Arctic Rain On Snow Study (AROSS)

A Knowledge & Data Hub to explore the causes and impacts of Arctic Rain on Snow events

What's New

Rain on Snow (ROS) events occur when rain falls onto an existing snowpack and freezes, forming an ice crust that can have severe consequences to wildlife, infrastructure, and communities. As the Arctic continues warms faster than ever before, it is predicted that ROS events will become more severe and frequent. The Arctic Rain on Snow Study (AROSS) at NSIDC seeks to understand if ROS events are indeed becoming more frequent as well as compile a comprehensive understanding of these extreme weather events and the extent of their impacts on wildlife, ecology, and communities. 

Visit this page to explore new stories, research and data including our interactive ROS events observation map (at the bottom of this page) made in collaboration with the LEO Network.

Reindeer herder in Siberia
A man stands with his reindeer sleigh in Yamal, Siberia, Russia. — Credit: Ganimat Pashazade/Pexels

From vision to journey: Arctic Rain on Snow Study

Spotlight: Helicopters hover over the Norwegian tundra. The pilots, scanning the landscape, find their targets and drop their payload. But this is no military mission; these intrepid aviators are out delivering food to the Arctic region’s starving reindeer herds.  




Ice covered cell tower after ROS event
After a rain-on-snow event this cellular tower turned into an ice-crusted snow tower, disrupting cellular service in western Alaska in 2018. — Credit:

Rainfall in the Arctic will soon be more common than snowfall

New research: More rain than snow will fall in the Arctic and this transition will occur decades earlier than previously predicted, a new study led by the University of Manitoba (UM) and co-authored by scientists at the National Snow and Ice Data Center (NSIDC) reports. 


New AROSS data product available

Inventory of Arctic Rain on Snow Events: Meteorological and Surface Condition

This data set contains surface and upper air data from global atmospheric reanalysis, and passive microwave brightness temperatures for rain on snow events in the Arctic region between 1979 and the present. Data are subsetted temporally to the time period of each event and spatially to the region experiencing the event. The time ranges and spatial extents of these subsets have been chosen to show the development of each event at the synoptic scale.

Rain on snow observations map

This interactive map was produced by the Arctic Rain on Snow Study in partnership with the LEO Network. The interactive web map displays local observations of rain on snow events collected by the LEO Network from 2013 to the present.

Click on the map icons below to browse rain on snow events across the world.