【作者】 胡鹏；

【导师】 何金海； 薛纪善；

【作者基本信息】 南京信息工程大学 ， 气象学， 2006， 博士

【摘要】 本文利用多年平均资料分析了南海夏季风建立的气候特征,对2004、2005年南海夏季风建立过程进行了详细分析,并利用GRAPES模式模拟了这两年南海夏季风建立的过程。对影响南海夏季风建立的印度洋西风和中纬度扰动等进行了数值试验。对南亚高压的西进特征进行了详细分析,揭示了南海夏季风建立前,南亚高压从海上移到中南半岛的过程是一个西部加强东部减弱的快速重建过程。并利用数值模式对重建过程进行了模拟。分析和研究的主要结论如下: (1)与南海夏季风爆发密切相关的气候特征是4～5月南亚高压迅速登上中南半岛,孟加拉湾槽加深加强,副热带高压带断裂并迅速东撤,西风经中南半岛东扩至南海。在南海夏季风建立前,南海及其周边地区中低纬南北温差存在符号转换现象,位于105°E附近的中南半岛是转换最早的区域。 (2)对多年平均资料的分析表明,南亚高压在4月份迅速西进时存在一个分裂重建过程。4月第5候南亚高压呈现为两个中心,西侧高压中心在中南半岛地区加强,东侧高压中心减弱消亡,高压中心的位置变化并非简单的西进,而是一个重建和替代的过程。对逐年资料的分析也表明存在这种现象,而且南亚高压重建完成的早晚对南海夏季风建立具有指示意义。 (3)与南亚高压重建的同时存在着对流自苏门达腊地区沿中南半岛向北扩展的过程。南亚高压中心重建与苏门达腊地区热带对流北推具有密切联系,深对流引发的凝结潜热释放可能是造成南亚高压重建的重要原因。 (4)利用GRAPES模式成功地模拟了南海夏季风爆发期间南海地区西风转向和西太平洋副高东撤的过程,数值试验表明中纬度扰动以及赤道印度洋西风对南海夏季风爆发具有触发作用 (5)利用Regcm准确地模拟了2004年南亚高压重建的过程,通过数值试验揭示了与南亚高压重建相关的影响因素。中南半岛地区加热的强度对南亚高压重建进程具有决定性作用。更多还原

【Abstract】 In term of NCEP / NCAR reanalysis data, the characteristics of the onset of South China Sea (SCS) summer monsoon and the westward of South Asia High (SAH) are analyzed. The onset of SCS summer Monsoon is simulated by means of numerical model. The main results are as follows:(1) It is found that the SCS summer monsoon establishment is characterized by the SAH migrating swiftly to Indo-China Peninsula (ICP) and the Bay of Bengal (BOB) trough deepening, the subtropical high belt break and withdraws associated with the westerly expanding to the South China Sea. The meridian temperature difference (MTD) experience abrupt change before the onset of SCS summer monsoon, While the area between 100 ~ 110°E belongs to the intermediate belt and the area where the sign of MTD switch vary the earliest.(2) By analyzing multi year mean data, it is revealed that during the SAH migrating westward in Mar., there is a splitting and reconstruction process. The SAH is not just moving west but split above Philippines, then the west part enhances and the eastern disappear. It can be verify by analyzing mutil year data, what’s more, the recon structure period can be used as the index of SCSM.(3)Associated with the reconstruction of SAH, the tropical convection expands north from Sumatra along ICP. The latent heat release might lead to the reconstruction of the SAH.(4) The numerical experiment shows that GRAPES successfully reproduces the evolution of summer monsoon’s onset, such as the rapid conversion of easterlies and the subtropical high withdrawing. With the NOAA17 AMSUB data assimilated into the initial field, the simulation has distinguished improvement. The disturb from mid- latitude and the westly of India Ocean have affect on the onset of SCSM.(5) Simulations of the reconstructive process of SAH have be done to reveal the relations between the SAH and the latent heat on Indo-China Peninsula.更多还原