亚洲-澳大利亚海陆地形与热力季节演变下的季风槽和季风降水

通过对1999-2007年美国NCEP FNL逐日全球大气分层分析资料和同期美国NASA热带测雨卫星(TRMM)降水产品资料进行气象要素分解,取其海陆差异影响的要素场,对亚洲-澳大利亚季风区的季风槽进行了逐候辨识,分析了亚澳季风区850 hPa各槽线的季节演变与降水的关系.结果发现在亚洲夏季风最强盛的时候青藏高原周边地区一共有五个季风槽,澳大利亚夏季风最强盛的时候在其周边地区存在三个季风槽,这些季风槽都有对应的降水出现并受当地半岛尺度地形的影响.南亚和东南亚的季风槽以及对应的降水持续时间约为半年(24-60候),东亚和澳大利亚季风期要短一些(28-48候和1-17候).东亚和澳大利亚北部地区都存在季风爆发之前的前汛期降水或过渡时期降水.

ASIAN-AUSTRALIAN MONSOON TROUGHS AND MONSOON PRECIPITATION INFLUENCED BY REGIONAL LAND-SEA HEATING CONTRASTS

Based on the NCEP FNL global daily analysis data and NASA TRMM precipitation data meteorological variables are decomposed to four components. One of components influenced by land-sea contrasts is picked up, and the monsoon troughs in Asia-Australia monsoon region are recognized in pentads. Five monsoon troughs around the Tibetan Plateau in the strongest season of Asia monsoon and three monsoon troughs around Australia in the strongest season of Australia monsoon are identified. Regional monsoon precipitation is influenced by both peninsula-scale terrain and monsoon trough. The monsoon troughs and precipitations in South Asia and Southeast Asia last for about half year (pentad 24-60), while others are shorter (pentad 28-48/pentad 1-17) in Asia and Australia respectively. However, precipitation in the pre-rainy season before the onset of the Asian monsoon and the north of Australia can be referred as the interim precipitation.