April 19, 2024

Riding the Atmospheric Rivers: Satellite Evidence of Record Water Gains in California

Consider the states Central Valley region (laid out in yellow, above) as a huge pool: GRACE-FO measurements consist of all the water consisted of in the lakes, rivers, soil, snowpack, and underground aquifers within that region. In between October 2022 and March 2023, storms offered enough water to raise the amount of water within the “swimming pool” by about 20 inches (about 500 millimeters). Thats about twice as much as the typical winter water gain considering that satellite-based water storage measurements started in 2002 with the first GRACE mission.
While surface area water basins are filling, underground shops of fresh water (aquifers) that are tapped for irrigation and other needs could take years to totally charge. “One good winter season of rain and snow wont offset years of extreme dry spell and extensive groundwater usage,” stated Felix Landerer, GRACE-FO task scientist at NASAs Jet Propulsion Laboratory in Southern California. The GRACE-FO team will continue to track how Californias water storage evolves through the summer season after the snowpack melts and water levels in the states rivers, tanks, and lakes begin to decline throughout drier weather.
The line graph shows seasonal modifications in the overall amount of water contained in Californias lakes, rivers, reservoirs, snowpack, and groundwater from 2002 to 2023. (The information space from late 2017 to early 2018 accompanies the decommissioning of the GRACE mission and the launch of its follower, GRACE-FO.) Credit: NASAs Scientific Visualization Studio
The observations were made possible through the unique sensing approach taken by both GRACE missions. As water walk around– in the type of ocean currents, falling rain, moving groundwater, ice, and so on– it modifies the planets mass near the surface, which alters Earths gravitational pull ever so a little. GRACE-FO steps these subtle modifications, allowing researchers to approximate changes in the overall volume of water in a location.
Like its predecessor, the GRACE-FO objective includes 2 identical satellites that fly one behind the other. As the lead satellite flies over a location with higher mass– such as an area with more water than another region– the minor modification in gravity pulls it forward, increasing the distance in between the 2 satellites. Microwave and laser instruments aboard the spacecraft specifically measure the minute distance modifications between the two, exposing information about the overall mass of water that triggered those modifications.
Illustration of GRACE-FO in orbit. Credit: NASA/JPL-Caltech
More About the Mission
JPL handled the GRACE mission and manages the GRACE-FO mission for NASAs Earth Science Division in the Science Mission Directorate in Washington. GRACE-FO is a collaboration between NASA and GFZ.

Thanks to a wet winter season, California saw tremendous gains in the quantity of water in the San Joaquin, Sacramento, and Tulare river basins (laid out in yellow) from October 2022 to March 2023, GRACE-FO information programs. The measurement includes water in lakes, rivers, tanks, snowpack, and groundwater aquifers. Credit: NASAs Scientific Visualization Studio
Early data shows the best net gain of water over the winter in nearly 22 years, but the states groundwater levels still struggle with the effects of years of dry spell.
After years of extreme drought and decreasing groundwater, California just saw its greatest year-over-year water gains in 2 years, according to information from the GRACE-FO (Gravity Recovery and Climate Experiment Follow-On) satellite objective, a partnership in between NASA and the German Research Centre for Geosciences (GFZ). This previous winter seasons treasure trove of atmospheric rivers reduced a few of the water deficit that the state sustained during durations of dry spell over the last 10 years, that included the 3 driest years on record in California.
This animation shows modifications in the total quantity of water within the California region laid out in yellow– including the Sacramento, San Joaquin, and Tulare river basins– from 2002 to 2023. The zero line on the chart represents the typical quantity of water in the region from 2004 to 2010. Credit: NASAs Scientific Visualization Studio

Thanks to a damp winter, California saw tremendous gains in the quantity of water in the San Joaquin, Sacramento, and Tulare river basins (described in yellow) from October 2022 to March 2023, GRACE-FO information shows. In between October 2022 and March 2023, storms offered enough water to raise the quantity of water within the “swimming pool” by about 20 inches (about 500 millimeters). Thats about two times as much as the typical winter water gain because satellite-based water storage measurements began in 2002 with the first GRACE objective.
While surface water basins are filling, underground shops of fresh water (aquifers) that are tapped for irrigation and other requirements could take years to totally recharge. The GRACE-FO group will continue to track how Californias water storage develops through the summer season after the snowpack melts and water levels in the states rivers, reservoirs, and lakes begin to decline during drier weather.