Characteristics and performance of the operational wind profiler network of the Japan Meteorological Agency

The Japan Meteorological Agency (JMA) started the operation of a wind profiler network, the WInd profiler Network and Data Acquisition System (WINDAS), in April 2001. The WINDAS is a network consisting of thirty-one 1.3 GHz-band wind profilers, with dense spatial resolution of 130 km on the average over the main islands of Japan. Operated with high data accuracy, under strict data quality control and high data availability, from reliable system operation. Height coverages of wind measurement are 67 km in summer, 3-4 km in winter and 5.3 km on the average through a year. The main purpose of the operation of WINDAS is to provide upper-air wind data to the numerical weather prediction (NWP) of the JMA, particularly to the hydrostatic (till 2004) and non-hydrostatic (from 2004) mesocale numerical model (MSM). The WINDAS data are assimilated into the MSM using a full forecast-analysis system, with 4-dimensional variational method. From statistical analyses and some case studies, it was conformed that the WINDAS data has contributed to improve accuracy of the MSM for mesoscale weather systems, particularly for heavy rainfall events. Being put on GTS, the wind data are distributed to the world in real-time. Although a problem of data contamination from migrating birds had occurred in the first year of the operation of the WINDAS, it was practically solved by developing a removal algorithm.