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1.
中国近海海平面变化与ENSO的关系 总被引：2，自引：1，他引：1
利用中国沿海台站潮位和中国近海及赤道太平洋的卫星测高、海表温度、风及气压资料,分析了中国近海海平面变化与ENSO的关系。分析结果表明:中国沿海海平面季节变化受ENSO影响明显,在厄尔尼诺事件期间,中国沿海海平面Sa分潮的振幅明显减小,其中年振幅的历史极小值均出现厄尔尼诺年,不同区域历史极小值出现的年份不同;另外,中国沿海Sa分潮的振幅对厄尔尼诺事件的响应与其强弱有关,在强事件中,响应区域和幅度较大,弱事件中,响应区域和幅度偏小。在厄尔尼诺年,中国沿海海平面多低于相邻年份,并且其年际变化存在明显的2~3a、4~7a、准9a、11a和准19a的周期,其中4~7a的周期在冬春季节震荡最显著,其震荡幅度接近2cm。中国近海海平面与赤道东太平洋区域的海表温度年际变化之间存在反相关关系,其相关系数为-0.42;同时与Nio4和Nio3.4指数序列也呈现反相关关系。针对典型的1997/1998年尼诺事件发生前后的风场和气压场分析发现,尼诺发生前的冬半年,冬季风偏强,气压梯度加强,中国沿海海平面偏低;到了厄尔尼诺的盛期,出现较强的南风异常,气压梯度反向,季风转向,过渡到了厄尔尼诺事件的衰减期,为拉尼娜事件做准备,此时海平面偏高。 相似文献
2.
冬季婆罗洲岛西北沿岸上升流的时空特征及机理研究 总被引：1，自引：0，他引：1
Winter coastal upwelling off northwest Borneo in the South China Sea(SCS) is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in December, matures in January, starts to decay in February and almost disappears in March. Both Ekman transport induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ekman transport is two times larger than Ekman pumping in January and February. Under the influence of El Ni?o-Southern Oscillation(ENSO), the upwelling shows remarkable interannual variability: during winter of El Ni?o(La Ni?a) years, an anticyclonic(a cyclonic) wind anomaly is established in the SCS, which behaves a northeasterly(southwesterly) anomaly and a positive(negative) wind stress curl anomaly off the northwest Borneo coast, enhancing(reducing) the upwelling and causing anomalous surface cooling(warming) and higher(lower) chlorophyll concentration. The sea surface temperature anomaly(SSTA) associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter. 相似文献
3.
南海沿海季节性海平面异常变化特征及成因分析 总被引：1，自引：1，他引：0
Based on sea level, air temperature, sea surface temperature(SST), air pressure and wind data during 1980–2014,this paper uses Morlet wavelet transform, Estuarine Coastal Ocean Model(ECOM) and so on to investigate the characteristics and possible causes of seasonal sea level anomalies along the South China Sea(SCS) coast. The research results show that:(1) Seasonal sea level anomalies often occur from January to February and from June to October. The frequency of sea level anomalies is the most in August, showing a growing trend in recent years. In addition, the occurring frequency of negative sea level anomaly accounts for 50% of the total abnormal number.(2) The seasonal sea level anomalies are closely related to ENSO events. The negative anomalies always occurred during the El Ni?o events, while the positive anomalies occurred during the La Ni?a(late El Ni?o) events. In addition, the seasonal sea level oscillation periods of 4–7 a associated with ENSO are the strongest in winter, with the amplitude over 2 cm.(3) Abnormal wind is an important factor to affect the seasonal sea level anomalies in the coastal region of the SCS. Wind-driven sea level height(SSH) is basically consistent with the seasonal sea level anomalies. Moreover, the influence of the tropical cyclone in the coastal region of the SCS is concentrated in summer and autumn, contributing to the seasonal sea level anomalies.(4) Seasonal variations of sea level, SST and air temperature are basically consistent along the coast of the SCS, but the seasonal sea level anomalies have no much correlation with the SST and air temperature. 相似文献
4.
中国科学院气候系统模式模拟的ENSO循环 总被引：1，自引：1，他引：0
On the basis of more than 200-year control run, the performance of the climate system model of Chinese Academy of Sciences(CAS-ESM-C) in simulating the El Ni?o-Southern Oscillation(ENSO) cycle is evaluated, including the onset, development and decay of the ENSO. It is shown that, the model can reasonably simulate the annual cycle and interannual variability of sea surface temperature(SST) in the tropical Pacific, as well as the seasonal phase-locking of the ENSO. The model also captures two prerequisites for the El Ni?o onset, i.e., a westerly anomaly and a warm SST anomaly in the equatorial western Pacific. Owing to too strong forcing from an extratropical meridional wind, however, the westerly anomaly in this region is largely overestimated. Moreover, the simulated thermocline is much shallower with a weaker slope. As a result, the warm SST anomaly from the western Pacific propagates eastward more quickly, leading to a faster development of an El Ni?o. During the decay stage, owing to a stronger El Ni?o in the model, the secondary Gill-type response of the tropical atmosphere to the eastern Pacific warming is much stronger, thereby resulting in a persistent easterly anomaly in the western Pacific. Meanwhile, a cold anomaly in the warm pool appears as a result of a lifted thermocline via Ekman pumping. Finally, an El Ni?o decays into a La Ni?a through their interactions. In addition, the shorter period and larger amplitude of the ENSO in the model can be attributed to a shallower thermocline in the equatorial Pacific, which speeds up the zonal redistribution of a heat content in the upper ocean. 相似文献
5.
为研究东部型和中部型两类厄尔尼诺(El Ni?o)事件与中国近海海表温度(sea surface temperature,SST)变化间的联系,基于中国科学院大气物理研究所连续80年(1940—2019年)的SST再分析数据,采用EOF分解、合成分析等方法做了初步分析,发现中国近海及毗邻海域近80年SST变化与全球变暖密切相关。并且两类El Ni?o事件对中国近海SST变化的影响存在显著差异。东部型El Ni?o事件发展过程中,中国近海及毗邻海域SST在发展年主要为负异常,衰退期为正异常;中部型ElNi?o事件发展过程中, SST变化区域差异大,发展年日本附近海域为正异常, 28°N以南为弱的负异常。两类El Ni?o事件引发西太平洋风场反气旋涡的时间、位置与强度等的不同,是造成中国近海风场与海表温度异常(sea surface temperature anomaly, SSTA)差异的主要原因。 相似文献
6.
茎柔鱼主要分布于东太平洋，是我国鱿钓渔船的主要捕捞对象，气候变化对其栖息地有较大影响。本研究依据1950?2015年海表温度(SST)、海表高度距平(SSHA)以及尼诺指数(Ni?o3.4指数)，计算秘鲁外海茎柔鱼栖息地适宜性指数(HSI)，分析在厄尔尼诺(El Ni?o)、正常气候和拉尼娜(La Ni?a)条件下适宜栖息地的时空变动。分析表明，海表温度距平(SSTA)和SSHA与Ni?o3.4指数的变化趋势基本相同，Ni?o3.4指数与SSTA和SSHA均呈显著正相关，但与HSI值呈显著负相关。依据气候事件的定义，将研究年份划分为El Ni?o年，正常年和La Ni?a年。研究发现，在El Ni?o年，茎柔鱼渔场水温变暖，海面高度上升，适宜的SST和SSHA范围缩小，导致适宜的栖息地面积范围缩减；而在正常气候和La Ni?a年份，茎柔鱼渔场水温变冷，海面高度下降，适宜的SST和SSHA范围增大，因此适宜的栖息地面积范围增加。此外，Ni?o3.4指数和茎柔鱼渔场HSI纬度重心呈显著正相关，在El Ni?o事件下适宜的栖息地纬度重心向南偏移。研究认为，不同ENSO事件下茎柔鱼渔场环境变化显著，进而影响茎柔鱼适宜的栖息地范围及其空间分布。 相似文献
7.
C. Franco-Gordo E. Godínez-Domínguez A.E. Filonov J. Freire 《Progress in Oceanography》2004,63(3):99-123
The temporal and spatial distributions of zooplankton biomass and larval fish recorded during 27 months (December 1995-December 1998) off the Pacific coast of central México are analyzed. A total of 316 samples were obtained by surface (from 40-68 to 0 m) oblique hauls at 12 sampling sites using a Bongo net. Two well-defined periods were observed: a pre-ENSO period (December 1995-march 1997) and an ENSO event (July 1997-September 1998) characterized by impoverishment of the pelagic habitat. The highest biomass concentrations occurred at coastal stations during the pre-ENSO period. During the El Niño period no spatial patterns were found in coastal waters. The months with highest biomass were those in which the lowest sea surface temperature (SST) occurred (January-May), and this pattern was also observed during the ENSO period. A typical, although attenuated, seasonal environmental pattern with enhanced phytoplankton (diatoms and dinoflagellates) was prevalent during the El Niño event in nearshore waters. During the El Niño period the phytoplankton was mainly small diatoms (microphytoplankton), while dinoflagellates were practically absent. The most parsimonious generalized linear models explaining spatial and temporal distribution of larval fish species included the ENSO index (MEI), upwelling index (UI) and distance to the coast. The environmental variability defined on an interannual time-scale by the ENSO event and the seasonal hydroclimatic pattern defined by the UI (intra-annual-scale) controlled the ecosystem productivity patterns. The small-scale distribution patterns (defined by a cross-shore gradient) of plankton were related to the hydroclimatic seasonality and modulated by interannual anomalies. 相似文献
8.
基于CESM气候模式的ENSO后报试验 总被引：1，自引：1，他引：0
基于美国国家大气研究中心(NCAR)开发的通用地球系统模式(CESM),本文设计了nudging次表层海温的同化方案,进行了后报实验。对1982-2011年后报结果的分析表明,通过nudging同化,模式对ENSO现象有一定的模拟和预报能力,对赤道太平洋SST、纬向风、降水等海洋、大气要素等的后报结果与GODAS和NCEP再分析资料较接近,可以较好地重现历次厄尔尼诺和拉尼娜事件中异常东传的过程,超前1、3、6个月时,模式预报的Nio3指数与CPC指数的相关性分别达到0.88、0.81、0.70。但模式同时也表现出一定的春季预报障碍,秋季起报的后报效果最好,春季最差。对1982/1983和1997/1999两个厄尔尼诺事件的分析表明,模式后报的纬向风、热通量、风应力等大气变量的响应较实际滞后,而海洋的变化与实际情况相似,这与我们的同化方案设置有关,即模式只同化了次表层海温,进而强迫大气的响应,从而导致大气的变化较滞后。 相似文献
9.
杨顶田 《海洋学报(英文版)》2017,36(3):14-19
It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the background of global warming along the south coast of Hainan Island of China, satellite and in situ data are used to retrieve the information of the coral reef status and surrounding environmental factors. The results show that cool water induced by upwelling along the south coast of Hainan Island is found in the area every summer month, especially in the relatively strong El Ni?o years(2002–2003 and 2005). From the NOAA satellite data, degree heating week(DHW) index does not exceed 3 in Sanya Bay even in the relatively strong El Ni?o years. By comparison of a coral reef growth rate in the Sanya Bay with respect to El Ni?o events from 1957 to 2000, coral's growth rate is relatively greater during 1972, 1991–1994 and 1998 El Ni?o event. By analyzing the environmental factors, it is found that the cool water induced by upwelling may be the main reason for protecting corals from global warming effects. 相似文献
10.
2002/03年厄尔尼诺事件,是暖海温中心出现在赤道中太平洋区域的一种新型厄尔尼诺,即中太平洋型厄尔尼诺。本文基于一个厄尔尼诺预测系统,利用三组回报试验来详细区分海洋表层和次表层初始状态对预报2002/03年中太平洋型厄尔尼诺事件的作用,并由此来探寻对预报厄尔尼诺演变过程最有利的初始条件。回报试验分为三组:(1)仅同化海表温度观测(sea surface temperature;简称SST)来优化海洋表层初始状态(Assim_SST);(2)仅同化海表高度观测(sea level;简称SL)来更新海洋次表层初始状态(Assim_SL);(3)同时同化SST和SL观测来一起更新海洋表层和次表层初始状态(Assim_SST+SL)。回报试验结果表明,三种不同的初始条件都可以使模式提前一年成功地预报2002/03年厄尔尼诺事件,并且"Assim_SST+SL"回报试验的效果最好。三组回报试验结果间的对比表明:海洋表层和次表层初始状态均对成功地预报该事件有重要作用,但其作用分别集中在事件发展的不同阶段。精确的海洋表层初始状态更容易激发模式预报出一次厄尔尼诺事件,而更合理的海洋次表层初始状态则能有效地提高厄尔尼诺事件预报的强度。 相似文献
11.
SST年循环对El Niño事件局地海气过程的影响 总被引：2，自引：0，他引：2
利用Hadley中心逐月海表温度、欧洲中心ERA-40的10 m风场及CMAP降水资料探讨了年循环对热带太平洋El Niño海气相互作用过程的影响。尽管El Niño对应的海表温度异常主要出现在赤道东太平洋,经向上呈南北对称分布,然而其对应的大气响应在El Niño年衰减阶段却有着强的向南移动特征。在El Niño发展年的11月之前,强的西风和降水异常主要出现在赤道中太平洋;在12月份之后,赤道上的西风和降水异常迅速南移至5°S,随后西风一直维持在该位置直至衰亡。同时,西太平洋负降水和反气旋异常向北移动。这种SST异常与其大气响应的经向移动不一致,主要是由热带中太平洋气候态SST的季节性南移导致的。由于对流与海温之间存在非线性关系,即当总SST超过一定的阈值,对流降水才会迅速增强;因此相应的对流响应也随着总海温的南移而南移,风场响应也同时南移。此外,南半球增强的对流会通过经向环流进一步抑制北半球的降水,从而使西太平洋负降水和反气旋异常增强并北移。通过分析有/无年循环的两组数值试验结果验证了上述结论,即有年循环的试验较真实地模拟出了观测中异常西风南移和西北太平洋反气旋异常的出现;无年循环试验尽管能模拟出El Niño年赤道中太平洋的西风异常,但其却没有南北向的移动,西北太平洋的反气旋也没有出现。因此,热带中太平洋气候态暖海温的季节循环对El Niño事件大气响应有着至关重要的作用。 相似文献
12.
利用1951—2015年NOAA气候预测中心的SST扩展重建资料（ERSST V3b）、国家气候中心提供的我国160站月降水量资料、美国国家环境预报中心/大气研究中心（NCEP/NCAR）提供的各气压层的水平风速、垂直速度和比湿资料,研究了印度洋不同海温模态对两类厄尔尼诺事件与我国南方秋季降水关系的影响。结果表明,虽然东部型（中部型）厄尔尼诺年秋季我国长江以南地区降水偏多（少）,但当东部型厄尔尼诺与印度洋正偶极子同时发生年秋季,我国长江以南地区降水偏多的程度显著提高;当中部型厄尔尼诺与印度洋正偶极子同时发生年秋季,我国西南地区降水转为偏多,其他南方地区降水仍然偏少;当中部型厄尔尼诺与印度洋一致增暖型海温同时发生年秋季,我国整个长江以南地区降水偏少,且偏少的幅度要显著高于不考虑印度洋海温异常的情况。此外还对印度洋不同海温模态对两类厄尔尼诺事件与我国南方秋季降水关系的影响的环流成因进行了分析。 相似文献
13.
The 1982-1983 El Niño event is examined in comparison with the other El Niño events in 1949-1983. The relationships of subtropical high to the sea surface temperature (SST) show the important influence of the atter, which vaired with the characters of El Niño events. 相似文献
14.
The Impact of the Indian Ocean Dipole(IOD) and the El Ni?o Southern Oscillation(ENSO) event for Indonesian rainfall has been investigated for the period from 1950 to 2011. Inter-annual change of IOD and ENSO indices are used to investigate their relationship with Indonesian rainfall. By using the wavelet transform method, we found a positive significant correlation between IOD and Indonesian rainfall on the time scale of nearly 2.5–4 years.Furthermore, the positive significant correlation between ENSO(sea surface temperature anomaly at Ni?o3.4 area indices) and Indonesian rainfall exists for shorter than 2 years and between 5.5 to 6.5-year time scales. 相似文献
15.
《African Journal of Marine Science》2013,35(2):237-246
Changes and fluctuations in sea surface temperature (SST) around the South African coast are analysed at a monthly scale from 1982 to 2009. There is a statistically significant negative trend of up to 0.5 °C per decade in the southern Benguela from January to August, and a cooling trend of lesser magnitude along the South Coast and in the Port Elizabeth/Port Alfred region from May to August. The cooling is due to an increase in upwelling-favourable south-easterly and easterly winds. There is a positive trend in SST of up to 0.55 °C per decade in most parts of the Agulhas Current system during all months of the year, except for KwaZulu-Natal where warming is in summer. The warming was attributed to an intensification of the Agulhas Current in response to a poleward shift of westerly winds and an increase in trade winds in the South Indian Ocean at relevant latitudes. This intensification of the Agulhas Current could also have contributed to the coastal cooling in the Port Alfred dynamic upwelling region. The El Niño Southern Oscillation (ENSO) is significantly positively correlated at a 95% level with the southern Benguela and South Coast from February to May, and negatively correlated with the Agulhas Current system south of 36° S. The correlation with the Antarctic Annular Oscillation is weaker and less coherent. El Niño suppresses upwelling along the coast, whereas La Niña increases it. Although there does not seem to be a linear relationship between the strength of the ENSO and the magnitude of coastal SST perturbation, El Niño and La Niña appear to be linked to major warm and cool events, respectively, at a seasonal scale in summer in the southern Benguela and along the South Coast. However, care must be taken in interpreting low-resolution reanalysed climate data (ERA40 and NCEP) and optimally interpolated Reynolds SST, such as used here. 相似文献
16.
In this study, El Niño Southern Oscillation (ENSO)-induced interannual variability in the South China Sea (SCS) is documented using outputs from an eddy-resolving data-assimilating model. It is suggested that during an El Niño (La Niña) event, off-equatorial upwelling (downwelling) Rossby waves induced by Pacific equatorial wind anomalies impinge on the Philippine Islands and excite upwelling (downwelling) coastal Kelvin waves that propagate northward along the west coast of the Philippines after entering the SCS through the Mindoro Strait. The coastal Kelvin waves may then induce negative (positive) sea level anomalies in the southeastern SCS and larger (smaller) volume transport through the Mindoro and Luzon Straits during an El Niño (La Niña) event. 相似文献
17.
During the 1997/1998 El Niño event, extensive oceanic temperature profiles were taken off the coast of California in January and February 1998 using Airborne Expendable Bathythermographs (AXBTs). These AXBT measurements are compared with altimetry-based upper-ocean temperature estimates using TOPEX and ERS satellite altimetry data. The altimetry-based temperature estimates are well correlated with the AXBT data, in particular when combining the two satellite data sets together to form a blended altimeter temperature estimate. Both the AXBT and altimetry data show that the nearshore coastal El Niño signal differed from that further offshore. The AXBT data show that near shore, the warm anomalies extended to much greater depths and had greater amplitude. A time series of the satellite-derived layer-averaged temperatures, averaged separately over the nearshore and offshore halves of the AXBT analysis domain, also shows a larger El Niño signal in the nearshore half. The role of local atmospheric forcing of the coastal oceanic temperature anomalies is analyzed using NCEP reanalysis and coastal upwelling data sets. The forcing terms include Ekman pumping, radiation, surface heat fluxes, precipitation, and alongshore wind stresses that drive coastal upwelling (expressed as a coastal downwelling index, CDI). The temperature forcing from all of the terms except the CDI anomalies are small. The CDI anomalies can explain most of the slowly varying temperature changes that occur near the coast during a two-year period spanning the El Niño event, as well as some of the larger amplitude, rapid (monthly) warming episodes that appear to be part of the El Niño signal. Several distinct rapid warming episodes, however, are not correlated with the CDI anomalies, and therefore we conclude that the nearshore El Niño signal originates from a combination of both a remote oceanic pathway and local atmospheric forcing. 相似文献
18.
Takashi Setoh Shiro Imawaki Alexander Ostrovskii Shin-Ichiro Umatani 《Journal of Oceanography》1999,55(3):385-394
Interdecadal variations of El Niño/Southern Oscillation (ENSO) signals and annual cycles appearing in the sea surface temperature (SST) and zonal wind in the equatorial Pacific during 1950–1997 are studied by wavelet, empirical orthogonal function (EOF) and singular value decomposition (SVD) analyses. The typical timescale of ENSO is estimated to be about 40 months before the late 1970s and 48–52 months after that; the timescale increased by about 10 months. The spatial pattern of the ENSO signal appearing in SST also changed in the 1970s; before that, the area of strong signal spread over the extratropical regions, while it is confined near the equator after that. The center of the strongest signal shifted from the central and eastern equatorial Pacific to the South American coast at that time. These SST fluctuations near the equator are associated with fluctuations of zonal wiond, whose spatial pattern also shifted considerably eastward at that time. In the eastern equatorial Pacific, amplitudes of annual cycles of SST are weak in El Niño years and strong in La Niña years. This relation is not clear, however, in the 1980s and 1990s. 相似文献
19.
使用卫星测高、海表温度以及中国沿海台站水位等数据，分析研究了ENSO对中国近海海平面影响的区域特征。结果表明:（1）赤道东太平洋海表温度与我国近海海平面存在显著的遥相关关系。相关系数自北至南呈梯度递增，分为3个影响明显的区域，分别是渤、黄海、东海和南海海域。南海海平面异常与赤道东太平洋区域的海表温度异常相关性最强，大部分区域的相关系数超过了0.6；东海海域海平面异常与赤道东太平洋海表温度的遥相关系数弱于南海，强于渤、黄海，大部分海域的遥相关系数超过了0.4；渤、黄海海域海平面异常与赤道东太平洋海表温度的遥相关系数最弱，但是大部分海域的遥相关系数超过了0.3，通过了显著性检验。（2）中国沿海海平面的季节变化与ENSO有明显的相关关系，且影响范围具有明显的区域特征，以长江口和台湾海峡为分界线分为长江口以北、长江口到台湾海峡以及台湾海峡以南3个区域。海平面的年振幅在厄尔尼诺年均出现偏低的现象，并且年振幅的极小值均出现在厄尔尼诺年。另外，海平面的年振幅对厄尔尼诺事件的响应与其强弱有关，在强厄尔尼诺事件中，响应区域和幅度较大，弱事件中，响应区域和幅度偏小。（3）南海、东海和渤、黄海这3个区域沿海的海平面变化均存在4~7 a的显著振荡周期，说明这3个区域的海平面均受ENSO的影响。其中，南海7 a周期的振荡幅度最大，约为1.5 cm；东海7 a周期的振荡幅度次之，约为1.3 cm；渤、黄海6 a周期的振荡幅度最小，不到1 cm。 相似文献
20.
本文根据1995-2010年我国中西太平洋金枪鱼围网生产统计数据,按年和月不同时间空间分辨率对金枪鱼围网渔场进行聚类分析,划定不同渔场类型;同时结合海表温度（SST）及Niño3.4区指数,探讨其渔场类型形成的原因。研究表明,在月为时间尺度下气候异常事件（El Niño和La Niña事件）发生频次与渔场聚类结果类别相关联,在1-12月发生气候异常事件频数分布可划分为以下几个阶段:1-3月、4-6、7-9月、10-12月,与月时间尺度下金枪鱼围网中心渔场4种聚类结果的时间范围具有一致性。通过渔场重心聚类结果和El Niño和La Niña事件分类统计对比发现,在年时间尺度下,气候异常事件的类型与聚类结果相关联,聚类结果同一类别包含的年份发生的气候异常事件具有一致性,即在同一类别下1995年、1997年为强El Niño年;1998年、2007、年、2009年为正常年份;2010年为强La Niña年;1999年、2000年、2001年为La Niña年;1996年、2008年为La Niña年;2002年、2004年为El Niño年。研究认为,中心渔场的年际聚类变化与El Niño、La Niña事件的发生分布具有很强的相关性,因此可以利用El Niño、La Niña指标来预测渔场的年间和月份间的变化。 相似文献