Method to Compute the Vertical Deflection Components

Abstract

To make a more exact mathematical model of the global atmosphere circulation and to improve the weather forecast one needs to take into account the Vertical Deflection Components (VDCs). The required accuracy for these tasks is 1-2′′ now and 0.4-1.0′′ in future. The VDCs were calculated by integration of the free air gravity anomalies (taken from the Internet site of Scripps Institute of Oceanography) on the grid of 2′ × 2′, an integration radius R = 4,000 or 5,000 km. Also the approaches to calculate the far zone contribution are discussed. As the first test the results are compared with the VDCs obtained from the global spherical harmonics expansion of the order of 1,800. For the Mariana trench area, where the variation of W-E component exceeds 50′′, the standard deviation from Wenzel's model is of 2′′. The other region for testing with a more dense grid 1′ × 1′ is the Kane fracture zone; standard deviations are about 0.6′′. © Springer-Verlag Berlin Heidelberg 2010.