The datasets included here were used to assess trends and geospatial patterns of river ice extent in the Copper River Basin of southcentral Alaska. Our goals were to document how river ice travel and wintertime access to traditional lands have been impacted by climate change, to support safe ice travel by identifying reaches with persistent open water vs early ice cover, and to understand the physical drivers of the local variation in freeze-up. Trends in ice extent for a section of the Copper River were analyzed using Landsat imagery from water years (WY, Oct. 1-Sep 30) 1973-2021. The direct observations of ice extent classes from each image date are provided (IceExtent_DirectObs.csv). These observations were gap-filled and summarized on a weekly basis, along with local air temperature metrics (IceExtent_AirTemps_Weekly_GapFilled.csv). Geospatial patterns of ice and open water extent for recent winters were assessed in two ways. First, we quantified reach-level late-winter open water extent of the Copper and Chitina rivers by digitizing Sentinel-2 multispectral images from WY 2018, 2020, and 2021, and combined these with river hydrologic and geomorphic characteristics (e.g. unit stream power, number of channels, river width, etc.). These data are provided in spatial (RiverReachData_Spatial.zip) and tabular (RiverReachData_Tabular.csv) formats. Second, we analyzed the progression of freeze-up by visualizing Sentinel-1 SAR imagery and compositing pixel-based classifications of water for Nov-Feb of WY 2018-2020 to show the seasonal and multiyear water occurrence (% season) (waterOccurrenceYYYY.tif, waterOccurrenceMultiYear.tif). The script for this SAR analysis in Google Earth Engine is provided (RiverIceAndOpenWater_SAR.js).

This dataset contains thermistor string observations from autonomous buoys and estimated ice thicknesses with the purpose of remote ice thickness monitoring in locations around the state of Alaska. Some buoys are co-located within or nearby partner observation communities for calibration purposes while others are more remote. These buoys were installed fall of 2019 and fall of 2020.

This dataset contains community based observations of ice thickness throughout the winters of 2019/2020, 2020/2021, and 2021/2022. Observations are co-located within or near communities participating in the Fresh Eyes on Ice project, seeking to expand spatial coverage of ice observations and science literacy in classrooms around the state. This spatially distributed dataset provides valuable information about ice thickness through the winter for the period of 2019-2022 on lakes and rivers around Alaska, including Big Lake near Venetie, Alaska, Brown's Slough in Bethel, Alaska, Noyes Slough in Fairbanks, Alaska, the Tanana River near Fairbanks, Alaska, Shageluk Lake near Shageluk, Alaska, Third Lake near Noatak, Alaska, Alexander Lake in Galena, Alaska, Smith Lake near Fairbanks, Alaska, Big Trail Lake near Fairbanks, Alaska, Toolik Lake at Toolik Research Station, Alaska, Jan Lake near Tok, Alaska, Float Pond Lake near Nenana, Alaska, unnamed lakes in the communities of Kenny Lake, Alaska, Arctic Village, Alaska, Sleetmute, Alaska, and McGrath, Alaska, Pippen Lake near Tonsina, Alaska, Yukon River near Eagle, Alaska, Long Lake near Eagle Village, Alaska, Sculpin Lake near Chitina, Alaska, and Dog Pits Lakes near Fairbanks, Alaska . These observations were made by drilling of 3 holes in an undisturbed location at the site by students, teachers, and community members, as well as members of the Fresh Eyes on Ice project. Snow depth was recorded at each of the holes prior to drilling.

This dataset contains community based observations of ice thickness throughout the winter of 2019/2020. Observations are co-located within or near communities participating in the Fresh Eyes on Ice project, seeking to expand spatial coverage of ice observations and science literacy in classrooms around the state. This spatially distributed dataset provides valuable information about ice thickness through the winter of 2019 and 2020 on lakes and rivers around Alaska, including Big Lake near Venetie, Alaska, Brown's Slough in Bethel, Alaska, Noyes Slough in Fairbanks, Alaska, the Tanana River near Fairbanks, Alaska, Shageluk Lake near Shageluk, Alaska, Third Lake near Noatak, Alaska, Alexander Lake in Galena, Alaska, Smith Lake near Fairbanks, Alaska, Big Trail Lake near Fairbanks, Alaska, and Toolik Lake at Toolik Research Station, Alaska. These observations were made by drilling of 3 holes in an undisturbed location at the site by students, teachers, and community members, as well as members of the Fresh Eyes on Ice project. Snow depth was recorded at each of the holes prior to drilling.

This dataset contains community based observations of ice thickness throughout the winter of 2019/2020. Observations are co-located within or near communities participating in the Fresh Eyes on Ice project, seeking to expand spatial coverage of ice observations and science literacy in classrooms around the state. This spatially distributed dataset provides valuable information about ice thickness through the winter of 2019 and 2020 on lakes and rivers around Alaska, including Big Lake near Venetie, Alaska, Brown's Slough in Bethel, Alaska, Noyes Slough in Fairbanks, Alaska, the Tanana River near Fairbanks, Alaska, Shageluk Lake near Shageluk, Alaska, Third Lake near Noatak, Alaska, Alexander Lake in Galena, Alaska, Smith Lake near Fairbanks, Alaska, Big Trail Lake near Fairbanks, Alaska, and Toolik Lake at Toolik Research Station, Alaska. These observations were made by drilling of 3 holes in an undisturbed location at the site by students, teachers, and community members, as well as members of the Fresh Eyes on Ice project. Snow depth was recorded at each of the holes prior to drilling.

This dataset contains observations of ice phenology throughout the winter of 2019/2020 (Water Year 2020). Observations are primarily co-located within or near communities participating in the Fresh Eyes on Ice project, seeking to expand spatial coverage of ice observations and inform a variety of user groups including river forecasters, community members, and remote sensing scientists. Sites were selected for a variety of factors including community interest and site feasibility. This spatially distributed dataset provides valuable information about ice conditions through the winter of 2019 and 2020 on rivers around Alaska, including the Kuskokwim River near Kwethluk (later Napaskiak), Alaska, the Tanana River near Fairbanks, Alaska, the Innoko River near Shageluk, Alaska, the Noatak River near Noatak, Alaska, the Yukon River in Galena, Alaska, the Yukon River at Paimute, Alaska, the Copper River below Tazlina, Alaska, the Kantishna River near its confluence, Alaska, and the Colville River near Nuiqsut, Alaska. These observations were made on a daily basis from remote camera installations.