Ice caps and glaciers in Greenland and Antarctica shed 150 billion tons of ice annually from 2003 to 2010 according to the world’s first comprehensive satellite study of glacial melt and ocean levels.
Two GRACE – Gravity Recovery and Climate Experiment – satellites traveled around the earth in tandem 16 times a day. The satellites measured changes in the earth’s gravity field caused by changes in the planet’s mass, including ice sheets and oceans.
Data gathered from the satellites shows that the earth’s ocean have risen 0.4 millimeters annually.
James Szabadics
Technical Development and R&D Manager, Plantation Timber Industry
Interesting. The long term trend for sea level rise is 3.2mm/yr so this figure of 0.4mm/yr is well below the long term trend. One could conclude that ice melt may be decellerating if this GRACE figure is accurate?
Patrick Anderson
logged in via Facebook
0.4 mm/yr is the rise in sea level due to the melt water. The other almost 3 mm/yr rise is due to thermal expansion.
James Szabadics
Technical Development and R&D Manager, Plantation Timber Industry
Yes thermal expansion is part of the picture of long term sea level rise but you appear to be making up the contribution level without any evidence there Patrick. Also the article talks about 0.4mm measured sea level rise.
CSIRO say From 1993 to 2003, the thermosteric contribution was estimated to be about 0.79 mm/year, about a quarter of the total GMSL trend of 3.3 mm/year over the same period. See Domingues et al. (2008). Given that OHC was increasing rapidly in the 93 to 3003 period but has levelled off over the GRACE period of observation how much thermal expansion are you really expecting during the GRACE period? Would you expect more than zero thermal expansion if there was zero incrase in heat content?
GRACE has some agreement with Colorado sea level measurements too. Not much sea level rise lately.
http://sealevel.colorado.edu/files/2012_rel1/sl_ns_global.png