GFZ provides these data as Associated Product Centre by order of the International Earth Rotation and Reference System Service (IERS). The data is public availably without any warranty of any kind what so ever, either express or implied, including warranties of merchantability. GFZ shall not be liable for incidental, consequential, or special consequences arising out of the use of this data.

PURPOSE
Atmospheric models, oceanic models, hydrological models together do generally not conserve their global mass. Especially most oceanic models keep their own mass constant and do not consider the mass exchange with atmosphere and land. The barystatic sea-level variations introduced here are necessary to obtain global mass conservation. This sea-level variations are not included in the the oceanic contribution NTOL. The sum of NTAL+NTOL+HYDL+SLEL represents the surface deformation of a globally mass conserving model system.

SEA-LEVEL MASS LOADS
Sea-level variations are derived by solving the sea-level equation for the total mass of terrestrial water storage and atmospheric surface pressure. The sea-level variation thus balances the continental and atmospheric mass variations to keep the total mass globally constant. In contrast to a global mean sea-level, solving the sea-level equation includes the effects of loading and self-attraction. Continental mass is taken from the global hydrological model LSDM, atmospheric mass is given by ECMWF.

LOADING CALCULATION / DATA SETS
please go back to the LOADING toplevel directory and have a look at /LOADING/README