An investigation of the quasi 3-D atmospheric loading response on gravity-Implementation and evaluation

A computational system of air loading effects on surface gravity is established by using a quasi three-dimensional (3-D) air distribution model based on the loading theory of an elastic earth. It uses the components of dry air and the temperature lapse rate related to the vertical profile of standard atmosphere under hydrostatic equilibrium. The effects and the admittance are evaluated using the gridded data from assimilated observations of pressure and temperature on earth's surface. Comparison with the results obtained from tidal analyses of superconducting gravimeters (SG) data of the Global Geodynamics Project, it is found that these admittances from the quasi 3-D modeling models are in good agreement with the SG observations. Numerical experiments indicate that the noise due to air loading in gravity measurements can be removed more quickly by using the quasi 3-D method instead of the full 3-D method. It has shown that the quasi 3-D method is more accurate than the standard air model.