Global River Ice Dataset - validation dataset

Documentation for nws_breakup_nogeo.csv and nws_freezeup_nogeo.csv Alaskan river ice records from National Weather Service (NWS), including nws_breakup_nogeo.csv containing location (description) and dates of ice breakup and related conditions and nws_freezeup_nogeo.csv containing location (description) and dates of ice freeze-up and related conditions. Note that both dataset do not contain exact geolocations of the observation. We thank Dr. Scott Lindsey at the Alaska-Pacific River Forecast Center for providing these datasets. Documentation for landsat_river_ice_validation.csv This file contains 20,687 same-day river ice condition from Landsat and from in situ, and consists of the following associated properties for each comparison: date: The date on which both the Landsat river ice (length) fraction and in situ river ice condition were observed (data type: string; format: "YYYY-MM-DD"). ice_in_situ: The ice condition on rivers observed in situ. For records from NWS, we assumed river has been ice covered between the date of "first_ice" to the date of "breakup" in the following year and ice-free between the date of "breakup" and the following "first_ice" date. For records from Water Survey of Canada, river was treated as ice-covered whenever the daily "Flow" data were flagged with "B"–meaning backwater effect (data type: integer; range: 0 (ice-free) or 1 (ice-covered)). ice_landsat: The river ice length fraction derived from Landsat image (data type: float; range: [0, 1]). cloud_landsat: The cloud fraction derived from Landsat image (data type: float; range: [0, 0.25]). LANDSAT_SCENE_ID: The unique Landsat TOA image identifier (data type: string). site_id: The ID of the site in its original dataset. dat_source: The source of the in situ river ice record (data type: string; values: ("National Weather Service (Alaska)", "Water Survey of Canada"). longitude: The longitude of the site (data type: float, format: decimal degree). latitude: The latitude of the site (data type: float, format: decimal degree). A subset (N = 18,930) of this dataset was used in the evaluation of the river ice classification. This subset was calculated by applying the following two constraints on the full dataset in the landsat_river_ice_validation.csv: \(cloud\_landsat ≤ 0.05\) \(site\_id \neq 10BE013\) & \(site\_id \neq 08KE016\) The second constraint exclude two Canadian sites from the evaluation as via manual inspection, we found that the Landsat-derived ice fraction for this two sites came from river reaches that were different from where the in situ records were observed.