Only two orbits are in common use for meteorological satellites. Geostationary satellites (GEOs) orbit at about 35 790 km above the equator with the same angular velocity as the earth, so that the satellite remains stationary above a selected meridian. This orbit has the considerable advantage that images can be made frequently, which allows the time evolution of rapidly developing weather phenomena to be observed and studied. Low earth orbiters (LEOs), such as the sunsynchronous NOAA satellites, orbit between about 600 and 1500 km above the surface. They have the advantage that a single instrument can observe the entire earth, but only the poles are observed frequently (once each orbit). Most of the rest of the earth is viewed twice per day.
Neither of these orbits serve the high latitudes well. The geostationary satellites cannot view the poles at all, and the high latitudes are observed poorly due to the slant angle. LEOs observe the high latitudes only two to four times per day, separated by long gaps.
Kidder and Vonder Haar (1990) pointed out that an orbit used by Soviet Molniya satellites for communications purposes acts like a part-time geostationary orbit for the high latitudes. To determine how useful a satellite in Molniya orbit might be for observing the atmosphere and ocean in the high latitudes, the Conference on the Meteorological and Oceanographic Uses of Satellites in Molniya Orbits was held on 3 May 1991, at the University of Alabama in Huntsville. This paper summarizes the conference. A proceedings volume is available from the author.
