与ENSO有关和无关年江、淮旱涝可能成因研究

利用Nio 3指数,把ENSO循环不同位相的夏季划分为四类并进行聚类分析,发现E1 Nio发展期和La Nia衰减期可以聚为一类;E1 Nio衰减期和La Nia发展期可以聚为一类。而后经过比较分析,考虑ENSO循环对江、淮地区降水的不同影响,定义了新的东亚副热带夏季风强度指数。并利用该指数研究了夏季风异常和ENSO循环与江、淮地区夏季降水年际变化的关系和成因。结果发现,ENSO年,淮河和长江中下游地区夏季降水的年际变化是ENSO和夏季风共同作用的结果。ENSO的不同位相对雨带的南北位置有重要影响,夏季风异常主要对雨量的偏多偏少起重要作用。而与ENSO无关的年份,易出现强夏季风,这种年份长江和淮河地区经常是一致的干旱。     

基于卫星亮温资料同化对2009年热带风暴“浪卡”的数值研究

本文利用三维变分同化系统（WRFDA）,设计了4个同化试验方案,将ATOVS卫星亮温资料直接同化到中尺度数值模式（WRF）中,研究同化ATOVS不同卫星亮温资料对2009年04号热带风暴“浪卡”数值模拟的影响。结果表明,直接同化卫星亮温资料能够改善初始场结构（大气流场、温度场）,尤其是对西太平洋反气旋系统,进而提高对热带气旋路径的模拟精度。同化不同类型的ATOVS卫星亮温资料对于热带气旋的移动路径有着不同程度的改善,其中以HIRS3和HIRS4资料同化对热带气旋移动路径改善效果最好。     

AN ANALYSIS OF THE ASYMMETRICAL STRUCTURE OF TYPHOON AERE'S PRECIPITATION

The structural characteristics of 2004 typhoon Aere's precipitation are analyzed using the high-resolution data from the Tropical Rainfall Measuring Mission(TRMM) of the National Aeronautics Space Administration(NASA).It is found that the typhoon's characteristics vary at different stages of its development.To analyze the asymmetric causation of precipitation distribution,data from the National Center for Environmental Prediction(NCEP) reanalysis are used to calculate the vertical integral of the water vapo...     

DIAGNOSIS OF LOW FREQUENCY COMPONENT OF ENSO VARIABILITY—PART Ⅰ:GLOBAL-SCALE DYNAMIC CHARACTERISTICS OF THE COMPONENT

Composite investigation is performed of global dynamic characteristics of >3—4-year period low-frequency oscillation in ENSO variability of air-sea coupling in the context of monthly mean wind andSSTA.Evidence suggests that the horizontal(vertical)anomaly circulation at tropical latitudes(equatorial)exhibits their evolution to be,in substance,a kind of low-frequency wave slowly travel-ling eastward,featured by wave number 2 moving along the equator and zonal wind swiftly decayingoff the equator in relation to divergence/convergence:the time that the low-frequency wave takes tomove around the equator in its halfway is precisely the period of the ENSO low-frequency component(LFC)(approximately 4 years);the ocean also displays corresponding response to the component.     

ON THE INTERACTIONS BETWEEN ENSO AND THE ASIAN MONSOON ON THE SCALE OF QUASI-BIENNIAL OSCILLATION

A diagnostic analysis is performed of the quasi-biennial oscillations during the ENSO cycle and the results are based to study the interactions between ENSO and the Asian monsoons. It shows that the Asian monsoons have significant influence on the ENSO cycle on the quasi-biennial scale. Materialized through the onset and southward progression of the winter monsoon, the influence appears in the tropical western Pacific to excite severe convection and to further affect the ENSO cycle. The phenomenon is not only reflected in the quasi-biennial mode but the annual variation of the Asian winter monsoon in reality.