TECO-2006 Geneva, Dec. 3-5, Improvements in the Upper-Air Observation Systems in Japan M. Ishihara, M. Chiba, Y. Izumikawa, N. Kinoshita, and N. Tsukamoto Japan Meteorological Agency WMO Technical Conference on Meteorology and Environmental Instruments and Methods of Observation TECO-2006Geneva December 3-5, 2006

TECO-2006 Geneva, Dec. 3-5, Outline  Background  Operations of wind profilers and Doppler radars  Automatic upper-air observation systems  Experiment on ground-based microwave radiometers for operational use  Operation of GPS-derived IWV Measurement

TECO-2006 Geneva, Dec. 3-5,  Improvement of observations and monitoring Modernization of upper-air observation systems  Improvement of forecasting Non-hydrostatic mesoscale model with 4D-VAR data assimilation  Enhancement of warning issue Decreasing size of warning areas and extension of warning lead-time Strategy of JMA for Severe Weather Events

TECO-2006 Geneva, Dec. 3-5, Mesoscale Wind Profiler Network 31 wind profilers are being operated at 1357MHz-band, and provide winds aloft from near the surface to about 5 km in height every 10 minutes. Wind Profiler Network and Data Acquisition System (WINDAS)

TECO-2006 Geneva, Dec. 3-5, Replacement of conventional radars with Doppler radars  A replacement project from conventional radars to Doppler radars is started in the radar network.  The main purpose of introducing Doppler radars is the assimilation of Doppler velocity data to the numerical weather prediction model, for increasing the accuracy of prediction for mesoscale severe weathers.

TECO-2006 Geneva, Dec. 3-5, Existing conventional radars Doppler radars being installed in , and 2008 Doppler weather radars being operated for aviation weathers Replacement Plan of Weather Radars in JMA

TECO-2006 Geneva, Dec. 3-5, Impact of Doppler Velocity Data to Numerical Weather Forecast  Assimilation of Doppler velocity data to the mesoscale numerical model using the 4D-VAR was started in Verification of 3-hour accumulated rainfall forecasts starting from 1800 UTC on 1 Feb (a) hour forecast without the assimilation of Doppler velocity data, (b) observation, and (c) forecast with the assimilation (Ishikawa and Koizumi, 2006). Circles indicate heavy rainfall areas. Tokyo

TECO-2006 Geneva, Dec. 3-5, Introduction of Automatic Upper-air Observation Systems Manned stations Automatic radiosonde observation systems being started in , and 2007

TECO-2006 Geneva, Dec. 3-5, Automatic Upper-air Observation Systems Station (year of installation)Manufacturer TypeRadiosonde Ground System 47678HACHIJOJIMA (2003)VAISALAAUTOSONDERS92-AGPDigiCORA III MINAMIDAITOJIMA (2005) VAISALAAUTOSONDERS92-AGPDigiCORA III 47918ISHIGAKIJIMA (2006)MEISEIARSRS-01GMRD-01G 47909NAZE (2007)MEISEIARSRS-01GMRD-01G HACHIJOJIMA (2003) MINAMIDAITOJIMA (2005) ISHIGAKIJIMA (2006)

TECO-2006 Geneva, Dec. 3-5, Automatic Radiosonde Observation Systems Being Suitable for Our Operation  The ballon-launching gear of the system was improved after the installation to endure to strong wind and high humidity at  600g balloons with internal parachutes are used at  Some balloons had been tore in the storage room of the system due to surface ozone at An air- filter was installed stop the inflow of ozone from the outside, and then the problem was resolved.  An unmanned hydrogen generator will be used at from 2007.

TECO-2006 Geneva, Dec. 3-5, Experiments of Ground-based Microwave Radiometers for Operational Use JMA starts a project for operational use of ground-based microwave radiometers. Field experiments are being made in some different climate conditions of Japan; in sub- tropics, in summer and winter at the mid-latitudes. Two methods; the built-in algorisms and the 1D- VAR with the mesoscale model, are being tested to retrieve temperature and humidity profiles.

TECO-2006 Geneva, Dec. 3-5, Field Experiments of ground-based Microwave Radiometers in Radiometric TP/WVP-3000 Naha Tsukuba Niigata Morioka Sendai Oct. to Dec., RPG HATPRO June to July, RDX WVP-3000 July to Sep., RPG HATPRO August to Dec., RDX WVP-3000 July to Dec., RDX WVP-3000 April to May and Jan. 2007, RDX WVP-3000 Jan , RPG HATPRO Radiometer Physics GmbH HATPRO

TECO-2006 Geneva, Dec. 3-5, A topic in the field experiment; the radiometer measurements with the rainfall mitigation system, and in this case, temperature and water vapor profiles was obtained in good accuracy even in strong rain as well as in light rain. strong rain light rain

TECO-2006 Geneva, Dec. 3-5, The operational measurement of integrated water vapor (IWV) measurement using the GPS receiver network (GEONET) of the Geophysical Survey Institute (GSI) has been planned. However, the information on the orbits and the clocks of the GPS satellites, which are needed to calculate IWV, are not available in real-time. 5. Operational Measurement of GPS-derived Integrated Water Vapor (IWV)

TECO-2006 Geneva, Dec. 3-5, The meteorological Institute of JMA (MRI) has developed a near-real time processing scheme. Using the ultra-rapid information and the GPS clocks corrected by the accurate clock of an International Global Navigation Satellite System Service (IGS) station. The scheme provides enough accuracy of integrated water vapour (IWV) for assimilation to NWP. JMA is going to make a contract with the Geophysical Survey Institute (GSI) to obtain the GPS network data in real-time probably in Near-real Time Processing of IWV

TECO-2006 Geneva, Dec. 3-5, Near-real Time Processing of IWV Ultra-Rapid Orbit (Predicted half) before 24 hours Ultra-Rapid Orbit (observed half) after hours Rapid Orbit after hours Final Orbit after 2 weeks Accuracy 1) Using the rapid orbit, the error on the most accurate clock in a GPS station of Japan (Usuda) is estimated. The error is extrapolated in the next 24 hours. 2) Using the corrected time of Usuda, errors on the clocks of the GPS satellites are corrected. 3) Using the corrected GPS satellite clocks and the ultra-rapid orbit, IWV is estimated at the each GPS stations. Rapidity (Shoji and Kunii, 2006)

TECO-2006 Geneva, Dec. 3-5, Convection nowcasting using horizontal water vapor flux convergence using GPS integrated water vapour (IWV) and surfade winds from the AWS network (AMeDAS). FLUX CONV (kg m -2 s -1 ) Radar EchoIWV Flux Convergence 05UTC 06UTC

TECO-2006 Geneva, Dec. 3-5, Issues and Future Plans Re-construction of radiosonde observation network using automatic systems including positive and negative targeting,Re-construction of radiosonde observation network using automatic systems including positive and negative targeting, Vertical profiling of water vapor from microwave radiometers, GPS occultation method, wind profilers,Vertical profiling of water vapor from microwave radiometers, GPS occultation method, wind profilers, Upper-air observations over the ocean.Upper-air observations over the ocean.