THE IMPACT OF ADDITIONAL AIRCRAFT DATA ON THE GODDARD EARTH OBSERVINGSYSTEM ANALYSES

The impact of utilizing additional densely spaced aircraft observation s on the Goddard Earth Observing System Data Assimilation System wind analyses is investigated. The additional data, the Global Aircraft Dat a Set (GADS), comes from flight data recordings of 30 British Airways Boeing 747-400 aircraft that are not used in operational analyses. The CADS experiment was created to provide data needed to improve analyse s of strong winds near jet streams. All major operational centers unde restimate such winds. The impact of including the GADS observations in the analyses is investigated using some cases from the 1995 Northern Hemisphere winter. The additional aircraft observations produce a subs tantial impact on the Goddard wind speed analyses in both sparse aircr aft data regions (North Africa, Middle East, South America) and dense aircraft data regions (west Atlantic, east Asia, North America). Examp les of the space and time extent of the impact are presented.