Air-sea interactions associated with tropospheric biennial oscillation in South China Sea summer monsoon and their effects on El Niño-Southern Oscillation     

ZHENG Bin  LU Feng  WEI Hongcheng 《海洋学报(英文版)》2013,32(6):6-12

The South China Sea summer monsoon (SCSSM) behaves with prominent climate variability from the intraseasonal to interdecadal time scales. On the interannual time scale, the biennial variability (so-called tropospheric biennial oscillation, TBO) is as important as the El Ni o-Southern Oscillation (ENSO) period. Some observed data sets, including reanalysis data, are used to explore the associated air-sea interactive physical processes and how the SCSSM TBO affects the ENSO. The results show that the shearing vorticity induced by the north Indian Ocean sea surface temperature anomalies (SSTAs) and the anomalous Philippine Sea anticyclone both contribute to the TBO in the SCSSM. The results also indicate that the ENSO has a weak effect on the SCSSM TBO, whereas the latter affects the ENSO to some extent.  相似文献   

关于ENSO事件监测指数的改进方案     

陈璇  郑崇伟  郝全成  吴雪剑 《气象科技》2022,50(1):114-120

为了改进气象行业标准(国标)推荐的厄尔尼诺/拉尼娜事件监测指数所涉及的异常数据带有趋势、间隔10年的修订所可能引入的额外周期、指数一致性及气候标准值变动所引起的事件属性、强弱的变化等系列问题,本文基于一个可以消除一阶趋势并舍弃气候标准值的异常计算方法用以构建相关指数.结果表明,该方案所计算的指数与原指数具有较好的一致性...  相似文献   

两类El Niño事件对中国近海及毗邻海域海表温度的影响     

李玲莉  王林慧  宋军  郭俊如  富砚昭  蔡宇 《海洋科学》2021,45(4):51-63

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   

Impact of Subsurface Entrainment on ENSO Prediction: 1997-98 El Nino          下载免费PDF全文

ZHOU Guang-Qing  ZHU Jie-Shun 《大气和海洋科学快报》2009,2(5):261-266

Twenty-one-year hindcasts of sea surface temperature (SST) anomalies in the tropical Pacific were performed to validate the influence of ocean subsurface entrainment on SST prediction.A new hybrid coupled model was used that considered the entrainment of subsurface temperature anomalies into the sea surface.The results showed that predictions were improved significantly in the new coupled model.The predictive correlation skill increased by about 0.2 at a lead time of 9 months,and the root-mean-square (RMS) errors were decreased by nearly 0.2°C in general.A detailed analysis of the 1997-98 El Nio hindcast showed that the new model was able to predict the onset,peak (both time and amplitude),and decay of the 1997-98 strong El Nio event up to a lead time of one year,factors that are not represented well by many other forecast systems.This implies,in terms of prediction,that subsurface anomalies and their impact on the SST are one of the controlling factors in ENSO cycles.Improving the presentation of such effects in models would increase the forecast skill.  相似文献   

Indices of El Nino and El Nino Modoki： An Improved El Nino Modoki Index   总被引：2，自引：0，他引：2  

LI Gen  REN Baohu  YANG Chengyun  ZHENG Jianqiu 《大气科学进展》2010,27(5):1210-1220

In recent years, El Nino Modoki (pseudo-El Nino) has been distinguished as a unique large-scale ocean warming phenomenon happening in the central tropical Pacific that is quite different from the traditional El Nino. Empirical Orthogonal Function (EOF) analysis is used to successfully separate El Nino and El Nino Modoki. The abilities of the NINO3 index, NINO3.4 index, NINO1+2 index and NINO4 index in characterizing the El Nino are explored in detail. It is suggested that the NINO3 index is comparatively optimal to monitor the El Nino among the four NINO indices, since other NINO indices either cannot well distinguish El Nino and El Nino Modoki signals or are easily disturbed by El Nino Modoki signals. Further, an improved El Nino Modoki index (IEMI) is introduced to better represent the El Nino Modoki that is captured by the second leading EOF mode of monthly tropical Pacific sea surface temperature anomalies (SSTA). The IEMI is an improvement of the El Nino Modoki index (EMI) through adjusting the inappropriate weight coefficients of the three boxes of EMI, and it effectively overcomes the lack of EMI in monitoring the two historical El Nino Modoki events and also avoids the possible risk of EMI in excluding the interference of El Nino signal, indicating the realistic and potential advantages.  相似文献   

1997／1998年El Nino事件发生、发展可能机制的进一步研究     

岳彩军  陆维松 《南京气象学院学报》2009,32(4):513-521

基于美国哥伦比亚大学Lamont—Doherty地球观象台LDEO（Lamont—DohertyEarth Observatory）海表温度资料和NCEP／NCAR再分析风场资料,分析了1997／1998年El Nino3期间西太平洋暖池海表温度和西风距平的时间演变特征,同时也分析了东太平洋暖池海表温度和北风距平的时间演变特征。结果表明,1997／1998年El Nino3事件期间,西太平洋暖池海表温度变化及异常西风和东太平洋暖池海表温度变化及异常北风都与Nino3指数变化密切相关。将东、西太平洋暖池及异常北风、西风一并结合起来考虑,进一步研究了1997／1998年El Nino3事件发生、发展的可能机制：异常西风驱动西太平洋暖池东端暖水向东伸展直接有利于赤道东太平洋海表温度增加;异常西风激发东传的暖Kelvin波对东太平洋的冷上升流有抑制作用,从而有利于赤道东太平洋海表温度增加;东传的异常西风可以通过埃克曼漂流效应将赤道两侧的海表暖水向赤道辐合从而加强了赤道附近的下沉流,也有利于赤道东太平洋赤道附近海表温度增加。几乎与此同时,北风距平通过产生北风吹流将东太平洋暖池暖水由北向南输送至赤道附近直接导致Nino3区海表温度增加。上述增温因素的叠加作用共同导致了1997／1998年El Nino事件迅速发生、异常强大。  相似文献   

The magmatic plumbing system beneath El Hierro (Canary Islands): constraints from phenocrysts and naturally quenched basaltic glasses in submarine rocks   总被引：1，自引：1，他引：0  

Nicole A. Stroncik  Andreas Klügel  Thor H. Hansteen 《Contributions to Mineralogy and Petrology》2009,157(5):593-607

A thermobarometric and petrologic study of basanites erupted from young volcanic cones along the submarine portions of the three El Hierro rift zones (NE-Rift, NW-Rift and S-Ridge) has been performed to reconstruct magma plumbing and storage beneath the island. Mineral-melt thermobarometry applied to naturally quenched glass and clinopyroxene rims yields pressures ranging from 350 to 1070 MPa with about 80% of the calculated pressures being in the range of 600–800 MPa. This corresponds to a depth range of 19–26 km, implying that the main level of final crystal fractionation is within the uppermost mantle. No systematic dependence between sample locality and fractionation pressures could be observed. Olivine and clinopyroxene crystals in the rocks are complexly zoned and have, on an inter-sample as well as on an intra-sample scale, highly variable core and rim compositions. This can best be explained by mixing of multiply saturated (olivine, magnetite, clinopyroxene, ilmenite), moderately evolved magmas with more mafic magmas being either only saturated with olivine + spinel or with olivine + spinel + clinopyroxene. The inter-sample differences indicate derivation from small, isolated magma chambers which have undergone distinct fractionation and mixing histories. This is in contrast to oceanic intraplate volcanoes situated on plumes with high melt supply rates, e.g. Kilauea Volcano (Hawaii), where magma is mainly transported through a central conduit system and stored in a shallow magma chamber prior to injection into the rift zones. The plumbing system beneath El Hierro rather resembles the magma storage systems beneath, e.g. Madeira or La Palma, indicating that small, intermittent magma chambers might be a common feature of oceanic islands fed by plumes with relatively low fluxes, which results in only limited and periodic magma supply.  相似文献   

The Effect of Tide on the Global Climate Change     

YANG Xuexiang  CHEN Zhen  CHEN Dianyou  Qiao Qiyuan 《世界地质(英文版)》2002,5(1)

The differential rotation between the solid and fluid spheres caused by tidal force could explain the 1500 to 1800-year cycle of the world's temperature. Strong tide increases the vertical and horizontal mixing of water in the oceans, drawing the cold Pacific water from the depths to the surface and the warm water from the west to the east, where it cools or warms the atmosphere above, absorbs or releases CO2 to decrease or increase greenhouse effect and to make La Nina or El Nino occur in the global. The moon's declination and obliquity of the ecliptic affect the tidal intensity. The exchange of tidal energy and tide-generating force caused by the sun, moon and major planets makes the earth's layers rotate in different speeds. The differenti-al rotation between solid and fluid of the earth is the basic reason for El Nino and global climate change.  相似文献   

NUMERICAL EXPERIMENTS FOR THE IMPACT OF ANTARCTIC ICE COVER AND SEA SURFACE TEMPERATURE ON CLIMATE VARIABILITY   总被引：2，自引：0，他引：2       下载免费PDF全文

缪群  陈隆勋 《Acta Meteorologica Sinica》1997,(1)

By using a three-level atmospheric general circulation model (AGCM),we have completed severalnumerical experiments to study the impacts of sea surface temperature anomaly (SSTA) and antarctic icecover anomaly (AICA) during 1981—1983 on climate variability.The results show that during the ElNino period of 1982—1983 the impact of SSTA overrides that of AICA.SSTA mainly affects equatorialzonal circulation and produces PNA wave train,and SE-NW wave train in East Asia to influence theweather of China.AICA produces west-east anomalous vortex streets in the middle latitudes of bothhemispheres and affects the intensity of the polar vortex of Southern Hemisphere.  相似文献   

论陆架波系动力学及其在厄尔尼诺信号传播中的作用     

巢纪平  徐小标 《气象学报》2001,59(5):515-523

文中讨论了陆架波系和赤道波系在动力学上的相似性，和赤道波系一样，陆架波系也由惯性重力波、Ｋｅｌｖｉｎ波、Ｒｏｓｓｂｙ（长、短）波和有条件的Ｒｏｓｓｂｙ－重力混合波组成。指出，当　海洋三边存在陆架而一边为赤道时（如北太平洋），则陆架波系和赤道波系中的Ｋｅｌｖｉｎ波，　将以逆时针方向携带信号绕海盆一周，而两个波系中的Ｒｏｓｓｂｙ长波，将以顺时针方向绕海盆一周，即通过陆架波和赤道波为海洋中某些信号的传播组织成一个绕海盆的环路。这种物理　过程可望用以解释发生在海洋中的某些长周期现象，如Ｅｌ　Ｎｉ　ｏ现象。文中进一步　讨论了陆架波的各种简化运动。  相似文献