ENSO事件期间热带印度洋和太平洋地区大尺度海气相互作用联系的研究

ANALYSIS OF THE LINKAGES OF LARGE-SCALE AIR-SEA INTERACTION BETWEEN THE TROPICAL INDIAN OCEAN AND THE PACIFIC OCEAN DURING EL NIO EVENTS

利用大气环流三维分解方法研究了1979—2008年ENSO事件期间热带印度洋和太平洋地区海气相互作用的机制。研究表明ENSO事件期间存在明显的三维"齿轮式"耦合特征;在ENSO事件盛期,与NCEP再分析资料的垂直运动相比,大气环流三维分解方法揭示的东印度洋-西太平洋地区的下沉运动更强,范围更宽。大气环流三维分解方法把垂直速度分解为纬向分量和经向分量两部分,纬向分量表现为很强的下沉运动,而经向分量表现为上升运动,垂直速度的纬向分量和经向分量相互抵消了一部分,综合的结果表现为很强的下沉运动。在热带地区,垂直速度ω*的纬向分量ωW要大于其经向分量ωH,ωW反映了ω*的主要特征;在分析垂直运动方面,与NCEP再分析资料中的垂直速度相比,大气环流三维分解方法具有一定的优点。

By utilizing three dimensional decomposition method of atmospheric circulation,we studied the linkages of air-sea interaction between the tropics Indian Ocean and the Pacific Ocean area during 1979—2008 ENSO events.We show that there is a clear three-dimensional gear-couple characteristic during the 1979—2008 El Nio events.Analysis reveals stronger and wider scope sinking movement in the eastern Indian Ocean-Western Pacific region during the mature phase of 1979—2008 ENSO events compared with the vertical velocity of the NCEP reanalysis data.The zonal components of vertical velocity demonstrates a strong sinking movement while the meridional components of vertical velocity shows a upward motion during the mature phase of ENSO events.In the tropics,the latitudinal component of the vertical velocity is greater than the meridional component reflecting the main features of the vertical velocity,so the overall results show a strong sinking motion.Compared with the vertical velocity of NCEP reanalysis data,vertical movement calculated through the three-dimensional decomposition method has some advantages.