'Precipitation, river discharges increase climate change'

Increased precipitation and river discharge in the Arctic Ocean has the potential to speed climate change as it can lower salinity and cause warmer surface temperatures, says a US study.

"As the Earth's climate continues to change, the high-latitude North is becoming even wetter than before," says study author Xiangdong Zhang, scientist at the University of Alaska Fairbanks International Arctic Research Centre (IARC).

"In particular, air moisture, precipitation and river discharge have increased, leading to a stronger water cycle. These recent changes may intensify climate system interactions and further advance climate change," adds Zhang, the journal Nature Climate Change reports.

Zhang and his co-authors — including IARC colleague Igor Polyakov — looked at water cycles in the Ob, Lena and Yenesei river drainages in the Eurasian Arctic during the last six decades, according to an IARC statement.

They found that atmospheric moisture into the areas increased by an average of 2.6% per decade and, consequently, river discharge increased at a rate of nearly 2% per decade. That means the three rivers today are dumping almost 39 cubic miles more fresh water into the Arctic Ocean per year than they did in the 1940s.

Their findings are important because studies have suggested that increased air moisture and precipitation, and the resulting increase in river discharge into the Arctic Ocean, can lower salinity and cause warmer surface temperatures, as well as create weaker water circulation in the Atlantic Ocean.

Those things in turn can affect multiple biological and weather systems, as well as things like sea ice and coastal erosion.