Discriminating between unresolved point sources and 'negative' Sunyaev–Zel'dovich clusters in cosmic microwave background maps     

J. A. Rubiño-Martín  R. A. Sunyaev 《Monthly notices of the Royal Astronomical Society》2003,344(4):1155-1174

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Wilkinson Microwave Anisotropy Probe data and the curvature of space     

Jean-Philippe Uzan  Ulrich Kirchner  George F. R. Ellis 《Monthly notices of the Royal Astronomical Society》2003,344(4):L65-L68

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Filtering techniques for the detection of Sunyaev–Zel'dovich clusters in multifrequency maps     

D. Herranz  J. L. Sanz  M. P. Hobson  R. B. Barreiro  †  J. M. Diego  E. Martínez-González  A. N. Lasenby 《Monthly notices of the Royal Astronomical Society》2002,336(4):1057-1068

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OBSERVATION RESEARCH FOR THE MEASURING RAINFALL CAPACITY OF TRMM/TMI-85.5G BASED ON PRECIPITATION DATA DURING THE HEAVY RAIN EXPERIMENT IN SOUTHERN CHINA     

吕艳彬  顾雷  李亚萍  高慧林  邵明轩  陶祖钰 《热带气象学报(英文版)》2001,7(2):218-224

The capacity of Tropical Rainfall Measuring Mission (TRMM) Satellite for measuring rainfall was examined by using TMI-85.5 GHz microwave image data and precipitation data during a heavy rainfall experiment in southern China. From comparisons with the distribution of rain amount in an hour with BB T of 85.5 GHz microwave, it is clear that the center of heavy rain corresponds with an area of low BB T value. The location and shape of BB T distribution is similar to that of precipitation, and the larger the rainfall rates, the lower the BB T . A statistic analysis shows that the correlation coefficients between BB T and rain rates is negative and significant. Especially, when the rain rate is over 7 mm/h, the correlation degree between BB T and rain rates is more significant. The results shows that TRMM/TMI-85.5 G has great ability to measure convective heavy rain.  相似文献   

Influence of Surface Temperature and Emissivity on AMSU-A Assimilation over Land          下载免费PDF全文

HE Wenying  LIU Zhiquan  CHEN Hongbin 《Acta Meteorologica Sinica》2011,25(5):545-557

AMSU-A (Advanced Microwave Sounding Unit-A) measurements for channels that are sensitive to the surface over land have not been widely assimilated into numerical weather prediction (NWP) models due to complicated land surface features. In this paper, the impact of AMSU-A assimilation over land in Southwest Asia is investigated with the Weather Research and Forecasting (WRF) model. Four radiance assimilation experiments with different land-surface schemes are designed, then compared and verified against radiosonde observations and global analyses. Besides the surface emissivity calculated from the emissivity model and surface temperature from the background field in current WRF variational data assimilation (WRF-VAR) system, the surface parameters from the operational Microwave Surface and Precipitation Products System (MSPPS) are introduced to understand the influence of surface parameters on AMSU-A assimilation over land. The sensitivity of simulated brightness temperatures to different surface configurations shows that using MSPPS surface alternatives significantly improves the simulation with reduced root mean square error (RMSE) and allows more observations to be assimilated. Verifications of 24-h temperature forecasts from experiments against radiosonde observations and National Centers for Environmental Prediction (NCEP) global analyses show that the experiments using MSPPS surface alternatives generate positive impact on forecast temperatures at lower atmospheric layers, especially at 850 hPa. The spatial distribution of RMSE for forecast temperature validation indicates that the experiments using MSPPS surface temperature obviously improve forecast temperatures in the mountain areas. The preliminary study indicates that using proper surface temperature is important when assimilating lower sounding channels of AMSU-A over land.  相似文献   

人工神经网络法反演晴空大气湿度廓线的研究   总被引：4，自引：0，他引：4  

刘旸  官莉 《气象》2011,37(3):318-324

高光谱分辨率大气红外探测器AIRS(Atmospheric Infrared Sounder)作为第一个超高光谱大气红外探测仪,开辟了卫星大气探测的新时代.以无线电探空值与SARTA(Stand-Alone Radiative Transfer Algorithm辐射传输模式)v1.05版的前向模式模拟出的AIRS辐射...  相似文献   

2009年深秋北京大雪过程的成因分析   总被引：4，自引：2，他引：2  

段丽  张琳娜  王国荣  段炼 《气象》2011,37(11):1343-1351

北京地区的初雪平均在11月28日前后。2009年10月31日夜间至11月1日白天北京出现雨转雨夹雪,再转大雪的天气过程。作为初雪,这是北京22年来罕见的。分析表明,这次过程降水前12和6 h华北中东部的黄河下游以北地区对流层中低层受一致的西北气流控制,前期水汽输送和积累不明显。北京地区在10月这样一个相对干燥的季节和前期水汽不充沛的环流形势下产生大雪局地暴雪,实不多见。文章利用中国气象局MICAPS常规气象资料和北京地区风廓线雷达、微波辐射仪、地面自动站等多种本地加密探测资料,对这次大雪过程进行了动力计算和成因分析。结果显示,由对流层上层贝加尔湖强冷空气向南爆发所引发的动力作用是北京这次初冬大雪形成的主要原因。大雪发生前500 hPa正涡度平流区、对流层中上层水平辐散中心、对流层中下层水平辐合中心呈垂直结构控制北京,为北京地区提供了有利的上升运动动力环境。山前和平原地区近地面东南风,边界层偏东风及边界层以上的对流层底层偏西风的风廓线分布在北京西部地形作用下产生动力抬升和局地对流,增强了北京西南部的降雪。这次北京大雪的水汽条件源于近地面偏南风和东南风的短时间局地增湿,以及这种增湿在高空强冷气团作用下产生的对流层中低层的局地水汽辐合。  相似文献   

贵阳地区太阳紫外辐射变化特征及主要影响因子分析          下载免费PDF全文

吉廷艳  王红丽  胡跃文  杨通礼 《高原气象》2011,30(4):1005-1010

利用贵阳地区近6年太阳紫外辐射的观测资料及相关的气象因子,分析了该地区太阳紫外辐射的变化特征。结果表明,贵阳地区紫外辐射逐时平均最大值为21W.m-2（四级强度）,瞬时最大值为26.4W.m-2,未出现很强辐射（五级）的情况;4～9月出现强紫外辐射的时段较长,在10：00～15：00可达四级;13：00强紫外辐射在4～...  相似文献   

2007年5—6月珠峰北坡不同高度气象要素特征分析     

张志刚  秦翔  何立富  王建凯 《气象》2011,37(8):977-983

依据在珠峰北坡海拔5200、5600、5800、6000和7028 m等处设立的自动气象站资料,分析了2007年5月5日至6月4日的风向、风速、气温、绝对湿度和气压等气象要素的日间平均分布规律,探讨了不同海拔高度气象要素分布差异,指出下垫面性质、地形环境、水陆分布以及太阳辐射分布差异是造成珠峰北坡不同海拔高度气象要素日变化特殊分布的原因,同时将本次观测资料与历史同期资料对比分析并指出存在差异的原因。为全面认识珠峰地区地面气象要素特征,考察珠峰环境及今后珠峰地区的登山和科学研究活动提供重要依据。  相似文献   

CINRAD/SA雷达中微波器件故障判别     

汤建国  周红根  周良  赵东 《气象科技》2011,39(2):222-226

雷达系统中有许多微波器件,在各个通道中起不同的作用,认识这些器件的形态、功能、原理以及故障判别对现场保障人员来说非常重要。文章对CINRAD/SA雷达的接收机保护器、声体波微波延迟线、无源限幅器、波导开关在功能原理以及技术指标和故障表现形式作了较为详细的介绍,目的是为了对系统有更进一步的了解和进行故障判别。  相似文献