1998年地面加热场的基本特征及其与南海夏季风爆发的可能联系

BASIC CHARACTERISTIC OF SURFACE HEAT FIELD IN 1998 AND THE POSSIBLE CONNECTIONS WITH THE SCS SUMMER MONSOON ONSET

中文关键词:  南海季风  海陆热力差异  中南半岛

英文关键词:SCS monsoon  Land-sea thermal contrast  Indochina Peninsula

中文摘要:

      文中对1998年1月1日到8月31日共243d的南海季风试验再分析资料的地面感热场和潜热场进行EOF分析,由感热的第一特征向量场发现,中南半岛地区、青藏高原的东北部和印度半岛的大部分是感热通量大值区,而海洋上是小值区,海陆热力差异十分明显,这种海陆感热对比是促使季风爆发的大背景。由感热的时间经度演变图可以看出,中南半岛所在经度范围内南北连续的感热分布对南海季风的早爆发具有重要作用。由温度平流项的分布可发现,中南半岛的加热作用明显早于青藏高原地区,使得中南半岛对南海季风的早期爆发有重要作用,而青藏高原对于南海季风的维持具有重要意义。由于印度半岛与中南半岛的海陆分布的差异,使得两个地区的温度平流项也有所不同。

英文摘要:

      The fluxes of sensible heat and latentheatin the South China Sea(SCS) and its neighboring regions are expanded by means of EOF in this paper based on the reanalyzed data of the SCSMEX from Jan.1 to Aug.31,1998.It is found that there exist three areas with higher values of sensible heatin the Indochina Peninsula,the northeastern Tibetan Plateau and the most part of the Indian Peninsula,whereas the area with lower values is located in the sea,therefore the land-sea thermal contrastis very obvious.It is the background of monsoon onset.The continuous sensible heat distribution from south tonorth within the longitude of Indochina Peninsula makes the monso on firstly onsetin SCS region.The heating effect of the Indochina Peninsula is evidently earlier than that of the Tibetan Plateau,therefore,the Indochina Peninsula has an important function in the early on set of the SCS monsoon,while the Tibetan Plateau has an important effecton the maintenance of the monso on.The temperature advection in the Indian Peninsul a and the Indochina Peninsula are different because of the land-sea thermal differences in these two regions.