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Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2015WR018457/full): A comprehensive study of the Gulf of Alaska (GOA) drainage basin was carried out to improve understanding of the coastal freshwater discharge (FWD) and glacier volume loss (GVL). Hydrologic processes during the period 1980–2014 were modeled using a suite of physically based, spatially distributed weather, energy-balance snow/ice melt, soil water balance, and runoff routing models at a high-resolution (1 km horizontal grid; daily time step). Meteorological forcing was provided by the North American Regional Reanalysis (NARR), Modern Era Retrospective Analysis for Research and Applications (MERRA), and Climate Forecast System Reanalysis...
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Permanently frozen ground, known as permafrost, is a critical feature of the Arctic landscape. As temperatures warm, permafrost is thawing, with potentially adverse impacts to infrastructure, communities, and the structure and function of Arctic ecosystems. However, the processes leading to changes in permafrost are not well understood, and there is a need to better understand the vulnerability of permafrost to thaw. Addressing these gaps in information regarding permafrost characteristics and dynamics, and what these changes will mean for human communities and ecosystems, will support management and planning efforts. This project seeks to address these gaps through several mechanisms. First researchers have synthesized...
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Permafrost is a layer of perennially frozen soil that primarily exists in and around the Arctic and Antarctic regions of the world. While a shallow near-surface soil layer (called active layer) thaws during the summer and re-freezes in the winter, the underlying permafrost remains perennially frozen, often underlying buildings, roads, and other infrastructure. As warmer temperatures become more common, thawing of permafrost could have major consequences for Alaska. Where thawing has already occurred, dramatic changes in ecosystems and existing infrastructure are evident. For example, thawing permafrost along the ocean shore and riverbanks in Northern Alaska is causing substantial coastal erosion and is impacting...
Abstract (from ScienceDirect): Ice wedge polygons on the North Slope of Alaska have been forming for many millennia, when the ground thermally contracts in the winter and water fills in the cracks during the snowmelt season. The infiltrated water then freezes and turns into ice. In this paper we investigate temperature dynamics around the ice wedges and surrounding permafrost. A 2-D nonlinear heat equation with phase change is utilized to compute temperature across the ice wedge and surrounding area. Thermal properties of the ground material are estimated by assimilating temperature measurements in the center of ice wedge polygons. The developed finite element model is successfully validated using two analytical...
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The hydrology of the Yukon River Basin has changed over the last several decades as evidenced by a variety of discharge, gravimetric, and geochemical analyses. The Indigenous Observation Network (ION), a community-based project, was initiated by the Yukon River Inter-Tribal Watershed Council and USGS. Capitalizing on existing USGS monitoring and research infrastructure and supplementing USGS collected data, ION investigates changes in surface water geochemistry and active layer dynamics throughout the Yukon River Basin. Over 1600 samples of surface water geochemistry (i.e., major ions, dissolved organic carbon, and 18O and 2H) have been collected at 35 sites throughout the Yukon River and its major tributaries...
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Ongoing climate change is impacting areas of snow and ice in high latitudes and high elevation areas and is thus anticipated to change the frequency and magnitude of snow and ice related hazards. In Alaska, snow avalanches are the deadliest natural hazard, and they affect a large portion of the state, significantly impacting the natural landscape, the built environment, and public safety. As climate warming continues, it is expected that Alaska’s vulnerability to avalanche hazards will also continue to increase. Currently, there is limited public awareness and available information to support adaptation, mitigation and preparedness efforts for these hazards. The goal of this project is to improve understanding...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016WR020033/full): High-resolution regional-scale hydrologic models were used to quantify the response of late 21st century runoff from the Gulf of Alaska (GOA) watershed to changes in regional climate and glacier extent. NCEP Climate Forecast System Reanalysis data were combined with five Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs) for two representative concentration pathway (RCP) scenarios (4.5 and 8.5) to develop meteorological forcing for the period 2070–2099. A hypsographic model was used to estimate future glacier extent given assumed equilibrium line altitude (ELA) increases of 200 and 400 m. GCM predictions show...
This product is an archive of the modeling artifacts used to produce a journal paper (Van Beusekom and Viger, 2016). The abstract for that paper follows. A module to simulate glacier runoff, PRMSglacier, was added to PRMS (Precipitation Runoff Modeling System), a distributed-parameter, physical-process hydrological simulation code. The extension does not require extensive on-glacier measurements or computational expense but still relies on physical principles over empirical relations as much as is feasible while maintaining model usability. PRMSglacier is validated on two basins in Alaska, Wolverine, and Gulkana Glacier basin, which have been studied since 1966 and have a substantial amount of data with which to...
During the summer in the northeast Pacific Ocean, the Alaska Coastal Current sweeps water with temperatures in excess of 12 °C past the mouths of glacierized fjords and bays. The extent to which these warm waters affect the mass balance of Alaskan tidewater glaciers is uncertain. Here we report hydrographic measurements made within Icy Bay, Alaska, and calculate rates of submarine melt at Yahtse Glacier, a tidewater glacier terminating in Icy Bay. We find strongly stratified water properties consistent with estuarine circulation and evidence that warm Gulf of Alaska water reaches the head of 40 km - long Icy Bay, largely unaltered. A 10 - 20 m layer of cold, fresh, glacially-modified water overlies warm, saline...
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Steep, mountainous watersheds, dramatic climate gradients, and tight links between the land and sea are common features of both the Pacific Islands and Southeast Alaska. In these "ridge-to-reef" and “icefield-to-ocean" ecosystems, environmental changes that occur at higher elevations have downstream impacts on the waters below. Today, these two ecosystems are undergoing changes in climate that are significantly impacting the terrestrial, freshwater, and coastal ecosystems that communities rely on for food, water, recreation, and tourism. For example, changing weather patterns are leading to more frequent and severe extreme storms, atmospheric rivers, droughts, and heat waves. Communities in both regions have deep...
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Glaciers are a central component to the hydrology of many areas in Alaska and the Pacific Northwest. Glacier melt plays a crucial role in the movement of nutrients through a landscape and into the ocean, and the flow of water into streams that sustain many species. As air temperatures rise, increased rates of glacier melt may have significant impacts to the hydrology and ecology in these areas. This project aims to broaden our understanding of the role of glaciers in the hydrology of Alaska and Washington state and incorporate this knowledge into two types of models that simulate past and future scenarios of water flow. The project team aims to develop a public web portal to allow users to explore content, access...
Abstract: We measured stream temperature continuously during the 2011 summer run-off season (May through October) in nine watersheds of Southeast Alaska that provide spawning habitat for Pacific salmon. The nine watersheds have glacier coverage ranging from 0% to 63%. Our goal was to determine how air temperature and watershed land cover, particularly glacier coverage, influence stream temperature across the seasonal glacial meltwater hydrograph. Multiple linear regression models identified mean watershed elevation (related to glacier extent) and watershed lake coverage (%) as the strongest landscape controls on mean monthly stream temperature, with the weakest (May) and strongest (July) models explaining 86% and...
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The Gulf of Alaska is one of the most productive marine ecosystems on Earth, supporting salmon fisheries that alone provide large economic benefits to Southeast Alaska. The region also has a vibrant and growing tourism industry. Glaciers are central to many of the area’s natural processes and economic activities, but the rates of glacier loss in Alaska are among the highest on Earth. Glacier loss threatens to significantly change the amount and timing of nutrients delivered by streams to near-shore habitats. Changes in glacier runoff into the ocean may also impact coastal currents that contribute to vibrant nearshore marine ecosystems. Improving our understanding of how ecosystems depend on glaciers and what glacier...
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The Nome Creek Experimental Watershed (NCEW) has been the site of multiple studies focused on understanding hydrology, biogeochemistry, and ecosystem changes related to permafrost thaw and fire in the boreal forest. The boreal forest is the Earth’s largest terrestrial biome, and thus plays a major role in biogeochemical cycling, creation of habitat for wildlife, as well as wilderness and resources for humans. This project specifically investigates tracers experiments designed to provide comparative hydrological and soils investigations in a small, fire impacted, boreal forest watershed with discontinuous permafrost. The dataset includes field collected data on soil moisture, meteorology, stream flow, aquatic biogeochemistry,...
map background search result map search result map Assessing Permafrost Changes and Related Impacts on Alaskan Infrastructure and Communities Ice2O: A Continued Assessment of Icefield-to-Ocean Change in the Pacific Coastal Temperate Rainforest Understanding the Impacts of Glaciers on Streamflow in Alaska and Washington Permafrost Change and Impacts on Infrastructure and Resources in Alaska: A Synthesis of Past Work Nome Creek Boreal, Fire and Permafrost Hydrology investigations Yukon River Basin Indigenous Observation Network Future Changes in Snow Avalanches in Southern Alaska Understanding Ridge-to-Reef and Icefield-to-Ocean Ecosystem Function in a Changing Climate Ice2O: A Continued Assessment of Icefield-to-Ocean Change in the Pacific Coastal Temperate Rainforest Assessing Permafrost Changes and Related Impacts on Alaskan Infrastructure and Communities Future Changes in Snow Avalanches in Southern Alaska Nome Creek Boreal, Fire and Permafrost Hydrology investigations Yukon River Basin Indigenous Observation Network Understanding the Impacts of Glaciers on Streamflow in Alaska and Washington Understanding Ridge-to-Reef and Icefield-to-Ocean Ecosystem Function in a Changing Climate Permafrost Change and Impacts on Infrastructure and Resources in Alaska: A Synthesis of Past Work