Arctic Sea Ice Decline: Introduction

Author(s):  
Eric T. DeWeaver
2014 ◽  
Vol 14 (7) ◽  
pp. 10929-10999 ◽  
Author(s):  
R. Döscher ◽  
T. Vihma ◽  
E. Maksimovich

Abstract. The Arctic sea ice is the central and essential component of the Arctic climate system. The depletion and areal decline of the Arctic sea ice cover, observed since the 1970's, have accelerated after the millennium shift. While a relationship to global warming is evident and is underpinned statistically, the mechanisms connected to the sea ice reduction are to be explored in detail. Sea ice erodes both from the top and from the bottom. Atmosphere, sea ice and ocean processes interact in non-linear ways on various scales. Feedback mechanisms lead to an Arctic amplification of the global warming system. The amplification is both supported by the ice depletion and is at the same time accelerating the ice reduction. Knowledge of the mechanisms connected to the sea ice decline has grown during the 1990's and has deepened when the acceleration became clear in the early 2000's. Record summer sea ice extents in 2002, 2005, 2007 and 2012 provided additional information on the mechanisms. This article reviews recent progress in understanding of the sea ice decline. Processes are revisited from an atmospheric, ocean and sea ice perspective. There is strong evidence for decisive atmospheric changes being the major driver of sea ice change. Feedbacks due to reduced ice concentration, surface albedo and thickness allow for additional local atmosphere and ocean influences and self-supporting feedbacks. Large scale ocean influences on the Arctic Ocean hydrology and circulation are highly evident. Northward heat fluxes in the ocean are clearly impacting the ice margins, especially in the Atlantic sector of the Arctic. Only little indication exists for a direct decisive influence of the warming ocean on the overall sea ice cover, due to an isolating layer of cold and fresh water underneath the sea ice.


2020 ◽  
Vol 47 (3) ◽  
Author(s):  
Qiang Wang ◽  
Claudia Wekerle ◽  
Xuezhu Wang ◽  
Sergey Danilov ◽  
Nikolay Koldunov ◽  
...  

2015 ◽  
Vol 112 (15) ◽  
pp. 4570-4575 ◽  
Author(s):  
Rong Zhang

Satellite observations reveal a substantial decline in September Arctic sea ice extent since 1979, which has played a leading role in the observed recent Arctic surface warming and has often been attributed, in large part, to the increase in greenhouse gases. However, the most rapid decline occurred during the recent global warming hiatus period. Previous studies are often focused on a single mechanism for changes and variations of summer Arctic sea ice extent, and many are based on short observational records. The key players for summer Arctic sea ice extent variability at multidecadal/centennial time scales and their contributions to the observed summer Arctic sea ice decline are not well understood. Here a multiple regression model is developed for the first time, to the author’s knowledge, to provide a framework to quantify the contributions of three key predictors (Atlantic/Pacific heat transport into the Arctic, and Arctic Dipole) to the internal low-frequency variability of Summer Arctic sea ice extent, using a 3,600-y-long control climate model simulation. The results suggest that changes in these key predictors could have contributed substantially to the observed summer Arctic sea ice decline. If the ocean heat transport into the Arctic were to weaken in the near future due to internal variability, there might be a hiatus in the decline of September Arctic sea ice. The modeling results also suggest that at multidecadal/centennial time scales, variations in the atmosphere heat transport across the Arctic Circle are forced by anticorrelated variations in the Atlantic heat transport into the Arctic.


2019 ◽  
Vol 32 (15) ◽  
pp. 4731-4752 ◽  
Author(s):  
Axel J. Schweiger ◽  
Kevin R. Wood ◽  
Jinlun Zhang

Abstract PIOMAS-20C, an Arctic sea ice reconstruction for 1901–2010, is produced by forcing the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) with ERA-20C atmospheric data. ERA-20C performance over Arctic sea ice is assessed by comparisons with measurements and data from other reanalyses. ERA-20C performs similarly with respect to the annual cycle of downwelling radiation, air temperature, and wind speed compared to reanalyses with more extensive data assimilation such as ERA-Interim and MERRA. PIOMAS-20C sea ice thickness and volume are then compared with in situ and aircraft remote sensing observations for the period of ~1950–2010. Error statistics are similar to those for PIOMAS. We compare the magnitude and patterns of sea ice variability between the first half of the twentieth century (1901–40) and the more recent period (1980–2010), both marked by sea ice decline in the Arctic. The first period contains the so-called early-twentieth-century warming (ETCW; ~1920–40) during which the Atlantic sector saw a significant decline in sea ice volume, but the Pacific sector did not. The sea ice decline over the 1979–2010 period is pan-Arctic and 6 times larger than the net decline during the 1901–40 period. Sea ice volume trends reconstructed solely from surface temperature anomalies are smaller than PIOMAS-20C, suggesting that mechanisms other than warming, such as changes in ice motion and deformation, played a significant role in determining sea ice volume trends during both periods.


2008 ◽  
Vol 2 (5) ◽  
pp. 759-776 ◽  
Author(s):  
J. O. Sewall

Abstract. Satellite observations and model predictions of recent and future Arctic sea ice decline have raised concerns over the timing and potential impacts of a seasonally ice-free Arctic Ocean. Model predictions of seasonally ice-free Arctic conditions are, however, highly variable. Here I present results from fourteen climate system models from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset that indicate modeled Arctic sea ice sensitivity to increased atmospheric CO2 forcing is strongly correlated with ice/ocean model horizontal resolution. Based on coupled model analyses and ice only simulations with the Los Alamos National Lab sea ice model (CICE), the correlation between declining Arctic sea ice cover and ice/ocean model resolution appears to depend largely on ocean model resolution and its influence on ocean heat transport into the Arctic basin. The correlation between model resolution, northward ocean heat transport, and the degree of Arctic ice loss is independent of ice model physics and complexity. This not only illustrates one difficulty in using numerical models to accurately predict the timing and magnitude of Arctic sea ice decline under increasing atmospheric greenhouse gas forcing, but also highlights one area where improved simulation (of northward ocean heat transport) could greatly decrease the uncertainties associated with predictions of future Arctic sea ice cover.


2020 ◽  
Author(s):  
David Lipson ◽  
Kim Reasor ◽  
Kååre Sikuaq Erickson

<p>The predominantly Inupiat people of Utqiaġvik, Alaska are among those who will be most impacted by<br>climate change and the loss of Arctic sea ice in the near future. Subsistence hunting of marine mammals<br>associated with sea ice is central to the Inupiat way of life. Furthermore, their coastal homes and<br>infrastructure are increasingly subject to damage from increased wave action on ice-free Beaufort and<br>Chukchi Seas. While the people of this region are among the most directly vulnerable to climate change,<br>the subject is not often discussed in the elementary school curriculum. Meanwhile, in many other parts<br>of the world, the impacts of climate change are viewed as abstract and remote. We worked with fifth<br>grade children in Utqiaġvik both to educate them, but also to engage them in helping us communicate<br>to rest of the world, in an emotionally resonant way, the direct impacts of climate change on families in<br>this Arctic region.<br>The team consisted of a scientist (Lipson), an artist (Reasor) and an outreach specialist (Erickson) of<br>Inupiat heritage from a village in Alaska. We worked with four 5th grade classes of about 25 students<br>each at Fred Ipalook Elementary in Utqiaġvik, AK. The scientist gave a short lecture about sea ice and<br>climate change in the Arctic, with emphasis on local impacts to hunting and infrastructure (with<br>interjections from the local outreach specialist). We then showed the students a large poster of<br>historical and projected sea ice decline, and asked the students to help us fill in the white space beneath<br>the lines. The artist led the children in making small art pieces that represent things that are important<br>to their lives in Utqiaġvik (they were encouraged to paint animals, but they were free to do whatever<br>they wanted). We returned to the class later that week and had each student briefly introduce<br>themselves and their painting, and place it to the large graph of sea ice decline, which included the dire<br>predictions of the RCP8.5 scenario. At the end we added the more hopeful RCP2.6 scenario to end on a<br>positive note. The artist then painted in the more hopeful green line by hand.<br>The result was a poster showing historical and projected Arctic sea ice cover, with 100 beautiful<br>paintings by children of things that are dear to them about their home being squeezed into a smaller<br>region as the sea ice cover diminishes. We scanned all the artwork to make a digital version of the<br>poster, and left the original with the school. These materials are being converted into an interactive<br>webpage where viewers can click on the individual painting for detail, and get selected recordings of the<br>children’s statements about their artwork. This project can serve as a nucleus for communicating to<br>other classes and adults about the real impacts of climate change in people’s lives.</p>


2014 ◽  
Vol 39 (1) ◽  
pp. 57-89 ◽  
Author(s):  
Uma S. Bhatt ◽  
Donald A. Walker ◽  
John E. Walsh ◽  
Eddy C. Carmack ◽  
Karen E. Frey ◽  
...  

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