High latitude atmospheric motion vectors from combined geostationary and polar orbiting observations

Deriving atmospheric motion vectors (AMV) from satellite observations has been successfully done for many years from geostationary platform and more recently from polar orbiting platform. The spatial coverage of satellite-derived AMV is generally equatorward of 60° latitude for geostationary satellites and poleward of 70° latitude for the polar satellites. This coverage results in a 10° gap, which has been noted as a problem by numerical weather prediction (NWP) centers. Specifically, the dynamically active polar jet stream can be located in this latitudinal zone and improper model initialization can lead to rapidly growing errors in the forecasts. Therefore, developing novel ways to fill this AMV-void gap is the next logical step toward providing complete wind coverage for the NWP applications. This requires an advanced image compositing technique designed to blend the data from the many polar and geostationary weather satellites. Combination of geostationary polar orbiting observations seen in Antarctic, and more recently Arctic, provide inspiration and an initiation point for this effort. AMV are successfully being calculated and derived from prototype composite observations. While the composites have the strength of observations from both geostationary and polar-orbiting platforms, it is not yet clear how well the AMV will validate as compared to the very limited radiosonde observations and aircraft reports in the latitude band study area, especially in the Southern Hemisphere. While verification and validation activities are currently on going, it is expected to continue this activity through the upcoming 2010-2011 Antarctic field season. This brings rise to the critical importance of aircraft reports (AIREPs) from US Antarctic Program aircraft (e.g. 109th New York Air National Guard LC-130s) and other aircraft that fly missions between the middle latitudes and the Antarctic. Similar needs exist over the Arctic. Observations of winds enroute has the potential to provide a significant set of validating observations needed to determine if the composite AMVs will be on the order of accuracy as its cousin polar orbiting and geostationary wind sets.