The fifth Pennsylvania State University and National Center for Atmospheric Research mesoscale model （MM5） is utilized to study the precipitation and wind speed during Typhoon Chanchu （2006）. Five model experiment...The fifth Pennsylvania State University and National Center for Atmospheric Research mesoscale model （MM5） is utilized to study the precipitation and wind speed during Typhoon Chanchu （2006）. Five model experiments with different physical parameterizations and sea surface temperature （SST） distributions are carried out. It is found that the control experiment configured with the Blakadar boundary scheme, Resiner2 moisture, the Betts-Miller cumulus scheme and daily updated SST has the most reasonable precipitation. The MRF boundary scheme tends to simulate a dryer boundary layer and stronger verticM mixing, which can greatly reduce the intensity of tropical cyclone （TC）, resulting in a smaller maximum wind speed but larger range of medium wind speed （25 30 m/s）. Constant SST through the TC cycle provides more energy from ocean surface, which could cause a significant increase in TC＇s intensity, thus resulting in the largest overestimation on rainfall and maximum wind speed. Longitudinally-uniform SST distribution before the rapid intensification could reduce TC＇s intensity and heat fluxes, which can partially compensate for the overestimation of precipitation in the control experiment.展开更多
In this paper,we first briefly review the history of air-sea coupled models,and then introduce the current status and recent advances of regional air-sea coupled models.In particular,we discuss the core technical and ...In this paper,we first briefly review the history of air-sea coupled models,and then introduce the current status and recent advances of regional air-sea coupled models.In particular,we discuss the core technical and scientific issues involved in the development of regional coupled models,including the coupling technique,lateral boundary conditions,the coupling with sea waves(ices),and data assimilation.Furthermore,we introduce the application of regional coupled models in numerical simulation and dynamical downscaling.Finally,we discuss the existing problems and future directions in the development of regional air-sea coupled models.展开更多
To improve the numerical simulation of the severe snow storms occurred in the south of China and the middle/lower reaches of Changjiang River during January of 2008, the observations from the automatic weather station...To improve the numerical simulation of the severe snow storms occurred in the south of China and the middle/lower reaches of Changjiang River during January of 2008, the observations from the automatic weather stations (AWS) over the Qinghai-Xizang Plateau (QXP) and its surrounding areas were assimi-lated into the Weather Research and Forecasts (WRF) model using multi-cycle 3-dimensional varia-tional data assimilation (3DVAR). Due to the large-scale special topography of the QXP and its sur-rounding areas which may reach up to the mid-troposphere, the AWS located at different height on the deep slope of the plateau are different to those located on plains and take a role analogous in some extent to that of radio soundings in obtaining the vertical "profile" information of the atmosphere, and have the advantages in the aspects of sampling frequency, location/height fixing, and synchronization. The information captured by these AWS may carry the early-warning "strong signals" in the upstream sensitive area for the downstream weather systems to the east of the plateau and thus the assimilation of these AWS data is expected to lead to significant improvements on the simulation of the severe weather system occurred in its downstream areas through adjusting the 3-dimensional structures of the atmospheric thermal-dynamics for the initial conditions of the model. This study indicates that the assimilated information of moisture, temperature and pressure carried in the observations of AWS over the Qinghai-Xizang Plateau and its surrounding areas is very important and useful in the forecasting of precipitation in its downstream areas.展开更多
基金jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA19060503,XDA11010304 and XDA13030103)National Natural Science Foundation of China (Grants Nos.41776028,41676016,41376021,and 41521005)+3 种基金the MOST of China (Grant No. 2014CB953904)Science and Technology Program of Guangzhou,China (Grant No.201607020043)supported by Science and Technology Planning Project of Guangdong Province,China (Grant No. 20150217)Funding of China Scholarship Council (Grant No. 201704910146)~~
基金The National Basic Research Program "973" program of China under contract Nos 2011CB403500 and 2011CB403504the Chinese Academy of Sciences under contract No.KZCX2-YW-Y202the National Natural Science Foundation of China under contract No.U0733002
文摘The fifth Pennsylvania State University and National Center for Atmospheric Research mesoscale model （MM5） is utilized to study the precipitation and wind speed during Typhoon Chanchu （2006）. Five model experiments with different physical parameterizations and sea surface temperature （SST） distributions are carried out. It is found that the control experiment configured with the Blakadar boundary scheme, Resiner2 moisture, the Betts-Miller cumulus scheme and daily updated SST has the most reasonable precipitation. The MRF boundary scheme tends to simulate a dryer boundary layer and stronger verticM mixing, which can greatly reduce the intensity of tropical cyclone （TC）, resulting in a smaller maximum wind speed but larger range of medium wind speed （25 30 m/s）. Constant SST through the TC cycle provides more energy from ocean surface, which could cause a significant increase in TC＇s intensity, thus resulting in the largest overestimation on rainfall and maximum wind speed. Longitudinally-uniform SST distribution before the rapid intensification could reduce TC＇s intensity and heat fluxes, which can partially compensate for the overestimation of precipitation in the control experiment.
基金supported by Knowledge Innovation Program of Chinese Academy of Sciences (Grant Nos. KZCX2-EW-208 and KZCX2-YW-Q11-02)the MOST of China (Grant No. 2011CB403504)National Natural Science Foundation of China (Grant No. 41076009)
文摘In this paper,we first briefly review the history of air-sea coupled models,and then introduce the current status and recent advances of regional air-sea coupled models.In particular,we discuss the core technical and scientific issues involved in the development of regional coupled models,including the coupling technique,lateral boundary conditions,the coupling with sea waves(ices),and data assimilation.Furthermore,we introduce the application of regional coupled models in numerical simulation and dynamical downscaling.Finally,we discuss the existing problems and future directions in the development of regional air-sea coupled models.
基金Supported Jointly by National Natural Science Foundation of China (Grant Nos. 90502003 and 40625017)LaSW Project (Grant No. 2008LASWZI04)+1 种基金the Key Project of AMS (Grant No. 2008Z006)the JICA Program and the International Sci-Tech Cooperative Project (Grant No. 2007DFB20210)
文摘To improve the numerical simulation of the severe snow storms occurred in the south of China and the middle/lower reaches of Changjiang River during January of 2008, the observations from the automatic weather stations (AWS) over the Qinghai-Xizang Plateau (QXP) and its surrounding areas were assimi-lated into the Weather Research and Forecasts (WRF) model using multi-cycle 3-dimensional varia-tional data assimilation (3DVAR). Due to the large-scale special topography of the QXP and its sur-rounding areas which may reach up to the mid-troposphere, the AWS located at different height on the deep slope of the plateau are different to those located on plains and take a role analogous in some extent to that of radio soundings in obtaining the vertical "profile" information of the atmosphere, and have the advantages in the aspects of sampling frequency, location/height fixing, and synchronization. The information captured by these AWS may carry the early-warning "strong signals" in the upstream sensitive area for the downstream weather systems to the east of the plateau and thus the assimilation of these AWS data is expected to lead to significant improvements on the simulation of the severe weather system occurred in its downstream areas through adjusting the 3-dimensional structures of the atmospheric thermal-dynamics for the initial conditions of the model. This study indicates that the assimilated information of moisture, temperature and pressure carried in the observations of AWS over the Qinghai-Xizang Plateau and its surrounding areas is very important and useful in the forecasting of precipitation in its downstream areas.
