Sacramento River

Sensitivity of Mountain Hydroclimate Simulations in Variable-Resolution CESM to Microphysics and Horizontal Resolution

American Geophysical Union (AGU) | July 31st, 2018

Serum concentrations of PFASs and exposure-related behaviors in African American and non-Hispanic white women

Journal of Exposure Science & Environmental Epidemiology (Springer) | January 8th, 2019

Per- and polyfluoroalkyl substances (PFASs) are used in a wide range of consumer products for their water- and grease-resistant properties, but few studies have e

Per- and polyfluoroalkyl substances (PFASs) are used in a wide range of consumer products for their water- and grease-resistant properties, but few studies have explored this exposure route. We used multiple regression to investigate associations between six self-reported behaviors hypothesized to influence PFAS exposure and serum concentrations of six PFAS chemicals in 178 middle-aged women enrolled in the Child Health and Development Studies, about half of whom are African American. Blood samples were collected in 2010–2013, and participants were interviewed about behavior in 2015–2016. Results showed that African American women had lower levels of perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS) compared with non-Hispanic white women. In African Americans, but not others, frequent consumption of prepared food in coated cardboard containers was associated with higher levels of four PFASs. Flossing with Oral-B Glide, having stain-resistant carpet or furniture, and living in a city served by a PFAS-contaminated water supply were also associated with higher levels of some PFASs. Product testing using particle-induced γ-ray emission (PIGE) spectroscopy confirmed that Oral-B Glide and competitor flosses contained detectable fluorine. Despite the delay between blood collection and interview, these results strengthen the evidence for exposure to PFASs from food packaging and implicate exposure from polytetrafluoroethylene (PTFE)-based dental floss for the first time.

Sharpening of cold-season storms over the western United States

Nature Portfolio (Springer Nature) | January 19th, 2023

Winter storms are responsible for billion-dollar economic losses in the western United States. Because storm structures are not well resolved by global climate models, it

Winter storms are responsible for billion-dollar economic losses in the western United States. Because storm structures are not well resolved by global climate models, it is not well established how single events and their structures change with warming. Here we use regional storm-resolving simulations to investigate climate change impact on western US winter storms. Under a high-emissions scenario, precipitation volume from the top 20% of winter storms is projected to increase by up to 40% across the region by mid-century. The average increase in precipitation volume (31%) is contributed by 22% from increasing area coverage and 19% from increasing storm intensity, while a robust storm sharpening with larger increase in storm centre precipitation compared with increase in storm area reduces precipitation volume by 10%. Ignoring storm sharpening could result in overestimation of the changes in design storms currently used in infrastructure planning in the region.

Shasta Dam Fish Passage Evaluation – Pilot Implementation Plan – U.S. Bureau of Reclamation

U.S. Bureau of Reclamation (USBR) | September 1st, 2015

Shasta Lake Water Resources Investigation

U.S. Bureau of Reclamation (USBR) | July 1st, 2015

The purpose of this Shasta Lake Water Resources Investigation (SLWRI) Feasibility Report is to document the U.S. Department of Interior (Interior), Bureau of Reclamation

The purpose of this Shasta Lake Water Resources Investigation (SLWRI) Feasibility Report is to document the U.S. Department of Interior (Interior), Bureau of Reclamation (Reclamation) and cooperating agencies’ evaluation of the potential enlargement of Shasta Dam and Reservoir to (1) improve anadromous fish survival in the upper Sacramento River, (2) increase water supply reliability in the Central Valley of California, and (3) address related water resource problems, needs, and opportunities. This Final Feasibility Report presents the results of planning, engineering, environmental, social, economic, and financial studies and potential benefits and effects of alternative plans, and is a companion document to the Final Environmental Impact Statement (EIS), published under separate cover. This Final Feasibility Report, along with the Final EIS, will be used by the U.S. Congress to determine the type and extent of Federal interest in enlarging Shasta Dam and Reservoir. The SLWRI is a feasibility study that was authorized by Congress in 1980 in Public Law 96-375 and is being conducted by Reclamation, in coordination with cooperating agencies, other resource agencies, stakeholders, and the public. The SLWRI is being conducted consistent with the 1983 U.S. Water Resources Council Economic and Environmental Principles and Guidelines for Water and Related Land Resources Implementation Studies (P&G), Reclamation directives and standards, National Environmental Policy Act (NEPA), and other pertinent Federal, State of California (State), and local laws and policies. The SLWRI is one of five surface water storage studies recommended in the July 2000 CALFED Bay-Delta Program (CALFED) Programmatic Environmental Impact Statement/Report (PEIS/R) and August 2000 Programmatic Record of Decision (ROD). Preliminary studies in support of the CALFED PEIS/R considered more than 50 surface water storage sites throughout California and recommended more detailed study of the five sites identified in the CALFED Programmatic ROD. The Final EIS, accompanying this Final Feasibility Report, tiers to the CALFED PEIS/R.

Shifts in the thermal niche of almond under climate change

Climatic Change (Springer) | December 5th, 2017

Delineating geographic shifts in crop cultivation under future climate conditions provides information for land use and water management planning, and insights to meeting

Delineating geographic shifts in crop cultivation under future climate conditions provides information for land use and water management planning, and insights to meeting future demand. A suitability modeling approach was used to map the thermal niche of almond cultivation and phenological development across the Western United States (US) through the mid-21st century. The Central Valley of California remains thermally suitable for almond cultivation through the mid-21st century, and opportunities for expansion appear in the Willamette Valley of western Oregon, which is currently limited by insufficient heat accumulation. Modeled almond phenology shows a compression in reproductive development under future climate. By the mid-21st century, almond phenology in the Central Valley showed ~ 2-week delay in chill accumulation and ~ 1- and ~ 2.5-week advance in the timing of bloom and harvest, respectively. Although other climatic and non-climatic restrictions to almond cultivation may exist, these results highlight opportunities for shifts in the geography of high-value cropping systems, which may influence growers’ long-term land use decisions, and shape regional water and agricultural industry discussions regarding climate change adaptation options.

Sierra Nevada Regional Report - California’s Fourth Climate Change Assessment

California Natural Resources Agency (CNRA) | August 16th, 2018

The Sierra Nevada region is critical to the environment and economy of California. Its places and peoples provide essential natural resources including fresh wate

The Sierra Nevada region is critical to the environment and economy of California. Its places and peoples provide essential natural resources including fresh water, clean power, working lands, and famous wilderness. The region encompasses tremendous geographical, climatological, and ecological diversity that spans majestic mountains to deep desert basins. The climate consists of cool, wet winters and warm, dry summers with large differences due to latitude (e.g., the southern Sierra is snowier than northern Sierra) and topography (e.g., the Westside is wetter than the Eastside). Variability is another notable feature of the climate with the region experiencing some of the largest year-to-year climatic fluctuations in the United States. Herein we summarize our assessment of climate-change vulnerabilities and adaptation actions in the region.

Sierra Valley Subbasin Groundwater Sustainability Plan

Sierra Valley Groundwater Management District | January 18th, 2022

This Groundwater Sustainability Plan (GSP) was developed by the Sierra Valley Groundwater Management District (SVGMD) and Plumas County, the Groundwater Sustainability Ag

This Groundwater Sustainability Plan (GSP) was developed by the Sierra Valley Groundwater Management District (SVGMD) and Plumas County, the Groundwater Sustainability Agencies (GSAs) for the Sierra Valley Groundwater Basin (SV Subbasin). Due to size, this file has been divided into five parts. Part 1, Part 2, Part 3, Part 4, Part 5

Simplified 1-D Hydrodynamic and Salinity Transport Modeling of the Sacramento–San Joaquin Delta: Sea Level Rise and Water Diversion Effects

University of California, Davis (UC Davis) | December 11th, 2013

Simulating and Evaluating Atmospheric River-Induced Precipitation Extremes along the U.S. Pacific Coast: Case Studies from 1980-2017

American Geophysical Union (AGU) | January 29th, 2020

Atmospheric rivers (ARs) are responsible for a majority of extreme precipitation and flood events along the U.S. West Coast. To better understand the present‐day charac

Atmospheric rivers (ARs) are responsible for a majority of extreme precipitation and flood events along the U.S. West Coast. To better understand the present‐day characteristics of AR‐related precipitation extremes, a selection of nine most intense historical AR events during 1980–2017 is simulated using a dynamical downscaling modeling framework based on the Weather Research and Forecasting Model. We find that the chosen framework and Weather Research and Forecasting Model configuration reproduces both large‐scale atmospheric features—including parent synoptic‐scale cyclones—as well as the filamentary corridors of integrated vapor transport associated with the ARs themselves. The accuracy of simulated extreme precipitation maxima, relative to in situ and interpolated gridded observations, improves notably with increasing model resolution, with improvements as large as 40–60% for fine scale (3 km) relative to coarse‐scale (27 km) simulations. A separate set of simulations using smoothed topography suggests that much of these gains stem from the improved representation of complex terrain. Additionally, using the 12 December 1995 storm in Northern California as an example, we demonstrate that only the highest‐resolution simulations resolve important fine‐scale features—such as localized orographically forced vertical motion and powerful near hurricane‐force boundary layer winds. Given the demonstrated ability of a targeted dynamical downscaling framework to capture both local extreme precipitation and key fine‐scale characteristics of the most intense ARs in the historical record, we argue that such a configuration may be highly conducive to understanding AR‐related extremes and associated changes in a warming climate.