Dec 19, 2017
Industrial-age doubling of snow accumulation in the Alaska Range linked to tropical ocean warming
by
,
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