Changes in the atmospheric pressure loading service

[Leonid Petrov <Leonid.Petrov@xxxxxxxxxxx>]

Dear colleagues,

   There are several changes in the atmospheric pressure loading service:

1) Currently, the atmospheric pressure loading service provides station
   displacements with respect to the center of the solid Earth, while
   the service of the atmospheric contribution to gravity provides atmospheric
   contribution to geopotential of the total Earth: the solid Earth and 
   the atmosphere. In order to eliminate this inconsistency, the new series
   of displacements with respect to the total Earth, the solid Earth and 
   the atmosphere are being computed. The new series will replace existing
   in mid June 2005.

2) The displacements caused by S1, S2 variations of the atmospheric pressure
   with respect to the total Earth has already been computed and are available
   at http://gemini.gsfc.nasa.gov/aplo

   These displacements were computed for both 619 sites and for nodes of the
   1.0x1.0 deg grid. These displacements were computed for both cases when 
   the inverted barometer hypothesis is invoked and when the ocean response
   is considered the same as the land response. 
 
   A small error in re-gridded Ponte-Ray model reported by T. van Dam has
   been fixed.

3) Numerous plots of gridded amplitudes and phases of the S1 and S2 atmospheric
   pressure variations, Up, East and North components of displacements
   caused by loading for both the IB and non-IB cases were posted at the
   atmospheric pressure loading Web page.

Sincerely,
Leonid Petrov
13-MAY-2005 15:12:09