Global atmospheric observing systems, such as those on Polar-orbiting Operational Environmental Satellites (POES), provide the basic data for Numerical Weather Prediction (NWP) forecasts and the means to monitor and assess the climate. The National POES System (NPOESS) is scheduled to fly in the 2007-2010 period. For the next 10 years, a considerable amount of effort must take place to define, develop and build the suite of instruments which will comprise the NPOESS. The forecast impact of current instruments can be assessed by Observing System Experiments, in which already existing observations are denied or added to observations from a standard data base. However, the impact of future instruments, such as spaceborne Doppler wind lidar (DWL) wind, must be assessed with experiments using simulated observations. These experiments are known as Observing System Simulation Experiments (OSSEs).
A forecast model run, of one month duration, made by the European Centre for Medium- Range Forecasts at resolution T213 and 31 levels starting on 5 February 1993 was chosen as the first "nature run" to simulate the atmosphere. The representativeness of the nature run was evaluated and found to be suitable to conduct OSSEs.
From the possible future instruments, DWL was selected as the first instrument to be tested by OSSEs. Data impact tests to elucidate the relative importance of wind and mass data for forecast accuracy are being conducted. DWL data, satellite radiance data and other conventional observation was simulated from this nature run for the OSSEs. The impact of simulated DWL data will be tested by the operational NCEP, NASA/DAO and other data assimilation system using simulated data.
* The Principal Investigator
** Corresponding Author Address:
Michiko Masutani
NOAA/NWS/NCEP/EMC, 5200 Auth Road, Camp Springs, MD 20746
michiko.masutani@noaa.gov
(301)763-8000 ext 7582
fax(301)763-8125