Customised mean sea surface maps from altimeter data

You can specify the area boundaries you are interested in below. The area plotted by default covers the Indian Ocean Triple Plate Junction.
Presently the Delft mean sea surface model only covers the South Indian Ocean.

(East) Longitude boundaries Latitude boundaries

To have consistent legend ranges from one image to the other, you can (optionally) specify the legend range. If not specified, the plotting program selects the optimal range for each map.

Legend range

You can choose between a number of representations of the mean sea surface. Default is the mean sea surface with respect to a low-order geoid (OSU91A truncated at degree 12). This shows the details in the mean sea surface well since the large slopes have been filtered off. The other options are the mean sea surface with respect to the reference ellipsoid (the "absolute" mean sea surface height), and a gravity anomaly map. The latter shows the fine details in the mean sea surface best.

For comparison you can request a second plot. You can compare the mean sea surface to the OSU91A geoid model and to the MSS93A mean sea surface model. You can either plot both maps and view them in one window, or you can subtract the two grids and view the differences.

The projection button offers the choice between a number of projection types. Conic or polar projection are recommended for area near the poles.

Contours are plotted by default, but this can also be switched off.
Shading, which gives a three-dimensional effect by applying illumination can also be switched off. You can regulate the intensity of the shading by filling in the box: the smaller the number, the higher the intensity. If left open, the shading intensity is chosen by the plotting program.

Shading intensity

Maps can be plotted in two sizes. Small quick look versions (560x420 pixels) and large high resolution maps (1280x1024 pixels). Please check a quick look map first before deciding to make a high-resolution map.

Press the following button when you have edited the form. It may take some time (a few minutes) before your map is ready.

This page is a contribution to the CEO Experimental Network