Recent decreases in snow water storage in western North America

Nature Portfolio (Springer Nature) | May 22nd, 2023

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Ind

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Index (SSI), representing the temporal phase difference between daily precipitation and surface water inputs—sum of rainfall and snowmelt into terrestrial systems—weighted by relative magnitudes. Different from snow water equivalent or snow fraction, the SSI represents the degree to which the snowpack delays the timing and magnitude of surface water inputs relative to precipitation, a fundamental component of how snow water storage influences the hydrologic cycle. In western North America, annual SSI has decreased (p 

Recent strengthening of eastern Pacific ENSO in the last millennium paleorecord

American Association for the Advancement of Science (AAAS) | August 27th, 2026

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of th

The Pacific El Niño–Southern Oscillation (ENSO) generates climate extremes that endanger ecosystems, infrastructure, and human well-being worldwide. The response of this system to climate warming is poorly constrained, due both to data scarcity and uncertainties in climate models. The geochemistry of Galápagos coral skeletons across the past millennium reveals a large recent increase in interannual variability of sea surface temperature in the eastern equatorial Pacific compared to existing paleorecords that exceeds simulated natural variability. This increase parallels rising global temperature and results from stronger El Niño events. Central Pacific coral data also show increased variability, although less distinctly than in the Galápagos. Our results provide long-term context for understanding ENSO variability trends, with troubling implications for climate extremes.

Recent warming of landfalling atmospheric rivers along the west coast of the United States

American Geophysical Union (AGU) | May 30th, 2019

Abstract: Atmospheric rivers (ARs) often generate extreme precipitation, with AR temperature strongly influencing hydrologic impacts by altering the timing and magni

Abstract: Atmospheric rivers (ARs) often generate extreme precipitation, with AR temperature strongly influencing hydrologic impacts by altering the timing and magnitude of runoff. Long‐term changes in AR temperatures therefore have important implications for regional hydroclimate—especially in locations where a shift to more rain‐dominated AR precipitation could affect flood risk and/or water storage in snowpack. In this study, we provide the first climatology of AR temperature across five US West Coast sub‐regions. We then assess trends in landfalling AR temperatures for each sub‐region from 1980 to 2016 using three reanalysis products. We find AR warming at seasonal and monthly scales. Cool‐season warming ranges from 0.69°C to 1.65°C over the study period. We detect monthly‐scale warming of >2°C, with the most widespread warming occurring in November and March. To understand the causes of AR warming, we quantify the density of AR tracks from genesis to landfall, and analyze along‐track AR temperature for each month and landfall region. We investigate three possible influences on AR temperature trends at landfall: along‐track temperatures prior to landfall, background temperatures over the landfall region, and AR temperature over the coastal ocean adjacent to the region of landfall. Generally, AR temperatures at landfall more closely match coastal and background temperature trends than along‐track AR temperature trends. The seasonal asymmetry of the AR warming and the heterogeneity of influences have important implications for regional water storage and flood risk—demonstrating that changes in AR characteristics are complex, and may not be directly inferred from changes in the background climate. Plain Language Summary: Atmospheric river (AR) storms are well known for their ability to accumulate snowpack, provide drought relief, and generate extreme precipitation and flooding along the West Coast of the United States. AR temperature is an important variable for determining the water resource impacts of a given event, such as the ratio of rain to snow delivered by an individual storm. As a result, changes in AR temperature have implications for both water storage and flood risk. We find substantial warming in ARs at both the seasonal and monthly scales, as well as seasonal and regional variations in the amount of warming along the US West Coast. To understand the warming of ARs at the landfall regions, we compare these monthly temperature trends with trends in temperature along the AR tracks, background temperature over the landfall region, and temperature over the coastal ocean adjacent to the landfall region. The most robust warming occurs in November and March, which has important implications for increased regional flood risk and decreased water storage, and motivates further investigation in other AR‐prone regions around the globe.

Recharge net metering (ReNeM) is a novel, cost-effective management strategy to incentivize groundwater recharge

Nature Portfolio (Springer Nature) | October 18th, 2023

Record of Decision Friant-Kern Canal Middle Reach Capacity Correction Project

U.S. Bureau of Reclamation (USBR) | November 4th, 2020

The United States Department of the Interior, Bureau of Reclamation (Reclamation), as the Federal lead agency under the National Environmental Policy Act (NEPA), and Fria

The United States Department of the Interior, Bureau of Reclamation (Reclamation), as the Federal lead agency under the National Environmental Policy Act (NEPA), and Friant Water Authority (FWA) as the State lead agency under the California Environmental Quality Act (CEQA), prepared the Friant-Kern Canal Middle Reach Capacity Correction Project (Project) Environmental Impact Statement/Environmental Impact Report (EIS/EIR) to assess impacts of the Project. The Project is being proposed to restore the capacity of a 33-mile reach of the Friant-Kern Canal (FKC) to its original design and constructed conveyance capacity. Click here for a directory with links to the federal environmental documents for the Friant-Kern Canal Middle Reach Capacity Correction Project.

Reduced Moisture Transport Linked to Drought Propagation Across North America

American Geophysical Union (AGU) | July 24th, 2019

Droughts reduce the availability of water, which affects communities and ecosystems worldwide. Recent studies have shown that droughts may travel up to thousands of kilom

Droughts reduce the availability of water, which affects communities and ecosystems worldwide. Recent studies have shown that droughts may travel up to thousands of kilometers across continents, but it is still unclear what are the reasons behind these observed drought displacements. While there may be several reasons, we study one particular way in which droughts may be able to travel across continents. Our idea is that a drought in one area may decrease evaporation locally, which will reduce water vapor in the air. As the wind blows, it will transport drier air, which may lead to less precipitation downwind. We find links between droughts that take place in different regions across North America, suggesting that droughts may travel in this way, for example, from the U.S. Southwest to the U.S. Midwest. We also show that the lower evaporation that took place over the western United States, likely due to droughts in the region in 2012, increased the severity of the drought in the U.S. Midwest that year. Our study highlights the importance of sustainable land use management and the need for coordination between communities in upwind and downwind regions to reduce drought risks. It may also help improve future drought predictions.

Regional patterns and proximal causes of the recent snowpack decline in the Rocky Mountains, U.S.

American Geophysical Union (AGU) | March 30th, 2013

Climatologies of Rocky Mountain snowpack are shown to be seasonally and regionally complex, with Pacific decadal variability positively reinforcing the anthropogenic warm

Climatologies of Rocky Mountain snowpack are shown to be seasonally and regionally complex, with Pacific decadal variability positively reinforcing the anthropogenic warming trend.

Regional water table (1996) and water-level changes in the Mojave River, Morongo, and Fort Irwin ground-water basins, San Bernardino County

U.S. Geological Survey (USGS) | July 1st, 1997

Regional water table (1998) and ground-water-level changes in the Mojave River and the Morongo ground-water basins, San Bernardino County, California

U.S. Geological Survey (USGS) | July 1st, 2000

Regional Water Table (1998) and Ground-Water-Level Changes in the Mojave River, and the Morongo Ground-Water Basins, San Bernardino County, California

U.S. Geological Survey (USGS) | July 15th, 2000

The Mojave River and the Morongo groundwater basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a ma

The Mojave River and the Morongo groundwater basins are in the southwestern part of the Mojave Desert in southern California. Ground water from these basins supplies a major part of the water requirements for the region. The rapid and continuous population growth in this area has resulted in ever-increasing demands on local ground-water resources. The continuing collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water systems and, consequently, water availability.