Dec 19, 2017

Industrial-age doubling of snow accumulation in the Alaska Range linked to tropical ocean warming

Dominic Winski, Erich Osterberg, David Ferris, Karl Kreutz, Cameron Wake, Seth Campbell, Robert Hawley, Samuel Roy, Sean Birkel, Douglas Introne, Michael Handley
Scientific Reports
  • States that North Pacific hydroclimate is dominated by the Aleutian Low, a semi-permanent wintertime feature characterized by frequent low-pressure conditions that is influenced by tropical Pacific Ocean temperatures through the Pacific-North American (PNA) teleconnection pattern
  • Presents a 1200-year seasonally- to annually-resolved ice core record of snow accumulation from Mt. Hunter in the Alaska Range developed using annual layer counting and four ice-flow thinning models
  • Shows a doubling of precipitation since ~1840 CE, with recent values exceeding the variability observed over the past millennium
  • Finds that the precipitation increase is nearly synchronous with the warming of western tropical Pacific and Indian Ocean sea surface temperatures
  • Concludes that while regional 20th century warming may account for a portion of the observed precipitation increase on Mt. Hunter, the magnitude and seasonality of the precipitation change indicate a long-term strengthening of the Aleutian Low