Sea Level Rise Temporarily Halted as a Result of Australia Hogging all the Rain

A long-term trend of rising sea levels was brought to a screeching halt between 2010 and 2011 when atmospheric patterns came together in such a way that much of the precipitation they carried was driven over Australia, which the continent thirstily soaked up.

Such is the scenario presented in a new study led by the National Center for Atmospheric Research (NCAR), which goes on to explain that, unlike other continents, Australia is designed to prevent nearly all of its precipitation from running off into the ocean.

"No other continent has this combination of atmospheric set-up and topography," NCAR scientist John Fasullo, the lead author of the study, said in a statement. "Only in Australia could the atmosphere carry such heavy tropical rains to such a large area, only to have those rains fail to make their way to the ocean."

All told, the region received almost one foot of rain more than average across an 18-month period beginning in 2010, which was coupled with a drop in ocean levels by 0.3 inches, more than offseting the annual rise of 0.1 inch that has defined recent decades.

However, now that these patterns have moved back into their original positions, that rain is once again falling over tropical oceans, causing the seas to rise once again, and more so even than in the past as Australia faces a major drought.

The data collected for the study came from a combination of sources, including NASA's Gravity Recovery and Climate Experiment (GRACE) satellites, which make detailed measurements of Earth's gravity field, thereby allowing scientists to monitor changes in continental mass. The Argo global array, which consists of 3,000 free-drifting floats, offered measurements of the salinity and temperature of the upper 6,000 feet of the world's oceans and satellite-based altimeters continuously calibrated against a network of tide gauges made it possible for the scientists to tease out variations, including seasonal variations, from global sea level changes.

Using these, the researchers were able to measure a clear increase in Australia's mass and, to a lesser degree, South America's as both underwent heavy, consistent rains -- a rise that clearly coincided with a decline in sea levels.

"It's a beautiful illustration of how complicated our climate system is," Fasullo said. "The smallest continent in the world can affect sea level worldwide. Its influence is so strong that it can temporarily overcome the background trend of rising sea levels that we see with climate change."