Impacts of LEOGEO Atmospheric Motion Vectors on East Asian weather forecasts

A study has been carried out to investigate the impact of the assimilation of Atmospheric Motion Vectors (AMVs) derived from the combination of LEO and GEO images (LEOGEO AMVs) on the accuracy of global model forecasts over East Asia for January 2017. In the cycled analysis and forecast experiments, the assimilation of LEOGEO AMVs shows globally significant benefits in wind analysis over the 50-70 degrees latitude band for all levels in both hemispheres. Even though its spatial coverage is confined to higher latitudes and the observable variable is wind, not mass, the assimilation of LEOGEO AMVs has a positive impact on the synoptic patterns represented by surface pressure weather charts over the East Asian domain. A bootstrapping technique was used for testing the statistical significance of the positive impact of the LEOGEO AMVs. Forecasts for the wind and, as a delayed response, temperature and surface pressure in the experiment assimilating the LEOGEO AMVs were improved compared to those in the control experiment without LEOGEO AMVs with a two-tailed 90% statistical significance.