根据IASI（Infrared Atmospheric Sounding Interferometer）的资料特征和GRAPES（Global/Regional Assimilation and Prediction System）同化系统的具体情况,建立了适用于业务使用的关于IASI辐射率资料的偏差订正方案,该方案包括扫描...根据IASI（Infrared Atmospheric Sounding Interferometer）的资料特征和GRAPES（Global/Regional Assimilation and Prediction System）同化系统的具体情况,建立了适用于业务使用的关于IASI辐射率资料的偏差订正方案,该方案包括扫描偏差订正和气团偏差订正。统计表明,IASI资料的扫描偏差不像微波资料一样具有明显的纬度依赖性,但在2x2的像元内存在某种特殊的扫描偏差,临边测量相对于星下点的扫描偏差可以用＂扫描角＂作为自变量而消除,而2x2的像元内的偏差只能通过稀疏化来规避;气团偏差主要根据当时的天气条件进行订正,利用模式背景场作为预报因子定量给出天气条件,采用1 000~300 h Pa的厚度、200~50 h Pa的厚度、50~20 h Pa的厚度以及模式地表温度作为预报因子。订正方案的试验结果显示,偏差能够长时间维持在比较低的稳定水平,订正结果显著。展开更多
In this paper, firstly, the bias between observed radiances from the Advanced TIROS-N Operational Vertical Sounder （ATOVS） and those simulated from a model first-guess are corrected. After bias correction, the obser...In this paper, firstly, the bias between observed radiances from the Advanced TIROS-N Operational Vertical Sounder （ATOVS） and those simulated from a model first-guess are corrected. After bias correction, the observed minus calculated （O-B） radiances of most channels were reduced closer to zero, with peak values in each channel shifted towards zero, and the distribution of O-B closer to a Gaussian distribution than without bias correction. Secondly, ATOVS radiance data with and without bias correction are assimilated directly with an Ensemble Kalman Filter （EnKF） data assimilation system, which are then adopted as the initial fields in the forecast model T106L19 to simulate Typhoon Prapiroon （2006） during the period 2-4 August 2006. The prediction results show that the assimilation of ATOVS radiance data with bias correction has a significant and positive impact upon the prediction of the typhoon＇s track and intensity, although the results are not perfect.展开更多
文摘根据IASI（Infrared Atmospheric Sounding Interferometer）的资料特征和GRAPES（Global/Regional Assimilation and Prediction System）同化系统的具体情况,建立了适用于业务使用的关于IASI辐射率资料的偏差订正方案,该方案包括扫描偏差订正和气团偏差订正。统计表明,IASI资料的扫描偏差不像微波资料一样具有明显的纬度依赖性,但在2x2的像元内存在某种特殊的扫描偏差,临边测量相对于星下点的扫描偏差可以用＂扫描角＂作为自变量而消除,而2x2的像元内的偏差只能通过稀疏化来规避;气团偏差主要根据当时的天气条件进行订正,利用模式背景场作为预报因子定量给出天气条件,采用1 000~300 h Pa的厚度、200~50 h Pa的厚度、50~20 h Pa的厚度以及模式地表温度作为预报因子。订正方案的试验结果显示,偏差能够长时间维持在比较低的稳定水平,订正结果显著。
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos KZCX2-YW-202 and KZCX2-YW-Q03-3)the Chinese Special Scientific Research Project for Public Interest (Grant No GYHY200906004)
文摘In this paper, firstly, the bias between observed radiances from the Advanced TIROS-N Operational Vertical Sounder （ATOVS） and those simulated from a model first-guess are corrected. After bias correction, the observed minus calculated （O-B） radiances of most channels were reduced closer to zero, with peak values in each channel shifted towards zero, and the distribution of O-B closer to a Gaussian distribution than without bias correction. Secondly, ATOVS radiance data with and without bias correction are assimilated directly with an Ensemble Kalman Filter （EnKF） data assimilation system, which are then adopted as the initial fields in the forecast model T106L19 to simulate Typhoon Prapiroon （2006） during the period 2-4 August 2006. The prediction results show that the assimilation of ATOVS radiance data with bias correction has a significant and positive impact upon the prediction of the typhoon＇s track and intensity, although the results are not perfect.
