Remote Sensing of 2000-2016 Alpine Spring Snowline Elevation in Dall Sheep Mountain Ranges of Alaska and Western Canada

The lowest elevation of spring snow (“snowline”) is an important factor influencing recruitment and survival of wildlife in alpine areas. In this study, we assessed the spatial and temporal variability of alpine spring snowline across major Dall sheep mountain areas in Alaska and northwestern Canada. We used a daily MODIS snow fraction product to estimate the last day of 2000–2016 spring snow for each 500-m pixel within 28 mountain areas. We then developed annual (2000–2016) regression models predicting the elevation of alpine snowline during mid-May for each mountain area. MODIS-based regression estimates were compared with estimates derived using a Normalized Difference Snow Index from Landsat-8 Operational Land Imager (OLI) surface reflectance data. We also used 2000–2009 decadal climate grids to estimate total winter precipitation and mean May temperature for each of the 28 mountain areas. Based on our MODIS regression models, the 2000–2016 mean May 15 snowline elevation ranged from 339 m in the cold arctic class to 1145 m in the interior mountain class. Spring snowline estimates from MODIS and Landsat OLI were similar, with a mean absolute error of 106 m. Spring snowline elevation was significantly related to mean May temperature and total winter precipitation. The late spring of 2013 may have impacted some sheep populations, especially in the cold arctic mountain areas which were snow-covered in mid-May, while some interior mountain areas had mid-May snowlines exceeding 1000 m elevation. We found this regional (>500,000 km2) remote sensing application useful for determining the inter-annual and regional variability of spring alpine snowline among 28 mountain areas.

[1]  Jean-Pierre Dedieu,et al.  On the Importance of High-Resolution Time Series of Optical Imagery for Quantifying the Effects of Snow Cover Duration on Alpine Plant Habitat , 2016, Remote. Sens..

[2]  Jadunandan Dash,et al.  Arctic lakes show strong decadal trend in earlier spring ice-out , 2016, Scientific Reports.

[3]  L. Adams.  Marrow fat deposition and skeletal growth in caribou calves , 2003 .

[4]  J. Dozier.  Spectral Signature of Alpine Snow Cover from the Landsat Thematic Mapper , 1989 .

[5]  L. Hay,et al.  A COMPARISON OF DELTA CHANGE AND DOWNSCALED GCM SCENARIOS FOR THREE MOUNTAINOUS BASINS IN THE UNITED STATES 1 , 2000 .

[6]  Robert S. Stone,et al.  Earlier spring snowmelt in northern Alaska as an indicator of climate change , 2002 .

[7]  B. Menounos,et al.  An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America , 2013 .

[8]  Thomas H. Painter,et al.  Assessment of methods for mapping snow cover from MODIS , 2011 .

[9]  R. White.  Foraging patterns and their multiplier effects on productivity of northern ungulates , 1983 .

[10]  J. Fox.  Forage Quality of Carex macrochaeta Emerging from Alaskan Alpine Snowbanks through the Summer , 1991 .

[11]  Rui A. P. Perdigão,et al.  Estimation of regional snowline elevation (RSLE) from MODIS images for seasonally snow covered mountain basins , 2014 .

[12]  Libo Wang,et al.  A multi‐data set analysis of variability and change in Arctic spring snow cover extent, 1967–2008 , 2010 .

[13]  S. Solomon.  The Physical Science Basis : Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , 2007 .

[14]  Nathalie Pettorelli,et al.  Early onset of vegetation growth vs. rapid green-up: impacts on juvenile mountain ungulates. , 2007, Ecology.

[15]  K. Hayhoe.  A standardized framework for evaluating the skill of regional climate downscaling techniques , 2010 .

[16]  S. Newman,et al.  ALASKA DEPARTMENT OF FISH AND GAME , 2019 .

[17]  J. Rachlow,et al.  Habitat selection by Dall's sheep (Ovis dalli): maternal trade‐offs , 1998 .

[18]  Tim Hammond,et al.  Spatial prediction of climatic state factor regions in Alaska , 1996 .

[19]  D. Coltman,et al.  Population genetic structure of North American thinhorn sheep (Ovis dalli) , 2004, Molecular ecology.

[20]  F. Bunnell,et al.  Nutrition of Stone's Sheep on Burned and Unburned Ranges , 1985 .

[21]  G. Wendler,et al.  Temperature and precipitation of Alaska: 50 year trend analysis , 2000 .

[22]  Arpat Ozgul,et al.  Coupled dynamics of body mass and population growth in response to environmental change , 2010, Nature.

[23]  R. O’Hara,et al.  The role of phenotypic plasticity in responses of hunted thinhorn sheep ram horn growth to changing climate conditions , 2010, Journal of Evolutionary Biology.

[24]  P. V. Soest.  Nutritional Ecology of the Ruminant , 1994 .

[25]  T. Painter,et al.  Retrieval of subpixel snow-covered area and grain size from imaging spectrometer data , 2003 .

[26]  G. Powell,et al.  Terrestrial Ecoregions of the World: A New Map of Life on Earth , 2001 .

[27]  P. Jones,et al.  Updated high‐resolution grids of monthly climatic observations – the CRU TS3.10 Dataset , 2014 .

[28]  M. Serreze,et al.  Geographic patterns and dynamics of Alaskan climate interpolated from a sparse station record , 2000, Global change biology.

[29]  C. Daly,et al.  Physiographically sensitive mapping of climatological temperature and precipitation across the conterminous United States , 2008 .

[30]  M. Boyce,et al.  Demography in an increasingly variable world. , 2006, Trends in ecology & evolution.

[31]  Thomas H. Painter,et al.  Retrieval of subpixel snow covered area, grain size, and albedo from MODIS , 2009 .

[32]  F. Bunnell.  Factors controlling lambing period of Dall's sheep. , 1980, Canadian journal of zoology.

[33]  Sergey A. Sokratov,et al.  The Changing Face of Arctic Snow Cover: A Synthesis of Observed and Projected Changes , 2011, AMBIO.

[34]  J. Briggs,et al.  Intra-annual rainfall variability and grassland productivity: can the past predict the future? , 2006, Plant Ecology.

[35]  A. Mysterud,et al.  Interacting effect of wolves and climate on recruitment in a northern mountain caribou population , 2010 .

[36]  Jessica D. Lundquist,et al.  Ground-based testing of MODIS fractional snow cover in subalpine meadows and forests of the Sierra Nevada , 2013 .

[37]  L. Prugh,et al.  Predator-Mediated Indirect Effects of Snowshoe Hares on Dall's Sheep in Alaska , 2010 .

[38]  G. Roe,et al.  Rain‐on‐snow events impact soil temperatures and affect ungulate survival , 2003 .

[39]  M. D. Fleming,et al.  Comparing Maps of Mean Monthly Surface Temperature and Precipitation for Alaska and Adjacent Areas of Canada Produced by Two Different Methods , 2010 .

[40]  B. Sæther,et al.  Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic , 2013, Science.