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1.
用南海西沙站观测资料诊断研究南海季风季节内振荡 总被引：1，自引：0，他引：1
应用Lanczos滤波和小波变换方法,对1958~2000年南海北部西沙站降水和1980~2001年850hPa风场观测资料进行分析,发现西沙站每日降水和850hPa风场都存在谱长度10~50d左右其峰值为10~20,30~50d的季节内振荡,降水和850hPa风场的季节内振荡都有明显的年变化.降水季节内振荡开始于5月中旬结束于10月中旬,与南海夏季风的爆发时间和终止时间一致.850hPa风场谱长度10~50d左右其峰值为10~20,30~50d的季节内振荡在一年中的大部分时间都存在.降水和850hPa风场季节内振荡的强弱年与南海夏季风的强弱年并不一致.研究表明南海夏季风存在季节内振荡,而南海夏季风与季节内振荡的关系比较复杂. 相似文献
2.
应用广东境内分布较均匀的２０个测站的降水资料，分析了Ｅ１Ｎｉｎｏ事件与广东各区域夏季（本文指５—８月，下同）降水的关系，以及赤道东太平洋海温、南海海温的变化对广东夏季降水的影响，并探讨了Ｅ１Ｎｉｎｏ事件与广东各区域历史旱涝的关系。结果表明，把广东看为一个整体，Ｅ１Ｎｉｎｏ事件与其夏季旱涝关系不明显。但把广东划分为西北部、东北部、中部及西南部，则在Ｅ１Ｎｉｎｏ事件当年，西北部偏旱，西南部偏涝；在Ｅ１Ｎｉｎｏ事件次年，西北部偏涝，西南部偏旱；而东北部及中部在Ｅ１Ｎｉｎｏ事件当年和次年雨量均偏多，但当年比次年的偏多率大。 相似文献
3.
有孔虫在生长发育过程中能够捕获或黏附周围海水中的钙质或硅质形成自己的壳体,因此有孔虫的地球化学特征能够记录古气候、古海洋和古环境信息。以2017年蛟龙号第136潜次在南海珍贝海山底部约2500 m水深位置精准采集的柱状样品为研究对象,对其中的G.ruber以及G.sacculifer两类浮游有孔虫壳体的Mg/Ca以及碳氧同位素组成进行了分析测试。结果表明自12.6 ka以来该海域表层海水温度(SST)的变化范围为24.4~29.3℃,平均温度为26.2℃,并能够识别出明显的气候突变事件,在时间范围上与新仙女木事件和全新世东亚夏季风突变事件大致吻合。这些突变事件可能受控于ENSO活动和热带辐合带(ITCZ)平均位置的纬向移动,并与北大西洋冰筏事件具有遥相关。此外,发现全新世期间浮游有孔虫G.sacculifer和G.ruber的碳同位素分馏值Δ^13CG.sacculifer-G.ruber与SST变化有关,SST降低时,Δ^13CG.sacculifer-G.ruber呈负偏;而在SST升高时,Δ^13CG.sacculifer-G.ruber呈正偏。 相似文献
4.
Trends of sea surface temperature and sea surface temperature fronts in the South China Sea during 2003–2017 总被引：2，自引：0，他引：2
The trends of the sea surface temperature(SST) and SST fronts in the South China Sea(SCS) are analyzed during2003–2017 using high-resolution satellite data. The linear trend of the basin averaged SST is 0.31°C per decade,with the strongest warming identified in southeastern Vietnam. Although the rate of warming is comparable in summer and winter for the entire basin, the corresponding spatial patterns of the linear trend are substantially different between them. The SST trend to the west of the Luzon Strait is characterized by rapid warming in summer, exceeding approximately 0.6°C per decade, but the trend is insignificant in winter. The strongest warming trend occurs in the southeast of Vietnam in winter, with much less pronounced warming in summer. A positive trend of SST fronts is identified for the coast of China and is associated with increasing wind stress. The increasing trend of SST fronts is also found in the east of Vietnam. Large-scale circulation, such as El Ni?o, can influence the trends of the SST and SST fronts. A significant correlation is found between the SST anomaly and Ni?o3.4 index, and the ENSO signal leads by eight months. The basin averaged SST linear trends increase after the El Ni?o event(2009–2010), which is, at least, due to the rapid warming rate causing by the enhanced northeasterly wind. Peaks of positive anomalous SST and negatively anomalous SST fronts are found to co-occur with the strong El Ni?o events. 相似文献
5.
6.
《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
7.
Using the National Center for Enviromental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and NOAA satellite-obser ved outgoing long-wave radiation (OLR) data, the development of the South China Sea (SCS) summer monsoon and intraseasonal (30-60 d) oscillation (ISO) have been examined. The results show that there exists obvious interannual variability of intraseasonal oscillaiton. Using the 16 a time series of filtered OLR averaged over the SCS, an index is defined to define ““onset events““ over the SCS on the ISO time scales. Of the 16 a examined here, 10 shows a strong ISO signal in the onset of monsoon convection over the SCS. In these cases, the ISO initially suppresses the seasonal development of southwesterly and cyclonic circulation over the SCS before the ISO onset. As the ISO propagates northeastward, the low frequency cyclonic circulation anomaly occurs in the SCS and the low frequency southwesterly wind and convection over here dramatically intensify. The northeast progression of the ISO anomaleis plays a role in the initial suppression and then acceleration of the seasonal cycle of the SCS summer monsoon. 相似文献
8.
1Introduction Indian Ocean dipole(IOD),a kind of localcharacteristics of variation of sea surface temperature(SST)in the Indian Ocean,behaves with an oppo-site SSTA symbol between the east and west parts ofthe tropical Indian Ocean(Yu and Liu,2004;Rongand… 相似文献
9.
热带印度洋SST海盆模态的“充电/放电”作用——对夏季南亚高压的影响 总被引：6，自引：0，他引：6
根据观测资料和海气耦合模式初值试验结果,通过比较分析热带太平洋SST主模态(ENSO模)和热带印度洋SST主模态(海盆模)对夏季南亚高压的影响,揭示了印度洋海盆模的"充电/放电"作用:赤道中东太平洋海温异常首先对印度洋进行"充电",形成热带印度洋SST对太平洋EN-SO的响应模态——海盆模。该模态在ENSO发生翌年春季达到峰值位相,而且有很好的持续性,可以从春季持续到夏季,该暖(冷)模态可以引起大气的"Matsuno-Gillpattern"响应,并通过亚洲夏季平均西南季风的异常水汽输送等使得夏季南亚高压偏强(弱),即为"放电"过程。而赤道中东太平洋海温异常对夏季南亚高压的直接影响并不显著,并指出了夏季南亚高压和超前3~12个月Nio3指数之间高的显著正相关关系只是一个表象,并不是太平洋海温异常对南亚高压的直接影响结果,而是通过印度洋海盆模态的"充电/放电"作用引起的。 相似文献
10.
海温是海洋环境影响因子之一,对于海洋生态环境、海水养殖业等尤为重要。本文以Argo数据提取的南海海洋温度场数据为例,结合GIS(GeographicInformationSystem)技术,研究南海海温点过程、面过程可视化表达的方法。利用GIS作为可视化框架提供南海海温场的可视化显示,包括放大、缩小和拖动等基本功能,绘制多种形式的数值图像并进行空间分析,包括海温数据曲线绘制、海温值查询、空间插值、等值线等。基于Argo数据可视化表达的结果,从南海海温年变化、随纬度的变化、垂向变化、季节分布特征四方面对南海的海温时空特征进行了分析,结果表明:(1)南海海表温度高温的持续时间比较长,升温过程比降温过程相对要短一些;(2)随着纬度的降低,温度整体升高,温度的年变化幅度越来越小。夏秋两季随着纬度的变化,温度变化不大,春冬两季的温度变化较大;(3)在0~30 m温度变化很小,在深度为30m处温度开始逐渐下降,到达500m以下,海温一年四季都比较接近;(4)冬季海温总体最低,夏季海温总体最高。冬季和秋季,在南海西南方向等值线呈现西北—东南向,等值线比较密集。海温的时空变化研究可以对海洋温跃层、海洋温度锋,海水不同层次的结构的研究提供一定参考。 相似文献
11.
Song Jiaxi 《海洋学报(英文版)》1991,10(4):555-564
Having been calculated and analysed, it is found in this research paper that there exist a close lag relationship between sea surface temperature (SST) change in the north of the North Atlantic and height change at 500 hPa level in South Asia. In this paper, it is focused on the analysis of physical processes of the relation between SST and height and their effect on summer monsoon in South Asia. 相似文献
12.
南海季风型海-气耦合模态的时空特征及其与中国夏季降水的关系 总被引：2，自引：0，他引：2
使用NCEP/NCAR的海表温度(SST)、海面10 m风场的月平均再分析资料,用联合SVD(CSVD)的方法研究了不同季节南海的海气耦合模的时空分布特征及其与中国夏季降水的关系。通过对不同季节的海-气耦合模的年际变化特征的分析。结果发现:第一模态为最显著模态,模态协方差贡献比在四季均超过80%,空间上SST表现为与南海等深线相一致的海盆模态,风场上主要表现为弱的冬季风或弱的夏季风,各个季节的海-气耦合模态都主要反映了SST-蒸发-风反馈这样1种正反馈的海-气相互作用过程,而且冬季风期间这种相互作用要更强烈些。时间系数均主要表现为一致的上升趋势和1976年前后的年代际突变,以及与ENSO相关的年际变化特征。冬、夏季弱的季风对应暖SST的特征体现了这种耦合模态隔季相关的特征,都对应夏季华南旱(涝)、江南涝(旱),华北、山东半岛旱(涝),东北涝(旱)这样1种波列状的旱涝相间分布。 相似文献
13.
华北地区夏季降雨量与南海海温长期变化的关系 总被引：6，自引：0，他引：6
比较了华北地区7个站与17个站1951-1997年夏季（6，7，8月）降雨量与气候随时间的变化特征，并对其成因作了探讨。结果表明，用北京、天津、邢台、烟台、郑州、太原和济南等7个站可代表该地区夏季降雨量与气候的多尺度变化特征，过去47a该地区依次经历了湿凉、湿热、湿凉、干热、湿热几个时期，降雨量的长期变化与南海前冬（1-2月）海温成负相关。前冬南海海温偏高，意味着初夏南海地区大气对流低频振动偏弱，南海夏季风爆发较晚，西南季风较弱，夏季西太平洋副高位置偏南，华北地区大气低层北风加强，华北地区夏季少雨，前冬南海海温偏低时情况则相反，考虑冬季（1-2月）南海南温和7-8月西太平洋副高脊线位置（纬度）的影响用均生函数建模，试验结果与用子波变换重构方法考虑华北地区夏季降雨量的变化趋势比较，二者相吻合，预测试验结果与过去3a的实况基本一致。 相似文献
14.
东亚冬夏季风对热带印度洋秋季海温异常的响应 总被引：5，自引：0，他引：5
利用多年的Reynolds月平均海表温度资料和NCEP/NCAR全球大气再分析资料,分析了热带印度洋秋季海表温度距平(SSTA)与后期东亚冬夏季风强度变化的关系。结果表明,热带印度洋秋季SSTA的主要模态是全区一致(USB)型和偶极子(IOD)型,USB型模态主要代表热带印度洋秋季SSTA的长期变化趋势,而IOD型模态主要反映热带印度洋秋季SSTA的年际变化。热带印度洋秋季海温气候变率中既存在着明显的ENSO信号,也有独立于ENSO的变率特征,独立于ENSO的热带印度洋秋季SSTA变化的主要模态仍是USB型和IOD型。前期秋季USB模态与东亚冬季风及东亚副热带夏季风之间为负相关关系;与前期正(负)IOD模态相对应,南海夏季风强度偏弱(强),而东亚副热带夏季风强度偏强(弱)。USB型和IOD型模态对后期东亚冬、夏季风强度变化的影响是独立于ENSO的,但ENSO起到了调节二者相关显著程度的作用。 相似文献
15.
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
16.
Variations of monsoon wind field in the sea area along the southeastern coast of China during the ENSO events and its influence on the sea level and sea surface temperature (SST) are explored mainly on the basis of the data of monthly mean wind at 850 hPa and five coastal stations during 1973-1987. The results from the analyses of the data and theoretical estimation show that the southwest wind anomalies appeared in the study area during the events, and northeast wind anomalies occurred in general before the events. With the coastline of the area being parallel basically to the direction of the wind, an Ekman transport will result in an accumulation of the water near the coast or a departure of the water from the coast. As a result , the sea level and SST there will be affected markedly. During the events, southwest wind will intensify in the summer, and northeast wind will weaken in the winter. Their total effect is that a large negative anomaly of the sea level and SST will occur. The estimations indi 相似文献
17.
厄尔尼诺期间和后期南海海面温度的两次显著增暖过程 总被引：5，自引：0，他引：5
通过分析ICOADS海洋气象资料,结合ISCCP短波辐射和OISST海面温度,研究并探讨了ENSO等大尺度海气相互作用过程背景下南海海表面温度（SST）的年际变化。研究表明,南海SSTA的年际变化和ENSO关系密切,并且分为两个阶段。以增暖事件为例,在厄尔尼诺（El Nino）发生年的冬季和消亡年的夏季,南海出现了两次显著增暖。第一次增暖出现在El Nino盛期,是El Nino影响的一部分,这时南海云量减少,净太阳辐射通量增加,SST上升。第二次增暖出现在El Nino结束后的夏季,不是El Nino直接作用的结果;这时夏季风减弱,一方面使得海洋的潜热损失减少,另一方面减弱了越南东部沿岸的上升流,两者的共同作用导致SST增加。 相似文献
18.
利用9层15波全球大气环流谱模式研究了太平洋海温异常对南海西南季风建立早晚的影响作用.结果表明:西-中太平洋海温异常数值试验结果最能反映出南海西南季风爆发早、晚年4～5月份大气环流的差异特征.数值试验结果显示:西太平洋海温正(负)异常可导致西太平洋副高减弱(加强);中太平洋海温正(负)异常主要使得中太平洋上空的洋中槽减弱(加深);东太平洋海温正(负)异常可造成东太平洋赤道两侧高层环流产生反气旋性(气旋性)变化,孟加拉湾-南海-西太平洋热带地区出现东风(西风)异常,西太副高加强(减弱).可见西太平洋海温异常和东太平洋海温异常都可以对副高强弱变化产生明显影响,从而对南海西南季风建立早晚产生影响,只不过西太平洋海温异常的影响作用更为显著.西太平洋正(负)海温异常与中太平洋负(正)海温异常经常是同时出现的,其激发出的与向东传的Kelvin波和向西传的行星波相联系的环流异常为南海季风建立早(晚)提供有利的条件,因而这一海温分布型是影响南海西南季风建立早晚的重要影响因子. 相似文献
19.
南大西洋副热带偶极子(South Atlantic Subtropical Dipole;SASD)为南大西洋海洋与大气相互作用的主要模态。它的空间型为海表面温度异常呈现东北-西南偶极子分布。当SASD指数大于1,为SASD正事件,小于-1,为负事件。根据1960-2016年HadISST(Hadley Center Global Sea Ice and Sea Surface Temperature)数据,本文鉴别出57年中共发生6次正事件和9次负事件。SASD存在显著的5~8年周期的年际变化特征。本文进一步利用1992-2016年ECCO2(Estimating the Circulation and Climate of the Ocean,PhaseⅡ)模式数据,根据温度倾向方程分别诊断了SASD西南极和东北极的混合层温度变化。诊断结果表明,SASD的年际变化主要来自于表面热力强迫项的年际变化。考虑到表面热力强迫项主要由短波辐射项控制,SASD的年际变化最终来源于短波辐射项的年际变化。 相似文献
20.
Argos表面漂流浮标在黑潮区的若干观测结果 总被引：3，自引：0，他引：3
利用近几年国家海洋局第二海洋研究所及国家海洋技术中心在南海和西北太平洋海域布放的部分卫星跟踪表面漂流浮标所取得的观测资料,分析了浮标流经海域的表层海流特征及浮标漂移路径上水温的变化。结果表明:2003年1月,黑潮表层水有入侵南海的趋势,夏季南海表层水经吕宋海峡流出,汇入黑潮主干;夏末冬初,黑潮主干经过东海时明显呈弯曲流动;2003年春季,日本以南海域黑潮弯曲不明显;台湾东北部海域存在一个强反气旋涡;表层海水的温度日变化和季节变化明显,在浮标漂移路径呈反气旋或气旋式转动的区域,对应出现了表层水温的高、低温区。 相似文献