El Niño－La Niña循环的海－气耦合机制研究

利用１９５０—１９８７年２°×２°格点综合海－气资料（ＣＯＡＤＳ），计算了赤道太平洋洋面（５°Ｓ—３°Ｎ）上逐月平均海温、气压、纬向风、比湿、云以及热量收支各分量的平均值和距平值，分析这些量的演变特征，得出：ＥｌＮｉｎｏ过程中，赤道太平洋洋面上气压梯度减小，东风减弱；赤道中、东太平洋洋面上空气中水汽和云量增加，洋面射入太阳辐射和有效长波辐射减少，感热和潜热交换加强，洋面净获得（损失）热量减少（增加）；ＬａＮｉｎａ过程中，情形相反。最后概括了ＥｌＮｉｎｏ－ＬａＮｉｎａ循环的两种海－气耦合反馈机制。

MECHANISM STUDY OF EL NINO-LA NINA CYCLE IN THE COUPLED AIR-SEA SYSTEM

In this paper,2°×2° mean monthly COADS grid data from 1950 to 1987 are used to compute the averages and deviations of the temperature,pressure,zonal wind,special humidity,cloud and the components of heat budget on the equatorial Pacific surface (5°S-3°N).In the processes of EI Nino,the pressure gradient and trade decreased on the equatorial Pacific surface,the sensible and latent heat exchanges increased,the net longwave radiation and incident solar radiation decreased and the net gain (loss) of heat reduced (increased) on the central and eastern equatorial Pacific surface.In the Processes of La Nina the circumstances were oposite.Finally,two feedback mechanisms of EI Nino-La Nina cycle which include the dynamic,thermal and hydrological processes in the coupled air-sea system are sumrnerized.