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| TRMM测雨雷达和微波成像仪对两个中尺度特大暴雨降水结构的观测分析研究 | |
| 引用本文： | 傅云飞,宇如聪,徐幼平,肖庆农,刘国胜.TRMM测雨雷达和微波成像仪对两个中尺度特大暴雨降水结构的观测分析研究[J].气象学报,2003,61(4):421-431. |
| 作者姓名： | 傅云飞 宇如聪 徐幼平 肖庆农 刘国胜 |
| 作者单位： | 1. 中国科学技术大学地球和空间科学学院,合肥,230026 2. 中国科学院大气物理研究所,LASG,北京,100029 3. 美国国家大气研究中心中小尺度部,科罗拉多,80307-3000 4. 美国佛罗里达州立大学气象系,佛罗里达,32306-4520 |
| 基金项目： | 国家自然科学基金(40175015和40233031)，中国科学院知识创新工程重要方向项目基金(ZKCXZ—SW—210)，中科院知识创新工程重点项目基金(KZCXZ—208)，国家科技部(2001CCA2200)，国家教育部留学归国人员科研启动基金，中国科学技术大学人才基金 |
| 摘 要： | 文中利用TRMM卫星的测雨雷达和微波成像仪探测结果,研究了1998年7月20日21时(世界时)和1999年6月9日21时发生在武汉地区附近和皖南地区的两个中尺度强降水系统的水平结构和垂直结构,以及TMI微波亮温对降水强弱和分布的响应。研究结果表明:这两个中尺度强降水系统中对流降水所占面积比层云降水面积小,但对流降水具有很强的降水率,它对总降水量的贡献超过了层云降水。降水水平结构表明,两个中尺度强降水系统由多个强雨团或雨带组成,它们均属于对流性降水;降水垂直结构分析表明,强对流降水的雨顶高度可达15km,强对流降水主体中存在垂直方向和水平方向非均匀降水率分布区,层云降水有清晰的亮度带,层云降水的上方存在多层云系结构。降水廓线分布表明:对流降水廓线与层云降水廓线有明显的区别,并且降水廓线清晰地反映了降水微物理过程的垂直分布。整个中尺度强降水系统中对流降水与层云降水的区别还反映在标准化的总降水率随高度的分布。微波信号分析表明:TMI85 GHz极化修正亮温,19.4与37.0,19.4与85.5,37.0与85.5 GHz的垂直极化亮温差均能较好地指示陆面附近的降水分布。 |
| 关 键 词： | TRMM PR TMI 降水结构 |
| 收稿时间： | 2003/5/19 0:00:00 |
| 修稿时间： | 2003年5月19日 |
ANALYSIS ON PRECIPITATION STRUCTURES OF TWO HEAVY RAIN CASES BY USING TRMM PR AND IMI |
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| Fu Yunfei,Yu Rucong,Xu Youping,Xiao Qingnong and Liu Guosheng.ANALYSIS ON PRECIPITATION STRUCTURES OF TWO HEAVY RAIN CASES BY USING TRMM PR AND IMI[J].Acta Meteorologica Sinica,2003,61(4):421-431. | |
| Authors: | Fu Yunfei Yu Rucong Xu Youping Xiao Qingnong and Liu Guosheng |
| Institution: | School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026;LASG, Institute of Atmospheric Physics, Chinese Academy of Sinices, Beijing 100029;LASG, Institute of Atmospheric Physics, Chinese Academy of Sinices, Beijing 100029;MMM Division, National Center for Atmospheric Research, Boulder, Colorado 80307-3000 USA;Department of Meteorology, Florida State University, Tallahassee, FL 32306-4520 USA |
| Abstract: | In order to expose precipitation structures in both horizontal and vertical, and responses of microwave brightness temperatures to precipitation distribution and intensity, in this study, we studied two meascale heavy rain systems happening near Wuhan on July 20, 1998 and the southern part of Anhui on June 9, 1999 by using standard data of 2A25 derived from TRMM PR and 1B11 from TMI. Results show that convective rains contribute much more rainfall to the total than stratiform rains although the former occupies less area than the latter inside the two heavy rain systems, respectively, due to the stronger rainfall rate of convective rains. Results also show the two heavy rain systems are consisted of several heavy convective rain blocks and rain bands in horizontal inside the two systems. Generally, the horizontal scale of rain blocks is from 10 km to 50 km, and rain bands have near a hundred kilometer in length with width from 10 km to 20 km inside the two mid - range scale heavy rain systems. Between the heavy rain blocks (bands), there exist weak rainfall regions or even no rain regions. Usually, strong convective precipitating clouds are surrounded by stratiform precipitating clouds. In vertical, the rain top of heavy convective rains can reach to 15 km from the surface. Inside these heavy convective rains, rainrate is distributed heterogeneously in vertical and horizontal. Meanwhile stratiform rains have a clear brightness band near freezing layer. Above the layer, there exist multi -layer clouds. Below the layer, the rainfall rate is almost constant, which means no collision process during rain droplets drop off from the layer. However, for convective rains, there exists a clear collision process for rain droplet below the freezing layer. But the depth of the collision process for convective rains varies possibly due to convective precipitating clouds are in their different stages. Below the layer of collision process, there may be a layer of droplet evaporation process or big droplet breaking process for convective rains. The differences between convective and stratiform rains are also indicated in their precipitation profiles and the normalized counter rain-rate altitude diagram (NCRAD). The NCRAD indicates that a wider distribution of rainfall rates for convective rains comparing with a narrow one for stratiform rains. Analysis on microwave brightness temperatures of TMI channels exposed bad responses of low frequency channels at 10. 7 GHz, 19. 4 GHz, 22 GHz and 37 GHz to rainfall over land. However, there are good responses of the polarization corrected temperature at 85.5 GHz and the vertical polarization differences between 19.4 GHz and 37 GHz, 19.7 GHz and 85.5 GHz, 37 GHz and 85. 5 GHz to surface rainfall over land. Results illustrate that rainfall region is covered by values of less than 270 K at the polarization corrected temperature at 85.5 GHz, and values of greater than zero at the vertical polarization differences between 19.4 GHz and 37 GHz, 19.7 GHz and 85.5 GHz, 37 GHz and 85.5 GHz. |
| Keywords: | TRMM PR TMI Precipitation structure |
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