3 during September-November. However, these anomalies are different from the signal associated with the basin-wide IOD wherein the remarkable dipole structure in SST and sea surface height anomalies are seen in the eastern and western Indian Ocean with a basin-wide scale (Figs 5 and 6). The above is consistent with a recent observational analysis of fossil corals off Sumatra (Mentawai Island) that traces an independent IOD signal back to the mid-Holocene (6000-yr) period (Abram et al. 2001).As discussed, IOD may evolve without the external forcing from the Pacific ENSO but it interacts with the Pacific phenomenon in some occasions possibly through the atmospheric bridge (Behera and Yamagata, 2002) and partly via the oceanic throughflow around the Australian continent. The strong seasonal phase-locking of the interannual IOD events may be related to the latter. However, it is crucially important to appreciate first the real unique nature of the Indian Ocean Dipole as the air-sea coupled phenomenon unique to the tropical Indian Ocean and then to clarify ways ofinteraction with other important phenomenon such as the ENSO events. We believe that this approach is a healthy way in understanding physics.We have not discussed here much about the subsurface IOD signals and successful coupled model simulations. Those who are interested are referred to Rao et al. (2002) and Iizuka et al. (2001). We hope that the present brief report on the Indian Ocean Dipole stimulates the world climate research community from a new angle of shedding light on old problems in the Asia-Pacific region.Table. 1 Years of positive and negative IOD yearss, and El Niño and La Niña years based on DMI and Niño-3 indices. Pure events are shown in bold i.e. no El Niño during positive IOD and no La Niña during negative IOD events considering a possible atmospheric bridge that can give rise to such interferences.References:Abram, N. J., M. K. Gagan, W. S. Hantoro, M. T. McCulloch, and J. Chappell, 2001: Coral records of the Indian Ocean Dipole, American Geophysical Union, Fall Meeting, San Francisco, Calif., Dec. 2001.Allan, R., D. Chambers, W. Drosdowsky, H. Hendon, M. Latif, N. Nicholls, I. Smith, R.Stone,Y. Tourre, 2001: Is there an Indian Ocean dipole, and is it independent of the El Niño - Southern Oscillation? CLIVAR Exchanges, 6, 18-22.Ashok, K., Z. Guan, and T. Yamagata, 2001: Impact of the Indian Ocean Dipole on the Decadal relationship between the Indian monsoon rainfall and ENSO, Geophys.Res. Lett., 28, 4499-4502.Baquero-Bernal, A., and M. Latif, 2002: On dipole-like variability in the tropical Indian Ocean. J. Climate, (in press).Behera, S. K., R. Krishnan, and T. Yamagata, 1999: Unusual ocean-atmosphere conditions in the tropical Indian Ocean during 1994. Geophys. Res. Lett., 26, 3001-3004.Bergman, J. W., and H. H. Hendon, 2000: Cloud radiative forcing of the low latitude tropospheric circulation: linear calculations. J. Atmos. Sci., 57, 2225-2245. Cadet, D. L., 1985: The Southern Oscillation over the Indian Ocean. J. Climatol., 5, 189-212.Carton, J.A., G. Chepurin, X. Cao, and B.S. Giese, 2000: A Simple Ocean Data Assimilation analysis of the global upper ocean 1950-1995, Part 1: methodology, J. Phys. Oceanogr., 30, 294-309.Clarke, A. J., and X. Liu, 1994: Interannual sea level in the Northern and Eastern Indian Ocean. J. Phys. Oceanogr., 24, 1224–1235.Dommenget, D. and M. Latif, 2002: A cautionary note on the interpretation of EOFs.J. Climate, 15, 216-225.Iizuka, S., T. Matsuura, and T. Yamagata, 2000: The Indian Ocean SST dipole simulated in a coupled general circulation model. Geophys. Res. Lett., 27, 3369-3372.Jolliffe, I. T., 1987: Rotation of principal components: some comments. J. Climotol. 7, 507-510.Kalnay, E. and Coauthors, 1996: The NCEP/NCAR 40-year reanalysis project. Bull.Amer. Meteor. Soc., 77, 437-471.Klein, S. A., B. J. Soden, and N. C. Lau, 1999: Remote sea surface temperature variations during ENSO: Evidence for a tropical atmospheric bridge. J. Climate, 12, 917-932Meyers, G., 1996: Variation of Indonesian throughflow and El Niño - Southern Oscillation, J. Geophys. Res., 101, 12,255-12,263.Murtugudde, R. G., J. P. McCreary, and A. J. Busalacchi, 2000: Oceanic processes associated with anomalous events in the Indian Ocean with relevance to 1997-1998. J. Geopys. Res., 105, 3295-3306.Newell, R. E., J. W. Kidson, D.G. Vincent and G. J. Boer, 1974, The General Circulation of the Tropical Atmosphere. V ol. 2, The MIT Press, 371 pp.Rao, A. S., S. K. Behera, Y, Masumoto, and T. Yamagata, 2001: Interannual variability in the subsurface tropical Indian Ocean. Deep- Sea Res. II, 49, 1549-1572. Rayner, N.A., E.B. Horton, D.E. Parker, C.K. Folland, and R.B. Hackett, 1996, Clim.Res. Tech. Note 74, UK Meteorological office, Bracknell.Saji, N. H., B. N. Goswami, P. N. Vinayachandran, and T. Yamagata, 1999: A dipole mode in the tropical Indian Ocean. Nature,401, 360-363.Saji, N. H., and T. Yamagata, 2002: Interference of teleconnection patterns generated from the tropical Indian and Pacific Oceans (under preparation).Venzke, S., M. Latif, and A. Villwock, 2000: The coupled GCM ECHO-2. Part II: Indian Ocean Response to ENSO. J. Climate, 13, 1371-1387. Vinayachandran, P.N., Krishna, ?, and T. Yamagata, 1999: ???, Geophys. Res. Lett. Vinayachandran, P. N., S. Iizuka, and T. Yamagata, 2002: Indian Ocean Dipole mode events in an ocean general circulation model, Deep- Sea Res., (In Press). Wallace, J. M., E. M. Rasmusson, T. P. Mitchell, V.E. Kousky, E. S. Sarachik, and H.von Storch, 1998: On the structure and evolution of ENSO-related climate variability in the tropical Pacific. J. Geophys. Res., 103, 14241-14260 Webster, P. J., A. M. Moore, J. P. Loschnigg, and R. R. Leben, 1999: The great Indian Ocean warming of 1997-98: Evidence of coupled-atmospheric instabilities.Nature,401, 356-360Figure Caption:Fig. 1: Anomalies of OLR for September-November. a) 1994, b) 1997.Fig. 2: Normalized indices of IOD, based on the anomalies of SST (SSTDMI) , zonal wind (UDMI), sea level (SSHDMI) and sea level pressure (SLPDMI).SSTDMI is obtained by taking anomaly difference between two regions (500E-700E, 100S-100N) and (900E-1200E, 100S-Eq), whereas SLPDMI is obtained by taking the difference between two boxes (860E-870E, 100S-90S) and (440E-450E, 150S-140S). The UDMI is obtained by taking area-average in the central equatorial region (700E-900E, 50S-50N). The SSHDMI is obtained by taking area -average of the TOPEX/POSEIODN sea level anomalies in a region in the eastern Indian Ocean (900E-1100E, 100S-Eq). The SSTDMI has a correlation coefficient above 0.65 with other indices. Niño-3 index from the eastern Pacific is shown for reference.Fig.3: Correlation between eastern pole and the whole basin anomalies after removal of anomalies due to the first EOF mode.Fig.4: September through November IOD composite ((positive events-negative events)/2) of zonal mass flux for (a) all IOD events (b) pure IOD events.Contour interval is 4*109 kg s-1.Fig. 5: Composite of SST anomalies during September through November for (a) all IOD events (b) pure IOD events, (c) all ENSO events and (d) pure ENSO events. Values are in 0C.Fig. 6: Same as in Fig. 4 but for the composite of SSH. Values are in cm.11。
写保护海洋的英语作文
写保护海洋的英语作文The ocean is one of the most vital components of our planet providing a home to a myriad of marine species and playing a crucial role in regulating the Earths climate. However it is currently facing numerous threats including pollution overfishing and climate change. As a result it is imperative that we take action to protect our oceans. Here is an essay on the importance of ocean conservation and the steps we can take to ensure their health and longevity.Title Protecting Our Oceans for a Sustainable FutureIntroductionThe oceans cover more than 70 of the Earths surface and are a vital part of the planets life support system. They are not only home to a diverse array of marine life but also serve as the worlds largest carbon sink absorbing about 25 of carbon dioxide emissions. Despite their importance oceans are under threat from human activities. It is our collective responsibility to protect and preserve these vast bodies of water for future generations.The Importance of Oceans1. Biodiversity Oceans are teeming with life from the tiniest plankton to the largest whales. This biodiversity is essential for maintaining the balance of marine ecosystems.2. Climate Regulation Oceans absorb a significant amount of carbon dioxide helping to mitigate the effects of global warming. They also influence weather patterns and climate around the world.3. Economic Value Fisheries and tourism related to oceans contribute billions to the global economy supporting millions of jobs.4. Cultural Significance For many communities oceans are not just a resource but also a part of their cultural identity and heritage.Threats to Our Oceans1. Pollution Plastic waste oil spills and chemical runoffs are poisoning marine life and disrupting ecosystems.2. Overfishing Unsustainable fishing practices are depleting fish stocks threatening the food chain and livelihoods that depend on the sea.3. Climate Change Rising sea temperatures and ocean acidification caused by increased carbon dioxide levels are harming coral reefs and other marine habitats.4. Habitat Destruction Coastal development and destructive fishing practices are destroying critical habitats like mangroves and seagrass beds.Strategies for Ocean Protection1. Reduce Reuse Recycle Minimizing plastic use and promoting recycling can significantly reduce the amount of waste that ends up in the oceans.2. Support Sustainable Fishing Encouraging and implementing sustainable fishing practices can help preserve fish populations and marine ecosystems.3. Protect Marine Areas Establishing marine protected areas MPAs can safeguard habitats and allow ecosystems to recover.4. Regulate Emissions Advocating for policies that reduce greenhouse gas emissions can help mitigate the impacts of climate change on oceans.5. Education and Awareness Educating the public about the importance of ocean conservation and the threats facing our seas can inspire action and change.ConclusionThe health of our oceans is intrinsically linked to the wellbeing of our planet and its inhabitants. It is time for individuals communities and governments to come together to take meaningful action towards ocean conservation. By adopting sustainable practices supporting policies that protect marine life and raising awareness about the importance of our oceans we can ensure a vibrant and thriving marine environment for generations to come.In conclusion protecting our oceans is not just an environmental imperative it is a moral and economic necessity. Let us commit to preserving these vast and vital ecosystems for the benefit of all life on Earth.。
多峇(Toba in Indonesia)巨灾理论
多峇(Toba in Indonesia)巨災理論[編輯首段]維基百科，自由的百科全書跳转到：导航, 搜尋阿拉斯加火山爆發根據多峇巨災理論，現代人的進化是受到近期一次在印尼多峇湖(Lake Toba)的大型火山爆發造成的巨災所影響。
這個理論由美國伊理諾大學(University of Illinios at Urbana-Champaign) 的史坦尼·安布魯士(Stanley Ambrose) 最先提出。
目錄[隱藏]∙ 1 理論∙ 2 地理證據o 2.1 遷移∙ 3 外部連結[編輯] 理論人類在最近三至五百萬年與其他靈長類動物在進化中分離。
人類之中產生了數種不同的物種。
根據這理論，一次大規模的火山爆發使人類數目大為減少。
這火山爆發可能在七至七萬五千年前在印尼多峇湖發生，強度為火山爆發指數的8級，即超大規模(mega-colossal)級數。
釋放的能量達到十億噸列性炸藥當量，或為1980年聖海倫火山爆發的三千倍。
大量的火山灰令全球溫度在之後數年間下降了攝氏3至3.5度，引起一次冰河時期。
突然的巨大環境改變可能令當時各種物種進入群體樽頸(Population bottleneck)，導致分散的人類群體加速異化，最終使現化人的先祖以外的人類絕種。
[編輯] 地理證據一些地理證據及電腦模擬支持多峇巨災的可能性。
基因遺傳證明現在的人類雖然表面看來分別頗大，但根據遺傳基因突變的平均速率推算，現代人全都是源自一個在多峇巨災發生的年代只有一千至一萬人的群體。
[編輯] 遷移按這理論，巨災之後一段時間，氣候及環境好轉，現代人的祖先從非洲出發，先到達印支半島及澳洲，然後再往中東雙子河流域，及亞洲其他各地。
[編輯] 外部連結∙Population Bottlenecks and Volcanic Winter∙1998 article based on news release regarding Ambrose's paper∙Homepage of Professor Stanley H. Ambrose∙Toba Volcano∙Article in The Economist∙/book/app-r/ch5_bottleneck/textr5.htm Chapter 5, Toba Volcano, by George Weber取自"/w/index.php?title=%E5%A4%9A%E5%B3%87%E5%B7%A8% E7%81%BD%E7%90%86%E8%AB%96&variant=zh-tw"1個分類: 人類學Toba catastrophe theoryFrom Wikipedia, the free encyclopediaJump to: navigation, searchAccording to the Toba catastrophe theory, 70,000 to 75,000 years ago a supervolcanic event at Lake Toba, on Sumatra, reduced the world's human population to 10,000 or even a mere 1,000 breeding pairs, creating a bottleneck in human evolution. The theory was proposed in 1998 by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign.[1][2]Contents[hide]∙ 1 History∙ 2 Evidence∙ 3 Migration∙ 4 See also∙ 5 References∙ 6 External links[edit] HistoryWithin the last three to five million years, after human and other ape lineages diverged from the hominid stem-line, the human line produced a variety of species.According to the Toba catastrophe theory, a massive volcanic eruption severely reduced the human population. This may have occurred around 70–75,000 years ago when the Toba caldera in Indonesia underwent an eruption of category 8 (or "mega-colossal") on the Volcanic Explosivity Index. This released energy equivalent to about one gigaton of TNT, which is three thousand times greater than the 1980 eruption of Mount St. Helens. According to Ambrose, this reduced the average global temperature by 5 degrees Celsius for several years and may have triggered an ice age.Ambrose postulates that this massive environmental change created population bottlenecks in the various species that existed at the time; this in turn accelerated differentiation of the isolated human populations, eventually leading to the extinction of all the other human species except for the two branches that became Neanderthals and modern humans.[edit] EvidenceSome geological evidence and computed models support the plausibility of the Toba catastrophe theory, and genetic evidence suggests that all humans alive today, despite their apparent variety, are descended from a very small population, perhaps between1,000 and 10,000 breeding pairs.[3][4]Using the average rates of genetic mutation, some geneticists have estimated that this population lived at a time coinciding with the Toba event. These estimates do not contradict the consensus estimates that Y-chromosomal Adam lived some 60,000 years ago, and that Mitochondrial Eve is estimated to have lived 140,000 years ago, since Toba is not conjectured to be an extremal bottleneck event, where the population was reduced to one breeding pair.Gene analysis of some genes shows divergence anywhere from 2 million to 60,000 years ago, but this does not contradict the Toba theory, again since Toba is not conjectured to be an extremal bottleneck event. The complete picture of gene lineages (including present-day levels of human genetic variation) allows the theory of a Toba-induced human population bottleneck.[5][edit] MigrationAccording to this theory, humans once again fanned out from Africa after Toba when the climate and other factors permitted. They migrated first to Arabia and India and onwards to Indochina and Australia (Ambrose, 1998, p. 631), and later to the Middle East and what would become the Fertile Crescent following the end of the Würm glaciation period (70,000–10,000 years bp).[edit] See also∙Supervolcano∙Volcanic winter∙Wallace line∙Year Without a Summer[edit] References1.^ Stanley H. Ambrose (1998). "Late Pleistocene human population bottlenecks,volcanic winter, and differentiation of modern humans". Journal of HumanEvolution34 (6): 623–651. doi:10.1006/jhev.1998.0219.2.^ Ambrose, Stanley H. (2005). Volcanic Winter, and Differentiation of ModernHumans. Bradshaw Foundation. Retrieved on 2006-04-08.3.^When humans faced extinction. BBC (2003-06-09). Retrieved on 2007-01-05.4.^Late Pleistocene human population bottlenecks, volcanic winter, anddifferentiation of modern humans by Stanley H. Ambrose5.^Dawkins, Richard (2004). "The Grasshopper's Tale", The Ancestor's Tale, APilgrimage to the Dawn of Life. Boston: Houghton Mifflin Company, 416. ISBN 0-618-00583-8.[edit] External links∙Population Bottlenecks and Volcanic Winter∙1998 article based on news release regarding Ambrose's paper∙Homepage of Professor Stanley H. Ambrose∙Toba Volcano, by George Weber∙Article in The Economist∙Journey of Mankind by The Bradshaw Foundation - includes discussion on Toba eruption, DNA and human migrations∙Geography Predicts Human Genetic Diversity ScienceDaily (Mar. 17, 2005) —By analyzing the relationship between the geographic location of current human populations in relation to East Africa and the genetic variability within thesepopulations, researchers have found new evidence for an African origin ofmodern humans.∙Out Of Africa -- Bacteria, As Well: Homo Sapiens And H. Pylori Jointly Spread Across The Globe ScienceDaily (Feb. 16, 2007) — When man made his way out of Africa some 60,000 years ago to populate the world, he was not alone: He was accompanied by the bacterium Helicobacter pylori...; illus. migration map.Retrieved from "/wiki/Toba_catastrophe_theory"Categories: Human evolution | TheoriesLake TobaFrom Wikipedia, the free encyclopediaLandsat photoLocation North Sumatra, IndonesiaCoordinates2°37′N, 98°49′ELake type Volcanic/ tectonicPrimaryoutflowsAsahan RiverBasin countries IndonesiaMax length100 kmMax width30 kmSurface area1,130 km²Max depth505 m[1]Water volume240 km³Surfaceelevation905 mIslands SamosirLake Toba (Indonesian: Danau Toba) is a lake, 100 km long and 30 km wide, and 505 m. (1,666 ft.) at its deepest point, in the middle of the northern part of the Indonesian island of Sumatra with a surface elevation of about 900 m (3,000 feet), stretching from 2.88° N 98.52° E to 2.35° N 99.1° E. It is the largest volcanic火山的,猛烈的火山岩 lake in the world.[citation needed]Contents[hide]∙ 1 Geologyo 1.1 The eruptiono 1.2 More recent activity∙ 2 People∙ 3 See also∙ 4 References5 External links[edit] GeologyIn 1949 the Dutch geologist Rein van Bemmelen reported that Lake Toba was surrounded by a layer of ignimbrite熔結凝灰岩 rocks, and that it was a large volcanic caldera噴火山口. Later researchers found rhyolite [地]流紋岩火山岩之一種ash similar to that in the ignimbrite around Toba (now called Young Toba Tuff凝灰岩to distinguish it from layers deposited in previous explosions) in Malaysia and India, 3,000 km away. Oceanographers discovered Toba ash, with its characteristic chemical "fingerprint", on the floor of the eastern Indian Ocean and the Bay of Bengal孟加拉.[edit] The eruption爆發,火山灰,出疹Main article: Toba catastrophe 大災難,大禍theoryLocation of Lake Toba shown in red on map.The Toba eruption (the Toba event) occurred at what is now Lake Toba about 67,500 to 75,500 years ago. It had an estimated Volcanic Explosivity Index of 8 (described as "mega-colossal巨大的, 龐大的"), making it possibly the largest explosive volcanic eruption within the last twenty-five million years. Bill Rose and Craig Chesner of Michigan Technological University deduced that the total amount of erupted material was about 2800 cubic km (670 cubic miles) — around 2,000 km³ of ignimbrite that flowed over the ground and around 800 km³ that fell as ash, with the wind blowing most of it to the west. By contrast, the 1980 eruption of Mount St. Helens ejected around 1.2 cubic km of material, whilst the largest volcanic eruption in historic times, at Mount Tambora in 1815, emitted the equivalent of around 100 cubic kilometres of dense rock and created the "Year Without a Summer" as far away as North America.The Toba eruption was the latest of a series of at least three caldera-forming eruptions which have occurred at the volcano. Earlier calderas were formed around 700,000 and 840,000 years ago.[2]To give an idea of its magnitude大小, 數量, 巨大, 廣大, 量級, consider that although the eruption took place in Indonesia, it deposited an ash layer approximately 15 cm (6 in) thick over the entire Indian subcontinent; at one site in central India, the Toba ash layer today is up to 6 m (20 feet) thick[3] and parts of Malaysia were covered with 9 m of ashfall.[4] In addition it has been calculated that 1010 metric tons of sulphuric acid was ejected into the atmosphere by the event, causing acid rain fallout.[5]Landsat photo of Sumatra surrounding Lake TobaThe subsequent collapse倒塌,崩潰,瓦解formed a caldera that, after filling with water, created Lake Toba. The island in the center of the lake is formed by a resurgent dome復生的,復活的復生的人,復活者-圓頂加圓頂成圓頂狀.Though the year can never be precisely determined, the season can: only the summer monsoon季節風,吹季節風的季節,雨季 could have deposited Toba ashfall in the South China Sea, implying that the eruption took place sometime during the northern summer.[6] The eruption lasted perhaps two weeks, but the ensuing隨后的,下一個 "volcanic winter" resulted in a decrease in average global temperatures by 3 to 3.5 degrees Celsius for several years. Greenland ice cores冰核record a pulse of starkly僵硬的,完全的,刻板的,明顯的,荒涼的,結實的 reduced levels of organic carbon sequestration假扣押;退隱. Very few plants or animals in southeast Asia would have survived, and it is possible that the eruption caused a planet-wide die-off. There is some evidence, based on mitochondrial DNA , 線粒體的that the human race may have passed through a genetic bottleneck within this timeframe框架,結構,體格, reducing genetic diversity差異,多樣性 below what would be expected from the age of the species. According to the Toba catastrophe theory proposed by Stanley H. Ambrose of the University of Illinois at Urbana-Champaign in 1998, human populations may have been reduced to only a few tens of thousands of individuals by the Toba eruption.[edit] More recent activityChildren playing in Lake TobaSmaller eruptions have occurred at Toba since. The small cone of Pusukbukit has formed on the southwestern margin of the caldera and lava 熔岩,火山岩domes圓頂. The most recent eruption may have been at Tandukbenua on the northwestern caldera edge, since the present lack of vegetation could be due to an eruption within the last few hundred years.[7]Some parts of the caldera have experienced uplift due to partial refilling of the magma chamber [地質]岩漿房, for example pushing Samosir Island and the Uluan Peninsula above the surface of the lake. The lake sediments on Samosir Island show that it has been uplifted by at least 450 metres[8] since the cataclysmic洪水的;大變動的 eruption. Such uplifts are common in very large calderas, apparently due to the upward pressure of unerupted magma. Toba is probably the largest resurgent caldera on Earth. Large earthquakes have occurred in the vicinity 接近,鄰近,附近地區,近處of the volcano more recently, notably in 1987 along the southern shore of the lake at a depth of 11 km.[9] Other earthquakes have occurred in the area in 1892, 1916, and 1920-1922.[10]Lake Toba lies near a fault line which runs along the centre of Sumatra called the Sumatra Fracture Zone斷裂帶.[11] The volcanoes火山 of Sumatra and Java are part of the Sunda Arc, a result of the northeasterly movement of the Indo-Australian Plate which is sliding under the eastward-moving Eurasian Plate. The subduction zone俯衝帶in this area is very active: the seabed near the west coast of Sumatra has had several major earthquakes since 1995, including the 9.3 2004 Indian Ocean Earthquake and the 8.7 2005 Sumatra earthquake, the epicenters 震中,中心of which were around 300 km from Toba.On September 12th, 2007, a magnitude 8.4 Earthquake shook the ground by Sumatra and was felt in the Indonesian capital, Jakarta. The epicenter for this earthquake was not as close as the previous two earthquakes, but it was in the same vicinity.[edit] PeopleToba HouseMost of the people who live around Lake Toba are ethnically人種的;民族的;種族的Bataks. Traditional Batak houses are noted for their distinctive roofs (which curve upwards at each end, as a boat's hull does) and their colorful decor.[edit] See also∙Toba catastrophe theory∙Supervolcano∙List of lakes in Indonesia∙List of volcanoes in Indonesia∙List of disasters∙Natural disaster[edit] References1.^2.^/vwdocs/volc_images/southeast_asia/indonesia/toba.html3.^ Acharyya S.K., and Basu P.K. 1992. "Toba ash on the Indian subcontinent andits implications for correlation of late pleistocene alluvium." QuaternaryResearch40:10-194.^ Scrivenor, J.B. 1931. The Geology of Malaya (London: MacMillan), noted byWeber.5.^ Huang C.Y., Zhao M.X., Wang C.C., and Wei G.J. 2001. "Cooling of the SouthChina Sea by the Toba eruption and correlation with other climate proxies ca.71,000 years ago." Geophysical Research Letters28:3915-3918, noted by Weber.6.^ Bühring C., and Sarnthein M. 2000. "Toba ash layers in the South China Sea:evidence of contrasting wind directions during eruption ca. 74 ka." Geology28:275-278.7.^/volcano-tours/volcanoes/indonesia/sumatra/toba/8.^/vwdocs/volc_images/southeast_asia/indonesia/toba.html9.^/eqcenter/eqarchives/significant/sig_1987.php10.^/vwdocs/volc_images/southeast_asia/indonesia/toba.html11.^/vwdocs/volc_images/southeast_asia/indonesia/toba.html∙Rampino, Michael R. and Stephen Self (1993). "Climate-volcanism feedback and the Toba eruption of 74,000 Years Ago". Quaternary Research40 (3): 269-280.doi:10.1038/359050a0.∙Vazquez, Jorge A. and Mary R. Reid (2004). "Probing the accumulation history of the voluminous Toba Magma". Science305 (5686): 991-994.[edit] External linksIndonesia Portal∙Satellite image on Google Maps∙Toba, Sumatra, Indonesia - Accessed 11 December2005∙Stanley H. Ambrose, Volcanic Winter, and Differentiation of Modern Humans Accessed 11 December2005∙Joel Achenbach, Who Knew, National Geographic Accessed 11 December2005∙George Weber, Toba Volcano∙Lake Toba travel guide from WikitravelRetrieved from "/wiki/Lake_Toba"Categories: All articles with unsourced statements | Articles with unsourced statements since September 2007 | Lakes of Indonesia | VEI-8 volcanoes | Subduction volcanoes | Mountains of Indonesia | Volcanoes of Sumatra | Volcanic calderas of Indonesia | Crater lakes | Supervolcanoes人类起源与进化系列：人类起源泥河湾与三星堆遗址华夏和周边民族史。
关于海洋发现与保护平衡的英语作文
关于海洋发现与保护平衡的英语作文Balancing Marine Exploration and Conservation: Navigating the Delicate Interplay.The vast expanse of the ocean, teeming with unfathomable biodiversity, beckons us with an irresistible allure, driving our insatiable quest for knowledge and resources. However, this pursuit, while essential for scientific advancement and economic sustenance, must be tempered with an unwavering commitment to preserving the ocean's delicate ecosystems. Striking a harmonious balance between marine exploration and conservation presents a complex challenge that demands our utmost diligence and thoughtful stewardship.The Importance of Marine Exploration.Marine exploration serves as a vital catalyst for scientific discovery, technological innovation, and informed decision-making. By venturing into unchartedwaters, scientists unravel the mysteries of the deep, uncovering new species, unlocking the secrets of marine ecosystems, and expanding our understanding of the planet's complex dynamics. Such knowledge empowers us to develop sustainable fishing practices, protect endangered species, and mitigate the impacts of human activities on ocean health.Moreover, marine exploration fosters technological advancements that drive scientific exploration and societal progress. The development of submersibles, deep-sea imaging systems, and environmental sensors has revolutionized our ability to delve into the depths of the ocean, unlocking previously inaccessible realms. These technological breakthroughs not only enhance scientific research but also have practical applications in various fields, such as offshore energy, medicine, and navigation.The Imperative of Marine Conservation.While marine exploration offers immense benefits, it also poses potential risks to the fragile ocean environment.Uncontrolled extraction of marine resources, pollution, and habitat destruction have led to a decline in biodiversity, disrupted ecosystem function, and impaired ocean health. Conservation measures are paramount to mitigate these impacts and ensure the long-term sustainability of ocean resources.Protecting marine ecosystems requires establishing marine protected areas (MPAs), reducing plastic pollution, combating overfishing, and implementing sustainable coastal development practices. MPAs, such as marine sanctuaries and national parks, provide safe havens for marine life, allowing populations to recover and ecosystems to thrive. Reducing plastic pollution involves implementing waste reduction strategies, promoting recycling, and advocating for the responsible disposal of plastics. Combating overfishing requires responsible fishing practices, including quotas, size limits, and closed fishing seasons. Sustainable coastal development incorporates environmentally friendly building techniques, erosion control measures, and habitat restoration projects to minimize the impacts of human activities on marineecosystems.Balancing Exploration and Conservation: A Delicate Act.Navigating the delicate interplay between marine exploration and conservation requires a holistic approach that embraces both scientific advancement and environmental sustainability. Sustainable exploration practices minimize the impact on marine ecosystems while allowing for valuable scientific research. For instance, researchers can utilize non-invasive sampling methods, such as remote sensing and environmental DNA analysis, to gather data without disturbing sensitive habitats.Collaboration and partnerships between scientists, conservationists, and policymakers are crucial for developing and implementing effective marine exploration and conservation strategies. Transdisciplinary research teams, involving experts from diverse fields, foster innovative solutions and ensure that scientific knowledge informs conservation efforts. Policymakers play a vitalrole in establishing regulations and incentives thatpromote sustainable exploration and protect marine ecosystems.Public engagement and education are equally importantin fostering a culture of ocean stewardship. Raising awareness about the importance of both marine exploration and conservation empowers individuals to make informed decisions and support policies that protect our oceans. Public outreach programs, such as citizen scienceinitiatives and educational campaigns, can engage thepublic in monitoring marine ecosystems, advocating for conservation measures, and promoting sustainable practices.Conclusion.The ocean, an indispensable resource for humanity, holds both immense promise and vulnerability. Balancing marine exploration and conservation is not merely a choice but a responsibility we must embrace with unwavering determination. By embracing sustainable exploration practices, fostering collaboration, engaging the public, and implementing comprehensive conservation measures, wecan unlock the ocean's secrets while ensuring its enduring legacy for generations to come. The delicate interplay between marine exploration and conservation is not one of compromise but rather of synergy, where scientific advancement and environmental sustainability walk hand in hand, charting a course towards a prosperous and sustainable future for our planet and its oceans.。
南亚高压的南北偏移与我国夏季降水的关系
南亚高压的南北偏移与我国夏季降水的关系魏维;张人禾;温敏【摘要】该文定义了一个能较好反映南亚高压南北偏移的指数,并发现该指数与我国夏季降水,尤其是华北和长江流域的降水,无论在年际变化上还是长期趋势上都具有十分显著的相关关系.南亚高压位置偏北时,在我国东部至日本上空存在一个显著的异常反气旋,其中心自上而下向南倾斜,在高层给华北地区带来辐散,在低层使得气流在长江流域辐散,在华北地区辐合,造成华北地区降水偏多,长江流域降水偏少.同时,南亚高压偏北对应着高层西风急流以及中层西太平洋副热带高压偏北,使得我国整个雨带偏北.此外,通过与海温的相关分析发现,南亚高压的长期偏南趋势可能受到印度洋增暖的直接影响.南北偏移指数可作为预测我国夏季区域降水的重要指标,在气候预测业务中有一定的应用价值.%South Asian High (SAH) is the most intense and stable upper level anticyclone in boreal summer. As a member of the East Asian Summer Monsoon system, SAH plays an important role in the regional climate anomaly over China.rnThe meridional variation of SAH is analyzed by using the monthly mean data derived from the European Center for Medium-Range Weather Forecasts (ECMWF) 40-year reanalysis (ERA-40) from 1958 to 2002. An index of SAH (SAHI) is defined to measure its meridional variation in summer and to analyze its relationship with the summer precipitation over China. The results show a significant correlation between the meridional position of SAH and the summer rainfall over China for both the interannual timescale variability and the long-term linear tendency. The correlation coefficients between SAHI and the summer rainfall in North China and in the Yangtze River Valleys are 0. 577and ?. 604, respectively, both of which exceeds 0. 01 level. When SAH locates further northward (southward), North China and South China are wetter (drier) than normal, while the Yangtze River Valleys is drier (wetter) than normal. And the southward linear trend of SAH corresponds with the decreasing trend of rainfall in North China and the increasing trend of rainfall in the Yangtze River Valleys.rnLinear regression analysis of the circulation reveals that when SAH locates further northward, an a-nomalous anticyclone controls eastern China with its center tilted southward from 200 hPa to 850 hPa. In the upper atmosphere, the anomalous anticyclone forms a divergence zone over North China. In the lower atmosphere, it results in flows diverging over the Yangtze River valley, and converging over North China. Besides, the northward movement of SAH would cause the upper-level westerly jet and the Western Pacific Subtropical High move northward, with the rainbelt locating in North China.rnThe meridional anomalous variation of SAH is closely related to the sea surface temperature anomalies (SSTA) of the Tropical Indian Ocean (TIO) , the Central and Eastern Equatorial Pacific, and the northern Pacific. And the TIO SSTA might modulate its meridional position directly. Positive TIO SSTA might lead to a southward expansion of SAH.rnDue to strong correlation with the summer rainfall over China and being modulated by the TIO SSTA, the meridional variation of SAHI could be considered as an important indicator used to predict the regional climate anomaly.【期刊名称】《应用气象学报》【年(卷),期】2012(023)006【总页数】10页(P650-659)【关键词】南亚高压;南北偏移;我国夏季降水;印度洋增暖【作者】魏维;张人禾;温敏【作者单位】中国气象科学研究院灾害天气国家重点实验室,北京100081;中国气象科学研究院灾害天气国家重点实验室,北京100081;中国气象科学研究院灾害天气国家重点实验室,北京100081【正文语种】中文该文定义了一个能较好反映南亚高压南北偏移的指数，并发现该指数与我国夏季降水，尤其是华北和长江流域的降水，无论在年际变化上还是长期趋势上都具有十分显著的相关关系。
赤道印度洋秋季Wyrtki急流盐度输运对正、负IOD事件的不对称响应
赤道印度洋秋季Wyrtki急流盐度输运对正、负IOD事件的不对称响应张莹;杜岩;张玉红;杨亚力【摘要】We analyzed the interannual variability of the Wyrtki Jet and its salinity transport associated with Indian Ocean Dipole (IOD) in fall season using observations and Simple Ocean Data Assimilation (SODA). During negative IOD events, the Wyrtki Jet strengthened in the equatorial Indian Ocean, forced by enhanced equatorial westerly wind, which favors a stronger eastward transport of high-salinity water. During positive IOD events, the above-mentioned processes reversed. In addition, both the Wyrtki Jet and associated salinity transport anomalies on the strength and spatial distribution displayed significant asymmetric characteristics between the positive and negative IOD events. The amplitudes of zonal velocity and salinity anomalies were stronger during the positive IOD events. The anomalies centered in the central equatorial Indian Ocean during the positive IOD events, but they moved to the east in the negative IOD events. Moreover, the velocity anomalies reached a deeper depth during the negative IOD events, even though the salinity anomalies occurred at a rather shallow depth.%采用海洋实测资料和简单海洋数据同化(SODA)模式再分析资料研究了印度洋偶极子(IOD)事件影响下赤道印度洋秋季Wyrtki急流及其盐度输运的年际变化特征.结果表明, 在正、负IOD事件盛期, 赤道流场和盐度异常不仅呈反位相特征,在空间分布及强度上还具有显著的不对称性.正IOD事件盛期, Wyrtki急流转向为西向流,将赤道印度洋东部低盐水向西输送;此时赤道流场和盐度负异常显著, 影响范围大, 南北扩张明显, 盐度异常中心偏西, 影响深度较深.负IOD事件盛期, Wyrtki急流增强,对赤道印度洋西部高盐水输送能力增强;此时盐度及流速异常较弱,极值范围小,盐度异常中心偏东, 影响深度较浅, 但流速异常影响深度较正IOD事件深.【期刊名称】《热带海洋学报》【年(卷),期】2015(034)005【总页数】10页(P1-10)【关键词】Wyrtki急流;盐度运输;印度洋偶极子;不对称性【作者】张莹;杜岩;张玉红;杨亚力【作者单位】热带海洋环境国家重点实验室(中国科学院南海海洋研究所),广东广州510301;中国科学院大学,北京 100049;热带海洋环境国家重点实验室(中国科学院南海海洋研究所),广东广州 510301;热带海洋环境国家重点实验室(中国科学院南海海洋研究所),广东广州 510301;热带海洋环境国家重点实验室(中国科学院南海海洋研究所),广东广州 510301;中国科学院大学,北京 100049【正文语种】中文【中图分类】P731印度洋10°S以北, 夏季盛行西南季风, 冬季盛行东北季风, 是全球海洋上最显著的季风区(Schott et al, 2001; Schott et al, 2009)。
重视海洋探索的英语作文
重视海洋探索的英语作文英文回答：The Importance of Ocean Exploration.The ocean covers over 70% of the Earth's surface and is home to an estimated 80% of all life on the planet. Despite its vast size and importance, only a small fraction of the ocean has been explored.Ocean exploration is essential for a number of reasons. First, it helps us to better understand the ocean's role in the Earth's climate system. The ocean absorbs and stores heat, and it plays a major role in regulating global temperatures. By exploring the ocean, we can learn more about how it interacts with the atmosphere and how it is responding to climate change.Second, ocean exploration helps us to identify and develop new resources. The ocean contains a wealth ofminerals, energy, and other resources that have the potential to benefit humanity. By exploring the ocean, we can learn more about these resources and how to sustainably use them.Third, ocean exploration helps us to protect and conserve marine life. The ocean is home to a vast array of marine life, from the smallest plankton to the largest whales. Many marine species are endangered due to overfishing, pollution, and other human activities. By exploring the ocean, we can learn more about these species and how to protect them.Fourth, ocean exploration helps us to inspire and educate the next generation of scientists and engineers. By exploring the ocean, we can capture the imaginations of children and adults alike and inspire them to pursue careers in science and engineering.Finally, ocean exploration is simply a matter of curiosity and adventure. Humans have always been drawn to the unknown, and the ocean is the last great unexploredfrontier on Earth. By exploring the ocean, we can satisfy our curiosity about the natural world and learn more about the planet we call home.中文回答：重视海洋探索。
为什么海洋勘探如此重要英语作文150字
为什么海洋勘探如此重要英语作文150字Title: The Importance of Ocean ExplorationIntroduction:Ocean exploration plays a crucial role in our understanding of the world around us. Beyond its aesthetic beauty, the oceans hold invaluable resources, influence global climate patterns, and provide a habitat for countless marine species. In this essay, we will delve into why ocean exploration is so vital and explore its significance in different aspects.1. Scientific Discoveries:Ocean exploration allows scientists to uncover hidden treasures of knowledge about the Earth's history and geology. By studying the geological formations found on the ocean floor or conducting deep-sea excavations, researchers can unravel mysteries surrounding plate tectonics or discover new species that offer insights into evolution.2. Climate Research:The oceans are an integral part of Earth's climate system. Through oceanographic studies, scientists are able to understand how currents distribute heat globally, regulate weather patterns, and impact long-term climate change. Monitoring changes in sea temperature and acidity levels enables us to assess the health of our oceans and predict future climatic shifts.3. Resource Exploration:The oceans hold vast reserves of untapped resources such as oil, natural gas, minerals, and even potential sources for renewable energy like wave power or thermal energy conversion systems. Ocean exploration allows us to locate and evaluate these resources sustainably while minimizing environmental impacts.4. Pharmacological Potential:Marine organisms have been a source of valuable compounds with medicinal properties that have benefited human health for centuries. Exploring marine biodiversity helps identify new drug leads for various diseases including cancer, bacterial infections, Alzheimer's disease, and more.5. Conservation Efforts:Effective conservation strategies depend on a comprehensive understanding of marine ecosystems. By exploring the ocean depths and studying fragile habitats like coral reefs or underwater caves, scientists can develop conservation initiatives that protect vulnerable species from environmental degradation.Conclusion:In conclusion, ocean exploration serves as a gateway to untold knowledge about our planet's history, climate systems, resource potential, pharmacological discoveries, and conservation efforts. Unveiling the mysteries of the oceans is pivotal for maintaining a sustainable future and preserving Earth's invaluable marine ecosystems. Continuous investment in ocean exploration is imperative if we are to address global challenges and make informed decisions that positively impact both present and future generations.。
海底对地球的影响英语作文
海底对地球的影响英语作文The impact of the ocean on the Earth is immense. The vast expanse of the sea covers more than 70% of theplanet's surface, making it a crucial component of our ecosystem. The ocean plays a vital role in regulating the Earth's climate, acting as a heat sink and absorbing a significant amount of carbon dioxide from the atmosphere. Its currents and tides also influence weather patterns and the distribution of heat around the globe.The ocean is a treasure trove of biodiversity. It is home to countless species, many of which are yet to be discovered. The coral reefs, for example, are not only breathtakingly beautiful but also provide habitats for a myriad of marine organisms. These reefs support a delicate balance of life, and their destruction could have devastating consequences for the entire ecosystem.Furthermore, the ocean serves as a source of food and livelihood for millions of people. Fishing communities relyon the ocean's resources for sustenance and income. However, overfishing and destructive fishing practices have led to the depletion of fish stocks and the destruction of marine habitats. This not only threatens the livelihoods of those dependent on the ocean but also disrupts the delicate balance of marine ecosystems.In addition to its ecological importance, the oceanalso has a profound impact on human health and well-being. The sea air is known for its therapeutic properties, and spending time by the coast can have a calming and rejuvenating effect on our minds and bodies. The sound of the waves crashing against the shore can provide a sense of tranquility and help alleviate stress.On the other hand, the ocean can also pose significant risks and challenges. Rising sea levels, caused by global warming, are a major concern. Coastal communities are particularly vulnerable to the impacts of sea-level rise, including increased flooding and erosion. Additionally, the ocean is a powerful force of nature, capable of unleashing destructive tsunamis and hurricanes that can causewidespread devastation.In conclusion, the ocean plays a crucial role in shaping our planet. Its influence extends far beyond its borders, affecting climate, biodiversity, livelihoods, and even our own well-being. It is our responsibility to protect and preserve this invaluable resource for future generations.。
The Impacts of Ocean Pollution on Marine Wildlife
The Impacts of Ocean Pollution onMarine WildlifeOcean pollution is a growing concern around the world, with devastating impacts on marine wildlife. This pollution comes in many forms, including plastic waste, oil spills, chemical pollutants, and nutrient runoff from agriculture. These pollutants can have a range of negative effects on marine animals, from entanglement and ingestion of plastic to poisoning from toxic chemicals.One of the most visible impacts of ocean pollution on marine wildlife is the entanglement of animals in plastic waste. Discarded fishing nets, plastic bags, and other debris can trap marine mammals, sea turtles, seabirds, and fish, leading to injuries, suffocation, and death. In addition to physical harm, ingesting plastic can also be deadly for marine animals. Plastic debris can block animals' digestive systems, leading to malnutrition and starvation. It can also release toxic chemicals into the animals' bodies, causing illness and even death.Oil spills are another major source of ocean pollution that can have devastating impacts on marine wildlife. When oil is spilled into the ocean, it coats the feathers and fur of seabirds and marine mammals, reducing their ability to stay warm and repel water. It can also be ingested by animals, leading to internal injuries and poisoning. Oil spills can have long-lasting effects on marine ecosystems, as they can contaminate food sources and breeding grounds, leading to population declines and even extinctions.Chemical pollutants, such as heavy metals, pesticides, and industrial chemicals, can also have serious impacts on marine wildlife. These pollutants can accumulate in the tissues of marine animals, leading to reproductive disorders, immune system suppression, and neurological damage. They can also disrupt hormonal balance, leading to developmental abnormalities and population declines. Nutrient runoff from agriculture can also contribute to ocean pollution, leading to harmful algal blooms that can suffocate marine life and create dead zones in the ocean.Overall, the impacts of ocean pollution on marine wildlife are profound and wide-ranging. From entanglement and ingestion of plastic to poisoning from oil spills and chemical pollutants, marine animals face numerous threats from human activities. To protect marine wildlife and preserve ocean ecosystems, it is crucial that we take action to reduce and prevent ocean pollution. This includes reducing our use of single-use plastics, properly disposing of waste, regulating the release of pollutants into the environment, and supporting conservation efforts to clean up and restore marine habitats. By taking these steps, we can help to mitigate the impacts of ocean pollution and ensure a healthier future for marine wildlife.。
海洋勘探重要性大学英语作文
海洋勘探重要性大学英语作文Title: The Indispensable Significance of Ocean Exploration in the Modern EraImagine you're holding an atlas, not just any ordinary one that depicts the continents and countries, but a detailed map that reveals the secrets hidden beneath the vast blue expanse we call the ocean. This analogy perfectly encapsulates the essence of ocean exploration, which is akin to turning the pages of an unread tome filled with mysteries waiting to be deciphered.The importance of ocean exploration in today's world cannot be overstated, especially within the context of our shared university experience where knowledge and discovery are paramount. Picture this: You’re a marine biology student on a research voyage, braving the waves for a glimpse into the deep-sea ecosystem –a universe teeming with life forms yet unknown to science. Or perhaps you're an engineering major involved in developing cutting-edge technology to explore the ocean floor, where untapped resources might hold the key to sustainable energy solutions.Ocean exploration is more than a mere academic pursuit; it’s a quest for understanding our planet's climate patterns,safeguarding biodiversity, and ensuring human survival. It's about delving into the ocean's abysses to unravel its role as Earth's climate regulator, storing carbon dioxide and producing over half of the oxygen we breathe. Moreover, it entails probing the ocean depths for clues to the origins of life, and possibly, other habitable environments beyond our planet.On a smaller scale, consider the economic implications. Underwater mineral reserves, potential new pharmaceuticals derived from marine organisms, and the largely unexplored fishing grounds could significantly boost global economies and food security. Ocean exploration also plays a crucial role in maritime safety by mapping sea floors to prevent disasters like shipwrecks and tsunamis.However, amidst these grand narratives lies the simple joy of discovery –the thrill of encountering a previously unseen coral reef or the awe at beholding a giant squid in its natural habitat. This excitement mirrors the curiosity that propels us all in our scholarly endeavors, making ocean exploration an integral part of our collective educational journey.In conclusion, the significance of ocean exploration resonates deeply with the ethos of a university education,fostering interdisciplinary learning, innovation, and stewardship of our planet. Each dive into the ocean's depths is a step towards expanding humanity's horizon of knowledge, nurturing empathy for our marine ecosystems, and ultimately, contributing to a better future for all. So, let's embark on this odyssey together, paddling through the waves of the unknown, because the ocean's story remains incomplete without our pen.。
大学英语六级(阅读)模拟试卷18(题后含答案及解析)
大学英语六级（阅读）模拟试卷18(题后含答案及解析) 题型有： 4. Reading Comprehension (Reading in Depth)Part IV Reading Comprehension (Reading in Depth) (25 minutes)Section BDirections: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.The news about the world’s oceans in 2003 wasn’t that they’re in trouble —that much was already clear —but that the scale of devastation is far greater than anyone had realized. A shocking study revealed that a full 90 percent of the species most desirable to fishmongers(鱼商)—tuna, halibut, sharks, swordfish, grouper —has been wiped out in the past half century. But there was hopeful news as well. An alternative to conventional fishing practices, while not a cure-all(万灵药), could significantly restore ravaged fish populations. The chilling centerpiece of last year’s marine research: just 50 years of industrial fishing has decimated(大批杀害)the world’s large predator(食肉动物)fish species, according to a report published in Nature in May. Irresponsible fishing practices have resulted severe casualties: Shrimp trawling(拖网捕捞)in the Gulf of Mexico, for example, a reckless process in which, for every ton of shrimp obtained, three tons of fin-fish(长须鲸)are destroyed and discarded —has shrunk large fish stocks a thousandfold. “Across the board we’ve removed everything bigger than a bicycle from the o-cean,”says Steve Palumbi, a Stanford University biologist, “and that has almost certainly changed the ocean in fundamental ways. “But the urgent need for large-scale conservation efforts is on a collision course with economic pressures to expand fishing even further, according to a 2003 report by the Pew Oceans Commission, an independent expert panel, as well as preliminary reports from members of the Bush-appointed U. S. commission on Ocean Policy. Americans are eating more seafood than ever: Consumption was up 7 percent in 2002, to 4. 5 billion pounds. Worldwide, more than 130 billion pounds of marine species are caught annually, and that doesn’t include the huge amount of sea life destroyed as by-catch. More than a billion people rely on fish for protein. “ We need to change the whole ethic of how we are viewing the oceans,”says Andrew Rosenberg, a member of the Commission on Ocean Policy, “ from a place that we use to a place we care for. “In September marine biologists Fiona Gell and Callum Roberts of the University of York in England offered a solution, boldly asserting that at least 30 percent of the world’s ocean habitat had to become safe zones for marine life. It’s a practical, not a sentimental matter, they contend. After studying 60 no-fishing zones around the world, Gell and Roberts discovered that the fish there live longer, grow larger, and produce more young than those in unprotected areas. Significantly, as populations growing, many fish head into less crowded areas outside the reserve, where fishermen reap the benefits indefinitely. “It’s a no-brainer(无需用脑的事), really, isn’t it?”Roberts observes. “Like money in the bank producing interest. “1．What’s the news about the oceans in 2003?A．People ignore what the oceans are suffering.B．The scale of the ocean devastation is out of our expectation.C．The fishmongers are making effort to improve their fishing practices.D．The oceans are losing many rare species.正确答案：B解析：事实细节题。
为什么海洋探索如此重要四级作文英语
The Vital Importance of Ocean ExplorationIn the vast and mysterious realm of the oceans, lie secrets that have remained unknown to mankind for centuries. The expanse of the oceans covers more than 70% of theEarth's surface, yet we have only scratched the surface of its depths. The importance of ocean exploration cannot be overstated, as it holds the key to understanding our planet, its resources, and the future of humanity.Firstly, ocean exploration is crucial for scientific research. The oceans are home to a diverse array of marine life and ecological systems that are yet to be fully discovered. Scientists can learn about the adaptations of marine organisms to extreme environments, which can then be applied to various fields, including medicine and biotechnology. Furthermore, the study of ocean currents and their impact on climate change is essential for predicting future weather patterns and mitigating the effects ofglobal warming.Secondly, ocean exploration offers immense economic benefits. The oceans are rich in resources such as oil, gas, and minerals that are essential for modern industries. Thediscovery and exploitation of these resources can lead to economic growth and development, particularly in coastal communities that rely on marine resources for their livelihoods. Additionally, the development of new technologies for ocean exploration, such as deep-seadrilling and mining, creates job opportunities and spurs innovation.Moreover, ocean exploration is essential for national security. Naval forces of various countries conduct oceanic patrols to safeguard their territorial waters and interests. By exploring and understanding the oceans, nations can ensure their sovereignty and prevent any potential threatsto their national security.Lastly, ocean exploration is vital for the preservation of marine ecosystems. As human activities expand into the oceans, there is an increasing risk of pollution, overfishing, and climate change, which can lead to the degradation of marine ecosystems. Through exploration, we can identify and protect vulnerable areas, monitor thehealth of marine ecosystems, and implement sustainable management practices to ensure their long-term viability.In conclusion, ocean exploration is crucial for scientific research, economic development, national security, and the preservation of marine ecosystems. It is a window to the unknown, offering infinite possibilities and opportunities for mankind. As we continue to explore the depths of the oceans, we gain a deeper understanding of our planet and its resources, paving the way for a sustainable future for all.**海洋探索的重要性**在广阔而神秘的海洋领域，隐藏着数百年来人类未知的秘密。
气候对我们的影响英语作文
气候对我们的影响英语作文Climate change has become one of the most pressing issues of our time, withfar-reaching implications for our planet and our lives. The impact of climate on our daily lives is undeniable, as it affects everything from the food we eat to the air we breathe. In this essay, we will delve into the ways in which climate influences our lives, exploring its historical background, different perspectives, case studies, and a critical evaluation of its effects. We will also consider the future implications and offer recommendations for addressing the challenges posed by climate change.The historical background of climate change can be traced back to the Industrial Revolution, when human activities began to significantly alter the composition of the Earth's atmosphere. The burning of fossil fuels, deforestation, and industrial processes have led to a rapid increase in greenhouse gas emissions, resulting in global warming and other climate-related changes. Over the years, the scientific community has amassed a wealth of evidence demonstrating the impact of human activities on the climate, leading to widespread consensus on the reality of climate change.From a scientific perspective, climate change is a clear and present danger, with the potential to cause widespread environmental and social disruption. Rising global temperatures have led to more frequent and severe weather events, such as hurricanes, droughts, and heatwaves. These events not only pose a direct threat to human lives and infrastructure but also have indirect effects on agriculture, water resources, and public health. Furthermore, the melting of polar ice caps and the rise in sea levels could lead to the displacement of millions of people living in coastal areas.On the other hand, there are those who remain skeptical about the severity of climate change and its human-caused origins. Some argue that natural climate variability, rather than human activities, is primarily responsible for the observed changes. Others question the economic implications of transitioning to alow-carbon economy, fearing that it could lead to job losses and reduced economic growth. These differing perspectives have led to a polarized debate on climate change, making it challenging to achieve consensus on effective solutions.To illustrate the impact of climate change, we can look at the case of the Maldives, a low-lying island nation in the Indian Ocean. The Maldives is particularly vulnerable to rising sea levels, as even a small increase could submerge a significant portion of its landmass. The government of the Maldives has been at the forefront of international efforts to address climate change, advocating for greater action to reduce greenhouse gas emissions and protect vulnerable communities. This case highlights the real and immediate consequences of climate change for those living in low-lying coastal areas.In evaluating the impact of climate change, it is essential to consider both its benefits and drawbacks. While the negative effects of climate change are well-documented, there are also potential benefits to be gained from addressing the issue. Transitioning to renewable energy sources, for example, could lead to cleaner air, reduced dependence on fossil fuels, and new job opportunities in the green economy. Furthermore, investing in climate resilience measures can help communities adapt to the changing climate and mitigate the potential risks.Looking ahead, it is clear that the implications of climate change will continue to shape our world in the coming decades. As such, it is imperative that we take decisive action to address the root causes of climate change and prepare for its inevitable consequences. This will require a coordinated effort at the local, national, and international levels, involving governments, businesses, and individuals alike. By investing in renewable energy, promoting sustainable practices, and supporting vulnerable communities, we can work towards a more resilient and sustainable future for all.。
海洋探险的重要英语作文
海洋探险的重要英语作文Title: The Significance of Ocean Exploration。
Ocean exploration plays a pivotal role in understanding our planet's vast and mysterious aquatic realm. Its importance transcends mere scientific curiosity, extending into realms of environmental conservation, resource management, and even cultural enrichment. In this essay, we delve into the significance of ocean exploration, highlighting its multifaceted impact on humanity and the planet.Firstly, ocean exploration serves as a gateway to unraveling the mysteries of marine ecosystems. The oceans cover over 70% of the Earth's surface, yet much of their depths remain uncharted and unexplored. Through expeditions and research voyages, scientists can study marine biodiversity, ecosystems, and geological features, contributing to our understanding of the complex interplay of life beneath the waves. This knowledge is crucial forconservation efforts aimed at preserving fragile marine habitats and endangered species.Moreover, ocean exploration provides valuable insights into the dynamics of climate change. The oceans play a crucial role in regulating the Earth's climate by absorbing excess heat and carbon dioxide from the atmosphere. By studying ocean currents, temperature patterns, and marinelife responses to environmental shifts, scientists canbetter predict and mitigate the impacts of climate changeon coastal communities and global weather patterns. This understanding is essential for developing sustainable adaptation strategies and mitigating the adverse effects of rising sea levels and ocean acidification.Furthermore, ocean exploration holds immense potential for the discovery of new resources and technologies. Thevast expanse of the oceans contains untapped reserves of minerals, energy sources, and genetic resources with applications ranging from medicine to renewable energy. By exploring deep-sea hydrothermal vents, underwater volcanoes, and deep-sea trenches, researchers can unlock valuableinsights into the Earth's geological processes and uncover novel bioactive compounds with potential therapeutic benefits. Additionally, innovations in marine biotechnology, such as biomimicry inspired by marine organisms, have the potential to revolutionize industries and address pressing global challenges.In addition to its scientific and economic significance, ocean exploration also fosters cultural exchange and understanding. Throughout history, the oceans have servedas conduits for trade, exploration, and migration, shaping the cultural identities of coastal communities around the world. By studying maritime archaeology and culturalheritage sites, researchers can uncover the stories of ancient civilizations and seafaring societies, enrichingour collective understanding of human history and heritage. Furthermore, collaborative research initiatives and international partnerships in ocean exploration promote cross-cultural dialogue and cooperation, fostering mutual respect and appreciation for the world's oceans as a shared heritage.In conclusion, ocean exploration is of paramount importance for humanity and the planet. From advancing scientific knowledge and addressing global challenges to preserving cultural heritage and fostering international cooperation, the significance of ocean exploration cannot be overstated. By investing in research, technology, and education, we can unlock the full potential of the oceans as a source of inspiration, innovation, and sustainability for future generations. As stewards of the oceans, it is our collective responsibility to explore, protect, and conserve these precious marine ecosystems for the benefit of all life on Earth.。
海洋探索有利不利英语作文
海洋探索有利不利英语作文Ocean exploration has both advantages and disadvantages. On one hand, it presents an opportunity for scientific discovery, environmental monitoring, and resource exploitation. On the other hand, it poses risks to marine ecosystems and raises ethical concerns. In this essay, Iwill discuss the pros and cons of ocean exploration.Firstly, ocean exploration offers numerous advantages.It allows scientists to discover new species, study marine habitats, and understand complex ecosystems. For example, expeditions to deep-sea trenches have led to the discoveryof unique organisms adapted to extreme conditions,providing valuable insights into evolutionary biology. Furthermore, ocean exploration enables researchers to monitor environmental changes, such as ocean acidification and coral bleaching, which are critical for assessing the health of marine ecosystems and informing conservation efforts.Moreover, ocean exploration has economic benefits. It supports industries such as fishing, shipping, and tourism, which rely on marine resources and infrastructure. For instance, exploration of underwater mineral deposits hasthe potential to open up new sources of rare metals used in electronics and renewable energy technologies. Additionally, the development of offshore oil and gas reservescontributes to energy security and economic growth.However, ocean exploration also has its drawbacks. One major concern is the impact on marine biodiversity and ecosystems. Activities such as deep-sea mining, oildrilling, and seabed trawling can disrupt fragile habitats and harm sensitive species. For example, bottom trawlingcan destroy coral reefs and seafloor communities, leadingto long-term ecological damage. Furthermore, noisepollution from shipping and underwater construction can disrupt marine life, including whales and dolphins, which rely on sound for communication and navigation.Another issue is the ethical dilemma surrounding resource exploitation in the ocean. While the potentialbenefits of extracting minerals and energy resources are undeniable, there are ethical considerations regarding the equitable distribution of profits and the rights of indigenous communities. Additionally, there is a risk of environmental damage and conflicts over resource ownership, particularly in areas beyond national jurisdiction where governance is limited.In conclusion, ocean exploration offers both opportunities and challenges. While it provides valuable scientific knowledge and economic benefits, it also poses risks to marine ecosystems and raises ethical concerns. Therefore, it is essential to approach ocean exploration with caution, taking into account environmental sustainability, ethical considerations, and the long-term interests of both present and future generations. Only through responsible stewardship can we ensure the health and vitality of our oceans for years to come.。
肯尼亚天气英语作文
肯尼亚天气英语作文Title: The Weather in Kenya: A Comprehensive Overview。
Kenya, a land of diverse landscapes and vibrant cultures, experiences a varied climate throughout its regions. From the savannahs of the Maasai Mara to the coastal shores of Mombasa, the weather patterns in Kenya exhibit a fascinating spectrum. In this essay, we delveinto the intricacies of Kenya's weather, exploring its seasonal variations, climatic influences, and the impact on local communities and ecosystems.Geographical Influences:Kenya's geography plays a pivotal role in shaping its weather patterns. Situated close to the equator, the country experiences a tropical climate characterized by relatively high temperatures throughout the year. However, the presence of diverse geographical features such as mountains, plateaus, and coastal plains introducessignificant variations in weather across different regions.Seasonal Variations:Kenya has two distinct seasons: the dry season and the wet season. The dry season typically occurs from June to October, while the wet season spans from November to May. During the dry season, clear skies and minimal rainfall prevail, making it an ideal time for wildlife safaris and outdoor adventures. In contrast, the wet season brings heavy rainfall, especially in the coastal and western regions, rejuvenating the landscapes and supporting agricultural activities.Temperature Patterns:Temperature variations in Kenya are influenced by altitude, proximity to water bodies, and seasonal changes. Coastal areas experience relatively stable temperatures throughout the year, with average highs ranging from 25°C to 30°C. Inland regions, especially those at higher elevations such as Nairobi and the central highlands, tendto be cooler, with temperatures ranging from 10°C to 25°C depending on the season.Climatic Regions:Kenya can be divided into several climatic regions,each exhibiting unique weather characteristics. The coastal region, with its proximity to the Indian Ocean, experiences high humidity and moderate temperatures year-round. Inland areas, including the Rift Valley and central highlands, boast a more temperate climate, while the arid and semi-arid regions in the north endure hot and dry conditions, punctuated by occasional droughts.Impact on Communities and Ecosystems:The weather patterns in Kenya profoundly influence the lives of its inhabitants and the natural environment. For rural communities dependent on agriculture, the timing and intensity of rainfall determine crop yields and livelihoods. Droughts and floods, exacerbated by climate change, pose significant challenges to food security and economicstability.In terms of ecosystems, Kenya's diverse flora and fauna are intricately linked to its weather patterns. Theseasonal migration of wildebeests in the Maasai Mara, for instance, is driven by the availability of water andgrazing resources during the dry and wet seasons. Similarly, the lush vegetation of the Aberdare Range owes itsexistence to the ample rainfall received in the region.Adaptation and Resilience:In the face of climatic uncertainties, Kenyan communities have demonstrated remarkable resilience and adaptation strategies. From implementing water conservation measures to embracing drought-resistant crops, local initiatives aim to mitigate the impacts of climatevariability and safeguard livelihoods. Furthermore, international collaborations and sustainable development projects seek to build adaptive capacity and foster climate resilience across various sectors.Conclusion:In conclusion, the weather in Kenya embodies a rich tapestry of climatic diversity and seasonal dynamics. From the arid landscapes of the north to the lush greenery ofthe highlands, each region contributes to the country's unique meteorological mosaic. While challenges such as climate change persist, the resilience and ingenuity of Kenyan communities offer hope for a sustainable future amidst shifting weather patterns. As we continue to unravel the complexities of Kenya's weather, let us recognize the interconnectedness of human societies and the natural world, striving for harmony and balance in our stewardship of the planet.。
南印度洋偶极子及其影响研究进展
南印度洋偶极子及其影响研究进展徐海明;张岚;杜岩【期刊名称】《热带海洋学报》【年(卷),期】2013(000)001【摘要】回顾了对南印度洋副热带海气相互作用的研究,总结了南印度洋偶极子事件背景下的气候变化.印度洋海表温度的方差表明南印度洋是整个印度洋海温变率最强的区域,年际海温变化最显著的特征就是海温呈现西南—东北向的偶极子型分布,被称为南印度洋偶极子(Southern Indian Ocean Dipole, SIOD).南印度洋海温偶极子的形成主要是受大尺度大气环流调整的影响.南印度洋副热带反气旋环流异常引起了印度洋热带东风异常和副热带西风异常的变化,影响了潜热通量、上升流和Ekman热输送,进而引起了海温变化.SIOD对热带和热带外大气环流也有影响,尤其会影响亚洲夏季风降水异常,例如我国的降水异常和南印度洋偶极子海温异常具有显著相关关系.此外,SIOD模态所引起的经向环流异常与南海、菲律宾地区的反气旋环流异常也有紧密联系.%This paper reviews the studies on the southern Indian Ocean (SIO) air-sea interaction and summarizes the climate variability in the SIO at the inter-annual time scale. Variance and correlation analysis of the Indian Ocean sea surface temperature (SST) indicates that a strong dipole oscillation occurs in the SIO, the so-called Southern Indian Ocean Dipole (SIOD). Large-scale atmospheric circulation in the midlatitude of the Southern Hemisphere plays a role in the formation of SIOD. A subtropical anticyclonic anomaly contributes to the tropical easterly anomalies and midlatitude westerly anomalies;this resultsin anomalies in latent heat flux, upwelling, and Ekman heat transport, and then changes the SST. Through changing the heat distribution in the atmosphere in the South Asia and tropical Pacific, the SIOD has an impact on tropical atmospheric circulation. In particular, it remotely influences the Asian summer monsoon rainfall;for example, a close relationship is found between SIOD and rainfall over China. In addition, the anomaly induced by the SIOD can result in anticyclonic atmosphere anomalies over the South China Sea and Philippine Islands.【总页数】7页(P1-7)【作者】徐海明;张岚;杜岩【作者单位】南京信息工程大学，大气科学学院，江苏南京 210044;南京信息工程大学，大气科学学院，江苏南京 210044; 中国科学院南海海洋研究所，热带海洋环境动力学重点实验室，广东广州 510301;中国科学院南海海洋研究所，热带海洋环境动力学重点实验室，广东广州 510301【正文语种】中文【中图分类】P732;P731【相关文献】1.南印度洋海温偶极子型振荡及其气候影响 [J], 贾小龙;李崇银2.南印度洋偶极子的变化特征及其与ENSO的关系 [J], 黄秀秀;代秀明;黄春丽3.南印度洋偶极子的变化特征及其与ENSO事件的联系 [J], 王黎娟;陈爽;张海燕4.南印度洋偶极子的特征及其与ENSO的关系 [J], 张岚;杜岩;张玉红;徐海明5.南印度洋偶极子与我国夏季降水的联系 [J], 章舒婧因版权原因，仅展示原文概要，查看原文内容请购买。