@article{5e4cea571692474480a9555276acbd75,
title = "Evaluation of Satellite-Derived Estimates of Lake Ice Cover Timing on Linn{\'e}vatnet, Kapp Linn{\'e}, Svalbard Using In-Situ Data",
abstract = "Arctic lakes are sensitive to climate change, and the timing and duration of ice presence and absence (i.e., ice phenology) on the lake surface can be used as a climate indicator. In this study of Linn{\'e}vatnet, one of the largest lakes on Svalbard, we compare inferences of lake ice duration from satellite data with continuously monitored lake water temperature and photographs from automatic cameras. Visible surface reflectance data from the moderate-resolution imaging spectroradiometer (MODIS) were used to observe the change in the lake-wide mean surface reflectance of Linn{\'e}vatnet from 2003–2019, and smoothing splines were applied to the to determine the date of summer ice-off (also called “break-up end”—BUE). Similarly, BUE and fall ice-on (or “freeze-up end”—FUE) were determined from lake-wide mean time series of Sentinel-1 microwave backscatter from 2014–2019. Overall, the ice timing dates identified from the satellite observations agree well with the in-situ observations (RMSE values of approximately 2–7 days for BUE and FUE, depending on the method and in-situ dataset), lending confidence to the accuracy of remote sensing of lake ice phenology in remote Arctic regions. Our observations of Linn{\'e}vatnet indicate that BUE dates do not have a significant trend, while FUE dates have been occurring approximately 1.5 days later per year during the study period. These results support an overall decrease in annual duration of lake ice cover in this part of Svalbard.",
keywords = "Lake ice, MODIS, Remote sensing, Sentinel-1, Svalbard, Water temperature",
author = "Tuttle, {Samuel E.} and Roof, {Steven R.} and Retelle, {Michael J.} and Alan Werner and Gunn, {Grant E.} and Bunting, {Erin L.}",
note = "Funding Information: Figure 1. (a) Three-dimensional digital elevation model (DEM) of Linn{\'e}vatnet and the surrounding Linn{\'e}dalen valley, along with inset map of Svalbard showing the location of Linn{\'e}vatnet on the Linn{\'e}dalen valley, along with inset map of Svalbard showing the location of Linn{\'e}vatnet on the western coast of Spitsbergen (red dot). Images from TopoSvalbard, courtesy of the Norwegian Polar western coast of Spitsbergen (red dot). Images from TopoSvalbard, courtesy of the Norwegian Polar Institute. (b) Bathymetric map of Linn{\'e}vatnet, showing the locations of water temperature profiles (indicated by white and black dots and labeled with capital letters). Water temperature from mooring G, located in the deepest part of the lake, was used in this analysis. The location of the automated G, located in the deepest part of the lake, was used in this analysis. The location of the automated cameras is shown in the green diamond near the southeast corner of the lake. 2.2. Data 2.2. Data 2.2.1. In-Situ Observations Linn{\'e}vatnet has been studied for 18 years as part of a United States National Science Linn{\'e}vatnet has been studied for 18 years as part of a United States National Science Foundation (NSF) Research Experiences for Undergraduates (REU) program and the Uni-Foundation (NSF) Research Experiences for Undergraduates (REU) program and the versity Centre in Svalbard (UNIS). Observations collected within or nearby the lake in-University Centre in Svalbard (UNIS). Observations collected within or nearby the lake clude lake water temperature, meteorology, sediment influx, and automated photographs of the lake [53]. The observations of most interest for this study are lake water temperature measurements and automated photographs. Publisher Copyright: {\textcopyright} 2022 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2022",
month = mar,
day = "1",
doi = "10.3390/rs14061311",
language = "English (US)",
volume = "14",
journal = "Remote Sensing",
issn = "2072-4292",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "6",
}