Typhoon Rananim （0414） has been simulated by using the non-hydrostatic Advanced Regional Prediction System （ARPS） from Center of Analysis and Prediction of Storms （CAPS）. The prediction of Rananim has generally ...Typhoon Rananim （0414） has been simulated by using the non-hydrostatic Advanced Regional Prediction System （ARPS） from Center of Analysis and Prediction of Storms （CAPS）. The prediction of Rananim has generally been improved with ARPS using the new generation CINRAD Doppler radar data. Numerical experiments with or without using the radar data have shown that model initial fields with the assimilated radar radial velocity data in ARPS can change the wind field at the middle and high levels of the troposphere; fine characteristics of the tropical cyclone （TC） are introduced into the initial wind, the x component of wind speed south of the TC is increased and so is the y component west of it. They lead to improved forecasting of TC tracks for the time after landfall. The field of water vapor mixing ratio, temperature, cloud water mixing ratio and rainwater mixing ratio have also been improved by using radar refiectivity data. The model＇s initial response to the introduction of hydrometeors has been increased. It is shown that horizontal model resolution has a significant impact on intensity forecasts, by greatly improving the forecasting of TC rainfall, and heavy rainstorm of the TC specially, as well as its distribution and variation with time.展开更多
Based on the data at^40°N at different longitudes during different stratospheric sudden warming(SSW)events,the responses of zonal winds in the stratosphere,mesosphere and lower thermosphere to SSWs are studied in...Based on the data at^40°N at different longitudes during different stratospheric sudden warming(SSW)events,the responses of zonal winds in the stratosphere,mesosphere and lower thermosphere to SSWs are studied in this paper.The variations of zonal wind over Langfang,China(39.4°N,116.7°E)by MF radar and the modern era retrospective-analysis for research and applications(MERRA)wind data during 2010 and 2013 SSW and over Fort Collins,USA(41°N,105°W)by lidar and MERRA wind data during 2009 SSW are compared.Results show that the zonal wind at^40°N indeed respond to the SSWs while different specifics are found in different SSW events or at different locations.The zonal wind has significant anomalies during the SSWs.Over Langfang,before the onset of 2010 and 2013 SSW,the zonal wind reverses from eastward to westward below about 60–70 km and accelerates above this region,while westward wind prevails from 30 to 100 km after the onset of2010 SSW,and westward wind prevails in 30–60 and 85–100 km and eastward wind prevails in 60–85 km after the onset of2013 SSW.Over Fort Collins during 2009 SSW,eastward wind reverses to westward in 20–30 km before the onset while westward wind prevails in 20–30 and 60–97 km and eastward wind prevails in 30–60 and in 97–100 km after the onset.Moreover,simulations by the specified dynamics version of the whole atmosphere community climate model(SD-WACCM)are taken to explain different responding specifics of zonal wind to SSW events.It is found that the modulation of planetary wave(PW)plays the main role.Different phases of PWs would lead to the different zonal wind along with longitudes and the different amplitudes and phases in different SSW events can lead to the different zonal wind responses.展开更多
基金Technical Plan Key Project of Zhejiang Province (2006C13025)Key Subsidiary Project for Meteorological Science of Wenzhou (S200601)Technical Plan Key Project of Wenzhou (S2003A011)
文摘Typhoon Rananim （0414） has been simulated by using the non-hydrostatic Advanced Regional Prediction System （ARPS） from Center of Analysis and Prediction of Storms （CAPS）. The prediction of Rananim has generally been improved with ARPS using the new generation CINRAD Doppler radar data. Numerical experiments with or without using the radar data have shown that model initial fields with the assimilated radar radial velocity data in ARPS can change the wind field at the middle and high levels of the troposphere; fine characteristics of the tropical cyclone （TC） are introduced into the initial wind, the x component of wind speed south of the TC is increased and so is the y component west of it. They lead to improved forecasting of TC tracks for the time after landfall. The field of water vapor mixing ratio, temperature, cloud water mixing ratio and rainwater mixing ratio have also been improved by using radar refiectivity data. The model＇s initial response to the introduction of hydrometeors has been increased. It is shown that horizontal model resolution has a significant impact on intensity forecasts, by greatly improving the forecasting of TC rainfall, and heavy rainstorm of the TC specially, as well as its distribution and variation with time.
基金supported by the National Natural Science Foundation of China (Grant No. 41104099)
文摘Based on the data at^40°N at different longitudes during different stratospheric sudden warming(SSW)events,the responses of zonal winds in the stratosphere,mesosphere and lower thermosphere to SSWs are studied in this paper.The variations of zonal wind over Langfang,China(39.4°N,116.7°E)by MF radar and the modern era retrospective-analysis for research and applications(MERRA)wind data during 2010 and 2013 SSW and over Fort Collins,USA(41°N,105°W)by lidar and MERRA wind data during 2009 SSW are compared.Results show that the zonal wind at^40°N indeed respond to the SSWs while different specifics are found in different SSW events or at different locations.The zonal wind has significant anomalies during the SSWs.Over Langfang,before the onset of 2010 and 2013 SSW,the zonal wind reverses from eastward to westward below about 60–70 km and accelerates above this region,while westward wind prevails from 30 to 100 km after the onset of2010 SSW,and westward wind prevails in 30–60 and 85–100 km and eastward wind prevails in 60–85 km after the onset of2013 SSW.Over Fort Collins during 2009 SSW,eastward wind reverses to westward in 20–30 km before the onset while westward wind prevails in 20–30 and 60–97 km and eastward wind prevails in 30–60 and in 97–100 km after the onset.Moreover,simulations by the specified dynamics version of the whole atmosphere community climate model(SD-WACCM)are taken to explain different responding specifics of zonal wind to SSW events.It is found that the modulation of planetary wave(PW)plays the main role.Different phases of PWs would lead to the different zonal wind along with longitudes and the different amplitudes and phases in different SSW events can lead to the different zonal wind responses.
