Land surfaces are storing more water slowing sea level rise
New measurements from a NASA satellite have allowed researchers to identify and quantify, for the first time, how climate-driven increases of liquid water storage on land have affected the rate of sea level rise.
A new study by scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, and the University of California, Irvine, shows that while ice sheets and glaciers continue to melt, changes in weather and climate over the past decade have caused Earth's continents to soak up and store an extra 3.2 trillion tons of water in soils, lakes and underground aquifers, temporarily slowing the rate of sea level rise by about 20 percent.
The water gains over land were spread globally, but taken together they equal the volume of Lake Huron, the world's seventh largest lake. The study is published in the Feb. 12 issue of the journal Science.
Each year, a huge amount of water evaporates from the ocean, then falls over land as rain or snow, and returns to the ocean through runoff and river flows. This is known as the global hydrological cycle. Scientists have long known that small changes in Earth's water cycle could lead to large, although temporary, changes in the rate of sea level rise. They did not know how large this effect could be, however, because there were no instruments that could measure these changes on a global scale.
The 2002 launch of NASA's Gravity Recovery and Climate Experiment (GRACE) twin satellites provided the first tool capable of quantifying these trends. By measuring the distance between the two satellites to within the width of a strand of human hair as they orbit the planet, researchers can record changes in Earth's gravitational pull that result from water moving across its surface. Careful analysis of these data, allowed the scientists to measure the change in water storage over land.
Field of wheat image via Shutterstock.
Read more at ScienceDaily.