为满足第十四届全国冬季运动会(简称“十四冬”)对复杂地形高精度天气预报服务的需求,结合大涡模拟技术及高精度地形数据,搭建了针对“十四冬”室外赛区的内蒙古次百米级数值预报系统(the Sub-hundred-meter Numerical Forecast System ...为满足第十四届全国冬季运动会(简称“十四冬”)对复杂地形高精度天气预报服务的需求,结合大涡模拟技术及高精度地形数据,搭建了针对“十四冬”室外赛区的内蒙古次百米级数值预报系统(the Sub-hundred-meter Numerical Forecast System of Inner Mongolia,SNFS)。以赛区站点观测资料为参考,根据风速预报检验指标及检验评分等参数,对SNFS在“十四冬”3个赛区的风场预报性能进行检验评估。结果表明:扎兰屯及喀喇沁赛区预报风速总体表现为系统性高估,凉城赛区为低估。对于海拔高度较低的测站,预报与观测风速偏差均以正偏差为主,随测站海拔高度增加,风速偏差转为负偏差,偏差离散程度增大。扎兰屯及喀喇沁赛区在各预报时效内都存在对小于6级实测风预报偏强,而对大于6级实测风预报偏弱的特点,凉城赛区则预报均偏弱,其中扎兰屯赛区对大于6级的实测风预报评分优势明显。进一步分析扎兰屯赛区一次大风天气个例表明,预报风向与观测风向基本吻合,风速变化趋势一致,SNFS可以刻画出局地流场特征,对复杂地形下的风场具有较好的预报能力。展开更多
利用2015年大连地区7个主要气象站的地面气温、降水、风向风速和相对湿度观测资料,针对东北区域中尺度数值模式(Weather Research and Forecast,WRF)产品中常规天气要素进行检验分析,了解掌握WRF模式对不同天气要素的预报能力,以期为天...利用2015年大连地区7个主要气象站的地面气温、降水、风向风速和相对湿度观测资料,针对东北区域中尺度数值模式(Weather Research and Forecast,WRF)产品中常规天气要素进行检验分析,了解掌握WRF模式对不同天气要素的预报能力,以期为天气预报业务中WRF模式产品的订正提供参考。结果表明:WRF模式产品的气温预报准确率整体上08时起报的比20时起报的稍好,最低气温预报效果比最高气温稍好,且WRF模式对升温和降温的趋势预报较好,具有一定参考性。WRF模式产品的降水预报准确率相对较高; WRF模式对风向的预报准确率可以达到50%左右,而风速的预报准确率可以达到60%—70%;大雾天气的预报,可以相应参考WRF模式的相对湿度。展开更多
A three-dimensional elastic nonhydrostatic mesoscale(β-γ)model with nested-grid is presented.It uses a set of full equations in terrain-following coordinates as its basic dynamic frame,which is solved with a time-sp...A three-dimensional elastic nonhydrostatic mesoscale(β-γ)model with nested-grid is presented.It uses a set of full equations in terrain-following coordinates as its basic dynamic frame,which is solved with a time-splitting algorithm for acoustic and gravity waves.The model physical parameterization includes a K-theory subgrid eddy mixing for cloud and free atmosphere,a bulk planetary boundary layer parameterization,and three types of sofisticated cloud microphysics schemes with double-parameters for hail-bearing clouds,warm clouds and snowing clouds respectively. The model is designed to be used flexibly for simulations of a variety of meso-and small-scale atmospheric processes, and can be improved as a regional and local operational NWP system in future.展开更多
The heaviest rainfall over 61 yr hit Beijing during 21-22 July 2012.Characterized by great rainfall amount and intensity,wide range,and high impact,this record-breaking heavy rainfall caused dozens of deaths and exten...The heaviest rainfall over 61 yr hit Beijing during 21-22 July 2012.Characterized by great rainfall amount and intensity,wide range,and high impact,this record-breaking heavy rainfall caused dozens of deaths and extensive damage.Despite favorable synoptic conditions,operational forecasts underestimated the precipitation amount and were late at predicting the rainfall start time.To gain a better understanding of the performance of mesoscale models,verification of high-resolution forecasts and analyses from the WRFbased BJ-RUCv2.0 model with a horizontal grid spacing of 3 km is carried out.The results show that water vapor is very rich and a quasi-linear precipitation system produces a rather concentrated rain area.Moreover,model forecasts are first verified statistically using equitable threat score and BIAS score.The BJ-RUCv2.0forecasts under-predict the rainfall with southwestward displacement error and time delay of the extreme precipitation.Further quantitative analysis based on the contiguous rain area method indicates that major errors for total precipitation（〉 5 mm h^（-1）） are due to inaccurate precipitation location and pattern,while forecast errors for heavy rainfall（〉 20 mm h^（-1）） mainly come from precipitation intensity.Finally,the possible causes for the poor model performance are discussed through diagnosing large-scale circulation and physical parameters（water vapor flux and instability conditions） of the BJ-RUCv2.0 model output.展开更多
文摘为满足第十四届全国冬季运动会(简称“十四冬”)对复杂地形高精度天气预报服务的需求,结合大涡模拟技术及高精度地形数据,搭建了针对“十四冬”室外赛区的内蒙古次百米级数值预报系统(the Sub-hundred-meter Numerical Forecast System of Inner Mongolia,SNFS)。以赛区站点观测资料为参考,根据风速预报检验指标及检验评分等参数,对SNFS在“十四冬”3个赛区的风场预报性能进行检验评估。结果表明:扎兰屯及喀喇沁赛区预报风速总体表现为系统性高估,凉城赛区为低估。对于海拔高度较低的测站,预报与观测风速偏差均以正偏差为主,随测站海拔高度增加,风速偏差转为负偏差,偏差离散程度增大。扎兰屯及喀喇沁赛区在各预报时效内都存在对小于6级实测风预报偏强,而对大于6级实测风预报偏弱的特点,凉城赛区则预报均偏弱,其中扎兰屯赛区对大于6级的实测风预报评分优势明显。进一步分析扎兰屯赛区一次大风天气个例表明,预报风向与观测风向基本吻合,风速变化趋势一致,SNFS可以刻画出局地流场特征,对复杂地形下的风场具有较好的预报能力。
文摘利用2015年大连地区7个主要气象站的地面气温、降水、风向风速和相对湿度观测资料,针对东北区域中尺度数值模式(Weather Research and Forecast,WRF)产品中常规天气要素进行检验分析,了解掌握WRF模式对不同天气要素的预报能力,以期为天气预报业务中WRF模式产品的订正提供参考。结果表明:WRF模式产品的气温预报准确率整体上08时起报的比20时起报的稍好,最低气温预报效果比最高气温稍好,且WRF模式对升温和降温的趋势预报较好,具有一定参考性。WRF模式产品的降水预报准确率相对较高; WRF模式对风向的预报准确率可以达到50%左右,而风速的预报准确率可以达到60%—70%;大雾天气的预报,可以相应参考WRF模式的相对湿度。
文摘A three-dimensional elastic nonhydrostatic mesoscale(β-γ)model with nested-grid is presented.It uses a set of full equations in terrain-following coordinates as its basic dynamic frame,which is solved with a time-splitting algorithm for acoustic and gravity waves.The model physical parameterization includes a K-theory subgrid eddy mixing for cloud and free atmosphere,a bulk planetary boundary layer parameterization,and three types of sofisticated cloud microphysics schemes with double-parameters for hail-bearing clouds,warm clouds and snowing clouds respectively. The model is designed to be used flexibly for simulations of a variety of meso-and small-scale atmospheric processes, and can be improved as a regional and local operational NWP system in future.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2013CB430106)China Meteorological Administration Special Public Welfare Research Fund(GYHY201206005)+1 种基金National Natural Science Foundation of China(41175087)National Fund for Fostering Talents(J1103410)
文摘The heaviest rainfall over 61 yr hit Beijing during 21-22 July 2012.Characterized by great rainfall amount and intensity,wide range,and high impact,this record-breaking heavy rainfall caused dozens of deaths and extensive damage.Despite favorable synoptic conditions,operational forecasts underestimated the precipitation amount and were late at predicting the rainfall start time.To gain a better understanding of the performance of mesoscale models,verification of high-resolution forecasts and analyses from the WRFbased BJ-RUCv2.0 model with a horizontal grid spacing of 3 km is carried out.The results show that water vapor is very rich and a quasi-linear precipitation system produces a rather concentrated rain area.Moreover,model forecasts are first verified statistically using equitable threat score and BIAS score.The BJ-RUCv2.0forecasts under-predict the rainfall with southwestward displacement error and time delay of the extreme precipitation.Further quantitative analysis based on the contiguous rain area method indicates that major errors for total precipitation（〉 5 mm h^（-1）） are due to inaccurate precipitation location and pattern,while forecast errors for heavy rainfall（〉 20 mm h^（-1）） mainly come from precipitation intensity.Finally,the possible causes for the poor model performance are discussed through diagnosing large-scale circulation and physical parameters（water vapor flux and instability conditions） of the BJ-RUCv2.0 model output.
