|Title||An initial evaluation of FY-3A satellite data|
|Publication Type||Technical memorandum|
|Secondary Title||ECMWF Technical Memorandum|
|Authors||Bell, W, Bauer, P, Bormann, N, Peubey, C|
FY-A, launched in May 2008, is the first in a series of seven meteorological satellites due to be launched in the period leading up to 2020 by China's Meteorological Administration. The FY3A pay load includes four instruments of particular interest for NWP: microwave temperature and humidity sounders; a microwave imager; and an infrared sounder. During 2009 data from the calibration-validation phase of the FY-3A mission were introduced into the ECMWF Integrated Forecasting System in order to assess data quality and provide feedback to FY-3A instrument teams. An analysis of first guess departures has shown the data to be of good quality overall. Several issues with instrument performance and ground segment processing have been identified. The most serious of these are: uncertainties in the temperature sounder passbands on-orbit; orbital biases in the infrared instrument affecting the highest peaking channels; and scan biases in the microwave humidity sounder. Variational bias correction partially corrects for these errors but more work remains to be done to correct the problems before operational implementation. In observing system experiments the FY-3A instruments, both individually and as a package, show considerable skill when added to observation depleted control experiments. When added to a full observing system the impacts are neutral to slightly positive, as expected. These initial results are encouraging and build confidence that the following series of FY-3 instruments will be widely used in NWP data assimilation systems. Preparations are under way to assess data from the next satellite in the series: FY-3B, due to be launched later in 2010.