Data from high frequency sampling of multiple carbon forms were collected in a predominately rain-fed watershed in Southeast Alaska during the main run-off season (May-October 2021). The dataset includes dissolved organic carbon, particulate organic carbon, coarse particulate organic carbon, and invertebrate biomass carbon point samples and daily stream flow. The objective of this study was to collect data on carbon export and flow to model watershed export of carbon forms.

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, quantity, and gas fluxes within the interior of Alaska. 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 isotopes, cations, anions, trace metals, and various in situ measurements including: pH, water temperature, air temperature, barometric pressure, secchi depth, dissolved oxygen, turbidity, fluorescent dissolved organic matter, and specific conductance. Sampling frequency varied across locations, with some sites sampled twice a year or more.

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, quantity, and gas fluxes within the interior of Alaska. 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 isotopes, cations, anions, trace metals, and various in situ measurements including: pH, water temperature, air temperature, barometric pressure, secchi depth, dissolved oxygen, turbidity, fluorescent dissolved organic matter, and specific conductance. Sampling frequency varied across locations, with some sites sampled twice a year or more.

The pore water of eight wetlands in Interior and Southcentral Alaska were collected in 2015 (17 July – 22 July) and 2016 (12 July – 16 July). Wetlands were selected to span a range in trophic status (e.g., from bog to fen). Using ultraclean trace metal clean protocols, pore waters were sampled from shallow (10‑15 cm) and deep (20-35 cm) depths below the water table. Field measurements reported for pore waters include temperature, specific conductance, pH, dissolved oxygen (DO) concentration, and oxidation-reduction potential (ORP). Pore waters were filtered on site and measured in-lab for major cations, inorganic anions, simple organic acids, inorganic sulfide, iron oxidation state, dissolved organic carbon (DOC), ultraviolet and visible light (UV-Vis) absorption, dissolved organic matter (DOM) fluorescence, electron release from DOM and iron(II), total mercury (HgT), and methylmercury (MeHg). Unfiltered pore water was collected for quantification of dissolved gaseous mercury (Hg(0)(aq)). Major cation concentrations (calcium, magnesium, manganese, iron, sodium) were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). Inorganic anion concentrations (chloride, nitrate, sulfate) and simple organic acid concentrations (acetate, formate, butyrate, propanoate, oxalate) were determined by ion chromatography (IC). Inorganic sulfide was measured by ion selective electrode. The distribution of iron oxidation state was determined using a spectrophotometric assay. DOC concentration was quantified by wet-oxidation. Ultraviolet (UV) absorbance at the wavelength of 254 nanometers was measured by UV-Vis spectrophotometry. Iron(III) absorbs UV light at 254 nanometers and, if present at appreciable concentration, can influence UV absorbance values. Therefore, UV absorbance values at 254 nanometers were corrected for the influence of iron(III). Specific UV Absorbance (SUVA) at 254 nanometers is a calculated parameter that correlates with the percent aromatic carbon of the DOM. SUVA at 254 nanometers was calculated using values of UV absorbance at a wavelength of 254 nanometers corrected for iron(III) interference. The DOM fluorescence index was measured and is a proxy for DOM source material. The release of electrons from DOM and iron(II) was measured in the field using a colorimetric assay. HgT, MeHg, and Hg(0)(aq) concentrations were quantified and used to calculate the concentration of inorganic divalent mercury (Hg(II)i).

These data include stream water chemistry from headwater streams to large rivers across three national parks in Arctic Alaska: Bering Land Bridge National Preserve, Kobuk Valley National Park, and Noatak National Preserve.

This dataset provides dissolved carbon dioxide (CO2) and methane (CH4) concentrations alongside their stable and radiocarbon isotopic compositions within the Arctic Sagavanirktok and Kuparuk River watersheds located on the North Slope of Alaska. The data were collected during the spring, fall, and summer seasons in 2022. In field separation of the bulk gaseous components (N2, CO2, and CH4) from the liquid phase was achieved using a degassing membrane contactor. Laboratory isotopic analyses were conducted at the W. M. Keck Carbon Cycle Accelerator Mass Spectrometer facility at UC Irvine. This collection aims to provide insights into the seasonal dynamics of greenhouse gas emissions in these critical Arctic environments, thereby contributing valuable information for climate change research and monitoring programs. The data are provided in comma separated values (CSV) format.

This data release documents the data used for the associated publication "Evaluating hydrologic region assignment techniques for ungaged watersheds in Alaska, USA" (Barnhart and others, 2022) The data sets within this release are stored in 14 files: (1) Streamflow observations and sites used. (2) Statistically estimated streamflow values computed for each site. (3) Streamflow statistics computed from observed and estimated streamflow values at each site, basin characteristics for each site, and hydrologic regions (clusters) for each site. (4) A dataset describing the optimal number of hydrologic regions into which the considered sites were grouped. (5) P-values from a multiple comparisons analysis testing for statistical differences between clusters for each basin characteristic and streamflow statistic. (6) A matrix of zeros and ones describing the performance of each hydrologic region assignment technique considered in the publication associated with this release. (7) A dataset of variable importance generated by random forest modeling-based hydrologic region assignment techniques evaluated. (8-14) Daily datasets of simulated SnowModel (Liston and Elder, 2006) runoff (snowmelt + rainfall), precipitation, glacial melt, snow water equivalent, snow covered area, liquid precipitation, and air temperature for Alaska, USA at a 1 km grid cell size.

Total and organic carbon values from soil samples taken from the Yukon River Basin, Alaska. These samples were used to create a relationship between total carbon and organic carbon for samples which were only run for total carbon.

Total and organic carbon values from soil samples taken from the Yukon River Basin, Alaska. These samples were used to create a relationship between total carbon and organic carbon for samples which were only run for total carbon.

Total and organic carbon values from soil samples taken from the Yukon River Basin, Alaska. These samples were used to create a relationship between total carbon and organic carbon for samples which were only run for total carbon.