Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Tags: Climate and Ecosystem Modeling (X)

762 results (44ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
The South Central U.S. encompasses a wide range of ecosystem types and precipitation patterns. Average annual precipitation is less than 10 inches in northwest New Mexico but can exceed 60 inches further east in Louisiana. Much of the region relies on warm-season convective precipitation – that is, highly localized brief but intense periods of rainfall that are common in the summer. This type of precipitation is a significant driver of climate and ecosystem function in the region, but it is also notoriously difficult to predict since it occurs at such small spatial and temporal scales. While global climate models are helpful for understanding and predicting large-scale precipitation trends, they often do not capture...
Abstract (from http://www.sciencedirect.com/science/article/pii/S1873965215000110): The goal of this study was to assess the importance of the 2007 sea ice retreat for hydrologic conditions on the Alaskan North Slope, and how this may have influenced the outbreak of tundra fires in this region. This study concentrates on two years, 2007 and 1996, with different arctic sea ice conditions and tundra fire activity. The year of 2007 is characterized by a low summer sea ice extent (second lowest) and high tundra fire activity, while 1996 had high sea ice extent, and few tundra fires. Atmospheric lateral boundary forcing from the NCEP/NCAR Reanalysis drove the Weather Research and Forecast (WRF) model, along with varying...
thumbnail
Mean modeled snow-water-equivalent (meters) on February 20, the date of peak basin-integrated mean modeled snow-water-equivalent (meters) for the T4 climate change scenario. Reference period: the period 1989 – 2011 for the Upper Deschutes River Basin domain, for which observed historical meteorology is used for model input. T4 scenario: the observed historical (reference period) meteorology is perturbed by adding +4°C to each daily temperature record in the reference period meteorology, and this data is then used as input to the model.
Future changes in the number of dry days per year can either reinforce or counteract projected increases in daily precipitation intensity as the climate warms. We analyze climate model projected changes in the number of dry days using 28 coupled global climate models from the Coupled Model Intercomparison Project, version 5 (CMIP5). We find that the Mediterranean Sea region, parts of Central and South America, and western Indonesia could experience up to 30 more dry days per year by the end of this century. We illustrate how changes in the number of dry days and the precipitation intensity on precipitating days combine to produce changes in annual precipitation, and show that over much of the subtropics the change...
thumbnail
Estimates of the probability of mortality in whitebark pine from mountain pine beetles as determined from a logistic generalized additive model of the presence of mortality as functions of the number of trees killed last year, the percent whitebark pine in each cell, minimum winter temperature, average fall temperature, average April - Aug temperature, and cummulative current and previous year summer precipitation. Analysis was done at a 1 km grid cell resolution. Data are a list of points in comma separated text format. Point coordinates are the center of each 1 km grid cell.
These data are netcdf files of the projected timing of the onset of thermal stress severe enough (>8 Degree Heating Weeks) to cause coral bleaching 2x per decade and 10x per decade (annual) under emissions scenarios RCP8.5 and RCP4.5. The projected timing (a year between 2006 and 2100) is the data value. Values are only shown for the ~60,000 four-km pixels where coral reefs are known to occur.
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016EF000479/full): Glacier hypsometry provides a first-order approach for assessing a glacier's response to climate forcings. We couple the Randolph Glacier Inventory to a suite of in situ observations and climate model output to examine potential change for the ∼27,000 glaciers in Alaska and northwest Canada through the end of the 21st century. By 2100, based on Representative Concentration Pathways (RCPs) 4.5–8.5 forcings, summer temperatures are predicted to increase between +2.1 and +4.6°C, while solid precipitation (snow) is predicted to decrease by −6 to −11%, despite a +9 to +21% increase in total precipitation. Snow is predicted to undergo a pronounced...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/hyp.10964/abstract): While the effects of land use change in urban areas have been widely examined, the combined effects of climate and land use change on the quality of urban and urbanizing streams have received much less attention. We describe a modelling framework that is applicable to the evaluation of potential changes in urban water quality and associated hydrologic changes in response to ongoing climate and landscape alteration. The grid-based spatially distributed model, Distributed Hydrology Soil Vegetation Model-Water Quality (DHSVM-WQ), is an outgrowth of DHSVM that incorporates modules for assessing hydrology and water quality in urbanized watersheds...
thumbnail
Hawaiʻi is considered a worldwide biodiversity hotspot, with nearly 90 percent of its native plants found nowhere else in the world. However, about half of these native plants are imperiled by threats including human development, non-native species, and climate change. Through this project, scientists modeled the relative vulnerability of over 1,000 native plant species to the effects of climate change. A panel of experts in Hawaiian plant species assisted with the development of the model and verified its results. From the model, researchers were able to develop a vulnerability score for each plant species and identify categories of species with high, medium, and low vulnerability to climate change. This information...
We developed a spatially explicit model that simulated future southern pine beetle (Dendroctonus frontalis, SPB) dynamics and pine forest management for a real landscape over 60 years to inform regional forest management. The SPB has a considerable effect on forest dynamics in the Southeastern United States, especially in loblolly pine (Pinus taeda) stands that are managed for timber production. Regional outbreaks of SPB occur in bursts resulting in elimination of entire stands and major economic loss. These outbreaks are often interspersed with decades of inactivity, making long-term modeling of SPB dynamics challenging. Forest management techniques, including thinning, have proven effective and are often recommended...
thumbnail
The percentage difference between mean modeled snow-water-equivalent (meters) on April 1 for the reference (1989-2011) climate period and mean modeled snow-water-equivalent on April 1 for the T4 climate change scenario. Reference period: the period 1989 – 2011 for the Upper Deschutes River Basin domain, for which observed historical meteorology is used for model input. T4 scenario: the observed historical (reference period) meteorology is perturbed by adding +4°C to each daily temperature record in the reference period meteorology, and this data is then used as input to the model.
The Hawaiian Islands are home to a variety of native species that have been subject to numerous threats including development of habitat for human use, predation by introduced herbivores, and competition with invasive plant species. In addition to these threats global climate change is expected to increase temperature and alter patterns of precipitation in Hawaii. This project models the relative vulnerability of native plant species to the effects of climate change, in order to assist resource managers in effectively allocating limited resources to efficiently preserve and protect current and future habitat for native plants. We modeled vulnerability by creating an expert system – a network model linking biological...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/1752-1688.12304/abstract): The hydrologic response to statistically downscaled general circulation model simulations of daily surface climate and land cover through 2099 was assessed for the Apalachicola-Chattahoochee-Flint River Basin located in the southeastern United States. Projections of climate, urbanization, vegetation, and surface-depression storage capacity were used as inputs to the Precipitation-Runoff Modeling System to simulate projected impacts on hydrologic response. Surface runoff substantially increased when land cover change was applied. However, once the surface depression storage was added to mitigate the land cover change and increases...
Abstract (from http://www.nature.com/articles/srep24441): The 170 National Forests and Grasslands (NFs) in the conterminous United States are public lands that provide important ecosystem services such as clean water and timber supply to the American people. This study investigates the potential impacts of climate change on two key ecosystem functions (i.e., water yield and ecosystem productivity) using the most recent climate projections derived from 20 Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that future climate change may result in a significant reduction in water yield but an increase in ecosystem productivity in NFs. On average, gross ecosystem productivity...
Abstract: P-band interferometric synthetic aperture radar (InSAR) data at 5 m resolution from Kahiltna Glacier, the largest glacier in the Alaska Range, Alaska, USA, show pronounced spatial variation in penetration depth, δ P. We obtained δ P by differencing X- and P-band digital elevation models. δ P varied significantly over the glacier, but it was possible to distinguish representative zones. In the accumulation area, δ P decreased with decreasing elevation from 18±3 m in the percolation zone to 10±4 m in the wet snow zone. In the central portion of the ablation area, a location free of debris and crevasses, we identified a zone of very high δ P (34±4 m) which decreased at lower elevations (23±3 m in bare ice...
thumbnail
These files include historical downscaled estimates of decadal average monthly snow-day fraction ("fs", units = percent probability from 1 – 100) for each month of the decades from 1900-1909 to 2000-2009 at 771 x 771 m spatial resolution. Each file represents a decadal average monthly mean. Version 1.0 was completed in 2015 Version 2.0 was completed in 2018 These snow-day fraction estimates were produced by applying equations relating decadal average monthly temperature to snow-day fraction to downscaled decadal average monthly temperature. Separate equations were used to model the relationship between decadal monthly average temperature and the fraction of wet days with snow for seven geographic regions in the...
This Project Snapshot provides a brief overview of the project "Development of Statistical Methods to Estimate Baseline and Future Low Flow Characteristics of Ungaged Streams in Hawai`i".


map background search result map search result map Establishing Climate Change Vulnerability Rankings for Hawaiian Native Plants Improving Representation of Extreme Precipitation Events in Regional Climate Models Probability of Whitebark Pine Mortality from Mountain Pine Beetle, 1997-2009, Northern Rockies Study Area Modeled snow-water-equivalent, percent difference between historical and projected April 1 values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Modeled snow-water-equivalent, projected seasonal peak values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Modeled snow-water-equivalent, percent difference between historical and projected April 1 values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Modeled snow-water-equivalent, projected seasonal peak values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Establishing Climate Change Vulnerability Rankings for Hawaiian Native Plants Probability of Whitebark Pine Mortality from Mountain Pine Beetle, 1997-2009, Northern Rockies Study Area Improving Representation of Extreme Precipitation Events in Regional Climate Models