Evaluation of Additional Aircraft Data in the Current NCEP GSI System

Aircraft data is a major part of the global observing system that is steadily expanding. New AMDAR data providers are facilitating improved coverage of upper-air observations in regions that have a small density of conventional data, such as Latin America. The assimilation of these added data is intended to improve the model analysis for those regions.

TAMDAR ( Tropospheric Airborne Meteorological Data Report) is another source of aircraft data that was recently reintroduced to the NCEP GSI system. These data are currently monitored, and are likely to provide improved vertical representation over and near smaller airports. The impact of these data is being assessed and evaluated.

Results from experiments with the GSI system are in general agreement, with the impact of added aircraft data being mostly neutral. Case studies are targeted to assess impact in specific regions with lower observational density, where aircraft data are projected to yield a greater positive impact.