|Left: Map of the surface mass balance today (in mm water equivalent per day). |
Right: The average surface mass balance for today’s calendar date over the period 1990-2011.
In the above figure, we show the daily surface mass balance (on the left) and you can see where it has snowed and melted (incl. sublimate) on the ice sheet over the last 24 hours. For comparison, the map to the right shows the average value for the same calendar date over the period 1990-2011. This historical average is based on weather from a somewhat different model and the two are therefore not always strictly comparable.
The surface mass balance is calculated over a year from September 1st to August 31st (the end of the melt season). The figure to the right shows the sum of all the daily changes from September 1st up to today. Next year on September 1st the map will be reset and we start over. This accumulated map illustrates how much the surface mass balance has contributed in each point across the ice sheet.
|Map of the accumulated surface mass balance |
(in mm water equivalent) from September 1st to now.