Jiangsu Meteorological Information Center
Jiangsu Meteorological Information Center
Shi G.,Nanjing University of Information Science and Technology |
Sun Z.,The Innovation Group |
Qiu X.,Nanjing University of Information Science and Technology |
Zeng Y.,Jiangsu Climate Center |
And 2 more authors.
Theoretical and Applied Climatology | Year: 2017
This paper evaluates the monthly mean air temperature over complex terrain in China determined using two methods: Australian National University spline and GridMet_Climate_Temperature (grid meteorological and climatic temperature (GMCT)) models. It is found that the macroscopic patterns of the temperature distributions by the two methods are very similar. The comparison of modelled temperatures with observations from 40 verification stations shows that both methods have the same value of total mean absolute bias errors (MABE) of 0.43 °C. Since the observational data used are from meteorological observational stations which are located on horizontal flat and open areas, these evaluation results only represent those on the flat open areas. In order to evaluate the effects of topographical factors on the temperature, a concept of relief amplitude is defined. The temperatures are grouped according to range of the relief amplitudes, and variation of temperature with relief amplitudes is worked out. It is found that the temperature difference between the two models varies significantly with relief amplitudes. The averaged maximum difference can be as large as 12 °C in January when the relief amplitude is greater than 700 m. The reasons for the temperature difference are investigated, and they are due to the effects of topographical slopes and aspects. One model (GMCT) includes these effects while the other does not. The evaluation results demonstrate that it is necessary to include the effects of topographical factors in the model simulation in order to produce realistic temperature distributions in the complex terrain areas. The distributions of temperature on the northern and southern slopes are determined using the GMCT model, and the results show that the temperatures on the southern slopes are clearly greater than those of the northern slopes, especially in winter. These results can be used as a guide for the reasonable and sustainable utilization of heat resources in the mountainous area. © 2017 Springer-Verlag GmbH Austria
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.