S1 and S2 Atmospheric Tide Loading Calculator
Based on the Proposed IERS Conventions... (PRELIMINARY UNTIL CONVENTIONS ARE APPROVED)
T. M. van Dam, University of Luxembourg
R. Ray, Space Geodesy Branch, NASA Goddard Space Flight Center
Anyone using this data set directly or products derived from this page is requested to use the following citation:
van Dam, T. and R. Ray, 2010, Updated October 2010. S1 and S2 Atmospheric Tide Loading Effects for Geodetic Applications.
The amplitude and phase of the predicted deformation of the diurnal, S1, and semi-diurnal, S2, tides derived from the Ray and Ponte model , using Farrell's  elastic Green's functions in the center of earth frame (CM) are shown here:
(click on image to enlarge as a downloadable pdf file).
The International Earth Rotation Service (IERS) Directing Board is currently considering the recommendatation that the periodic displacements of the Earth driven by the S1 and S2 atmospheric tidal model of Ray and Ponte  be included in the station motion model.
This web site provides users with two options for computing the 3-dimensional deformations of the earth due to the S1 and S2 atmospheric tides:
- Have us compute the results for any number of sites using a global convolution
- Download gridded 3-D deformations and a fortran program for interpolating the gridded 3-D deformations to any point
Finally, we provide corrections for both the center of mass of the solid Earth system (Earth+load=CM) and the center of the solid Earth (CE).
There is no difference between the results. The user must decide which product suits their applications most appropriately.