航空气象数据转发(Aircraft Meteorological Data Relay,AMDAR)资料具有采样频度高、探测层次密集等特点,能够有效补充高空资料时空分辨率的不足。利用2020年3月1日至5月31日(春季)国家气象信息中心提供的中国区域AMDAR资料和美国国家...航空气象数据转发(Aircraft Meteorological Data Relay,AMDAR)资料具有采样频度高、探测层次密集等特点,能够有效补充高空资料时空分辨率的不足。利用2020年3月1日至5月31日(春季)国家气象信息中心提供的中国区域AMDAR资料和美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)提供的全球预报模式(Global Forecast System,GFS)资料,对不同高度的AMDAR观测资料进行质量分析和控制,通过两周循环同化对比试验检验同化质量控制后的AMDAR资料对分析场和预报场的影响。结果表明:AMDAR资料风速与GFS资料的均方根误差(Root Mean Square Error,RMSE)呈明显的随高度增加而增大趋势,风速、温度的偏差(Bias)也存在随高度增加而增大趋势。对不同高度的AMDAR资料进行质量控制后,AMDAR与GFS资料的RMSE和Bias都有所改进,且AMDAR资料和GFS资料的差值(Observation Minus Background,OMB)更加符合高斯分布。同化质量控制后的AMDAR资料对风、温度和位势高度分析场有一定的改进作用,并且改进可以影响到12 h甚至24 h预报场。同化质量控制后的AMDAR资料能一定程度上提高降水预报技巧,其中中等量级降水预报改进效果明显。展开更多
Aircraft Meteorological Data Relay(AMDAR)observations have been widely used in numerical weather prediction(NWP)because of its high spatiotemporal resolution.The observational error of AMDAR is influenced by aircraft ...Aircraft Meteorological Data Relay(AMDAR)observations have been widely used in numerical weather prediction(NWP)because of its high spatiotemporal resolution.The observational error of AMDAR is influenced by aircraft flight altitude and atmospheric condition.In this study,the wind speed and altitude dependent observational error of AMDAR is estimated.The statistical results show that the temperature and the observational error in wind speeds slightly decrease as altitude increases,and the observational error in wind speed increases as wind speed increases.Pseudo single AMDAR observation assimilation tests demonstrate that the wind speed and altitude dependent observational error can provide more reasonable analysis increment.Furthermore,to assess the performance of wind speed and altitude dependent observational error on data assimilation and forecasting,two-month 3-hourly cycling data assimilation and forecast experiments based on the Weather Research and Forecasting Model(WRF)and its Data Assimilation system(WRFDA)are performed for the period during 1 September-31 October,2017.The results of the two-month 3-hourly cycling experiments indicate that new observational error improves analysis and forecast of wind field and geo-potential height,and has slight improvements on temperature.The Fractions Skill Score(FSS)of the 6-h accumulated precipitation shows that new wind speed and altitude dependent observational error leads to better precipitation forecast skill than the default observational error in the WRFDA does.展开更多
文摘航空气象数据转发(Aircraft Meteorological Data Relay,AMDAR)资料具有采样频度高、探测层次密集等特点,能够有效补充高空资料时空分辨率的不足。利用2020年3月1日至5月31日(春季)国家气象信息中心提供的中国区域AMDAR资料和美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)提供的全球预报模式(Global Forecast System,GFS)资料,对不同高度的AMDAR观测资料进行质量分析和控制,通过两周循环同化对比试验检验同化质量控制后的AMDAR资料对分析场和预报场的影响。结果表明:AMDAR资料风速与GFS资料的均方根误差(Root Mean Square Error,RMSE)呈明显的随高度增加而增大趋势,风速、温度的偏差(Bias)也存在随高度增加而增大趋势。对不同高度的AMDAR资料进行质量控制后,AMDAR与GFS资料的RMSE和Bias都有所改进,且AMDAR资料和GFS资料的差值(Observation Minus Background,OMB)更加符合高斯分布。同化质量控制后的AMDAR资料对风、温度和位势高度分析场有一定的改进作用,并且改进可以影响到12 h甚至24 h预报场。同化质量控制后的AMDAR资料能一定程度上提高降水预报技巧,其中中等量级降水预报改进效果明显。
基金National Key R&D Program of China(2017YFC1502102,2018YFC1506802)National Natural Science Foundation of China(41675102)。
文摘Aircraft Meteorological Data Relay(AMDAR)observations have been widely used in numerical weather prediction(NWP)because of its high spatiotemporal resolution.The observational error of AMDAR is influenced by aircraft flight altitude and atmospheric condition.In this study,the wind speed and altitude dependent observational error of AMDAR is estimated.The statistical results show that the temperature and the observational error in wind speeds slightly decrease as altitude increases,and the observational error in wind speed increases as wind speed increases.Pseudo single AMDAR observation assimilation tests demonstrate that the wind speed and altitude dependent observational error can provide more reasonable analysis increment.Furthermore,to assess the performance of wind speed and altitude dependent observational error on data assimilation and forecasting,two-month 3-hourly cycling data assimilation and forecast experiments based on the Weather Research and Forecasting Model(WRF)and its Data Assimilation system(WRFDA)are performed for the period during 1 September-31 October,2017.The results of the two-month 3-hourly cycling experiments indicate that new observational error improves analysis and forecast of wind field and geo-potential height,and has slight improvements on temperature.The Fractions Skill Score(FSS)of the 6-h accumulated precipitation shows that new wind speed and altitude dependent observational error leads to better precipitation forecast skill than the default observational error in the WRFDA does.
