1 DEVELOPMENT OF AMV HEIGHT ASSIGNMENT DIRECTLY LINKED TO FEATURE TRACKING AT JMA

The Height Assignment (HA) is one of the most important sources of errors in the operational Atmospheric Motion Vectors (AMVs) extraction schemes. The main difficulty in HA is to estimate the AMV height using individual image pixels that really lead to the feature tracking process. Following recent study which had been conducted by Japan Meteorological Agency (JMA) and EUMETSAT, the Meteorological Satellite Center (MSC) of JMA plans to develop a HA scheme that includes information on the individual-pixel contribution rate to the tracking process by cross-correlation matching. In this study, a new prototype scheme which is based on the weighted mean of IR1 (10.8 micro-meter) pixel radiances by the individual-pixel contribution rate to tracking process is tested. In the research comparing the heights of IR AMVs estimated by the new scheme to the ones obtained by the current JMA’s HA scheme, the application of the new scheme reduces the fast-wind-speed bias in the middle troposphere, which is presently observed in the current JMA’s AMVs.