EGU22-6800, updated on 31 May 2023
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Intensifying hydrologic drought in California

Donald Argus1, Hilary Martens2, Adrian Borsa3, David Wiese1, Ellen Knappe3, Stacy Larochelle4, Mackenzie Anderson5, Athina Peidou1, Ashlesha Khatiwada2, Nicholas Lau3, Alissa White2, Zachary Hoylman2, Matthew Swarr2, Qian Cao5, Ming Pan3, Kristel Chanard6, Jean-Philippe Avouac4, Gardner Payton2, and Felix Landerer1
Donald Argus et al.
  • 1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, NASA
  • 2University of Montana, Missoula
  • 3University of California, San Diego
  • 4California Institute of Technology, Pasadena
  • 5University of California, Los Angeles
  • 6Institut de Physique du Globe de Paris

Drought has struck the southwest U.S. for the fourth time this millennium, reducing freshwater available to agriculture and urban centers.  We are bringing new insight by quantifying change in water in the ground using GPS elastic displacements, GRACE gravity, artificial reservoir levels, and snow models. Precipitation in Water Year 2021 was half of normal; the rise in total water in autumn and winter is 1/3 of the seasonal average (estimated using chiefly GPS); water was parched from the ground in the spring and summer, bringing water in the ground to its historic low (estimated using primarily GRACE).  In the Central Valley, soil moisture plus groundwater each year increases by 11 km3 and is maximum in April.  Only half of groundwater lost during periods of drought is replenished in subsequent years of heavy precipitation.  The Central Valley has lost groundwater at 2 km3/year from 2006 to 2021, with 2/3 of the loss coming from the southern Valley.

How to cite: Argus, D., Martens, H., Borsa, A., Wiese, D., Knappe, E., Larochelle, S., Anderson, M., Peidou, A., Khatiwada, A., Lau, N., White, A., Hoylman, Z., Swarr, M., Cao, Q., Pan, M., Chanard, K., Avouac, J.-P., Payton, G., and Landerer, F.: Intensifying hydrologic drought in California, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6800,, 2022.


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