Version History for: Glacier-Wide Mass Balance and Compiled Data Inputs Current Citation: U.S. Geological Survey Benchmark Glacier Program, 2016, Glacier-wide mass balance and compiled data inputs (ver 8.1, February 2024): U.S. Geological Survey data release, https://doi.org/10.5066/F7HD7SRF ======================================== Version 1.0 posted online August 11, 2016 Original Title: USGS Alaska Benchmark Glacier Mass Balance Data - Phase 1; Gulkana and Wolverine Glaciers Overview: Benchmark mass balance data from Gulkana and Wolverine Glaciers ======================================== Version 2.0 posted online August, 2017 Changes in version 2.0 1. Appended data for 2016. 2. Re-naming of dataset to "Glacier-Wide Mass Balance and Input Data: Alaska Benchmark Glaciers, 1966-2016" 3. Minor edits to the PDF README and XML metadata. ======================================== Version 2.1 posted online June, 2018 New title: Glacier-Wide Mass Balance and Compiled Data Inputs: USGS Benchmark Glaciers Changes in version 2.1 1. Added daily 2006-2016 temperature data for Sperry Glacier. 2. Re-naming of dataset to reflect inclusion of Sperry Glacier data: "Glacier-Wide Mass Balance and Compiled Data Inputs: USGS Benchmark Glaciers" 3. Additional authors for Montana glacier. 3. Minor edits to the PDF README and XML metadata. ======================================== Version 3.0 posted online July, 2019 Changes in version 3.0 1. Addition of full data suite for Lemon Creek, South Cascade, and Sperry glaciers. 2. Additional authors for Washington glacier (South Cascade) 3. Re-structuring of data to reflect transition from the legacy index-method used in Alaska, to a uniform balance profile method applied identically across all glaciers as described in O'Neel (2019; in prep). 4. Edits to the PDF README and XML metadata reflecting the change in methods form the index method to a uniformly applied, reanalyzed and geodetically calibrated timeseries. ======================================== Version 4.0 posted online November, 2019 Changes in version 4.0 1. Addition of provisional mass balance data for 2019. This will be updated following Spring 2020 glacier fieldwork. 2. For Lemon Creek Glacier data, changed date from Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) from the date of collection, in February 2000, to 1999, in order to more accurately reflect its measurement of the 1999 fall summer surface, rather than the February 2000 snow surface, due to the known penetration of SRTM several meters into the seasonal snow. See supplement to O'Neel and others (2019) for further details. ======================================== Version 5.0 posted online Febrary, 2021 Changes in version 5.0 1. Finalized mass balance data for 2019 replaces provisional data. Provisional data for 2020 is provided. 2. Prior to Version 5.0, a lapse rate of -6.5 C/km was used to calculate on-glacier temperatures across at all Benchmark Glaciers. In Version 5.0 forward, using local weather stations the Lemon Creek Glacier lapse rate was optimized, resulting in a -5.0 C/km lapse rate as detailed in McNeil et. al 2020, "Explaining mass balance and retreat dichotomies at Taku and Lemon Creek Glaciers, Alaska". ======================================== Version 6.0 posted online January, 2022 Changes in version 6.0 1. Finalized mass balance data for 2020 replaces provisional data. Provisional data for 2021 is provided. 2. Slight correction to Sperry Site Z coordinate, per previously published value in Clark et. al 2017, "Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005–2015. 3. Additional language added to the metadata explaning the multi-year relationship of weather data to observed mass balances. 4. Minor data-entry errors for input glaciological data from 2015 to 2020 at Gulkana were corrected in input glaciological data. Placeholder fall dates for measurements (October 1 of a given year) were replaced with 'nan', when none occured, and stratigraphic balances are used. Occasions where winter ablation or summer accumulation were not measured were corrected from a measureuemt of 0 to a value of nan. ======================================== Version 7.0 posted online December, 2022 Changes in version 7.0 1. Finalized mass balance data for 2021. Provisional data for 2022 is provided. 2. Note that local weather station records at Gulkana and Wolverine suffered power issues during 2021-2022. The Gulkana 1480 weather station failed 4/2022 and was retired in fall 2022. The Wolverine station suffered power loss and issues with the weighing precipitation gage, but has an onging record. ======================================== Version 8.0 posted online November, 2023 Changes in version 8.0 1. Finalized mass balance data for 2022. Provisional data for 2023 is provided. 2. Data from Taku Glacier was added to this release. Previously, Taku Glacier data was published under a separate data release: "Glacier-wide mass balance and compiled data inputs: Juneau Icefield glaciers: U.S. Geological Survey data release, https://doi.org/10.5066/P9YBZ36F". 3. Removed phrase "USGS Benchmark Glaciers" from previous title "Glacier-Wide Mass Balance and Compiled Data Inputs: USGS Benchmark Glaciers", to reflect addition of Taku Glacier. 4. Updated geodetic mass balance input that is used for glacier-wide mass balance calibration. Prior to Version 8, geodetic input was provided as a height change. It is now presented in units of mass change, as calculated with average glacier area and automated co-registration (Florentine et al., in press). Geodetic input was extended using digital elevation models published in the data release: "Geodetic data for the USGS Benchmark Glaciers: Orthophotos, Digital Elevation Models, Glacier Boundaries and Surveyed Positions, https://doi.org/10.5066/P9R8BP3K". ======================================== Version 8.1 posted online February, 2024 Changes in version 8.1 Data corrections in two Taku Glacier files: Input_Taku_Area_Altitude_Distribution.csv -we corrected an interpolation error Output_Taku_Glacier_Wide_solutions_calibrated.csv -reflects the changes from updating that input file.