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Variations of Precipitation Structure and microwave Tbs During the Evolution of a Hailstorm from TRMM Observations

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Acta meteorologica Sinica 2007年第2期21卷 153-167页

作者：何文英陈洪滨 LAGEO Institute of Atmospheric Physics CAS

In this paper, a hailstorm occurring on 9 May 1999 in Huanghuai region was studied by using the combined data from the precipitation radar （PR）, microwave image （TMI）, and visible infrared scanner （VIRS） on the Tropical Rainfall Measuring Mission （TRMM） satellite. According to the 3-orbit observations of 5- h duration from the TRMM satellite, the variation characteristics of the precipitation structures as well as cloud top temperature and microwave signals of the precipitating cloud were comprehensively analyzed during the evolution of hailstorm. The results show that the precipitation is obviously converted from early hail cloud with strong convection into the later storm cloud with weak convection. For hail cloud, there exists some strong convective cells, and the heavy solid precipitation is shown at the middle-top levels so that the contribution of rainfall amount above the freezing-layer to the column precipitation amount is rather larger than that within the melting-layer. However, for storm cloud, the convective cells are surrounded by the large area of stratiform precipitation, and the precipitation thickness gradually decreases, and the rainfall above the freezing-layer obviously reduces and the contribution of rainfall amount within the melting-layer rapidly increases. Therefore, the larger ratio of rainfall amount above the freezing layer to column precipitation amount is, the more convective the cloud is; reversely, the larger proportion of rainfall below the melting layer is, the more stable the stratiform cloud is. The different changing trends of microwave signals at different precipitation stages show that it is better to consider the structures and stages of precipitating cloud to choose the optimal microwave channels to retrieve surface rainfall.

关键词： Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) hailstorm precipitation structure microwave brightness temperature

Evaluating effects of Dielectric Models on the surface soil moisture retrieval in the Qinghai-Tibet Plateau

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Research in Cold and Arid Regions 2021年第1期13卷 62-76页

作者： Rong Liu Xin Wang ZuoLiang Wang Jun Wen Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China College of Atmospheric Sciences Chengdu university of Information TechnologyChengduSichuan 610225China

Based on the measurement of L-band ground-based microwave radiometer(ELBARA-III type)in the Qinghai-Tibet Plateau and theτ-ωradiative transfer model,this research evaluated the effects of four soil dielectric models,i.e.,Wang-Schmugge,Mironov,Dobson,and Four-phase,on the L-band microwave brightness temperature simulation and soil moisture *** results show that with the same vegetation and roughness parameterization scheme,the four soil dielectric models display obvious differences in microwave brightness temperature *** the soil moisture is less than 0.23 m3/m3,the simulated microwave brightness temperature in Wang-Schmugge model is significantly different from that of the other three models,with maximum differences of horizontal polarization and vertical polarization reaching 8.0 K and 4.4 K,respectively;when the soil moisture is greater than 0.23 m3/m3,the simulated microwave brightness temperature of Four-phase significantly exceeds that of the other three models;when the soil moisture is saturated,maximum differences in simulated microwave brightness temperature with horizontal polarization and vertical polarization are 6.1 K and 4.8 K respectively,and the four soil dielectric models are more variable in the microwave brightness temperature simulation with horizontal polarization than that with vertical *** for the soil moisture retrieval based on the four dielectric models,the comparison study shows that,under the condition of horizontal polarization,Wang-Schmugge model can reduce the degree of retrieved soil moisture underestimating the observed soil moisture more effectively than other parameterization schemes,while under the condition of vertical polarization,the Mironov model can reduce the degree of retrieved soil moisture overestimating the observed soil ***,based on the Wang-Schmugge model and FengYun-3C observation data,the spatial distribution of soil moisture in the study area is retrieved.

关键词： L-band microwave brightness temperature soil dielectric model soil moisture retrieval

Evaluation of the Community microwave Emission Model Coupled with the Community Land Model over East Asia

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Atmospheric and Oceanic Science Letters 2011年第4期4卷 209-215页

作者： JIA Bing-Hao XIE Zheng-Hui State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The Community microwave Emission Model (CMEM) developed by the European Centre for Me-dium-Range Weather Forecasts (ECMWF) can provide a link between surface states and satellite observations and simulate the passive microwave brightness temperature of the surface at low frequencies (from 1 GHz to 20 GHz).This study evaluated the performance of the CMEM cou-pled with the Community Land Model (CLM) (CMEM-CLM) using C-band (6.9 GHz) microwave brightness temperatures from the Advanced microwave Scanning Radiometer on Earth Observing System (AMSR-E) over East *** results support the argument that the simulated brightness temperatures of CMEM-CLM from July 2005 to June 2010 are comparable to AMSR-E observational ***-CLM performed better for vertical polarization,for which the root mean square error was approximately 15 K,compared to over 30 K for horizontal *** evaluation performed over seven sub-regions in China indicated that CMEM-CLM was able to capture the temporal evolution of C-band brightness temperatures well,and the best correlation with AMSR-E appeared over western Northwest China (over 0.9 for vertical polarization).However,larger biases were found over southern North China and the middle and lower reaches of the Yangtze River.

关键词： Community microwave Emission Model Community Land Model microwave brightness temperature AMSR-E

Simultaneous estimation of soil moisture and hydraulic parameters using residual resampling particle filter

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Science China Earth Sciences 2014年第5期57卷 824-838页

作者： BI HaiYun MA JianWen QIN SiXian ZHANG HongJuan Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences University of the Chinese Academy of Sciences

Land data assimilation(DA) has gradually developed into an important earth science research method because of its ability to combine model simulations and *** new observations into a land surface model by the DA method can correct the predicted trajectory of the model and thus,improve the accuracy of state *** can also reduce uncertainties in the model by estimating some model parameters *** the various DA methods,the particle filter is free from the constraints of linear models and Gaussian error distributions,and can be applicable to any nonlinear and non-Gaussian state-space model;therefore,its importance in land data assimilation research has *** this study,a DA scheme was developed based on the residual resampling particle *** brightness temperatures were assimilated into the macro-scale semi-distributed variance infiltration capacity model to estimate the surface soil moisture and three hydraulic parameters ***,to verify the scheme,a series of comparative experiments was performed with experimental data obtained during the Soil Moisture Experiment of 2004 in *** results show that the scheme can improve the accuracy of soil moisture estimations *** addition,the three hydraulic parameters were also well estimated,demonstrating the effectiveness of the DA scheme.

关键词： data assimilation residual resampling particle filter microwave brightness temperature soil moisture hydraulic parameter

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