青藏高原及其下游地区降水厚度季、日变化的气候特征分析

利用10年的TRMM卫星降水雷达观测资料, 首次对青藏高原及其下游平原及海洋地区降水厚度的地区差异进行了对比分析, 并对青藏高原及其周边地区对流和层云降水厚度的水平分布及其日变化和季节变化进行了统计分析, 结果表明: (1) 青藏高原地区对流和层云降水厚度都要比下游平原地区更为浅薄, 东部海洋地区对流降水厚度比平原地区小, 而层云降水厚度与平原地区相当。青藏高原及其下游平原地区对流降水厚度的日变化特征非常明显, 海洋地区对流降水厚度日夜差异则不大。层云降水厚度在各地区的日变化特征都不明显。青藏高原、下游平原及海洋地区对流和层云降水厚度的季节变化都非常明显, 从冬至夏, 对流和层云降水逐渐变得深厚, 而从夏入冬, 对流和层云降水则逐渐变得浅薄。(2) 青藏高原及其周边地区对流和层云平均降水厚度的分布形式和降水量分布具有较好的对应关系, 降水量大的地区其降水厚度一般较为深厚, 降水少的地区则降水厚度比较浅薄。对流和层云降水厚度存在明显差异, 对流降水一般要比层云降水深厚。青藏高原及其周边地区降水厚度水平分布的日夜差距不大, 但季节变化非常明显, 且与气候系统的季节变化紧密相关。     

Properties of cloud and precipitation over the Tibetan Plateau

The characteristics of seasonal precipitation over the Tibetan Plateau(TP) were investigated using TRMM(Tropical Rainfall Measuring Mission) precipitation data(3B43). Sensitive regions of summer precipitation interannual variation anomalies were investigated using EOF(empirical orthogonal function) analysis. Furthermore, the profiles of cloud water content(CWC) and precipitable water in different regions and seasons were analyzed using TRMM-3A12 data observed by the TRMM Microwave Imager. Good agreement was found between hydrometeors and precipitation over the eastern and southeastern TP, where water vapor is adequate, while the water vapor amount is not significant over the western and northern TP.Further analysis showed meridional and zonal anomalies of CWC centers in the ascending branch of the Hadley and Walker Circulation, especially over the south and east of the TP. The interannual variation of hydrometeors over the past decade showed a decrease over the southeastern and northwestern TP, along with a corresponding increase over other regions.     

用华南暴雨试验雨量资料对TRMM/TMI-85.5GHz测雨能力的考察

利用华南暴雨试验期间稠密的雨量资料对热带测雨卫星（TRMM）微波成像仪（TMI）频率为85．5GHz（波长0．35cm）的测雨能力进行了考察。通过TMI－85．5GHz亮温分布和一小时雨量分布的对比发现，对流性降水的强雨量中心与TMI－85．5GHz亮温的低值区有很的对应关系，雨带分布和低亮温分布的位置及形状都很相似，雨强的大小和亮温的关系也相当密切：雨强越大，亮温值越低。亮温数值和雨强（指每小时雨量，下同）的相关统计进一步表明：雨强的大小与亮温呈明显的负相关，特别是当雨强达到或超达7mm/h时的相关程度非常显著，从而确认了TMI－85．5GHz的微波遥感对对流性强降水有较好的测雨能力。     

基于TMI产品资料对数值模式水凝物模拟能力的检验分析

本文利用热带测雨卫星(Tropical Rainfall Measuring Mission,TRMM)搭载微波成像仪(TRMM Microwave Imager,TMI)的探测及反演结果,结合微波辐射传输模式,就2004年17号台风暹芭(Chaba)过程,对AREM(Advanced Regional Eta-coo...     

用TRMM资料研究1998年长江流域暴雨

热带测雨卫星ＴＲＭＭ资料于１９９８年６月起向公众用户开放。本文使用了１９９８年７月２０日世界时２１：４０分的ＴＲＭＭ资料对长江流域暴雨作了初步研究。ＴＲＭＭ导出的降水产品亦与雨量计，地面雷达观测以及数值模拟结果进行了比较。由此得出，ＴＲＭＭ资料非常适合于暴雨监测研究。此外，它们还有其他广泛得用途。     

Correlation Between Total Lightning Activity and Precipitation Particle Characteristics Observed from 34 Thunderstorms

A total of 34 thunderstorms around Shanghai and Wuhan of China are analyzed in order to determine the relationship between total lightning activity and precipitation particle characteristics.Precipitation particle concentration data are obtained from the 2A12 product of TRMM/TMI(Tropical Rainfall Measuring Mission/TRMM Microwave Image) and lightning activity data are from the TRMM/LIS(Lightning Imaging Sensor) and SAFIR3000(Surveillance et Alerte Founder par Interferometric Radioelectirque).On a spatial ...     

Evaluation of WRF Model Hydrometeors Based on TMI Observations Using an Indirect Method

Using a microwave radiative transfer(MWRT) model with microwave brightness temperatures(TBs) observed from the Tropical Rainfall Measuring Mission(TRMM) Microwave Imager(TMI),an indirect approach evaluated hydrometeors generated from the Weather Research and Forecasting(WRF) model in the process of CHABA typhoon in August 2004.This study compares the simulated TBs generated from the microwave radioactive transfer model connected to the WRF model with the observed TBs derived from TMI and analyzes the differences between these TBs.The results indicate that the WRF model underestimates the amount and area of liquid and ice hydrometeors inside the typhoon center.The results also indicate relatively better agreement between the simulated and the observed TBs in the vertical polarization than in the horizontal polarization.     

Diurnal Variability of Precipitation Depth Over the Tibetan Plateau and its Surrounding Regions

The diurnal variability of precipitation depth over the Tibetan Plateau and its surrounding regions is investigated using nine years of Tropical Rainfall Measuring Mission(TRMM) precipitation radar(PR) measurements.The Tibetan Plateau,the plains area,and the East China Sea are selected as the focus regions in this study.The average precipitation depths(PD) are about 4.6 km,5.8 km,and 5.6 km,while convective(stratiform) PDs are about 6.6(4.5) km,7.5(5.7) km,and 6.0(5.6) km over the plateau,the plains,and the...     

A modeling analysis of rainfall and water cycle by the cloud-resolving WRF model over the western North Pacific

Simulated regional precipitation, especially extreme precipitation events, and the regional hydrologic budgets over the western North Pacific region during the period from May to June 2008 were investigated with the high-resolution （4-km grid spacing） Weather Research and Forecast （WRF v3.2.1） model with explicit cloud microphysics. The model initial and boundary conditions were derived from the National Centers for Environmental Prediction/Department of Energy （NCEP/DOE） Reanalysis 2 data. The model precipitation results were evaluated against the Tropical Rainfall Measuring Mission （TRMM） Multisatellite Precipitation Analysis 3B42 product. The results show that the WRF simulations can reason- ably reproduce the spatial distributions of daily mean precipitation and rainy days. However, the simulated frequency distributions of rainy days showed an overestimation of light precipitation, an underestimation of moderate to heavy precipitation, but a good representation of extreme precipitation. The downscaling approach was able to add value to the very heavy precipitation over the ocean since the convective processes are resolved by the high-resolution cloud-resolving model. Moreover, the water vapor budget analysis indi- cates that heavy precipitation is contributed mostly by the stronger moisture convergence; whereas, in less convective periods, the precipitation is more influenced by the surface evaporation. The simulated water vapor budgets imply the importance in the tropical monsoon region of cloud microphysics that affects the precipitation, atmospheric latent heating and, subsequently, the large-scale circulation.     

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...     

Climatological characteristics of summer precipitation over East Asia measured by TRMM PR: A review

Precipitation is an important indicator of climate change and a critical process in the hydrological cycle, on both the global and regional scales. Methods of precipitation observation and associated analyses are of strategic importance in global climate change research. As the first space-based radar, the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) has been in operation for almost 17 years and has acquired a huge amount of cloud and precipitation data that provide a distinctive view to help expose the nature of cloud and precipitation in the tropics and subtropics. In this paper we review recent advances in summer East Asian precipitation climatology studies based on long-term TRMM PR measurements in the following three aspects: (1) the three-dimensional structure of precipitation, (2) the diurnal variation of precipitation, and (3) the recent precipitation trend. Additionally, some important prospects regarding satellite remote sensing of precipitation and its application in the near future are discussed.     

Climatological Characteristics of Summer Precipitation over East Asia Measured by TRMM PR:A Review

Precipitation is an important indicator of climate change and a critical process in the hydrological cycle, on both the global and regional scales. Methods of precipitation observation and associated analyses are of strategic importance in global climate change research. As the first space-based radar, the Tropical Rainfall Measuring Mission(TRMM)Precipitation Radar(PR) has been in operation for almost 17 years and has acquired a huge amount of cloud and precipitation data that provide a distinctive view to help expose the nature of cloud and precipitation in the tropics and subtropics. In this paper we review recent advances in summer East Asian precipitation climatology studies based on long-term TRMM PR measurements in the following three aspects:(1) the three-dimensional structure of precipitation,(2) the diurnal variation of precipitation, and(3) the recent precipitation trend. Additionally, some important prospects regarding satellite remote sensing of precipitation and its application in the near future are discussed.     

基于TRMM卫星对一次华南飑线的闪电活动及其与降水结构的关系研究

利用热带测雨计划任务卫星（TRMM）的测雨雷达(PR)、 闪电成像仪(LIS)和微波辐射计(TMI)资料, 研究了2005年5月6日发生在我国华南的一次强飑线过程的闪电活动及其与降水结构之间的关系。结果表明, 该飑线系统中对流降水面积仅为层云的一半, 但是总降水率却远大于层云的总降水率。绝大多数闪电发生在对流区, 有少数闪电出现在层云区域。在6 km高度上, 闪电发生附近的最大雷达反射率因子主要集中在35～50 dBZ区间, 峰值频数在40～45 dBZ, 35 dBZ以下较少。研究还表明, 对流单体的最大雷达反射率垂直廓线可以很好地指示单体的闪电频数和对流发展强度。对闪电与微波亮温的研究表明, 大多数闪电发生在低亮温区域, 特别是低于200 K亮温区, 而在240～260 K的区域也可观测到少量闪电, 这一般对应于飑线的层云区域。结合2003年4月17日黄淮地区的另一次强飑线系统的进一步研究发现, 在单体尺度上, 总闪电频数和冰相降水含量之间表现出非常密切而稳定的关系, 相关系数达0.92。总闪电频数和冰相降水含量之间的稳定关系在中尺度数值模式中闪电资料的同化和飑线系统的闪电参数化研究中均有较大的应用潜力。     

TRMM卫星及其数据产品应用

简要介绍了热带降水测量(TRMM--Tropical Rainfall Measuring Mission)卫星所携带的观测仪器及其主要产品。概述了TRMM卫星资料产品在热带降水测量、提高预报准确率、暴雨研究、资料同化、反演热带海面温度、热带气旋观测等领域的应用。     

Validation of satellite rainfall products over Greece

Six widely available satellite precipitation products were extensively validated and intercompared on monthly-to-seasonal timescales and various spatial scales, for the period 1998–2006, using a dense station network over Greece. Satellite products were divided into three groups according to their spatial resolution. The first group had high spatial (0.5°) resolution and consists only of Tropical Rainfall Measuring Mission (TRMM) products: the TRMM Microwave Imager (TMI) precipitation product (3A12) and the TRMM multisatellite precipitation analysis products (3B42 and 3B43). The second group comprised products with medium spatial (1°) resolution. These products included the TRMM 3B42 and 3B43 estimates (remapped to 1° resolution) and the Global Precipitation Climatology Project one-degree daily (GPCP-1DD) analysis. The third group consisted of low spatial (2.5°) resolution products and included the 3B43 product (remapped to 2.5° resolution), the GPCP Satellite and Gauge (GPCP-SG) product, and the National Oceanographic and Atmospheric Administration Climate Prediction Center (NOAA-CPC) Merged Analysis (CMAP). Rain gauge data were first gridded and then compared with monthly and seasonal precipitation totals as well as with long-term averages of the six satellite products at different spatial resolutions (2.5°, 1°, and 0.5°). The results demonstrated the excellent performance of the 3B43 product over Greece in all three spatial scales. 3B42 from the first and second group and CMAP from the third exhibited a reasonable skill.     

20 TO 30-DAY AND 30 TO 60-DAY OSCILLATIONS IN ASSIMILATED GLOBAL DATASETS USING TRMM RAINFALL OBSERVATIONS

The influences of Tropical Rainfall Measuring Mission (TRMM) precipitation products on the structure and underlying physics of intraseasonal oscillation (ISO) are investigated with the U.S.National Aeronautics and Space Administration Goddard Earth Observing System model version 3 (GEOS-3) data assimilation system (DAS).The strong ISO phase in the 1998 summer is apparently located in the Asian monsoon region and the east equatorial Pacific region.The eastward propagation is a dominant feature for the tropical ISO at 20 to 30-day oscillation while the northeastward propagation is the salient ISO at 30 to 60-day oscillation over the 10°N to 25°N belt region.It appears that the Kelvin wave structure is for the tropical 20 to 30-day oscillation.The tropical 30 to 60-day oscillation has the characteristics of the Kelvin-Rossby wave.The impact of satellite-derived precipitation (and its associated latent heating) on the ISO intensity is limited in the GEOS-3 assimilation system.However,its impact on the ISO spatial structures is obvious.Overall,the results demonstrate a better eastward propagation and a northward propagation of ISO with the TRMM precipitation simulation,indicating that latent heating is very important in exciting the equatorial ISO.     

TRMM卫星测雨雷达及其应用研究综述

热带降水测量卫星测雨雷达（TRMM－PR）是第一部星载测雨雷达。卫星于1997年11月28日成功发射，其测雨雷达经过在轨测试定标之后，已向地面发回大量的雷达观测信息。本文主要根据1999年7月如开的第29届雷达气象国际会议的文集和作者所看到的其它文献资料，简要介绍该卫星、星载测雨雷达及其测信息处理和应用的一些研究成果。     

TRMM测雨雷达对1998年东亚降水季节性特征的研究

利用热带测雨计划卫星上的测雨雷达得到的降水资料,对1998年东亚降水,特别是中国大陆东部、东海和南海的降水,进行了分析研究,并对比了热带降水研究结果。年统计结果表明,东亚地区层状云降水出现概率极高(比面积达83.7％),对流云降水的比面积仅占13.6％,然而两者对总降水量的贡献相当。结果还表明,暖对流云降水出现的比例和对总降水量的贡献很小。在季节尺度,对流云和层状云降水的比与两者的面积比成比例关系。除夏季外,测雨雷达降水量与GPCP降水量可比性好。研究结果还指出:在中纬度陆地和海洋上对流云和层状云的比降水量和比面积呈相反方向作季节性南北移动,这一活动与东亚季风变化一致;该地区降水的季节性变化还表现为降水垂直廓线的变化。除冬季外,南海地区降水垂直结构呈热带特征。CRAD分析表明,对流云降水的地面雨强变化大,尤其在陆地上,而层状云多表现为地面弱降水。     

1909号超强台风“利奇马”强降水特征的诊断

基于TRMM卫星降雨资料、MERRA-2卫星位势高度、风速、垂直速度等资料，对1909号台风"利奇马"的移动特征及其引发浙江、江苏、山东等地暴雨进行诊断分析.分析结果发现，台风"利奇马"是北上型台风，移动路径主要受副高与1910号台风"罗莎"等系统影响.在北上的过程中，由于台风倒槽与西风槽携带的冷空气配合，且存在大量不稳定能量，引发了此次强降水过程.此外，低空急流及西风槽为降水提供了良好的动力上升条件，南海西南季风与台风"罗莎"是台风"利奇马"充沛的水汽与能量来源，为暴雨提供了良好的水汽条件.     

The East Asian subtropical summer monsoon: Recent progress

The East Asian subtropical summer monsoon (EASSM) is one component of the East Asian summer monsoon system, and its evolution determines the weather and climate over East China. In the present paper, we firstly demonstrate the formation and advancement of the EASSM rainbelt and its associated circulation and precipitation patterns through reviewing recent studies and our own analysis based on JRA-55 (Japanese 55-yr Reanalysis) data and CMAP (CPC Merged Analysis of Precipitation), GPCP (Global Precipitation Climatology Project), and TRMM (Tropical Rainfall Measuring Mission) precipitation data. The results show that the rainy season of the EASSM starts over the region to the south of the Yangtze River in early April, with the establishment of strong southerly wind in situ. The EASSM rainfall, which is composed of dominant convective and minor stratiform precipitation, is always accompanied by a frontal system and separated from the tropical summer monsoon system. It moves northward following the onset of the South China Sea summer monsoon. Moreover, the role of the land–sea thermal contrast in the formation and maintenance of the EASSM is illustrated, including in particular the effect of the seasonal transition of the zonal land–sea thermal contrast and the influences from the Tibetan Plateau and midlatitudes. In addition, we reveal a possible reason for the subtropical climate difference between East Asia and East America. Finally, the multi-scale variability of the EASSM and its influential factors are summarized to uncover possible reasons for the intraseasonal, interannual, and interdecadal variability of the EASSM and their importance in climate prediction.