Greenland ice sheet well above average in 2018

Rinks Glacier, West Greenland
[image credit: NSIDC]

However this is interpreted, ‘sixth highest on record’ doesn’t quite support the ‘rapid melting’ story so beloved of man-made climate alarm believers. It looks a lot more like natural variability.

It’s time for the Greenland ice sheet’s annual health report, brought to you by scientists from the Danish Meteorological Institute and Polar Portal.

The end of August traditionally marks the end of the melt season for the Greenland ice sheet as it shifts from mostly melting to mostly gaining snow, says ScienceNordic.

As usual, this is the time when the scientists at DMI and our partners in the Polar Portal assess the state of the ice sheet after a year of snowfall and ice melt. Using daily output from a weather forecasting model combined with a model that calculates melt of snow and ice, we calculate the “surface mass budget” (SMB) of the ice sheet.

This budget takes into account the balance between snow that is added to the ice sheet and melting snow and glacier ice that runs off into the ocean.

The ice sheet also loses ice by the breaking off, or “calving”, of icebergs from its edge, but that is not included in this type of budget. As a result, the SMB will always be positive – that is, the ice sheet gains more snow than the ice it loses.

For this year, we calculated a total SMB of 517bn tonnes, which is almost 150bn tonnes above the average for 1981-2010, ranking just behind the 2016-17 season as sixth highest on record.

By contrast, the lowest SMB in the record was 2011-2012 with just 38bn tonnes, which shows how variable SMB can be from one year to another.

Continued here.