94 Assimilation and Forecast Impact of Combined-Platform Leo/Geo AMVs in the GDAS/GFS

Wednesday, 17 August 2016
Grand Terrace (Monona Terrace Community and Convention Center)
Brett T. Hoover, CIMSS, Madison, WI; and D. Santek and M. M. Madsen

The region from 60-70 degrees latitude in both hemispheres is difficult to sample with atmospheric motion vector (AMV) observations, because neither geostationary (Geo) nor low-earth-orbiting (Leo) satellite platforms can adequately provide imagery on their own to produce AMVs. However, an advanced image compositing technique has been used at CIMSS to combine imagery from Leo and Geo platforms, producing imagery capable of providing AMVs. Imagery from Leo platforms (e.g. NOAA AVHRR, Metop AVHRR, Terra/Aqua MODIS) and Geo platforms (e.g. GOES, Meteosat, Himawari 8) are combined, with deference to the higher-spatial-resolution Leo imagery where it is available, to produce Leo/Geo AMVs capable of sampling the 60-70 degree latitude ‘AMV gap corridor'. These observations are currently assimilated at several operational centers, including the US Navy and the European Centre for Medium Range Weather Forecasts (ECMWF).

Leo/Geo AMVs are being experimentally assimilated into the Global Data Assimilation System (GDAS) and the impact on the Global Forecast System (GFS) forecast is being evaluated. We will report on our latest assimilation and forecast experiments, and how the results compare with earlier experiments in the non-hybrid ensemble/3DVAR GDAS environment, as well as report on plans to bring Leo/Geo AMVs into NCEP operations.

- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner