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Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were cut into 15 cm thick sections, and deep active-layer (15-30 cm above the permafrost boundary) and shallow permafrost (15-30 cm below the permafrost boundary) sections were thawed and leached with deionized water. Soil leachates were analyzed for DOC, TDN, nitrate (NO3-), and ammonium (NH4+) concentrations, dissolved organic matter...
Categories: Data;
Tags: Alaska,
Ecology,
Soil Sciences,
USGS Science Data Catalog (SDC),
Water Quality,
This product consists of multiple tabular datasets and associated metadata of water quality information related to rivers, streams, and lakes in the Yukon River watershed between 2014 and 2018. This data release is apart of the National Aeronautics and Space Administration (NASA) funded Arctic-Boreal Vulnerability Experiment (ABoVE) and is an assessment of water quality and greenhouse gas fluxes within the interior of Alaska. Sampling frequency varied across locations, with some sites sampled twice a year or more. Data consist of: organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen and deuterium...
Categories: Data;
Types: Data,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Alaska,
Boot Lake,
CH4,
CO2,
CO2 Bubble Trap,
NOTE: This data release has been deprecated. In support of the USGS LandCarbon project, field observations of stream and lake carbon gas fluxes and other water-quality data were collected from surface waters in the conterminous US. The sampling was designed to cover a variety of geographic, climatic, and environmental settings to better understand the ranges and distributions of carbon gas fluxes from surface waters. Field observations of carbon gas concentration and flux were paired with laboratory measurements of stream chemical characteristics. Locations were derived from field GPS values or from listed coordinates of USGS streamgages located at the sampling site. Discharge data was either measured in the field...
Categories: Data;
Types: Citation;
Tags: Carbon cycle,
Conterminous U.S.,
Inland waters,
USGS Science Data Catalog (SDC),
Water Resources
This collection of hydrologic, biogeochemical, geophysical, soil, thermal, and physical data provides a framework for investigating the vulnerability of water and carbon cycles to changing permafrost conditions across boreal Alaska. Multidisciplinary data are needed to evaluate the effects of fire and climate on subsurface permafrost, soil physical, and hydrological conditions, which in turn are used to inform hydrological modeling of surface and subsurface water distribution, flow, and water availability in response to change. Vulnerability of the aquatic carbon cycle is investigated by detailed characterization of the chemistry, age, and degradability of permafrost carbon sources and their biogeochemical change,...
A better understanding of how hydrological and biogeochemical processes control dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) composition from headwaters downstream to large rivers is needed. We examined a large DOM dataset from the National Water Information System of the U.S. Geological Survey, which represents approximately 100,000 measurements of DOC concentration and DOM composition at many sites along rivers across the United States. Application of quantile regression revealed a tendency towards downstream spatial and temporal homogenization of DOC concentrations and a shift from dominance of aromatic DOM in headwaters to more aliphatic DOM downstream. The DOC concentration...
Categories: Publication;
Types: Citation
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