Landsat Reveals Vanishing River Ice

February 25, 2020

Landsat Reveals Vanishing River Ice

February 25, 2020

mean river ice extent map — Map showing mean river ice extent in northern hemisphere winter (Dec.–Feb.) and southern hemisphere winter (June–Aug.). Most ice-covered rivers are found in the Northern Hemisphere. Image credit: Joshua Stevens, NASA Earth Observatory, using data from Yang, X., et al. (2020)

A natural-color NASA/USGS Landsat 8 image showing ice breaking up in the Lena River Delta on June 11, 2015. Some of the ponds appear green because they have a layer of melt water over a lower layer of ice. Image credit: Joshua Stevens, NASA Earth Observatory / NASA/USGS Landsat 8

A first-of-its-kind study has used 400,000 NASA/USGS Landsat images collected between 1984 and 2018 to understand global river ice trends. According to the study, published in Nature on Jan. 1, 2020, the extent of wintertime river ice has declined globally over the past three decades, with rivers of the Tibetan Plateau, Alaska, and eastern Europe showing the biggest declines.

Led by researchers at the University of North Carolina–Chapel Hill and Texas A&M University, the study projects six days less of river ice cover for every 1ª C rise in global temperature. Rivers of the Rocky Mountains and northeastern U.S. will experience heavy future ice cover declines (along with rivers of eastern Europe and the Tibetan Plateau).

A NASA/USGS Landsat 8 image from April 30, 2019 showing ice cover on the Yukon River approaching its confluence with the Tanana River in Alaska.

More than half of Earth’s rivers are covered with ice seasonally, these rivers drain a third of the planet’s landmass. The later freeze-ups and earlier thaws that global rivers are experiencing, come with ecologic and economic impacts.

For more information, see:

+ River Ice Is Disappearing, Eos

+ Rivers Are Getting Less Icy, NASA Earth Observatory

+ New study estimates the global extent of river ice loss as Earth warms, UNC–Chapel Hill University Communications

Reference:

Yang, Xiao, Tamlin M. Pavelsky, and George H. Allen. 2020. “The past and future of global river ice.” Nature 577 (7788):69-73. doi: 10.1038/s41586-019-1848-1.