High-latitude winds from molniya orbit - a mission concept for NASA's Earth system science pathfinder program

Abstract

The successful application of winds from MODIS in global assimilation and forecast systems has demonstrated that high-latitude wind observations can have a very substantial impact on forecast. The positive impact of these winds generally extends well into the lower latitudes, and the impact tends to be largest when the forecast skill is lowest. Much of the success of the MODIS winds is attributed to the 6.7μ water vapor channel imagery that provides the vast majority of the wind vectors. In this light, it is unfortunate that after the end of the MODIS mission in 2008, high-latitude water vapor imagery will not be available until at least the 2014/2015 timeframe. A meteorological imager launched in a Molniya orbit would be a natural MODIS follow-on mission from a satellite winds perspective. The Molniya orbit is a highly eccentric orbit with a stable high-latitude apogee. Due to the second Kepler law of planetary motion, the satellite spends about two thirds of the time near its apogee where it provides a quasi-geostationary perspective centered over the high latitudes. This will allow us to extend the time-continuous imagery coverage all the way to the pole and will enable the nearreal time (60 minutes or better) dissemination of high-latitude winds and other derived products based on high refresh rate imagery, including one or more water vapor channels.