The role of Arctic ice reduction in the formation of climatic trends

2021 ◽  
Author(s):  
Gennady Platov ◽  
Vladimir Krupchatnikov ◽  
Vyacheslav Gradov ◽  
Evgeny Volodin ◽  
Irina Borovko
Keyword(s):  

The Arctic Mediterranean Seas constitute an oceanic region in which the thermohaline circulation has a strong advective component and deep ventilation processes are very active relative to other oceanic areas. Details of the nature of these circulation and ventilation processes have been revealed through use of Cs and Sr isotopes from bomb-fallout and nuclear-waste sources as ocean tracers. In both cases, their regional input is dominated by advective supply in the Norwegian Atlantic Current and Norwegian Coastal Current, respectively. The different temporal, spatial, and compositional input patterns of these tracers have been used to study different facets of the regional circulation. These input differences and some representative applications of the use of these tracers are reviewed. The data discussed derive from samples collected both from research vessels and from Arctic ice camps. The topics addressed include: ( a ) the role of Arctic Intermediate Water as source, supplying recent surface water to North Atlantic Deep Water via the Denmark Strait overflow; ( b ) deep convective mixing in the Greenland Sea; ( c ) circulation or recirculation of Atlantic water in the Arctic basins; and ( d ) the role of Arctic shelfwaters in the ventilation of intermediate and deep water in the Eurasian and Canadian basins.


2010 ◽  
Vol 29 (25-26) ◽  
pp. 3590-3597 ◽  
Author(s):  
F. Colleoni ◽  
G. Krinner ◽  
M. Jakobsson
Keyword(s):  

Author(s):  
Gennady Platov ◽  
Vladimir Krupchatnikov ◽  
Viacheslav Gradov ◽  
Irina Borovko ◽  
Evgeny Volodin

The amplified Arctic warming is one of several factors influencing atmospheric dynamics. In this work, we consider a series of numerical experiments to identify the direct role of the Arctic sea ice reduction process in forming climatic trends in the northern hemisphere. Aimed at this, we used two more or less independent mechanisms of ice reduction. The first is traditionally associated with increasing the concentration of carbon dioxide in the atmosphere from the historic level of 360 ppm to 450 ppm and 600 ppm. This growth increases air temperature and decreases the ice volume. The second mechanism is associated with a reduction in the reflectivity of ice and snow. We assume that comparing the results of these two experiments allows us to judge the direct role of ice reduction. The most prominent consequences of ice reduction, as a result, were the weakening of temperature gradient at the tropopause level in mid-latitudes, the slower zonal wind at 50-60∘N, intensification of wave activity in Europe, Western America, and Chukotka, and its weakening in the south of Siberia and Kazakhstan. We also consider how climate change may alter regimes such as blocking and stationary Rossby waves. The study used the INM-CM48 climate system model .


2012 ◽  
Vol 25 (4) ◽  
pp. 1176-1193 ◽  
Author(s):  
Josefino C. Comiso

Abstract The perennial ice area was drastically reduced to 38% of its climatological average in 2007 but recovered slightly in 2008, 2009, and 2010 with the areas being 10%, 24%, and 11% higher than in 2007, respectively. However, trends in extent and area remained strongly negative at −12.2% and −13.5% decade−1, respectively. The thick component of the perennial ice, called multiyear ice, as detected by satellite data during the winters of 1979–2011 was studied, and results reveal that the multiyear ice extent and area are declining at an even more rapid rate of −15.1% and −17.2% decade−1, respectively, with a record low value in 2008 followed by higher values in 2009, 2010, and 2011. Such a high rate in the decline of the thick component of the Arctic ice cover means a reduction in the average ice thickness and an even more vulnerable perennial ice cover. The decline of the multiyear ice area from 2007 to 2008 was not as strong as that of the perennial ice area from 2006 to 2007, suggesting a strong role of second-year ice melt in the latter. The sea ice cover is shown to be strongly correlated with surface temperature, which is increasing at about 3 times the global average in the Arctic but appears weakly correlated with the Arctic Oscillation (AO), which controls the atmospheric circulation in the region. An 8–9-yr cycle is apparent in the multiyear ice record, which could explain, in part, the slight recovery in the last 3 yr.


The Holocene ◽  
2012 ◽  
Vol 23 (2) ◽  
pp. 255-269 ◽  
Author(s):  
A Sousa ◽  
J Morales ◽  
L García-Barrón ◽  
P García-Murillo

This paper analyses a reconstruction of changes from the 17th to the 20th centuries in peat bogs with Erica ciliaris Loefl. ex L. heathlands in southwestern Europe. The reconstruction is performed by means of a multidisciplinary method based on photointerpretation, the examination of historical sources (documentation and maps), and an analysis of microtopography. Historical sources and aerial photos from 1956 and 1987 have also been used to reconstruct the impacts of anthropic activity. In the study area, Doñana Natural Park (SW Iberian Peninsula), peat bogs currently occupy slightly more than 8% of the area that they covered at the beginning of the 17th century. A parallel analysis of anthropic activity in the area over the last four centuries reveals the key role of humans in the disappearance of these peat bogs. This drastic reduction of peat bog area during the 20th century is due to a lowering of the water-table as a result of the impacts of anthropic activity, primarily the establishment of monocultures of Eucalyptus spp. and Pinus pinea. An earlier lowering of the water-table, before these plantations, is attributable to a process of aridisation associated with post-‘Little Ice Age’ warming. Therefore, the impacts associated with climatic trends are synergistically superimposed on those derived from the intense anthropic activity that occurred during the second half of the 20th century. This synergy resulted in a reduction of the surface occupied by the studied peat bogs and their associated E. ciliaris heathlands by 91.1% in SW Europe.


Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 373
Author(s):  
Gennady Platov ◽  
Vladimir Krupchatnikov ◽  
Viacheslav Gradov ◽  
Irina Borovko ◽  
Evgeny Volodin

The amplified warming of the Arctic is one of several factors influencing atmospheric dynamics. In this work, we consider a series of numerical experiments to identify the role of Arctic sea ice reduction in affecting climate trends in the Northern Hemisphere. With this aim in mind, we use two independent mechanisms of ice reduction. The first is traditionally associated with increasing the concentration of carbon dioxide in the atmosphere from the historic level of 360 ppm to 450 ppm and 600 ppm. This growth increases air temperature and decreases the ice volume. The second mechanism is associated with a reduction in the reflectivity of ice and snow. We assume that comparing the results of these two experiments allows us to judge the direct role of ice reduction. The most prominent consequences of ice reduction, as a result, are the weakening of temperature gradient at the tropopause level in mid-latitudes; the slower zonal wind at 50–60∘ N; intensification of wave activity in Europe, Western America, and Chukotka; and its weakening in the south of Siberia and Kazakhstan. We also consider how climate change may alter regimes such as blocking and stationary Rossby waves. The study used the INM-CM48 climate system model.


1997 ◽  
Vol 25 ◽  
pp. 102-106 ◽  
Author(s):  
James Maslanik ◽  
Jeremy Dunn

The role of dynamics in modifying the response of the Arctic ice pack to inter-annually varying forcings and to climate perturbations is investigated using simulations from a two-dimensional ice model and a global climate model (GCM). Inter-annual variability in ice-covered area for 1985-93 is dominated by ice transport, and different transport regimes affect substantially the response of the ice pack to climate perturbations. The thermodynamic-only simulations are more sensitive to initial ice conditions, and respond less than the dynamk-thermodynamic model to small perturbations, but with a greater response to larger perturbations. Comparisons of GCM simulations that use different ice treatments highlights the importance of considering the distribution of ice thickness and extent in assessing climate-change responses.


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