In this paper, a new bias estimation method is proposed and applied in a regional ensemble Kalman filter （EnKF） based on the Weather Research and Forecasting （WRF） Model. The method is based on a homogeneous linea...In this paper, a new bias estimation method is proposed and applied in a regional ensemble Kalman filter （EnKF） based on the Weather Research and Forecasting （WRF） Model. The method is based on a homogeneous linear bias model, and the model bias is estimated using statistics at each assimilation cycle, which is different from the state augmentation methods proposed in pre- vious literatures. The new method provides a good estimation for the model bias of some specific variables, such as sea level pres- sure （SLP）. A series of numerical experiments with EnKF are performed to examine the new method under a severe weather condi- tion. Results show the positive effect of the method on the forecasting of circulation pattern and meso-scale systems, and the reduc- tion of analysis errors. The background error covarianee structures of surface variables and the effects of model system bias on EnKF are also studied under the error covariance structures and a new concept ＇correlation scale＇ is introduced. However, the new method needs further evaluation with more cases of assimilation.展开更多
Abstract By improving the extended homogeneous balance method, a general method is suggested to derive a new auto-Bgcklund transformation （BT） for （3-k l）-Dimensional Jimbo-Miwa （JM） equation. The auto-BT obtain...Abstract By improving the extended homogeneous balance method, a general method is suggested to derive a new auto-Bgcklund transformation （BT） for （3-k l）-Dimensional Jimbo-Miwa （JM） equation. The auto-BT obtained by using our method only involves one quadratic homogeneity equation written as a bilinear equation. Based on the auto-BT, two-soliton solution of the （3＋1）-Dimensional JM equation is obtained.展开更多
The problem as to whether the sub-T0 separation and complete regularity are invariant under homeomorphism is answered negatively.And,the problem of multiplicativity of the complete regularity in general L-fuzzy topolo...The problem as to whether the sub-T0 separation and complete regularity are invariant under homeomorphism is answered negatively.And,the problem of multiplicativity of the complete regularity in general L-fuzzy topological spaces is also answered negatively.展开更多
基金supported by the Provincial Science and Technology Development Program of Shandong under Grant No.2008GG10008001Key Technology Integration and Application Program of China Meteorological Administration,under Grant No.CMAGJ2011M32+1 种基金Forecaster Research Program of China Meteorological Administration,under Grant No.CMAYBY2012-031Science and Technology Research Programs of Shandong Provincial Meteorological Bureau,under Grant Nos.2012sdqxz03,2012sdqxz01,2010sdqxz01
文摘In this paper, a new bias estimation method is proposed and applied in a regional ensemble Kalman filter （EnKF） based on the Weather Research and Forecasting （WRF） Model. The method is based on a homogeneous linear bias model, and the model bias is estimated using statistics at each assimilation cycle, which is different from the state augmentation methods proposed in pre- vious literatures. The new method provides a good estimation for the model bias of some specific variables, such as sea level pres- sure （SLP）. A series of numerical experiments with EnKF are performed to examine the new method under a severe weather condi- tion. Results show the positive effect of the method on the forecasting of circulation pattern and meso-scale systems, and the reduc- tion of analysis errors. The background error covarianee structures of surface variables and the effects of model system bias on EnKF are also studied under the error covariance structures and a new concept ＇correlation scale＇ is introduced. However, the new method needs further evaluation with more cases of assimilation.
基金Supported by National Natural Science Foundation of China under Grant No.11071209 the Natural Science Foundation of the Higer Education Institutions of Jiangsu Province under Grant No.10KJB110011
文摘Abstract By improving the extended homogeneous balance method, a general method is suggested to derive a new auto-Bgcklund transformation （BT） for （3-k l）-Dimensional Jimbo-Miwa （JM） equation. The auto-BT obtained by using our method only involves one quadratic homogeneity equation written as a bilinear equation. Based on the auto-BT, two-soliton solution of the （3＋1）-Dimensional JM equation is obtained.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 19701020) the Teaching and Research Award for Outstanding Young Teachers in Higher Education Institutions of MOE, China.
文摘The problem as to whether the sub-T0 separation and complete regularity are invariant under homeomorphism is answered negatively.And,the problem of multiplicativity of the complete regularity in general L-fuzzy topological spaces is also answered negatively.
