annual-decadal modifications of the mean sea surface 1993-2008


The Monarch-A annual sea level model is currently available for download at the Technical University of Denmark, DTU Space official website, but will shortly become available at the Monarch-A website as well. The official web address is

Here the MONARCH-A annual model is available as amplitude and phase fields as well as cosine and sine fields (for correct interpolation).  All files are named

The MONARCH-A Annual model is available as model where there is correction made for annual variations in the “weight” of the atmosphere and a model which is uncorrected for the atmosphere via the inverse barometer correction (IB). The IB corrected model has been corrected and the NoIB model is un-corrected. Dependent on the application the correct version of the model should be used. The model is available in 1 degree resolution in two file formats. The .grd ASCII file format and .xyz ASCII file format.

The .grd file format is the GRAVSOFT file format often used by the Geodetic community. The file contain a header and a data block. The header contains info on min latitude, max latitude, min longitude, max longitude, delta latitude and delta longitude. The number of elements in the grid is calculated from: N_lat =(max latitude – min latitude ) / delta latitude + 1N_lon =(max longitude – min longitude ) / delta longitude + 1Subsequent the data are stored starting in upper west corner (max latitude, and min longitude) in a scan line fashion where the first N-lon elements are the first latitude line and so forth for the next latitude line. The .xyz file ASCII format. All fields are also available as a ASCII line file format which can be imported into most commercial programs.  The file contains on each line:                      Station id, latitude, longitude, height, model Normally the station id and height (set constant to 0.0) is not used and only the latitude, longitude and model value is read.

Contact Information
Ole Baltazar Andersen