Water Cycle is Speeding Up Over Much of the U.S.
Jul 26, 2019 at 3:00pm
Water is everywhere on Earth, and it is a unique molecule that is critical for life. Where, when, and how it moves—the water cycle—is equally critical.
Water falls over Earth’s surface as rain, snow, or ice. From there, it evaporates and returns to the atmosphere; seeps into the ground as soil moisture or groundwater; or runs off into rivers or streams. It continually evaporates from bodies of water, gets transpired from vegetation, sublimes from ice and snow, condenses, and precipitates along these pathways.
In new research, scientists from the U.S. Geological Survey (USGS) showed that there has been an increase in the flow between the various stages of the water cycle over most the U.S. in the past seven decades. The rates of ocean evaporation, terrestrial evapotranspiration, and precipitation have been increasing. In other words, water has been moving more quickly and intensely through the various stages.
“As the planet warms we anticipate that the warmer air, which holds more moisture, will lead to more evaporation and precipitation,” said Tom Huntington, the study’s first author and a research hydrologist at USGS. “If those processes are increasing, it is evidence for an intensifying water cycle. But no one had really shown that trend quantitively.” Until now.