Xu D.,Nanjing University of Information Science and Technology |
Min J.,Nanjing University of Information Science and Technology |
Shen F.,Nanjing University of Information Science and Technology |
Ban J.,U.S. National Center for Atmospheric Research |
Chen P.,Jiangsu Meteorological Information Center
Journal of Advances in Modeling Earth Systems | Year: 2016
Chan-hom and Linfa were binary typhoons that occurred in the western North Pacific in 2015. In this study, the impacts of FY-3B satellite Microwave Humidity Sounder (MWHS) radiance observations on the analyses and forecasts of Linfa and Chan-hom are assessed. The regional Weather Research and Forecasting model and its data assimilation (DA) systems, using three-dimensional variational (3DVAR) and Hybrid (ensemble/3DVAR) methods are used. Assimilation of the FY-3B MWHS data using the 3DVAR method slightly improves the descriptive wind and temperature fields. Positive impacts on the specific humidity forecasts, for levels higher than 850 hPa, are also obvious. 3DVAR adjusts the typhoons' initial positions and their dynamic structures favorably, yielding better tracks, intensities, and precipitation forecasts, compared to the experiment run without MWHS data (control). With the Hybrid method, the water vapor information from the MWHS data better improve the analyses through multivariable correlations with the flow-dependent background error. The Hybrid method further improves the track, intensities, and precipitation forecasts. For Typhoon Linfa, with the coexistence of Typhoon Chan-hom, the Hybrid method provides a more descriptive background error covariance matrix, than using 3DVAR. Experiments on multiple binary typhoon cases are also provided to further validate the robustness of the results on the FY-3B satellite MWHS radiance data assimilation. © 2016. The Authors.
Liu D.-Y.,Wuxi Meteorological Observatory of Jiangsu Province |
Wei J.-S.,Observatory of Jiangsu Province |
Yan W.-L.,Observatory of Jiangsu Province |
Lu J.,Jiangsu Meteorological Information Center |
Sun Y.,Observatory of Jiangsu Province
Huanjing Kexue/Environmental Science | Year: 2014
Based on the surface meteorological data of Jiangsu Province during 1980-2012, climatic characteristics and trends of the weather phenomenon of haze were analyzed. The result indicates that during 1980-2012, the haze day increased, and the severe and moderate haze days significantly increased. In the northern and coastal cities, haze days had a significant increase. Haze is often appeared in the fall and winter, and is rare in the summer, it also occurs inland, and is less in the coast. The haze happens more frequently in June since the straw burning during summer harvest time. The haze day was evenly distributed during the 80's, and increased during the 90's over southern and southwestern Jiangsu Province, middle and northern Jiangsu haze days had a growing after 2000, especially after 2010. The continuous, regional, and regional-continuous haze days were in an increasing trend. As the urban built-up area has been expanded each year, industrial emissions, coal consumption, and car ownership increase every year, resulting in regional temperature increase and relative humidity decrease, resulting in urban heat island and dry island effects. Thence the haze formation and maintenance conditions increased, which led to the increasing of haze days, and the continuous, regional and regional-continuous haze days were significantly increased.