1991—1992年ENSO事件的特征

根据美国国家海洋大气局气候分析中心（ＣＡＣ）和中国气象局气候监测公报所提供的海－气资料，综合分析了１９９１－１９９２年ＥＮＳＯ事件的形成、发展过程。这次ＥＮＳＯ事件的主要特点是：①在ＥＮＳＯ事件爆发前一年内热带太平洋海气特性频频呈现异常，暖水堆积在赤道中太平洋（５°Ｎ－５°Ｓ，１６０°Ｅ－１６０°Ｗ）约１２个月，然后自西向东传输，爆发１９９１－１９９２年ＥＮＳＯ事件。②对ＥＮＳＯ事件作出响应的西太     

热带西太平洋海─气热量通量研究──Ⅱ．热带气旋状况下海─气热量交换的特征

本文根据ＴＯＧＡ研究计划第１，２，３，８个航次考察结果，计算了热带西太平洋海－气热量交换值。研究结果表明：在热带气旋环流内海－气界面热量交换非常强烈，在双子台风环流内Ｑｋ出现负值，在台风环流内Ｑｅ也出现减弱现象。１９８６／１９８７年ＥｌＮｉｎｏ事件发生后，热带中太平洋水温异常增暖，热带西太平洋西部洋域表层水也在增暖，但是，热带西太平洋洋域海－气界面间热量交换反而减弱。西风爆发首先出现在中太平洋热带洋域，然后逐渐往西扩展。     

热带西太平洋海温变化及其与赤道东太平洋海温变化的关系

利用１９５１－１９８８年１０°Ｓ－５０°Ｎ太平洋的ＳＳＴ资料对热带西太平洋海表温度的变化及其与赤道东太平洋海表温度变化的关系进行了分析，发现热带西太平洋ＳＳＴ存在准两年周期的变化。这种变化与ＥＮＳＯ活动相联系：Ｅｌ Ｎｉｎｏ年的ＳＳＴ距平值位于谷值；反Ｅｌ Ｎｉｎｏ年的ＳＳＴ距平值位于峰值。热带西太平洋与赤道东太平洋的ＳＳＴ变化存在弱的反相关关系。两者间存在位相差，前者的变化比后者超前几个月甚至１     

热带太平洋经向风应力异常与ElNio的发生──(Ⅰ)资料诊断(英文)

对热带太平洋海表经向风应力异常与 Ｅ１ Ｎｉ　ｏ事件之间的关系进行了诊断分析。结果表明，超前的经向风应力距平场与ＮＩＮＯ３区（１５°－９０°Ｗ，５°Ｓ－５°Ｎ）的海面温度异常（ＳＳＴＡ）有显著的超前相关，这种相关性在超前６个月甚至更早一些就有显示。利用奇异值分解方法分析超前的经向风应力距平场与太平洋海表温度异常场之间的耦合模，结果表明对应于赤道中东太平洋的海面温度异常升高，大气风应力场在超前６个月甚至更早的时候，在赤道中东太平洋表现为辐合的经向异常风应力场，即赤道以北为北风异常应力，赤道以南为南风异常应力。这种耦合模的时间系数与 ＮＩＮＯ３ ＳＳＴＡ指数所表示的 ＥＩｉｏ事件有很好的对应关系，表明这种耦合模反映的正是超前的经向风应力异常与 Ｅｌ ＮｉＢ　ｏ事件所对应的海表温度异常之间的相关核态。通过与热带西太平洋纬向风应力异常的比较，赤道中东太平洋辐合的经向风应力异常与ＥｌＮｉｆｉｏ事件发生的同样具有重要的联系。     

海岸地区TIBL廓线与局地海风环流的数值试验

对三次ＥｌＮｉｎｏ发生前后的ＥＣＭＷＦ资料用滤波方法（带通,低通）进行分析,得到的结果清楚地表明,在ＥｌＮｉｎｏ发生前热带季节内振荡较强,而伴随ＥｌＮｉｎｏ发生,季节内振荡明显减弱,这种能量变化最明显的地区是赤道东太平洋地区;对于周期在９０天以上的热带准定常波,伴随ＥｌＮｉｎｏ的发生其能量明显增加,这种增加反映最显著的区域是从大西洋往西一直到西太平洋。对中纬度（２５－３５°Ｎ）及中高纬度（４０－５０°Ｎ）地区的准定常波能量分析表明,中纬度地区的准定常波能量比低纬大,准定常波能量变化在中纬度（２５－３５°Ｎ）表现出与低纬能量变化一致的情形,即伴随着ＥｌＮｉｎｏ的发生,准定常波能量增加;中高纬度（４０－５０°Ｎ）只在亚洲大陆（１００－１７０°Ｅ）表现出与热带一致的能量变化。结果还显示,热带季节内振荡在低层的东传对赤道西风异常及对ＥｌＮｉｎｏ的发生、发展起着很重要的作用。     

太平洋海－气热通量与长江流域降水及东亚500 hPa环流的遥相关

本文采用对两种气象要素场的相关场作ＥＯＦ分解的方法，对１９５１－１９７９年太平洋海－气感热、潜热通量与长江流域降水和东亚５００hPa环流作了分析。结果表明，太平洋海－气感热、潜热通量与后期（τ＝６）长江流域降水存在显著相关区，感热和潜热的异常分布能造成长江流域降水分布不均。同时，冬季（１２—２月）太平洋潜热通量的变化与夏季（６—８月）对流层中层的赤道辐合带、副热带高压等系统有较密切的联系。     

1986～1987年El Niño期间热带西太平洋及南海海气热量交换研究

文中根据热带西太平洋海气相互作用研究（ＴＯＧＡ）第１～５及第８航次和南海科学考察结果,对热带西太平洋和南海海气热量交换作了分析。结果表明：ＥｌＮｉｎｏ事件发生前,热带西太平洋及南海海气热量交换非常强烈;ＥｌＮｉｎｏ事件发生后,热带西太平洋及南海海气热量交换反而减弱。     

冬季东亚槽异常与EINino的关系

通过对东亚大槽强度与ＥｌＮｉｎｏ事件的统计分析，揭露了在多数ＥｌＮｉｎｏ（反ＥｌＮｉｎｏ）事件的前期冬季，东亚大槽强度偏弱（偏强）的事实，对１０个ＥｌＮｉｎｏ事件的合成分析亦表明，ＥｌＮｉｎｏ前冬季东亚西太平洋中高纬地区５００ｈＰａ为显著的高工正距平。谱分析进一步指出，冬季东亚大槽强度与赤道东太平洋各季ＳＳＴ有密切的关系，它们都具有显著的３－４年周期振荡，且槽强度的变前于ＳＳＴ约４－８个月。     

TOGA－COARE强化期（IOP）西太平洋海域的辐射特征

该文利用ＴＯＧＡ－ＣＯＡＲＥ强化观测期（ＩＯＰ）所获得的辐射观测资料（１９９２年１１月１０日—１９９３年２月１８日），对考察点（２°１５′Ｓ，１５８°００′Ｅ）的辐射分量进行了分析，其中包括总辐射、直接辐射、散射辐射、海表长波辐射、大气逆辐射、海表反射辐射及其反照率、净辐射及有效辐射。结果表明：和其它地区（如高原）比较，观测点的总辐射、直接辐射均很强；反射率小，晴天平均为０．０４—０．０５，阴天为０．０６—０．０８；海表长波辐射大而日变化小，大气逆辐射强而日变化大；有效辐射小而净辐射大。     

10──20天准双周振荡的经向传播及地理特征

本文采用ＥＣＭＷＦ１９８３年７月１日至９月１２日逐日２００ｈＰａ纬向风场资料，用复经验正交方法讨论了１０－２０天低频振荡的经向传播及地理特征。结果表明：（１）１０－－２天振荡有三个显著区域：贝加尔湖附近地区；赤道９０°Ｅ附近以及新加坡、马来西亚地区；８０－１００°Ｅ，２２－３２°Ｎ之间。（２）源于较高纬度地区的振荡与源于赤道附近地区的振荡在１０５°Ｅ，１７—２３°Ｎ附近同位相相遇，在９０°Ｅ，２０°Ｎ附近反位相相叠加，振荡相互削弱，在２５°Ｎ附近同位相相遇。（３）从振荡位相来看，中南半岛东南部、马来西亚北部、菲律宾以西区域的振荡向北传播到中国东南沿海，向西传播到孟加拉湾印度半岛；２０°Ｎ以南低纬度地区的振荡很少能传播到８０°Ｅ以东３０°Ｎ附近地区；位于９０－９５°Ｅ，２５－２７°Ｎ之间的振荡以及贝加尔湖附近地区的振荡可以向南北两个方向传播。     

STUDY ON AIR-SEA HEAT EXCHANGE MECHANISM IN EL NINO AND LA NINA EVENTS

2°×2° mean monthly COADS grid data in 1974 and 1987 of E1 Nino and La Nina years are used to compute thesensible and latent heat fluxes,the net longwave radiation,the incident solar radiation and heat budget on the tropicalPacific surface(30°S—30°N).The difference of the heat budget between El Nino and La Nina mainly occurred on theequatorial ocean surface,especially the water area west of Ecuador and Peru.During El Nino,the sensible and latentheat exchange increased,the net longwave radiation and incident solar radiation decreased and the net gain(loss) of heatreduced(increased) on the ocean surface.During La Nina,the circumstances were opposite.Finally an ideal model ofair-sea heat exchange mechanism for the El Nino-La Nina cycle is summarized. Key words:El Nino,La Nina,air-sea heat exchange,COADS grid data     

A STUDY OF CLIMATOLOGICAL ASPECTS OF FLOW FIELD AND HEAT EXCHANGE ON TROPICAL PACIFIC SURFACE IN THE EL NINO AND LA NINA EVENTS

In this paper, based on the 2°× 2° grid data COADS from 1950—1987 the flow field and heatexchange anomalies on the tropical (11°S—11°N, 120°E—80°W) Pacific surface (TPS) are studiedin El Nino and La Nina events. During E1 Nino, the zonal pressure gradient and the trade windsdecrease on the TPS, the tropical convergence strengthens on the TPS, especially on the centralTPS, the sensible and latent heat exchanges increase, the net longwave radiation and incident solarradiation decrease and the net gain (loss) of heat reduces (increases) on the central and easternTPS. During La Nina the results turn out the contrary. Finally, two feedback mechanisms whichinclude the dynamic, thermal and hydrological processes during E1 Nino and La Nina are summa-rized and a conceptive model for El Nino-La Nina cycle is given.     

A study on flow field and heat exchange anomalies on tropical pacific surface in the El Nino and La Nina events

Summary In this paper, based on the 2°×2° grid data COADS from 1950–1987 the flow field and heat exchange anomalies on the (11°S–11°N, 120° E-80°W) tropical Pacific surface (TPS) have been studied in El Nino and La Nina events. During El Nino, the zonal pressure gradient and trade winds decreased on the TPS, the tropical convergence strengthened on TPS, especially on the central TPS, the sensible and latent heat exchange increased, the net longwave radiation and incident solar radiation decreased and the net gain (loss)of heat reduced (increased) on the central and eastern TPS. During La Nina the results were opposite. Finally, two feedback mechanisms which include the dynamic, thermal and hydrological processes during El Nino and La Nina have been summarized and a conceptive model for El Nino-La Nina cycle is given. An estimated period for the El Nino-La Nina cycle is obtained.     

Impact of diurnal atmosphere–ocean coupling on tropical climate simulations using a coupled GCM

The impacts of diurnal atmosphere–ocean (air–sea) coupling on tropical climate simulations are investigated using the SNU coupled GCM. To investigate the effect of the atmospheric and oceanic diurnal cycles on a climate simulation, a 1-day air–sea coupling interval experiment is compared to a 2-h coupling experiment. As previous studies have suggested, cold temperature biases over equatorial western Pacific regions are significantly reduced when diurnal air–sea coupling strategy is implemented. This warming is initiated by diurnal rectification and amplified further by the air–sea coupled feedbacks. In addition to its effect on the mean climatology, the diurnal coupling has also a distinctive impact on the amplitude of the El Nino-Southern Oscillation (ENSO). It is demonstrated that a weakening of the ENSO magnitude is caused by reduced (increased) surface net heat fluxes into the ocean during El Nino (La Nina) events. Primarily, decreased (increased) incoming shortwave radiation during El Nino (La Nina) due to cloud shading is responsible for the net heat fluxes associated with ENSO.     

热带太平洋表面水中CO2对El Niño事件响应的数值模拟

文中用一个带生物泵的三维全球海洋碳循环模式模拟了热带太平洋表面水中CO2总量(TCO2)在ElNi     

热带太平洋和印度洋热源对大气影响的季节变化特征

本文利用1970—1979年COADS2°×2°格点月平均资料,计算了30°S—30°N热带太平洋和印度洋洋面上的有效长波辐射、感热和潜热通量以及它们的季节变化和年变化。结果指出:在冬季半球热带海洋外侧有大量的长波辐射、感热和潜热向大气输送,输送通量的季节变化大;热带太平洋地区西北部热通量的季节变化最大,赤道洋面地区热通量的年变化最小,潜热是洋面上热量输送的最大项,季节变化也最大;感热的输送量虽不及有效长波辐射,但其季节变化与有效长波辐射的变化相当;赤道地区是有效长波辐射和潜热通量的低值区,暖池地区是有效长波辐射的低值中心,靠近秘鲁海域的东南赤道太平洋是感热通量的负值区;热带太平洋西北部和阿拉伯海、孟加拉湾地区的热通量及年、季变化与亚洲季风有密切的关系,同时对我国和南亚地区的气候有重要的影响。      

Weakened SST variability in the tropical Atlantic Ocean since 2000

A prominent weakening in equatorial Atlantic sea surface temperature (SST) variability, occurring around the year 2000, is investigated by means of observations, reanalysis products and the linear recharge oscillator (ReOsc) model. Compared to the time period 1982–1999, during 2000–2017 the May–June–July SST variability in the eastern equatorial Atlantic has decreased by more than 30%. Coupled air–sea feedbacks, namely the positive Bjerknes feedback and the negative net heat flux damping are important drivers for the equatorial Atlantic interannual SST variability. We find that the Bjerknes feedback weakened after 2000 while the net heat flux damping increased. The weakening of the Bjerknes feedback does not appear to be fully explainable by changes in the mean state of the tropical Atlantic. The increased net heat flux damping is related to an enhanced response of the latent heat flux to the SST anomalies (SSTa). Strengthened trade winds as well as warmer SSTs are suggested to increase the air–sea specific humidity difference and hence, enhancing the latent heat flux response to SSTa. A combined effect of those two processes is proposed to be responsible for the weakened SST variability in the eastern equatorial Atlantic. The ReOsc model supports the link between reduced SST variability, weaker Bjerknes feedback and stronger net heat flux damping.     

STUDY ON THE QUASI-FOUR YEAR OSCILLATION OF AIR-SEA INTERACTION

Complex Singular Value Decomposition(CSVD)analysis technique was applied to study theQuasi Four year Oscillation(QFO)of air sea interaction and its coupled pattern evolution duringdifferent phases.Results show that:(1)CSVD method can better reveal phase relation betweentwo physical fields:(2)Not only northerly anomalies from Northern Hemisphere but alsosoutherly anomalies from Southern Hemisphere contribute to EI Nino.They converge in westernequatorial Pacific,leading to outburst of strong equatorial westerly anomalies,and result in strongEl Nino event onset:(3)An abnormal subtropical anticyclone circulation appears overnorthwestern Pacific while El Nino developing.It favors transitions from the warm SST(EINino)to the cold SST(La Nina),just as the tropical westerly anomalies produced by abnormalcyclone during a decaying La Nina.which encourage the development of El Nino:(4)Thewesterly anomalies in equatorial Pacific are mainly induced by eastward abnormal subtropicalcyclone pairs,which are located in north and south Pacific respectively,and are not the eastwardwesterly anomalies from equatorial Indian Ocean.     

Impacts of an improved low-level cloud scheme on the eastern Pacific ITCZ-cold tongue complex

A statistically-based low-level cloud parameterization scheme is introduced, modified, and applied in the Flexible coupled General Circulation Model (FGCM-0). It is found that the low-level cloud scheme makes improved simulations of low-level cloud fractions and net surface shortwave radiation fluxes in the subtropical eastern oceans off western coasts in the model. Accompanying the improvement in the net surface shortwave radiation fluxes, the simulated distribution of SSTs is more reasonably asymmetrical about the equator in the tropical eastern Pacific, which suppresses, to some extent, the development of the double ITCZ in the model. Warm SST biases in the ITCZ north of the equator are more realistically reduced, too. But the equatorial cold tongue is strengthened and extends further westward, which reduces the precipitation rate in the western equatorial Pacific but increases it in the ITCZ north of the equator in the far eastern Pacific. It is demonstrated that the low-level cloud-radiation feedback would enhance the cooperative feedback between the equatorial cold tongue and the ITCZ. Based on surface layer heat budget analyses, it is demonstrated that the reduction of SSTs is attributed to both the thermodynamic cooling process modified by the increase of cloud fractions and the oceanic dynamical cooling processes associated with the strengthened surface wind in the eastern equatorial Pacific, but it is mainly attributed to oceanic dynamical cooling processes associated with the strengthening of surface wind in the central and western equatorial Pacific.