SWOT Satellite Analyzes Water Depth in Death Valley's Seasonal Lake

SWOT Satellite Analyzes Water Depth in Death Valley's Seasonal Lake
by Clarence Oxford
Los Angeles CA (SPX) Apr 16, 2024
In a surprising development, Death Valley, North America's driest region, has sustained a temporary lake since the end of 2023. Recent studies spearheaded by NASA have leveraged the U.S.-French Surface Water and Ocean Topography (SWOT) satellite, launched in December 2022, to determine the water depths of this transient lake through early 2024.

Researchers reported that during a six-week monitoring period in February and March 2024, the lake's depth fluctuated between approximately 3 feet (1 meter) and less than 1.5 feet (0.5 meters). This interval coincided with a spate of storms in California that delivered unprecedented rainfall levels.

The team employed SWOT's water level data, enhanced by subtracting U.S. Geological Survey topographical measurements from Badwater Basin, to assess the lake, informally named Lake Manly. Variations in water levels were observed every 10 days in alignment with the SWOT's orbital data collections, showing significant changes in depth and area during and after the storms.

Tamlin Pavelsky, NASA's freshwater science lead for SWOT and a hydrologist at the University of North Carolina, Chapel Hill, commented on the significance of these findings. "This is a really cool example of how SWOT can track how unique lake systems work," he explained.

Unique to Death Valley, the lake's temporary and shallow nature allows strong winds to shift the entire water body several miles. Without permanent monitoring equipment in Badwater Basin, SWOT provides critical data for studying these rare aquatic phenomena.

Since its deployment, SWOT has been instrumental in measuring global water heights, offering an unprecedented overview of Earth's oceans, lakes, and rivers. This includes the ability to discern water extents and surface levels, which, when integrated with other data, facilitates detailed assessments of inland water bodies.

The SWOT science team relies on the Ka-band Radar Interferometer (KaRIn) to measure water surface heights. With two antennas placed 33 feet apart, KaRIn's unique configuration allows it to produce detailed radar pulse reflections from water surfaces, enabling precise altitude data that enhance our understanding of hydrological processes from space.

"We've never flown a Ka-band radar like the KaRIn instrument on a satellite before," Pavelsky noted, emphasizing the value of these novel observations for both scientific and engineering communities.