scholarly journals The Atmospheric Response to Realistic Reduced Summer Arctic Sea Ice Anomalies

2013 ◽  
pp. 91-110 ◽  
Author(s):  
Uma S. Bhatt ◽  
Michael A. Alexander ◽  
Clara Deser ◽  
John E. Walsh ◽  
Jack S. Miller ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Arctic Sea

scholarly journals Autumn atmospheric response to the 2007 low Arctic sea ice extent in coupled ocean–atmosphere hindcasts

2011 ◽  
Vol 38 (11-12) ◽  
pp. 2437-2448 ◽  
Author(s):  
Yvan J. Orsolini ◽  
Retish Senan ◽  
Rasmus E. Benestad ◽  
Arne Melsom
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Sea Ice Extent ◽  
Arctic Sea ◽  
Ocean Atmosphere ◽  
Low Arctic ◽  
Arctic Sea Ice Extent

scholarly journals Atmospheric Response to Arctic and Antarctic Sea Ice: The Importance of Ocean–Atmosphere Coupling and the Background State

2017 ◽  
Vol 30 (12) ◽  
pp. 4547-4565 ◽  
Author(s):  
Doug M. Smith ◽  
Nick J. Dunstone ◽  
Adam A. Scaife ◽  
Emma K. Fiedler ◽  
Dan Copsey ◽  
...  
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
The North ◽  
Antarctic Sea Ice ◽  
Arctic Sea ◽  
Ocean Atmosphere ◽  
The North Atlantic ◽  
Background State

The atmospheric response to Arctic and Antarctic sea ice changes typical of the present day and coming decades is investigated using the Hadley Centre global climate model (HadGEM3). The response is diagnosed from ensemble simulations of the period 1979 to 2009 with observed and perturbed sea ice concentrations. The experimental design allows the impacts of ocean–atmosphere coupling and the background atmospheric state to be assessed. The modeled response can be very different to that inferred from statistical relationships, showing that the response cannot be easily diagnosed from observations. Reduced Arctic sea ice drives a local low pressure response in boreal summer and autumn. Increased Antarctic sea ice drives a poleward shift of the Southern Hemisphere midlatitude jet, especially in the cold season. Coupling enables surface temperature responses to spread to the ocean, amplifying the atmospheric response and revealing additional impacts including warming of the North Atlantic in response to reduced Arctic sea ice, with a northward shift of the Atlantic intertropical convergence zone and increased Sahel rainfall. The background state controls the sign of the North Atlantic Oscillation (NAO) response via the refraction of planetary waves. This could help to resolve differences in previous studies, and potentially provides an “emergent constraint” to narrow the uncertainties in the NAO response, highlighting the need for future multimodel coordinated experiments.

scholarly journals Are 100 ensemble members enough to capture the remote atmospheric response to +2°C Arctic sea ice loss ?

2021 ◽  
pp. 1-54
Author(s):  
Y. Peings ◽  
Z. Labe ◽  
G. Magnusdottir
Keyword(s):  
Sea Ice ◽  
General Circulation ◽  
Internal Variability ◽  
General Circulation Models ◽  
Arctic Sea Ice ◽  
Model Assessment ◽  
Atmospheric Response ◽  
Arctic Sea ◽  
Ocean Atmosphere ◽  
Arctic Sea Ice Loss

AbstractThis study presents results from the Polar Amplification Multimodel Intercomparison Project (PAMIP) single-year time-slice experiments that aim to isolate the atmospheric response to Arctic sea ice loss at global warming levels of +2°C. Using two General Circulation Models (GCMs), the ensemble size is increased up to 300 ensemble members, beyond the recommended 100 members. After partitioning the response in groups of 100-ensemble members, the reproducibility of the results is evaluated, with a focus on the response of the mid-latitude jet streams in the North Atlantic and North Pacific. Both atmosphere-only and coupled ocean-atmosphere PAMIP experiments are analyzed. Substantial differences in the mid-latitude response are found among the different experiment subsets, suggesting that 100-member ensembles are still significantly influenced by internal variability, which can mislead conclusions. Despite an overall stronger response, the coupled ocean-atmosphere runs exhibit greater spread due to additional ENSO-related internal variability when the ocean is interactive. The lack of consistency in the response is true for anomalies that are statistically significant according to Student’s-t and False Discovery Rate tests. This is problematic for the multi-model assessment of the response, as some of the spread may be attributed to different model sensitivities while it is due to internal variability. We propose a method to overcome this consistency issue, that allows for more robust conclusions when only 100 ensemble members are used.

Role of the internal climate variability in the atmospheric response to a sudden summer Arctic sea ice loss

2021 ◽  
Author(s):  
Steve Delhaye ◽  
Thierry Fichefet ◽  
François Massonnet ◽  
David Docquier ◽  
Christopher Roberts ◽  
...  
Keyword(s):  
Climate Variability ◽  
Sea Ice ◽  
Signal To Noise Ratio ◽  
Horizontal Resolution ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Signal To Noise ◽  
Internal Climate Variability ◽  
Arctic Sea ◽  
Arctic Sea Ice Loss

<p>The retreat of Arctic sea ice for the last four decades is a primary manifestation of the climate system response to increasing atmospheric greenhouse gas concentrations. This retreat is frequently considered as a possible driver of atmospheric circulation anomalies at mid-latitudes. However, the year-to-year evolution of the Arctic sea ice cover is also characterized by significant fluctuations attributed to internal climate variability. It is unclear how the atmosphere will respond to a near-total retreat of summer Arctic sea ice, a reality that might occur in the foreseeable future. This study uses sensitivity experiments  with higher and lower horizontal resolution configurations of three global coupled climate models to investigate the local and remote atmospheric responses to a reduction in Arctic sea ice cover during the preceding summer. Recognizing that these responses likely depend on the model itself and on its horizontal resolution, and that the model’s internally-generated climate variability may obscure the atmospheric response, we design a protocol to compare each source separately. After imposing a 15-month albedo perturbation resulting in a sudden summer Arctic sea ice loss, the remote mid-latitude climate response has a very low signal-to-noise ratio such that internal climate variability dominates the uncertainty of the response, regardless of the atmospheric variable. Indeed, more than 28, 165 and 210 members are needed to detect a robust response in surface air temperature, precipitation and sea level pressure to sea ice loss in Europe, respectively. Finally, we find that horizontal resolution plays a secondary role in the uncertainty of the atmospheric response to substantial perturbation of Arctic sea ice. These findings suggest that even with higher resolution model configurations, it is important to have large ensemble sizes to increase the signal to noise ratio for the mid-latitude atmospheric response to sea ice changes.</p>

scholarly journals Dynamical and thermodynamical contributions to the mid-latitude atmospheric response to Arctic sea ice decline

2021 ◽  
Author(s):  
Svenya Chripko ◽  
Rym Msadek ◽  
Emilia Sanchez-Gomez ◽  
Laurent Terray ◽  
Laurent Bessières ◽  
...  
Keyword(s):  
North America ◽  
Sea Ice ◽  
Central Asia ◽  
Climate Model ◽  
Temperature Response ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Near Surface ◽  
Sea Ice Decline ◽  
Arctic Sea

<p>Previous climate model studies have shown that Arctic sea ice decline can solely affect weather and climate at lower latitudes during the cold season. However, the mechanisms beneath this linkage are poorly understood. Whether sea ice loss have had an influence on the lower latitudes climate over the past decades is also uncertain (Barnes and Screen 2015). The goal of this work is to better understand the relative contributions of dyncamical and thermodynamical changes in the atmospheric response to Arctic sea ice loss, which have been suggested to oppose each other (Screen 2017). We conducted two sets of sensitivity transient experiments that allow to isolate the effect of Arctic sea ice decline on the mid-latitudes from other climate forcings, using the climate model CNRM-CM6 (Voldoire et al. 2019) in a coupled configuration or with an atmosphere-only. The first set of experiments, that is part of the European H2020 PRIMAVERA project, consists of a 100-member ensemble in which sea ice albedo is reduced to the ocean value (PERT) in the fully coupled CNRM-CM6, and which is compared to a 1950 control run (CTL) (Haarsma et al. 2016). This yields idealised ice-free conditions in summer and a more moderate sea ice reduction during the following months. The second set of experiments, that is part of the CMIP6 Polar Amplification Model Intercomparison Project (PAMIP, Smith et al. 2019), consists of a 300-member ensemble in which the atmospheric component of CNRM-CM6 is forced by sea ice anomalies associated with a future 2°C warming (FUT) and present day sea surface temperatures (SSTs). These are compared to experiments in which the atmosphere is forced by present-day sea ice conditions (PD) and the same SSTs. To extract the dynamical component of the response in the two sets of experiments, we use a dynamical adjustment method (Deser et al. 2016) based on a regional reconstruction of circulation analogs. We focus on three mid-latitudes regions in which a significant near-surface temperature response has been identified, namely North America, Europe and central Asia. We show that the cooling occurring over central Asia in both sets of experiments is dynamically-induced through an intensification of the Siberian High, and that opposed temperature responses over North America between the two sets of experiments could be explained by opposed dynamical components occurring in response to the imposed Arctic sea ice decline. Finally, we discuss whether different dynamical and thermodynamical contributions in the PAMIP multi-model experiments could explain the multi-model differences in the atmospheric response to sea ice loss.</p>

Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models

2018 ◽  
Vol 11 (3) ◽  
pp. 155-163 ◽  
Author(s):  
James A. Screen ◽  
Clara Deser ◽  
Doug M. Smith ◽  
Xiangdong Zhang ◽  
Russell Blackport ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Arctic Sea ◽  
Arctic Sea Ice Loss

Response of Northern Hemisphere weather and climate to Arctic sea ice decline: The role of resolution in Polar Amplification Model Intercomparison Project (PAMIP) simulations

2021 ◽  
Author(s):  
Jan Streffing ◽  
Tido Semmler ◽  
Lorenzo Zampieri ◽  
Thomas Jung
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Model Intercomparison ◽  
Polar Amplification ◽  
Sea Ice Decline ◽  
Arctic Sea ◽  
Weather And Climate ◽  
Intercomparison Project ◽  
The Mean

<p>The impact of Arctic sea ice decline on the weather and climate in mid-latitudes is still much debated, with observation suggesting a strong and models a much weaker link. In this study, we use the atmospheric model OpenIFS, in a set of model experiments following the protocol outlined in the Polar Amplification Model Intercomparison Project (PAMIP), to investigate whether the simulated atmospheric response to future changes in Arctic sea ice fundamentally depends on model resolution. More specifically, we increase the horizontal resolution of the model from 125km to 39km with 91 vertical levels; in a second step resolution is further increased to 16km with 137 levels in the vertical. We find that neither the mean atmospheric response nor the ensemble convergence toward the mean are strongly impacted by the model resolutions considered here.</p>

The Atmospheric Response to Realistic Arctic Sea Ice Anomalies in an AGCM during Winter

2004 ◽  
Vol 17 (5) ◽  
pp. 890-905 ◽  
Author(s):  
Michael A. Alexander ◽  
Uma S. Bhatt ◽  
John E. Walsh ◽  
Michael S. Timlin ◽  
Jack S. Miller ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Arctic Sea

scholarly journals The Effect of QBO Phase on the Atmospheric Response to Projected Arctic Sea Ice Loss in Early Winter

2019 ◽  
Vol 46 (13) ◽  
pp. 7663-7671 ◽  
Author(s):  
Zachary Labe ◽  
Yannick Peings ◽  
Gudrun Magnusdottir
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Response ◽  
Early Winter ◽  
Arctic Sea ◽  
Arctic Sea Ice Loss
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