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Water-vapor source shift of Xinjiang region during the recent twenty years

Progress in Natural Science:Materials International 2007年第5期17卷 569-575页

作者： Dai Xingang , Li Weijing , Ma Zhuguo and Wang Ping (Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, china Laboratory for Climate Change, Chinese meteorological administration, Beijing {3., china) Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Laboratory for Climate Change Chinese Meteorological Administration Beijing 100081 China

The aim of this paper is to investigate the climate water-vapor sources of Xinjiang region and their shifts during the past 20 years. First, the principle and steps are roughly regulated to seek the water-vapor sources. Second, the climate stationary water-vapor transport in troposphere is calculated to distinguish where the water vapor comes from by ERA-40 reanalysis. In addition, the collocation between the transport and the atmospheric column water vapor content is analyzed. The results show that the major vapor comes from the west side of Xinjiang for mid-month of seasons, apart from July while the water vapor comes from the north or northwest direction. The water vapor sources are different for different seasons, for example, the Caspian Sea and Mediterranean are the sources in January and April, the North Atlantic and the Arctic sea in July, and the Black Sea and Caspian Sea in October, respectively. In recent ten years more water vapor above Xinjiang comes from the high latitudes and the Arctic sea with global warming, and less from Mediterranean in comparison with the case of 1973.1986. In fact, the air over subtropics becomes dry and the anomalous water vapor transport direction turns to west or southwest during 1987—2000. By contrast, the air over middle and high latitudes is warmer and wetter than 14 years ago.

关键词： global warming water-vapor source water-vapor transport precipitable water Xinjiang climate inter-decadal change.

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Advances in estimation methods of vegetation water content based on optical remote sensing techniques

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Science china(Technological Sciences) 2010年第5期53卷 1159-1167页

作者： ZHANG JiaHua1,XU Yun1,YAO FengMei2,WANG PeiJuan1,GUO WenJuan1,LI Li1 & YANG LiMin3.1 Chinese Academy of meteorological Sciences,Beijing 100081,china 2 Graduated University of Chinese Academy of Sciences,Beijing 100049,china 3.USGS/EROS Data center,South Dakota 57198,USA Chinese Academy of meteorological Sciences Graduated University of Chinese Academy of Sciences

Quantitative estimation of vegetation water content(VWC) using optical remote sensing techniques is helpful in forest fire as-sessment,agricultural drought monitoring and crop yield *** paper reviews the research advances of VWC retrieval using spectral reflectance,spectral water index and radiative transfer model(RTM) *** also evaluates the reli-ability of VWC estimation using spectral water index from the observation data and the *** on two main definitions of VWC-the fuel moisture content(FMC) and the equivalent water thickness(EWT),the retrieval accuracies of FMC and EWT using vegetation water indices are ***,the measured information and the dataset are used to estimate VWC,the results show there are significant correlations among three kinds of vegetation water indices(i.e.,WSI,NDⅡ,NDWI1640,WI/NDVI) and canopy FMC of winter wheat(n=45).Finally,the future development directions of VWC detection based on optical remote sensing techniques are also summarized.

关键词： optical remote sensing vegetation water content estimation method water index FMC EWT radiative transfer model

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Surface deformation at the epicenter of the May 12,2008 Wenchuan M8 Earthquake,at Yingxiu Town of Sichuan Province,china

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Science china(Technological Sciences) 2008年第S2期51卷 154-163页

作者： DONG ShaoPeng,HAN ZhuJun & AN YanFen national center of Seismic Fault Study,Institute of Geology,china Earthquake {3.,Beijing 100029,china national center of Seismic Fault Study Institute of Geology China Earthquake Administration Beijing China

Surface deformation,along national Highway 213.at the epicenter of Wenchuan M8 earthquake,at Yingxiu Town of Sichuan Province,china,is surveyed and measured in *** results show two distinct *** is that no horizontal displacement displays,or dextral strike-slip component at the observation point can not be found basically,the other is that uplift amount is 2.72 m,and the short-ening amount is 0.3. m,which reflects thrust shortening deformation is not *** crust uplift amount of 2.71 m is distributed in a belt with width of 60 *** model of lower crustal flow proposed by Royden et al.(1997) about the dynamic process in eastern margin of the Tibetan Plateau seems more suitable to explain the seismic surface deformation characteristics at Yingxiu Town,the epicenter of the May 12,2008 Wenchuan M8 Earthquake.

关键词： Wenchuan M8 Earthquake Yingxiu Town surface deformation

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Model calculation of air-sea heat fluxes over ocean area near china with GEOS DAS system

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Acta Oceanologica Sinica 1999年第3期18卷 401-411页

作者：周明煜钱粉兰 Natl. Mar. Environ. Forecast. center State Oceanic Administration Beijing 100081 China

The sensible and latent heat fluxes over the ocean area near china were calculated and analyzed by usingthe Goddard Earth Observing System (GEOS) - four-dimensional Data Assimilation System (DAS). The calculated results showed that the sensible heat flux had its large value in winter and autumn , small value in spring and summer overthe ocean area near china. In winter, the sensible heat flux increased distinctly with latitude, and its isolines were verycrowded. Over the ocean area east of Taiwan Province and south of Japan, the direction of isoline was from southwestto northeast. In the South china Sea the sensible heat flux was lower than that of surrounding ocean areas,and its isoline was distributed into a type of an inverted trough. In autumn and winter, the maximum {3. of latent heat flux appeared over the ocean area northeast of Taiwan Province and south and southeast of Japan, meanwhile, the isoline wasin the direction of southwest to northeast. In spring and summer, the latent heat flux had minimum value in the Huanghai Sea. At the same time, the maximum value {3. of latent heat flux appeared over the ocean area south of Japan inspring.

关键词： GEOS DAS system the ocean area near china sensible heat flux latent heat flux

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Prediction of solar cycle based on the invariant

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Chinese Science Bulletin 2003年第23期48卷 2568-2571页

作者： LIU Shijun, YU Xiaoding & CHEN Yongyi Chinese meteorological administration Training Centre, Beijing 100081, {3. Correspondence should be addressed to Liu Shijun (e-mail: liushj@ ***) Chinese meteorological administration Training Centre

A new method of predicting solar activities has been introduced in this paper. The method can predict both the occurrence time and the maximum number of sunspot at the same time. By studying the variation of sunspot, we find that the combination of the several variables was nearly in-variable during the entire solar cycles, as called invariant. And just only by determining the start time of a cycle, we can predict the occurrence time of cycles peak value accurately. Furthermore, according to observational data of the sunspot cycles, it showed that the sunspot maximum number has correlation not only with the prophase variety of the number in the cycle but also with the anaphase of the previous period. So we can introduce an equivalent regression coefficient, which can dynamically self-adapt to different cycle lengths, and effectively solve the inconsistency between the accuracy and the lead-time of the forecast. It can guarantee the satis-fied accuracy and effectively increases the lead-time of the forecast. This method can predict the maximum sunspot number for solar cycle at the approximate half rise of the period. This method predicts that the occurrence time of the maximum sunspot number for cycle 24 will be in January 2011.

关键词：太阳黑子太阳活动周期周期预测地磁指数

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Simulation of 1991-2005 Meiyu seasons in the Yangtze-Huaihe region using BCCRegCM 1.0

Simulation of 1991-2005 Meiyu seasons in the Yangtze-Huaihe ...

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第七届全国优秀青年气象科技工作者学术研讨会

作者： HU YaMin1,2 DING YiHui3.1 Guangdong Climate center, Guangzhou 510080, china 2 Institute of Tropical and Marine Meteorology, china meteorological administration, Guangzhou 510080, china 3.national Climate center, china meteorological administration, Beijing 100081, china

By using BCCegCM 1.0 (RegCM for short) from Beijing Climate center (BCC), china meteorological administration (CMA), the Meiyu season characters over the Yangtze-Huaihe region during 1991～2005 are simulated. The major conclusions of this study may be summarized as the following: (1) RegCM can reproduce the interannual variation and the spatial distribution of the summertime precipitation and temperature in the Yangtze-Huaihe region. (2) By use of a generalized Meiyu criterion and in accordance with model-calculated precipitation and temperature, the Meiyu onset and ending date have been determined. Compared with the observation, RegCM can simulate the interannual variation of the Yangtze-Huaihe Meiyu with preferable capability for most of the normal Meiyu years (such as 1995, 1997, 2000, 2001, 2002 and 2004), especially for the rich Meiyu years of 1996, 1998 and 1999. (3. In terms of the average simulation for the recent 15a, the timings of onset and ending of Meiyu occur on June 1 and July 13. respectively, which are earlier than the climatological observation. For duration, Meiyu persists for 3. day, 3.days shorter than the observation. The index of Meiyu intensity is 2.45, while the climatological one is 3.00. Therefore, RegCM is capable of simulating the climatological Meiyu duration and intensity, while the capability of simulating the onset and ending date of Meiyu still needs to be improved.

关键词： regional climate model Meiyu in Yangtze-Huaihe region Meiyu onset Meiyu ending Meiyu rainfall

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A stochastic method for convective storm identification,tracking and nowcasting

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Progress in Natural Science:Materials International 2008年第12期18卷 1557-1563页

作者： Lei Han~(a,b) Shengxue Fu~a Guang Yang~c Hongqing Wang~b Yongguang Zheng~d Yingjing Lin~b a College of Information Science and Engineering.Ocean University of china,Qingdao 266101,china b Department of Atmospheric Science,Peking University,Beijing 100871,china c Department of Probability and Statistics,Peking University,Beijing 100871,china d national meteorological center,Beijing 100081,china College of Information Science and Engineering Ocean University of China Qingdao 266101 China Department of Atmospheric Science Peking University Beijing 100871 China Department of Probability and Statistics Peking University Beijing 100871 China national meteorological center Beijing 100081 China

The convective storm identification,tracking and nowcasting method is one of the important nowcasting methodologies against severe convective *** severe convective cases,such as storm shape or rapid velocity changes,existing methods are apt to provide unsatisfied storm identification,tracking and nowcasting *** overcome these difficulties,this paper proposes a novel approach to identify,track and short-term forecast (nowcast) of convective storms.A mathematical morphology-based storm identification method is adopted which can identify storm cells accurately in a cluster of *** for the difficult tracking problem,sequential Monte Carlo (SMC) method is utilized to simplify the tracking *** is not only inherently suitable for handling complicated splits and mergers, but also capable of handling the case of storm-missing *** order to provide more accurate forecast of a storm position,this method takes the advantages of the cross-correlation *** qualitative and quantitative evaluations show the efficiency and robustness of the proposed approach.

关键词： Convective storm Doppler radar Nowcasting

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Effects of 4DVAR with multifold observed data on the typhoon track forecast

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Chinese Science Bulletin 2003年第S2期48卷 93-98页

作者： WANG Yunfeng, WANG Bin, MA GANG & WANG Yushun 1. LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences. Beijing 100029, china: 2. national Satellite meteorological {3., Beijing 100081. china Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China Natl Satellite Meteorol Ctr Beijing 100081 Peoples R China

Effects of 4-dimension variational data assimi-lation (4DVAR) with multifold observed data on the typhoontrack forecast are studied, by using the MM5V3.model, theRTTOVS-5 model and their adjoint models. The data usedfor assimilation include large-scale background fields data,bogus data, cloud-derived wind data, satellite inverse data,and high resolution infrared radiation sounder data (HIRS).There are 5 typhoon cases are used to perform the numericalexperiments and assimilation experiments. The numericalresults show that with 4DVAR the initial fields can be greatlyimproved and the initial typhoon structure can be clearlydescribed.

关键词： multifold observed data 4DVAR typhoon track. DOI: 10.13.0/03.d0456

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FY Satellites Applied in Disaster Prevention and Mitigation

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Aerospace china 2011年第2期12卷 2-5页

作者： china meteorological administration

china is one of the countries that are most frequently hit by natural disasters. meteorological disasters contribute to 70% of all

关键词： CMA

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A New Approach to the On-Orbit Evaluation of Point Spread Function of Thermal Infrared Images With Applications to FY-2 Satellite Products

A New Approach to the On-Orbit Evaluation of Point Spread Fu...

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作者： Qiang Guo,Changjun Yang,and Caiying Wei the national Satellite meteorological center,{3.,Beijing 100081,china,the Key Laboratory of Radiometric Calibration and Validation for Environmental Satellite,{3.,Beijing 100081,china

Spatial characteristics of thermal infrared(TIR) images are generally described by image-derived point spread function(IDPSF) for sampled imaging *** investigators working on IDPSF on-orbit evaluation focus on visible and near-infrared images and pay little attention on TIR ones,the reason of which lies on the fact that the assumption of an observed target with an ideal step profile is not suitable for TIR band. A new approach for TIR images is proposed here based on a more common slope-profile model,where the transition features, i.e.,the sample number(N) and the beginning position of slope interval,are extracted from the observed *** results show that the estimation performance will be increased, with lower noise level as well as higher system modulation transfer function value at half of normalized spatial frequency(MTF) or smaller *** a good performance system with noise squared-root variance(SRV) no more than 1.0 count and MTF between 0.3.and 0.4,the relative error between simulated and estimated MTF\s is less than 20%.The IDPSF of FY-2C satellite TIR band is estimated,and the derived MTF0.5 is properly close to on-ground testing *** image quality of FY-2C TIR band has been improved by using Wiener filtering and the estimated IDPSF,which eventually benefits the cloud detection product with more detectable low fractus and increased detection accuracy by about 1%in *** a step-profile target as a special case of this model,the proposed approach is also suitable for visible and near-infrared images.

关键词： Index Terms—Infrared imaging optical image processing optical transfer functions.

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