Skip to main content
Advanced Search

Filters: Tags: {"scheme":"https://www.sciencebase.gov/vocab/category/NCCWSC/DroughtFireandExtremeWeather"} (X) > partyWithName: Southwest CSC (X)

32 results (90ms)   

View Results as: JSON ATOM CSV
thumbnail
Streamflow in the Colorado River is heavily influenced by high-elevation snowpack. Warming temperatures in spring can reduce snow-fed flows, with serious implications for the water supplies that support communities and wildlife. While it is already well-known that precipitation has a significant influence on river flow, recent observations suggest that temperature and the amount of water in soil may also influence streamflow. In the face of a changing climate, it is important that resource managers understand how factors such as changing temperatures and precipitation will affect this vital water source. To address this need, researchers are examining records of streamflow, temperature, soil moisture, and precipitation...
Abstract (from http://www.bioone.org/doi/abs/10.3417/2017006): The Earth system is undergoing rapid, profound anthropogenic change. The primary axes of change include not only the climate system, but also the spread of invasive species, altered biogeochemical and hydrological cycles, modified disturbance regimes, and land degradation and conversion. These factors are influencing the distribution of species and the structure and function of ecosystems worldwide, interacting with climatic stressors that may preclude the persistence of many current species distributions and communities. Ecological disturbances such as wildfires and insect outbreaks can interact with climate variability to precipitate abrupt change...
A new method for automatic detection of atmospheric rivers (ARs) is developed and applied to an atmospheric reanalysis, yielding an extensive catalog of ARs land-falling along the west coast of North America during 1948–2017. This catalog provides a large array of variables that can be used to examine AR cases and their climate-scale variability in exceptional detail. The new record of AR activity, as presented, validated and examined here, provides a perspective on the seasonal cycle and the interannual-interdecadal variability of AR activity affecting the hydroclimate of western North America. Importantly, AR intensity does not exactly follow the climatological pattern of AR frequency. Strong links to hydroclimate...
thumbnail
The distribution and abundance of cheatgrass, an invasive annual grass native to Eurasia, has increased substantially across the Intermountain West, including the Great Basin. Cheatgrass is highly flammable, and as it has expanded, the extent and frequency of fire in the Great Basin has increased by as much as 200%. These changes in fire regimes are associated with loss of the native sagebrush, grasses, and herbaceous flowering plants that provide habitat for many native animals, including Greater Sage-Grouse. Changes in vegetation and fire management have been suggested with the intent of conserving Greater Sage-Grouse. However, the potential responses of other sensitive-status birds to these changes in management...
Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/JHM-D-16-0194.1): This study investigates the spatial and temporal variability of cloudiness across mountain zones in the western United States. Daily average cloud albedo is derived from a 19-yr series (1996–2014) of half-hourly Geostationary Operational Environmental Satellite (GOES) images. During springtime when incident radiation is active in driving snowmelt–runoff processes, the magnitude of daily cloud variations can exceed 50% of long-term averages. Even when aggregated over 3-month periods, cloud albedo varies by ±10% of long-term averages in many locations. Rotated empirical orthogonal functions (REOFs) of daily cloud albedo anomalies over high-elevation...
thumbnail
Forests across the southwestern U.S. are crucial components of recreation and play an important role in state and local economies. Healthy forests also provide needed habitat for many wildlife species and contribute many other important services to our planet. “Hotter droughts” (otherwise normal droughts whose effects on ecosystems are exacerbated by higher temperatures) are an emerging climate change threat to forests with some of their earliest and strongest appearances happening in the Southwest. The Leaf to Landscape project uses California’s unusually hot drought as a potential preview of the future, allowing us to collect information that will help guide forest management in the face of a warming climate....
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2015GL067613/full): This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture...
thumbnail
California’s Central Valley is a nexus for water resources in the state, draining the Sacramento and San Joaquin River watersheds. Urban centers, agricultural operations, and the environment all compete for limited water, and demand is expected to only increase as the population grows and agriculture intensifies. At the same time, the water supply is projected to decrease as temperatures rise, precipitation patterns change, and the frequency of extreme droughts increases. The Central Valley also provides critical wetland habitats to migratory waterbirds, and wetland managers require information on how to best use water resources to support wildlife objectives, particularly during drought. This project seeks to...
thumbnail
In the dry southwestern United States, snowmelt plays a crucial role as a water source for people, vegetation, and wildlife. However, snow droughts significantly lower snow accumulations, disrupting these critical water supplies for local communities and ecosystems. Despite its large influence on land- and water-resource management, snow drought has only recently been properly defined and its historical distribution and effects on key natural resources are essentially unknown. To remedy this serious knowledge gap, project researchers are examining the causes, effects, and forecastability of snow drought to provide needed scientific information and guidance to planners and decision makers. The central goals of...
A new satellite-derived low cloud retrieval reveals rich spatial texture and coherent space-time propagation in summertime California coastal low cloudiness (CLC). Throughout the region, CLC is greatest during May–September but has considerable monthly variability within this summer season. On average, June is cloudiest along the coast of southern California and northern Baja, Mexico, while July is cloudiest along northern California's coast. Over the course of the summer, the core of peak CLC migrates northward along coastal California, reaching its northernmost extent in late July/early August, then recedes while weakening. The timing and movement of the CLC climatological structure is related to the summer evolution...
From http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2809.html, the Correspondence begins: California is currently experiencing a record-setting drought that started in 2012 and recently culminated in the first ever mandatory state-wide water restriction 1. The snowpack conditions in the Sierra Nevada mountains present an ominous sign of the severity of this drought: the 1 April 2015 snow water equivalent (SWE) was at only 5% of its historical average 2. In the Mediterranean climate of California, with 80% of the precipitation occurring during winter months, Sierra Nevada snowpack plays a critical role in replenishing the state's water reservoirs and provides 30% of its water supply 3. As a result,...
Abstract (from http://link.springer.com/article/10.1007%2Fs11069-015-2003-4): In the Sierra Nevada mountains (USA), and geographically similar areas across the globe where human development is expanding, extreme winter storm and flood risks are expected to increase with changing climate, heightening the need for communities to assess risks and better prepare for such events. In this case study, we demonstrate a novel approach to examining extreme winter storm and flood risks. We incorporated high-resolution atmospheric–hydrologic modeling of the ARkStorm extreme winter storm scenario with multiple modes of engagement with practitioners, including a series of facilitated discussions and a tabletop emergency management...
thumbnail
The Salt and Verde river basins in northeastern Arizona are a vital source of fresh water for the greater Phoenix metropolitan area and for two Native American tribes who rely on the basins’ natural resources for their livelihoods. The region depends on winter rain and snow to replenish the river basins’ water supply. Atmospheric rivers – long, narrow channels in the atmosphere that carry water vapor from the Pacific Ocean – supply a substantial portion of this winter precipitation. While atmospheric rivers are critical for maintaining water resources and preventing drought, they occasionally cause extreme storms that lead to flooding. Scientists project that climate change will affect the intensity and frequency...
Abstract (from Wiley): With increasing concerns about the impact of warming temperatures on water resources, more attention is being paid to the relationship between runoff and precipitation, or runoff efficiency. Temperature is a key influence on Colorado River runoff efficiency, and warming temperatures are projected to reduce runoff efficiency. Here, we investigate the nature of runoff efficiency in the upper Colorado River (UCRB) basin over the past 400 years, with a specific focus on major droughts and pluvials, and to contextualize the instrumental period. We first verify the feasibility of reconstructing runoff efficiency from tree‐ring data. The reconstruction is then used to evaluate variability in runoff...
Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/JAMC-D-15-0167.1): Annual precipitation in California is more variable than in any other state and is highly influenced by precipitation in winter months. A primary question among stakeholders is whether low precipitation in certain months is a harbinger of annual drought in California. Historical precipitation data from 1895 to 2013 are investigated to identify leading monthly indicators of annual drought in each of the seven climate divisions (CDs) as well as statewide. For this study, drought conditions are defined as monthly/annual (October–September) precipitation below the 20th/30th percentile, and a leading indicator is defined as a monthly drought...
thumbnail
In 2017, California was experiencing its most severe drought in over a millennia. Low rainfall and record high temperatures resulted in increased tree mortality and complete forest diebacks across the West. Though land managers scrambled to respond, they lacked information needed to make informed decisions. Focusing on California’s central and southern Sierra Nevada Mountains, this project seeks to determine whether a key forest management practice – forest thinning via prescribed fire – can help forests better survive drought. Prescribed fire is commonly used in the western U.S. to remove potential wildfire fuel, such as small trees and shrubs. It is also thought that this act of selectively removing trees helps...
thumbnail
The Colorado River is a crucial water source for millions of people in the Southwest. Warming temperatures, clearly documented in climate records for the Colorado River basin, are having an impact on the amount of annual streamflow yielded from rain and snow. Recent work has revealed that warming temperatures have played an increasingly important role over the past decades, both exacerbating droughts and dampening the effects of wet winters on high stream flows. Understanding and anticipating how warming temperatures will influence future water supply in the Colorado River basin is increasingly important for resource management, particularly in light of recent drought conditions. The overarching goals of this...
thumbnail
In California, the near-shore area where the ocean meets the land is a highly productive yet sensitive region that supports a wealth of wildlife, including several native bird species. These saltmarshes, mudflats, and shallow bays are not only critical for wildlife, but they also provide economic and recreational benefits to local communities. Today, sea-level rise, more frequent and stronger storms, saltwater intrusion, and warming water temperatures are among the threats that are altering these important habitats. Much of the existing research on anticipating the effects of changing conditions on coastal ecosystems relies on global or regional scale data, meaning that the detailed information necessary for local-scale...
thumbnail
Estuaries are located at the interface where rivers meet the sea, creating unique ecosystems with complex physical and biological processes. Coastal wetlands provide essential ecosystem services to people, including flood protection from high tides and storm surges, commercial fisheries, carbon sequestration, improved water quality, and wildlife food and habitat. Coastal wetlands are also home to hundreds of migratory and resident wildlife species including threatened and endangered species of management concern. Wetlands also have the unique ability to increase their elevation relative to sea-level rise, therefore protecting nearby communities from flooding. In California, prolonged drought and extreme storm events...
Abstract (from Springer): Analyses of observed non-Gaussian daily minimum and maximum temperature probability distribution functions (PDFs) in the Southwest US highlight the importance of variance and warm tail length in determining future heat wave probability. Even if no PDF shape change occurs with climate change, locations with shorter warm tails and/or smaller variance will see a greater increase in heat wave probability, defined as exceedances above the historical 95th percentile threshold, than will long tailed/larger variance distributions. Projections from ten downscaled CMIP5 models show important geospatial differences in the amount of warming expected for a location. However, changes in heat wave probability...
map background search result map search result map Examining the Influence of Temperature and Precipitation on Colorado River Water Resources: Reconstructing the Past to Understand the Future Effects of Sea-Level Rise and Extreme Storms on California Coastal Habitats: Part 2 Possible Future Changes to Water Resources in the Salt and Verde River Basins Associated with Atmospheric River Events Relations Among Cheatgrass, Fire, Climate, and Sensitive-Status Birds across the Great Basin The Impact of Drought on Waterbirds and Their Wetland Habitats in California’s Central Valley Can Prescribed Fire Help Forests Survive Drought in the Sierra Nevada Mountains? Leaf to Landscape: Understanding and Mapping the Vulnerability of Forests to Hotter Droughts Learning From Recent Snow Droughts to Improve Forecasting of Water Availability for People and Forests Anticipating Future Impacts of Temperature on Streamflow in the Colorado River Basin Climate Extremes and Ecological Impacts to California Estuaries Leaf to Landscape: Understanding and Mapping the Vulnerability of Forests to Hotter Droughts Possible Future Changes to Water Resources in the Salt and Verde River Basins Associated with Atmospheric River Events The Impact of Drought on Waterbirds and Their Wetland Habitats in California’s Central Valley Can Prescribed Fire Help Forests Survive Drought in the Sierra Nevada Mountains? Examining the Influence of Temperature and Precipitation on Colorado River Water Resources: Reconstructing the Past to Understand the Future Anticipating Future Impacts of Temperature on Streamflow in the Colorado River Basin Climate Extremes and Ecological Impacts to California Estuaries Effects of Sea-Level Rise and Extreme Storms on California Coastal Habitats: Part 2 Relations Among Cheatgrass, Fire, Climate, and Sensitive-Status Birds across the Great Basin Learning From Recent Snow Droughts to Improve Forecasting of Water Availability for People and Forests