New data product may help better monitor and predict extremes in snow and sea ice melt timing in the northern Alaska region
Early and late extremes in timing of snowmelt have recently been observed in northern Alaska. Forecasts of this timing with lead times of weeks to months are important for area stakeholders including industry, environmental managers and Arctic communities.
In a new study to be published in Geophysical Research Letters, scientists from the NOAA Earth System Research Laboratory, CIRES, and the US Geological Survey have found that transport of air masses from the north Pacific influences the timing of melt on Alaska’s North Slope and the adjacent seas. Motivated by this finding, the researchers developed a new index called the Aleutian Low – Beaufort Sea Anticyclone (ALBSA) as a metric sensitive to the regional atmospheric circulations responsible for the transport of the air masses. When ALBSA is positive, warm Pacific air is observed over the Bering Strait and in the far western Arctic seas, and correspondingly the metric is correlated with the timing of spring melt. While individual weather events are ultimately responsible for melt, the index is sensitive to the position of the storm track, which varies more slowly than the weather events embedded within, potentially extending the lead time for advanced warning of the likelihood of early melt in the Alaskan Arctic region in spring.
This new climate index is proposed by the authors as a tool in support of advancing forecasts of spring melt timing at subseasonal-to-seasonal lead times in northern Alaska and the Pacific Arctic.
The authors of The Aleutian Low – Beaufort Sea Anticyclone: A climate index correlated with the timing of springtime melt in the Pacific Arctic cryosphere are: Christopher Cox, Robert Stone, David Douglas, Diane Stanitski, and Michael Gallagher.
Posted: July 17, 2019