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Arctic grayling (Thymallus arcticus) have a life-history strategy specifically adapted to the extreme climate of the North. These fish migrate to spawning grounds just after breakup in the spring, then migrate to feeding sites in early summer, and finally in the fall migrate back to their overwintering sites. The Kuparuk River is a perennial stream originating in the northern foothills of the Brooks Range on the North Slope of Alaska. Sections of the Kuparuk are periodically intermittent in that, during low flows in the system, these channel reaches appear dry. The flow varies between surface and subsurface in this permafrost-dominated environment, with subsurface flow being limited to the unfrozen thaw bulb around...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Academics & scientific researchers,
Arctic Landscape Conservation Cooperative data.gov,
DISCHARGE/FLOW,
DISCHARGE/FLOW,
FISH,
Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrostand snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fishand Creek drainage basin is composed of three watersheds that represent a gradient of theACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevationmodel, and river gauging and climate records to better understand ACP watershed structureand processes. We show that...
There is a great deal of interest in whether and how Alaska’s precipitation is changing but little agreement in the existing peer-reviewed literature. To provide insight on this question, we have selected three commonly used 0.5° resolution gridded precipitation products that have long-term monthly data coverage (Climatic Research Unit TS3.10.1, Global Precipitation Climatology Centre Full Data Reanalysis version 5, and University of Delaware version 2.01) and evaluated their homogeneity and trends with multiple methods over two periods, 1950–2008 and 1980–2008. All three data sets displayed common broadscale features of Alaska’s precipitation climatology, but there were substantial differences between them in terms...
Interactions and feedbacks between abundant surface waters and permafrost fundamentally shapelowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceedslake depth and mean annual bed temperatures (MABTs) remain below freezing. However, decliningMIT since the1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity towinter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data.Empirical model experiments suggest that shallow (1m depth) lakes have warmed substantially over the last30years (2.4°C), withMABT above freezing5 of the last 7years.This is incomparison to slower ratesofwarming...
Many Arctic shorebird populations are declining, and quantifying adult survival and the effects of anthropogenic factorsis a crucial step toward a better understanding of population dynamics. We used a recently developed, spatially explicitCormack–Jolly–Seber model in a Bayesian framework to obtain broad-scale estimates of true annual survival rates for 6species of shorebirds at 9 breeding sites across the North American Arctic in 2010–2014. We tested for effects ofenvironmental and ecological variables, study site, nest fate, and sex on annual survival rates of each species in thespatially explicit framework, which allowed us to distinguish between effects of variables on site fidelity versus truesurvival. Our...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Arctic Landscape Conservation Cooperative data.gov,
BIRDS,
BIRDS,
BREEDING PRODUCTIVITY,
BREEDING PRODUCTIVITY,
The Arctic Coastal Plain (ACP) of Alaska is an important region for millions of migrating and nesting shorebirds. However, this region is threatened by climate change and increased human development (e.g., oil and gas production) that have the potential to greatly impact shorebird populations and breeding habitat in the near future. Because historic data on shorebird distributions in the ACP are very coarse and incomplete, we sought to develop detailed, contemporary distribution maps so that the potential impacts of climate-mediated changes and development could be ascertained. To do this, we developed and mapped habitat suitability indices for eight species of shorebirds (Black-bellied Plover [Pluvialis squatarola],...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Academics & scientific researchers,
BIRDS,
Conservation NGOs,
Federal resource managers,
GEOGRAPHIC INFORMATION SYSTEMS,
This paper explores the impacts of shrinking glaciers on downstream ecosystems in the Arctic National Wildlife Refuge. Glaciers here are losing mass at an accelerating rate and will largely disappear in the next 50–100 years if current trends continue. We believe this will have a measurable and possibly important impact on the terrestrial and estuarine ecosystems and the associated bird and fish species within these glaciated watersheds.
Lakes are dominant and diverse landscapefeatures in the Arctic, but conventional land coverclassification schemes typically map them as a singleuniform class. Here, we present a detailed lake-centricgeospatial database for an Arctic watershed in northernAlaska. We developed a GIS dataset consisting of 4362lakes that provides information on lake morphometry,hydrologic connectivity, surface area dynamics,surrounding terrestrial ecotypes, and other importantconditions describing Arctic lakes. Analyzing thegeospatial database relative to fish and bird survey datashows relations to lake depth and hydrologic connectivity,which are being used to guide research and aid in themanagement of aquatic resources in the NationalPetroleum...
The Arctic Coastal Plain (ACP) of northern Alaskaconsists of an extremely low gradient, lake-richlandscape that is characterized by a complex networkof aquatic habitats and surface features stronglyinfluenced by permafrost dynamics. Much is unknownabout the form, function, and ecological conditions inthis unique hydrologic setting. Amplified climatechange and landscape responses in the Arctic furthercomplicate the capacity to separate natural variabilityfrom land use effects that may occur with petroleumdevelopment. A comprehensive, multi-disciplinaryreview and analysis of recent studies and initialinventory and monitoring in the Fish Creek watershedon the ACP provided guidance to develop a frameworkfor future aquatic...
Numerous studies have evaluated precipitation trends in Alaska and come to different conclusions. These studies differ in analysis period and methodology and do not address the issue of temporal homogeneity. To reconcile these conflicting results, we selected 29 stations with largely complete monthly records, screened them for homogeneity, and then evaluated trend over two analysis periods (1950–2010 and 1980–2010) using three methods: least absolute deviation regression, ordinary least squares regression (with and without transformation), and Mann-Kendall trend testing following removal of first-order autocorrelation. We found that differences in analytical period had a significant impact on trends and that the...
Beaded streams are widespread in permafrost regionsand are considered a common thermokarst landform.However, little is known about their distribution, how andunder what conditions they form, and how their intriguingmorphology translates to ecosystem functions and habitat.Here we report on a circum-Arctic survey of beaded streamsand a watershed-scale analysis in northern Alaska using remotesensing and field studies.We mapped over 400 channelnetworks with beaded morphology throughout the continuouspermafrost zone of northern Alaska, Canada, and Russiaand found the highest abundance associated with mediumto high ground-ice content permafrost in moderately slopingterrain. In one Arctic coastal plain watershed, beaded...
ire-induced permafrost degradation is well documented in boreal forests, but the role of fires in initiating thermokarst development in Arctic tundra is less well understood. Here we show that Arctic tundra fires may induce widespread thaw subsidence of permafrost terrain in the first seven years following the disturbance. Quantitative analysis of airborne LiDAR data acquired two and seven years post-fire, detected permafrost thaw subsidence across 34% of the burned tundra area studied, compared to less than 1% in similar undisturbed, ice-rich tundra terrain units. The variability in thermokarst development appears to be influenced by the interaction of tundra fire burn severity and near-surface, ground-ice content....
Throughout the Arctic most pregnant polar bears (Ursus maritimus) construct maternity dens in seasonal snowdrifts that form in wind-shadowed areas. We developed and verified a spatial snowdrift polar bearden habitat model (SnowDens-3D) that predicts snowdrift locations and depths along Alaska’s Beaufort Sea coast. SnowDens-3D integrated snow physics, weather data, and a high-resolution digital elevation model (DEM) to produce predictions of the timing, distribution, and growth of snowdrifts suitable for polar bear dens. SnowDens-3D assimilated 18 winters (1995 through 2012) of observed daily meteorological data and a 2.5 m grid-increment DEM covering 337.5 km2 of the Beaufort Sea coast, and described the snowdrift...
Lakes are prevalent in the Arctic and thus play a key role in regional hydrology. Since manyArctic lakes are shallow and ice grows thick (historically 2 m or greater), seasonal ice commonly freezes tothe lake bed (bedfast ice) by winter’s end. Bedfast ice fundamentally alters lake energy balance and meltoutprocesses compared to deeper lakes that exceed the maximum ice thickness (floating ice) and maintainperennial liquid water below floating ice. Our analysis of lakes in northern Alaska indicated that ice-out ofbedfast ice lakes occurred on average 17 days earlier (22 June) than ice-out on adjacent floating ice lakes (9July). Earlier ice-free conditions in bedfast ice lakes caused higher open-water evaporation,...
In Arctic ecosystems, freshwater fish migrateseasonally between productive shallow water habitatsthat freeze in winter and deep overwinter refuge in riversand lakes. How these movements relate to seasonal hydrologyis not well understood.We used passive integratedtransponder tags and stream wide antennae to track1035 Arctic grayling in Crea Creek, a seasonally flowingbeaded stream on the Arctic Coastal Plain, Alaska. Migrationof juvenile and adult fish into Crea Creek peakedin June immediately after ice break-up in the stream. Fishthat entered the stream during periods of high flow andcold stream temperature traveled farther upstream thanthose entering during periods of lower flow and warmertemperature. We used generalized...
Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba), and Nunavik (Quebec). These landscapes represent the broad range of thermokarst environments...
Field measurements, satellite observations, and models document a thinning trend in seasonal Arcticlake ice growth, causing a shift from bedfast to floating ice conditions. September sea iceconcentrations in the Arctic Ocean since 1991 correlate well (r=+0.69, p<0.001) to this lakeregime shift. To understand how and to what extent sea ice affects lakes, we conducted modelexperiments to simulate winters with years of high (1991/92) and low (2007/08) sea ice extent forwhich we also had field measurements and satellite imagery characterizing lake ice conditions. Alakeice growth model forced with Weather Research and Forecasting model output produced a 7%decrease in lake ice growth when 2007/08 sea ice was imposed on...
Rural Arctic communities are vulnerable to climate change and residents seek adaptive strategies that will protect public health. In the Inupiat community of Selawik, climate change is impacting the weather, land, river, wildlife, plants, and the lives of the people who live there. This report identifies health concerns related to food and water security and community infrastructure. This report documents these issues as described by the local people and interpreted through the lens of public health. It is the fifth report in a series describing climate change in Northwest Alaska.
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