|Title||Evaluation and impact of aircraft humidity data in ECMWF's NWP system|
|Publication Type||Technical memorandum|
|Secondary Title||ECMWF Technical Memoranda|
|Authors||Ingleby, B, Isaksen, L, Kral, T|
Assimilation of temperature and wind data from aircraft is very well established, but about 10% of the commercial aircraft reports now include humidity data - mainly over North America so far but with some reports over Europe. This report primarily evaluates the quality and impact of aircraft humidity data on global NWP. Two different systems are available: 1) laser diode measurements, available in some AMDAR (Aircraft Meteorological DAta Relay) reports, mainly from long-haul aircraft), 2) TAMDAR (Tropospheric Airborne Meteorological Data Reporting) capacitive humidity measurements, mainly from short-haul aircraft with more ascent/descent profiles but less data in the upper troposphere.