Extreme summer weather in northern mid-latitudes linked to a vanishing cryosphere

Author:  ["Qiuhong Tang","Xuejun Zhang","Jennifer A. Francis"]

Publication:  Nature Climate Change

CITE.CC academic search helps you expand the influence of your papers.

Tags:     Climate environment

Abstract

The Northern Hemisphere has seen record declines in the summer sea-ice and snow cover at high latitudes, as well as a recent increase in extreme summer events at mid latitudes. The connection between these has been unclear; however, changes in atmospheric circulation attributable to the reduced cryosphere are now shown to be linked to the summer extremes. The past decade has seen an exceptional number of unprecedented summer extreme weather events1,2,3,4 in northern mid-latitudes, along with record declines in both summer Arctic sea ice5,6 and snow cover on high-latitude land7. The underlying mechanisms that link the shrinking cryosphere with summer extreme weather, however, remain unclear8,9,10,11,12. Here, we combine satellite observations of early summer snow cover and summer sea-ice extent13 with atmospheric reanalysis data14 to demonstrate associations between summer weather patterns in mid-latitudes and losses of snow and sea ice. Results suggest that the atmospheric circulation responds differently to changes in the ice and snow extents, with a stronger response to sea-ice loss, even though its reduction is half as large as that for the snow cover. Atmospheric changes associated with the combined snow/ice reductions reveal widespread upper-level height increases, weaker upper-level zonal winds at high latitudes, a more amplified upper-level pattern, and a general northward shift in the jet stream. More frequent extreme summer heat events over mid-latitude continents are linked with reduced sea ice and snow through these circulation changes.

Cite this article

Tang, Q., Zhang, X. & Francis, J. Extreme summer weather in northern mid-latitudes linked to a vanishing cryosphere. Nature Clim Change 4, 45–50 (2014). https://doi.org/10.1038/nclimate2065

View full text

>> Full Text:   Extreme summer weather in northern mid-latitudes linked to a vanishing cryosphere

Sensitivity of collective action to uncertainty about climate tipping points

El Niño–La Niña cycle and recent trends in continental evaporation