Impacts of Arctic sea ice on cold season atmospheric variability and trends estimated from observations and a multimodel large ensemble

• Main Authors: Liang, Yu-Chiao, Frankignoul, Claude, Kwon, Young-Oh, Gastineau, Guillaume, Manzini, Elisa, Danabasoglu, Gokhan, Suo, Lingling, Yeager, Stephen G., Gao, Yongqi, Attema, Jisk J., Cherchi, Annalisa, Ghosh, Rohit, Matei, Daniela, Mecking, Jennifer V., Tian, Tian, Zhang, Ying
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Meteorological Society 2021
• Subjects: Arctic; Sea ice; Atmospheric circulation; Climate models; Suo; North Atlantic; North Atlantic oscillation
• Online Access: https://hdl.handle.net/1912/28966

Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Liang, Y.-C., Frankignoul, C., Kwon, Y.-O., Gastineau, G., Manzini, E., Danabasoglu, G., Suo, L., Yeager, S., Gao, Y., Attema, J. J., Cherchi, A., Ghosh, R., Matei, D., Mecking, J., Tian, T., & Zhang, Y. Impacts of Arctic sea ice on cold season atmospheric variability and trends estimated from observations and a multimodel large ensemble. Journal of Climate, 34(20), (2021): 8419–8443, https://doi.org/10.1175/JCLI-D-20-0578.s1. To examine the atmospheric responses to Arctic sea ice variability in the Northern Hemisphere cold season (from October to the following March), this study uses a coordinated set of large-ensemble experiments of nine atmospheric general circulation models (AGCMs) forced with observed daily varying sea ice, sea surface temperature, and radiative forcings prescribed during the 1979–2014 period, together with a parallel set of experiments where Arctic sea ice is substituted by its climatology. The simulations of the former set reproduce the near-surface temperature trends in reanalysis data, with similar amplitude, and their multimodel ensemble mean (MMEM) shows decreasing sea level pressure over much of the polar cap and Eurasia in boreal autumn. The MMEM difference between the two experiments allows isolating the effects of Arctic sea ice loss, which explain a large portion of the Arctic warming trends in the lower troposphere and drive a small but statistically significant weakening of the wintertime Arctic Oscillation. The observed interannual covariability between sea ice extent in the Barents–Kara Seas and lagged atmospheric circulation is distinguished from the effects of confounding factors based on multiple regression, and quantitatively compared to the covariability in MMEMs. The interannual sea ice decline followed by a negative North Atlantic Oscillation–like ...