what is snowEx?

Snow is a vital source of water for drinking, agriculture, and electrical power in the western United States and other locations around the world.

What is snowex? 

 To know how much water will be available the following spring, water resource managers and hydrologists need to know where snow has fallen, how much there is and how is characteristics change as it melts. Measuring snow water equivalent, or SWE, tells them how much water is contained within the snowpack.

NASA currently has no global satellite mission to track and study SWE. 

SnowEx’s airborne measurements, ground measurements, and computer modeling are paving the way for future development of a global snow satellite mission. Here are some things they will be watching for in the 2020 campaign.

In the air …

Snow is challenging to measure because its characteristics change depending on what terrain it falls on, how deep it is and whether it is melting. 

No one tool or measurement can measure all types of snow all the time, the team said.

“The research gaps in snow remote sensing can be grouped by snow climate classes — tundra snow, snow in forests, snow in maritime areas – and by how snow evolves over time,” said Carrie Vuyovich, a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and SnowEx 2020’s current deputy project scientist. 

Tracking snow-water equivalent (SWE) across the season helps hydrologists and water resource managers know what water will be available when it melts in the spring, as well as plan for possible floods or droughts.

It’s not so much the depth of the snow – that’s the measure most people are probably familiar with,” said Ed Kim, a research scientist at Goddard and SnowEx’s former project scientist. “You know, in the winter, if it snows and you’ve got to shovel your driveway, you want to know how many centimeters of snow you have to shovel. But we’re after the water equivalent: How much water that snow represents and what it means for floods and droughts.”

The SnowEx airborne campaign will fly radar and lidar (light detection and ranging) to measure snow depth, microwave radar and radiometers to measure SWE, optical cameras to photograph the surface, infrared radiometers to measure surface temperature, and hyperspectral imagers to document snow cover and composition.