New satellite data on Earth’s gravity help scientists to get a clearer idea of what sea level rise will look like.
Accurately assessing sea level rise (SLR) is difficult and complex, but is important in monitoring the global climate. A special kind of satellite – an altimetry satellite – measures the distance form itself to the sea’s surface. New data from altimetry satellites suggest that global SLR was 2.39 mm/year from 2005 to 2011 – much higher than the Argo project’s ocean floats suggest.
Scientists have now compared and combined data from the Argo floats with data from the GRACE satellite mission, which sheds light on changes in earth’s gravity and how mass (including oceans) is being redistributed around the world. Combined, these data show SLR of 2.4 mm/yr over the same period, verifying the altimetry satellite data (and contradicting more conservative IPCC report estimates of these causes). GRACE data also support other observations about accelerated rates of ice sheet and mountain glacier melt. By using data like this to more accurately predict future SLR, we hope to be able to pick up on patterns like this more quickly in the future.
- Science for Environment Policy: Mapping global sea level rise: new gravity data help provide more accurate predictions (pdf)