青藏高原地区TRMM PR地面降雨率的修正
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摘要
为掌握并改进青藏高原地区TRMM卫星降水雷达(precipitation radar,PR)地面降雨率准确度,统计分析了2005—2007年TRMM PR 2A25资料和逐小时地面雨量计,结果表明:青藏高原地区TRMM PR地面降雨率在层云降水时平均偏低35%,在对流云降水时平均偏高42%。Z-R关系的适用性是PR产生偏差的原因之一,研究将TRMM PR层云降水模型中20℃层Z-R关系的初始系数A和b分别修正为0.0288和0.6752,对流云降水模型中20℃层的初始系数A和b分别修正为0.0406和0.5809,得到两类降水模型0℃层与20℃层之间不同高度Z-R关系的更新系数。检验结果表明,修正降水模型后能够提高青藏高原地面降雨率测量的准确度。
In order to reveal and improve the accuracy of surface rainfall rates derived from precipitation radar(PR) on TRMM satellite over the Tibetan Plateau,TRMM PR 2A25 products and hourly rain gauge data from 2005 to 2007 are compared.Results show that PR has a relative error of —35%in stratiform rain and42%in convective rain over the Tibetan Plateau.The applicability of Z-R relation is one of the cause for the bias of PR.Based on the analysis,the initial coefficients A and b in Z-R relations at 20℃ level are modified to 0.0288 and 0.6752 for stratiform rain,respectively,also modified to 0.0406 and 0.5809 for convective rain,thus the Z-R relation at different altitudes between 0 ℃ and 20 ℃ height are updated.Results suggest that the modified models can achieve better accuracy in estimating surface rainfall rates over the Tibetan Plateau.
In order to reveal and improve the accuracy of surface rainfall rates derived from precipitation radar(PR) on TRMM satellite over the Tibetan Plateau,TRMM PR 2A25 products and hourly rain gauge data from 2005 to 2007 are compared.Results show that PR has a relative error of —35%in stratiform rain and42%in convective rain over the Tibetan Plateau.The applicability of Z-R relation is one of the cause for the bias of PR.Based on the analysis,the initial coefficients A and b in Z-R relations at 20℃ level are modified to 0.0288 and 0.6752 for stratiform rain,respectively,also modified to 0.0406 and 0.5809 for convective rain,thus the Z-R relation at different altitudes between 0 ℃ and 20 ℃ height are updated.Results suggest that the modified models can achieve better accuracy in estimating surface rainfall rates over the Tibetan Plateau.
引文
[1]徐祥德,陈联寿.青藏高原大气科学试验研究进展.应用气象学报,2006,17(6):756-772.
[2]杨明,李维亮,刘煜,等.近50年我国西部地区气象要素的变化特征.应用气象学报,2010,21(2):198-205.
[3]Kummerow C,Barnes W,Kozu T,et al.The Tropical Rainfall Measuring Mission(TRMM)sensor package.J Atmos Ocean Technol,1998,15(3):809-817.
[4]游然,卢乃锰,邱红,等.用PR资料分析热带气旋卡特里娜降水特征.应用气象学报,20ll,22(2):203-213.
[5]陈廷娣,王连仲,窦贤康.TRMM卫星与机载雷达在降雨反演中的数据对比个例研究.应用气象学报,2008,19(4):454-462.
[6]吴庆梅,程明虎,苗春生.用TRMM资料研究江淮、华南降水的微波特性.应用气象学报,2003,14(2):206-214.
[7]Prat O P.Barros A P.Assessing satellite-based precipitation estimates in the Southern Appalachian mountains using rain gauges and TRMM PR.Advances in Geosciences,2010,25:143-153.
[8]Barros A P.Joshi M.Putkonen J,et al.A study of the 1999monsoon rainfall in a mountainous region in central Nepal vising TRMM products and rain gauge observations.Geophys Res Lett,2000,27(22):3683-3686.
[9]刘鹏,傅云飞,冯沙,等.中国南方地基雨量计观测与星载测雨雷达探测降水的比较分析.气象学报,2010,68(6):822-835.
[10]Stout G E,Mueller E A.Survey of relationships between rainfall rate and radar reflectivity in the measurement of precipitation.J Appl Meteor,1968,7(3):465-474.
[11]Prat O P.Barros A P.Exploring the transient behavior of Z-R relationships:Implications for radar rainfall estimation.J Applied Meteor&Climatology,2009,48(10);2027-2143.
[12]史锐,程明虎,崔哲虎,等.用反射率因子垂直廓线联合雨量计校准估测夏季区域强降水.应用气象学报,2005,16(6):737-745.
[13]Iguchi T,Kozu T.Meneghini R.et al.Rain-profiling algorithm for the TRMM precipitation radar.J Applied Meteor,2000,39(12):2038-2052.
[14]Iguchi T.Kozu T.Kwiatkowski J.et al.Uncertainties in the rain profiling algorithm for the TRMM precipitation radar.気象集誌,2009,87(2):1-30.
[15]郑媛媛,谢亦峰,吴林林,等.多普勒雷达定量估测降水的三种方法比较试验.热带气象学报,2004,20(2):192-197.
[2]杨明,李维亮,刘煜,等.近50年我国西部地区气象要素的变化特征.应用气象学报,2010,21(2):198-205.
[3]Kummerow C,Barnes W,Kozu T,et al.The Tropical Rainfall Measuring Mission(TRMM)sensor package.J Atmos Ocean Technol,1998,15(3):809-817.
[4]游然,卢乃锰,邱红,等.用PR资料分析热带气旋卡特里娜降水特征.应用气象学报,20ll,22(2):203-213.
[5]陈廷娣,王连仲,窦贤康.TRMM卫星与机载雷达在降雨反演中的数据对比个例研究.应用气象学报,2008,19(4):454-462.
[6]吴庆梅,程明虎,苗春生.用TRMM资料研究江淮、华南降水的微波特性.应用气象学报,2003,14(2):206-214.
[7]Prat O P.Barros A P.Assessing satellite-based precipitation estimates in the Southern Appalachian mountains using rain gauges and TRMM PR.Advances in Geosciences,2010,25:143-153.
[8]Barros A P.Joshi M.Putkonen J,et al.A study of the 1999monsoon rainfall in a mountainous region in central Nepal vising TRMM products and rain gauge observations.Geophys Res Lett,2000,27(22):3683-3686.
[9]刘鹏,傅云飞,冯沙,等.中国南方地基雨量计观测与星载测雨雷达探测降水的比较分析.气象学报,2010,68(6):822-835.
[10]Stout G E,Mueller E A.Survey of relationships between rainfall rate and radar reflectivity in the measurement of precipitation.J Appl Meteor,1968,7(3):465-474.
[11]Prat O P.Barros A P.Exploring the transient behavior of Z-R relationships:Implications for radar rainfall estimation.J Applied Meteor&Climatology,2009,48(10);2027-2143.
[12]史锐,程明虎,崔哲虎,等.用反射率因子垂直廓线联合雨量计校准估测夏季区域强降水.应用气象学报,2005,16(6):737-745.
[13]Iguchi T,Kozu T.Meneghini R.et al.Rain-profiling algorithm for the TRMM precipitation radar.J Applied Meteor,2000,39(12):2038-2052.
[14]Iguchi T.Kozu T.Kwiatkowski J.et al.Uncertainties in the rain profiling algorithm for the TRMM precipitation radar.気象集誌,2009,87(2):1-30.
[15]郑媛媛,谢亦峰,吴林林,等.多普勒雷达定量估测降水的三种方法比较试验.热带气象学报,2004,20(2):192-197.