Snow depth measurements from satellite could be revolutionised by a method used to follow ants beneath

Credit: Pixabay/CC0 Public Domain

When it comes to better understanding the health of our world in the face of a climate crisis, ants may be the unlikely heroes. A team of scientists, including those from NASA, has discovered a way to assess the depth of snow from space using ants that live deep beneath the surface.

Yongxiang Hu, a NASA Langley Research Center scientist who used inspiration from physics and biology to develop a novel snow depth model, is one of the team’s members. If you divide the volume of your colony by its surface area, you get about four times the amount of time an ant spends walking around the colony.

When in a colony, Photons move like ants.

“It occurred to me that light bounces about cloud particles in a random fashion, just like the movement of ants in their nest. It occurred to me at this point, since snow comes from clouds, that the ants idea would perhaps apply to snow as well “Hu went on to explain.

After entering the snow and being scattered by snow particles, an ant returns to its colony, just as a photon of light from the lidar instrument is scattered by the snow particles until it departs the snow and is picked up by ICESat-2’s telescope (Ice, Cloud and land Elevation Satellite-2).

Researchers were able to determine the average distance a photon went in snow using a model simulation identical to that used to predict how far an ant colony may travel. This indicated that the snow depth was nearly half of the average distance that the photon travelled within the snow.

The unbreakable relationship between ice and snow

ICESat-2 was launched in 2018 to measure the thickness of Earth’s ice sheets and sea ice. In the past, determining snow depth required combining lidar and microwave observations, which proved difficult.

Scientists will have a better idea of how the climate issue affects sea ice thickness and glacier thickness over land with this new innovation utilised to quantify how deep the snow layer covers sea ice surfaces and mountains.

“Many regions, such as the western United States and parts of Europe, Africa, and Asia, rely on snowpack for water supplies. For water resource management, snow depth and predicted snow density are critical “Hu made a point of pointing out.

By how much do you think the snowstorm will fall?

As a result of its reflective properties, snow has a vital function to play in regulating climate. Global warming will increase if there is less snow on the ground.

Climate models regularly predict an increase in worldwide rainfall of between 3% and 7%, but projecting how snowfalls may diminish in mid-latitude regions as a result of global warming is significantly more difficult. There are a lot of ways this new method can make an impact here.

It is Hu’s goal that this strong physics-based technique for predicting snow qualities will be progressively adopted by climate scientists from NASA, the University of Arizona, Stevens Institute of Technology, and Ball Aerospace in the future.

When it comes to future snow forecasting and sea ice modelling, Hu is optimistic that this technique will transform the field. “We have already begun developing a new satellite generation just for snow depth,” Hu said.

Further information: Yongxiang Hu et al, Deriving Snow Depth From ICESat-2 Lidar Multiple Scattering Measurements, Frontiers in Remote Sensing (2022). DOI: 10.3389/frsen.2022.855159

Journal information: Frontiers in Remote Sensing

Source: Frontiers