PASADENA, Calif., Feb. 12 (UPI) -- New research suggests sea level rise has been stunted or hidden by the uptake of water by land.
Much of the more abstract and complex branches of science -- astronomy, geology, climatology -- involves working to get theoretical models to play nicely with concrete measurements. That's been a problem for climate scientists who've found a disconnect with the levels of glacier melting and sea level rise.
New data has helped scientists explain the discrepancy. Changes in weather and climate have precipitated an uptake in land-based water storage. At least 20 percent of the water released by melting glaciers is being contained in soils, lakes and underground aquifers.
Large quantities of ocean water are constantly evaporating. That water in the atmosphere forms clouds and eventually returns as rain or snow, much of it over land. The majority of the land-based precipitation eventually makes its way back to the ocean. But not all of it.
Scientists have long understood the nature of the global hydrological cycle, but measuring it on a global scale is quite difficult. That's changing thanks new satellite technologies.
NASA's Gravity Recovery and Climate Experiment uses twin satellites to precisely measure variations in the Earth's gravitational pull. These variations can reveal the shifts in water storage across the planet's surface.
The experiment's latest data allowed scientists to locate the missing glacial water their climate models and polar readings predicted. The new findings were published in the journal Science.
"We always assumed that people's increased reliance on groundwater for irrigation and consumption was resulting in a net transfer of water from the land to the ocean," lead study author J.T. Reager, a researcher with NASA's Jet Propulsion Laboratory, said in a press release. "What we didn't realize until now is that over the past decade, changes in the global water cycle more than offset the losses that occurred from groundwater pumping, causing the land to act like a sponge."
"These new data are vital for understanding variations in sea level change," Reager continued. "The information will be a critical complement to future long-term projections of sea level rise, which depend on melting ice and warming oceans."