Seasonal air and water mass redistribution effects on LAGEOS and Starlette

Abstract

We computed zonal geopotential coefficients from average seasonal variations in global air and water mass distribution. These coefficients are used to predict the seasonal variations of LAGEOS' and Starlette's orbital node, δΩ, and the seasonal δJ3 for Starlette. A comparison of these predictions with the observed values indicates that air pressure and, to a lesser extent, water storage may be responsible for a large portion of the currently unmodeled variation in the earth's gravity field.