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The robustness of midlatitude weather pattern changes due to arctic sea ice loss

Chen, Hans W. LU ; Zhang, Fuqing and Alley, Richard B. (2016) In Journal of Climate 29(21). p.7831-7849
Abstract

The significance and robustness of the link between Arctic sea ice loss and changes in midlatitude weather patterns is investigated through a series of model simulations from the Community Atmosphere Model, version 5.3, with systematically perturbed sea ice cover in the Arctic. Using a large ensemble of 10 sea ice scenarios and 550 simulations, it is found that prescribed Arctic sea ice anomalies produce statistically significant changes for certain metrics of the midlatitude circulation but not for others. Furthermore, the significant midlatitude circulation changes do not scale linearly with the sea ice anomalies and are not present in all scenarios, indicating that the remote atmospheric response to reduced Arctic sea ice can be... (More)

The significance and robustness of the link between Arctic sea ice loss and changes in midlatitude weather patterns is investigated through a series of model simulations from the Community Atmosphere Model, version 5.3, with systematically perturbed sea ice cover in the Arctic. Using a large ensemble of 10 sea ice scenarios and 550 simulations, it is found that prescribed Arctic sea ice anomalies produce statistically significant changes for certain metrics of the midlatitude circulation but not for others. Furthermore, the significant midlatitude circulation changes do not scale linearly with the sea ice anomalies and are not present in all scenarios, indicating that the remote atmospheric response to reduced Arctic sea ice can be statistically significant under certain conditions but is generally nonrobust. Shifts in the Northern Hemisphere polar jet stream and changes in the meridional extent of upper-level large-scale waves due to the sea ice perturbations are generally small and not clearly distinguished from intrinsic variability. Reduced Arctic sea ice may favor a circulation pattern that resembles the negative phase of the Arctic Oscillation and may increase the risk of cold outbreaks in eastern Asia by almost 50%, but this response is found in only half of the scenarios with negative sea ice anomalies. In eastern North America the frequency of extreme cold events decreases almost linearly with decreasing sea ice cover. This study's finding of frequent significant anomalies without a robust linear response suggests interactions between variability and persistence in the coupled system, which may contribute to the lack of convergence among studies of Arctic influences on midlatitude circulation.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Arctic, Atmospheric circulation, Climate models, Climate variability, Ensembles, Sea ice
in
Journal of Climate
volume
29
issue
21
pages
19 pages
publisher
American Meteorological Society
external identifiers
  • scopus:84995480650
ISSN
0894-8755
DOI
10.1175/JCLI-D-16-0167.1
language
English
LU publication?
no
id
7f2e780a-2fe7-4d83-8d11-7ab335a6a0b7
date added to LUP
2019-11-13 16:24:03
date last changed
2020-05-26 05:35:19
@article{7f2e780a-2fe7-4d83-8d11-7ab335a6a0b7,
  abstract     = {<p>The significance and robustness of the link between Arctic sea ice loss and changes in midlatitude weather patterns is investigated through a series of model simulations from the Community Atmosphere Model, version 5.3, with systematically perturbed sea ice cover in the Arctic. Using a large ensemble of 10 sea ice scenarios and 550 simulations, it is found that prescribed Arctic sea ice anomalies produce statistically significant changes for certain metrics of the midlatitude circulation but not for others. Furthermore, the significant midlatitude circulation changes do not scale linearly with the sea ice anomalies and are not present in all scenarios, indicating that the remote atmospheric response to reduced Arctic sea ice can be statistically significant under certain conditions but is generally nonrobust. Shifts in the Northern Hemisphere polar jet stream and changes in the meridional extent of upper-level large-scale waves due to the sea ice perturbations are generally small and not clearly distinguished from intrinsic variability. Reduced Arctic sea ice may favor a circulation pattern that resembles the negative phase of the Arctic Oscillation and may increase the risk of cold outbreaks in eastern Asia by almost 50%, but this response is found in only half of the scenarios with negative sea ice anomalies. In eastern North America the frequency of extreme cold events decreases almost linearly with decreasing sea ice cover. This study's finding of frequent significant anomalies without a robust linear response suggests interactions between variability and persistence in the coupled system, which may contribute to the lack of convergence among studies of Arctic influences on midlatitude circulation.</p>},
  author       = {Chen, Hans W. and Zhang, Fuqing and Alley, Richard B.},
  issn         = {0894-8755},
  language     = {eng},
  month        = {01},
  number       = {21},
  pages        = {7831--7849},
  publisher    = {American Meteorological Society},
  series       = {Journal of Climate},
  title        = {The robustness of midlatitude weather pattern changes due to arctic sea ice loss},
  url          = {http://dx.doi.org/10.1175/JCLI-D-16-0167.1},
  doi          = {10.1175/JCLI-D-16-0167.1},
  volume       = {29},
  year         = {2016},
}