Training & Information

Peltier GIA data sets

This page provides 4 files kindly supplied by Prof. Richard Peltier of the University of Toronto. All questions about the data themselves should be addressed to Prof. Peltier's colleague Dr. Rosemarie Drummond rmarie@atmosp.physics.utoronto.ca.

All four files give the present-day rate-of-change of relative sea level as predicted by the GIA models. Two are ascii files which refer to the locations of tide gauges in the PSMSL data set. GIA has been calculated for these using a high-spatial resolution model so as to account for the sharp gradients at the coast. However, for general interest there are also two netcdf files with rate-of-change-of-rsl values on a 1-degree grid.

The ice-model used throughout is ICE-5G v1.2. There are 2 earth models (VM2 and VM4), both with a 90 km lithosphere.

The two ascii files are:

drsl.PSMSL.ICE5G_VM2_L90.txt for VM2
drsl.PSMSL.ICE5G_VM4_L90.txt for VM4

Each shows the coordinates of PSMSL stations followed by 3 rows showing rates-of-change:

(1) a value using the predicted difference in rsl for the last 100yrs
(2) a value using the predicted difference in rsl for the coming 100yrs
(3) a value centred on "now" using the predicted rsl at now +/- 100yrs

Obviously (3) is the average of (1) and (2) and we suggest you use this number. The other 2 can give some idea of how smooth the predicted variation is (but is definitely not to be called an error-bar!)

The two netcdf files are:

dsea.ICE5G_VM2_L90.nc for VM2
dsea.ICE5G_VM4_L90.nc for VM4

REFERENCES

Peltier W.R 1998 Postglacial Variations in the Level of the Sea: Implications for Climate Dynamics and Solid-Earth Geophysics. Reviews of Geophysics 1998. 36(4),603-689.

Peltier W.R 2004 Global Glacial Isostasy and the Surface of the Ice-Age Earth: The ICE-5G(VM2) model and GRACE. Ann. Rev. Earth. Planet. Sci. 2004. 32,111-149.

Peltier W.R 2005 On the Hemispheric Origins of Meltwater Pulse 1A. Quat. Sci. Rev., 24, 1655-1671.

ACCURACY

These predictions were obtained from calculations employing spherical harmonics of order 256.

FORMAT OF NETCDF FILES

Predictions are supplied on a 1-degree lat-lon grid Latitudes 89.5 to -89.5. Longitudes 0. to 359.