南印度洋海区大风天气高纬低压系统模型研究  

Synoptic Models of Strong Winds over the South Indian Ocean

作　　者：杨涛[1] 朱持则 翟国庆[1] 陈信雄[3] 

机构地区：[1]浙江大学地球科学系,浙江杭州310027 [2]浙江省气象科学研究所,浙江杭州310000 [3]中国卫星海上测控部气象室,江苏江阴214431

出　　处：《海洋预报》2007年第4期71-79,共9页Marine Forecasts

摘　　要：本文根据多年的天气图、卫星云图以及1980～1990年的NCEP再分析资料,通过统计分析和合成分析等方法建立了能够在南印度洋特定海区引起12m/s以上大风天气的高纬低压系统概念模型,并对主要的南印度洋西部副高型、南印度洋倒"品"字型作了详细的阐述。该天气概念模型主要发生在南半球的冬、春季。(1)南印度洋西部副高天气过程多由高纬度低压系统发展引起。在这一过程中,副高与高纬低压系统由纬向型向经向型转变,海平面气压槽和850hPa高度槽受到槽后冷平流的驱动不断向东北方向移动,并扫过南印度洋东部。(2)南印度洋倒"品"字天气模型中,低压槽受斜压系统的驱动东移并发展加深,与南印度洋东部的副高中心之间形成大风带。该天气概念模型的建立对南印度洋海区大风的预报可起到一定指导作用。The major purpose of this research is to establish some guide lines for the forecasting of the strong wind over the region that we concerned in the South Indian Ocean. It lies off Australia＇ s east coastal line and it is about 2000kin or more away from Australia and extends from 90°E to 100°E in the east-to-west direction, and from 35°S to 30°S in the south-to-north direction. First, we used NCEP global reanalysis data spanning the period 1980-1990 to choose the typical cases in which the synoptic systems caused strong winds whose speed exceeded 12m/s in the region. Then we employed composite analysis to establish three typical conceptual models as guidelines for the forecasting of strong winds. All of the three models mainly occur in the late autumn, winter and early spring. In one of the models, subtropical high pressure center lies over the west part of the South Indian Ocean and deep depressions located around the Antarctic play an important role. In this process, both of the two systems tra nsform from zonal to meridional and cause strong wind in the region. In other two models strong winds are caused by baroclinic systems and mid latitude cyclones separately.

关 键 词：南印度洋 合成分析 大风天气模型 

分 类 号：P731[天文地球—海洋科学]