title: Incorporating cold-air pooling into downscaled climate models increases potential refugia for snow-dependent species within the Sierra Nevada Ecoregion, CA.
abstract: We present a unique water-balance approach for modeling snowpack under historic, current and future climates throughout the Sierra Nevada Ecoregion. Our methodology uses a finer scale (270 m) than previous regional studies and incorporates cold-air pooling, an atmospheric process that sustains cooler temperatures in topographic depressions thereby mitigating snowmelt. Our results are intended to support management and conservation of snow-dependent species, which requires characterization of suitable habitat under current and future climates. We use the wolverine (Gulo gulo) as an example species and investigate potential habitat based on the depth and extent of spring snowpack within four National Park units with proposed wolverine reintroduction programs. Our estimates of change in spring snowpack conditions under current and future climates are consistent with recent studies that generally predict declining snowpack. However, model development at a finer scale and incorporation of cold-air pooling increased the persistence of April 1st snowpack. More specifically, incorporation of cold-air pooling into future climate projections increased April 1st snowpack by 6.5% when spatially averaged over the study region and the trajectory of declining April 1st snowpack reverses at mid-elevations where snow pack losses are mitigated by topographic shading and cold-air pooling. Under future climates with sustained or increased precipitation, our results indicate a high likelihood for the persistence of late spring snowpack at elevations above approximately 2,800 m and identify potential climate refugia sites for snow-dependent species at mid-elevations, where significant topographic shading and cold-air pooling potential exist.
authors.affiliation: U. S. Geological Survey, California Water Science Center, Eureka, California, United States of America.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Curtis
authors.affiliation: U. S. Geological Survey, California Water Science Center, Sacramento, California, United States of America.
authors.forename: Lorraine E
authors.initials: LE
authors.lastname: Flint
authors.affiliation: U. S. Geological Survey, California Water Science Center, Placer Hall, California, United States of America.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Flint
authors.affiliation: University of Washington, Department of Civil and Environmental Engineering, Seattle, Washington, United States of America.
authors.forename: Jessica D
authors.initials: JD
authors.lastname: Lundquist
authors.affiliation: Institute for Wildlife Studies, Arcata, California, United States of America.
authors.forename: Brian
authors.initials: B
authors.lastname: Hudgens
authors.affiliation: U. S. Geological Survey, Western Ecological Research Center, Thousand Oaks, California, United States of America.
authors.forename: Erin E
authors.initials: EE
authors.lastname: Boydston
authors.affiliation: U. S. Department of Agriculture, Wildlife Services, National Wildlife Research Center and Utah State University, Wildland Resources Department, Logan, Utah, United States of America.
authors.forename: Julie K
authors.initials: JK
authors.lastname: Young
mesh_terms: D000222:Adaptation, Physiological; D000388:Air / Q000032:analysis*; D000818:Animals; D002140:California; D002980:Climate; D057231:Climate Change; D003080:Cold Temperature; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005260:Female; D008297:Male; D015233:Models, Statistical; D045969:Mustelidae / Q000502:physiology*; D000068236:Refugium; D012621:Seasons; D014919:Wind