Proceedings with Extended Abstracts (single PDF file) - Radio ...

THE WIND PROFILER NETWORK OFTHE JAPAN METEOROLOGICAL AGENCYMasahito Ishihara1, Shoichiro Fukao2 and Hiroyuki Hashiguchi21Observations Department, Japan Meteorological Agency, Japan2Radio Science Center for Space and Atmosphere, Kyoto University, JapanE-Mail : ishihara_masahito@met.kishou.go.jp1. INTRODUCTIONThe Japan Meteorological Agency(JMA) established the operational Wind ProfilerNetwork and Data Acquisition System(WINDAS) for the enhancement of capabilityto watch and predict severe weather in Japan.The network consists of thirty-one 1.3GHzwind profilers which are located across Japanand the Control Center at the JMA headquartersin Tokyo. 25 wind profilers started to be inoperation in April 2001 and 6 profilers has beenadded by June 2003.Characteristics and performance of thesystem and effect of the profiler data onnumerical weather prediction of heavy rainfallare presented.2. BACKGROUND AND OBJECTIVESOF WINDASAtmospheric radars originally developedin 1970s for the research of the mesosphere andstratosphere have been extensively applied tooperational use for observations of thetroposphere wind fields since 1990s asdemonstrated by the Wind ProfilerDemonstration Network (NOAA, 1994) andCOST74/76 (Oakley et al, 2000). In Japan,more than ten profilers including the MU(middle and upper atmosphere) radar of KyotoUniversity are being operated for research use.The Meteorological Research Institute (MRI) ofJMA started basic research on wind profilers in1989. Through the research in MRI andevaluation of profilers data on the numericalweather prediction (NWP) models, JMAdecided to install an wind profiler network(Ishihara and Goda, 2000). Considering thecost performance and the allocation conditionof radio frequencies in Japan, 1.3GHz windprofilers were selected for the network.The major aim of WINDAS is to obtain initialwind fields for the operational NWP models. Aspecial role given to WINDAS is to improvethe accuracy of the mesoscale model (MSM)for forecasting severe rainfalls, which oftencause heavy damages due to floods andlandslips in Japan. The horizontal grid size of10km in MSM allows prediction weathersystems organized in meso-beta scale which areresponsible for these events. Although windmeasurements using 1.3GHz wind profilers arerestricted to the middle and lower troposphere,almost all the amount of water vapor isconcentrated in the layers and then streams ofmoist air could be well depicted with theprofiler data. WINDAS and MSM are the twomajor tools in JMA to predict mesoscale severeweather events.The profiler data have been put onto theGlobal Telecommunication System(GTS) forglobal exchange on an operational basis sinceApril 2002 and are also published in CD-ROMfor general usage.3. SYSTEM AND CHARACTERISTICSOF WINDASAs shown in Figure 1, the locations of31 profilers were selected giving the highpriority on observations in the middle andwestern Japan where heavy rain storms occuralmost every year. The intervals of windprofiler sites are ranged from 67 to 262 km and120 km on average over the four main islandsof Japan.352