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Contributions of aerosol‐cloud interactions to mid‐Piacenzian seasonally sea ice‐free Arctic Ocean
Author(s) -
Feng Ran,
OttoBliesner Bette L.,
Xu Yangyang,
Brady Esther,
Fletcher Tamara,
Ballantyne Ashley
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl083960
Subject(s) - arctic sea ice decline , arctic geoengineering , sea ice , ice albedo feedback , arctic , climatology , arctic ice pack , environmental science , arctic dipole anomaly , oceanography , drift ice , atmospheric sciences , geology
Forcings and feedbacks controlling the seasonally sea ice‐free Arctic Ocean during the mid‐Piacenzian Warm period (3.264–3.025 Ma, MPWP), a period when CO 2 level, geography, and topography were similar to present day, remain unclear given that many complex Earth System Models with comparatively higher skills at simulating twentieth century Arctic sea ice tend to produce perennial Arctic sea ice for this period. We demonstrate that explicitly simulating aerosol‐cloud interactions and the exclusion of industrial pollutants from model forcing conditions is key to simulating seasonally sea ice‐free Arctic Ocean of MPWP. The absence of industrial pollutants leads to fewer and larger cloud droplets over the high‐latitude Northern Europe and North Pacific, which allows greater absorption of solar radiation at the surface during the early summer. This enhanced absorption triggers the seasonally runaway sea ice surface albedo feedback that gives rise to September sea ice‐free Arctic Ocean and strongly amplified northern high‐latitude surface warmth.