Filters: Tags: Water, Coasts and Ice (X)1,178 results (73ms)
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.
Categories: Data; Types: Citation, NetCDF OPeNDAP Service; Tags: Climate change, Coral bleaching, Coral reefs, Global, Marine ecology,
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...
Prioritizing Stream Temperature Data Collection to Meet Stakeholder Needs and Inform Regional Analyses
Changes in stream temperature can have significant impacts on water quality and the health and survival of aquatic fish and wildlife. Water managers, planners, and decision makers are in need of scientific data to help them prepare for and adapt to changes and conserve important resources. Scientists are tasked with ensuring that this data is produced in useful formats and is accessible to these stakeholders. In October 2015, project researchers hosted and facilitated a 1.5 day workshop, “Data Storage, Dissemination and Harvesting”, that brought together over 50 stakeholders from state and federal agencies, tribal governments, universities, and non-profit organizations interested in monitoring stream temperature...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 2015, Alaska, Alaska CASC, CASC, Projects by Region,
Abstract (from http://www.bioone.org/doi/abs/10.2112/JCOASTRES-D-13-00202.1): Traditional long-term (decadal) and large-scale (hundreds of kilometers) shoreline change modeling techniques, known as single transect, or ST, often overfit the data because they calculate shoreline statistics at closely spaced intervals along the shore. To reduce overfitting, recent work has used spatial basis functions such as polynomials, B splines, and principal components. Here, we explore an alternative to such basis functions by using regularization to reduce the dimension of the ST model space. In our regularized-ST method, traditional ST is an end member of a continuous spectrum of models. We use an evidence information criterion...
Categories: Publication; Types: Citation; Tags: B splines, Data Visualization & Tools, Pacific Islands CASC, Science Tools For Managers, Sea-Level Rise and Coasts,
An Assessment of Diurnal and Seasonal Cloud Cover Changes over the Hawaiian Islands Using Terra and Aqua MODIS
Abstract (from http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0088.1): A comprehensive understanding of the spatial, seasonal, and diurnal patterns in cloud cover frequency over the Hawaiian Islands was developed using high-resolution image data from the National Aeronautics and Space Administration’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard the Terra and Aqua satellites. The Terra and Aqua MODIS cloud mask products, which provide the confidence that a given 1-km pixel is unobstructed by cloud, were obtained for the entire MODIS time series (10-plus years) over the main Hawaiian Islands. Monthly statistics were generated from the daily cloud mask data, including mean cloud cover...
Categories: Publication; Types: Citation; Tags: Cloud Cover, Other Water, Pacific Islands CASC, Plants, Remote Sensing,
Project Snapshot: Development of Statistical Methods to Estimate Baseline and Future Low Flow Characteristics of Ungaged Streams in Hawai`i
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".
Project Snapshot: Coral reef resilience to climate change in the Commonwealth of the Northern Mariana Islands
This Project Snapshot provides a brief overview of the project "Coral reef resilience to climate change in the Commonwealth of the Northern Mariana Islands".
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12875/abstract): Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost ecosystems. We synthesized existing methane (CH 4) and carbon dioxide (CO 2) production measurements from anaerobic incubations of boreal and tundra soils from the geographic permafrost region to evaluate large-scale controls of anaerobic CO 2 and CH 4 production and compare the relative importance...
Categories: Publication; Types: Citation; Tags: Alaska CASC, Alaska CASC, Glaciers and Permafrost, Water, Coasts and Ice, anaerobic incubation,
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...
Categories: Publication; Types: Citation; Tags: Alaska CASC, Forests, Glaciers and Permafrost, Landscapes, Sea-Level Rise and Coasts,
This project snapshot provides a brief overview of the project "Hawaiian Seascapes and Their Management Implications".
Historical and Projected Decadal Average Monthly Snowfall Equivalent and the Ratio of Snowfall Equivalent to Precipitation Across Alaska 771m CMIP5/AR5/CRU TS3.1
These files include climatological summaries of downscaled historical and projected decadal average monthly snowfall equivalent ("SWE", in millimeters), the ratio of snowfall equivalent to precipitation, and future change in snowfall for October-March at 771-meter spatial resolution across the state of Alaska. **Derived snow variables and summaries. Data are for summary October to March Alaska climatologies for:** 1) historical and future snowfall equivalent ("SWE"), produced by multiplying snow-day fraction by decadal average monthly precipitation and summing over 6 months from October to March to estimate the total SWE on April 1. 2) historical and future ratio of SWE to precipitation ("SFEtoP"), SFEtoP is the...
A cocktail of land-based sources of pollution threatens coral reef ecosystems, and addressing these has become a key management and policy challenge in the State of Hawaii, other US territories, and globally. In West Maui, Hawai'i, nearly one quarter of all living corals were lost between 1995 and 2008. Onsite disposal systems (OSDS) for sewage leak contaminants into drinking water sources and nearshore waters. In recognition of this risk, the Hawaii State Department of Health (DOH) is prioritizing areas for cesspool upgrades. Independently, we applied a decision analysis process to identify priority areas to address sewage pollution from OSDS in West Maui, with the objective of reducing nearshore coral reef exposure...
Categories: Publication; Types: Citation; Tags: Coral Reefs, Data Visualization & Tools, Pacific Islands CASC, Science Tools For Managers, Water, Coasts and Ice
Effect of Extreme Tidal Events on Future Sea-Level Rise Scenarios for He‘eia Fish Communities undergoing Ahupua‘a Restoration
For the past few years, “king tides,” or the highest tides of the year, have been occurring more frequently and significantly affecting coastal environments across Hawaiʻi. Now, disappearing beaches and waves crashing over roadways are seemingly the “new normal.” In response, the state of Hawaiʻi is implementing adaptation strategies to combat tidal flooding in coastal areas. While flood management strategies are being implemented in urban areas, less is known about how tidal flooding, and associated inundation into surface and groundwater, might influence watershed dynamics and the native animals that depend on estuarine environments where freshwater meets the sea. Efforts for biocultural restoration of ecosystem...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 2021, CASC, Data Visualization & Tools, Data Visualization & Tools, Fish,
Seasonal and spatial variabilities in northern Gulf of Alaska surface water iron concentrations driven by shelf sediment resuspension, glacial meltwater, a Yakutat eddy, and dust
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016GB005493/abstract): Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate depletion began. Sediment resuspension during winter and spring storms generated high “total dissolvable Fe” (TDFe) concentrations of ~1000 nmol kg−1 along the entire continental shelf, which decreased beyond the shelf break. In July, high...
Categories: Publication; Types: Citation; Tags: Glaciers and Permafrost, National CASC, Rivers, Streams and Lakes, Sea-Level Rise and Coasts, Water, Coasts and Ice
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2014GL060199/abstract): While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high-latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater-dominated estuary. We find that 85% of “dissolved” Fe is removed in the low-salinity region of the estuary along with 41% of “total dissolvable” iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater-derived...
Categories: Publication; Types: Citation; Tags: Biogeochemistry, Geochemical cycles, Glaciers and Permafrost, National CASC, Rivers, Streams and Lakes,
Climate Change Simulations Predict Altered Biotic Response in a Thermally Heterogeneous Stream System
Categories: Publication; Tags: Fish, National CASC, Rivers, Streams and Lakes, Water, Coasts and Ice, Wildlife and Plants
Categories: Publication; Types: Citation; Tags: Fish, National CASC, Rivers, Streams and Lakes, Water, Coasts and Ice, Wildlife and Plants
Source code used in support of "A statistical method to predict flow permanence in dryland streams from time series of stream temperature"
This data release is provided in support of Arismendi, I., Dunham, J.B., Heck, M.P., Schultz, L.D., Hockman-Wert, D.P., 2017, A statistical method to predict flow permanence in dryland streams from time series of stream temperature: Water, v. 9, no. 12, p. 946, https://doi.org/10.3390/w9120946. This code release contains all of the source code from the "Hidden Markov Model" sections of the associated manuscript. The source code was written using the R programming language (www.r-project.org, version 3.3.1). Running the code requires knowlege of the R programming language. The code snippet requires the folder location containing the data, and the site being processed, to be updated. The code requires certain R packages,...
Categories: Data; Tags: Drought, Drought, Fire and Extreme Weather, National CASC, Rivers, Streams and Lakes, Water, Coasts and Ice