Recent advances in understanding the Arctic climate system state and change from a sea ice perspective: a review

Abstract

Abstract. Sea ice is the central component and most sensitive indicator of the Arctic climate system. Both the depletion and areal decline of the Arctic sea ice cover, observed since the 1970s, have accelerated since the millennium. While the relationship of global warming to sea ice reduction is evident and underpinned statistically, it is the connecting mechanisms that are explored in detail in this review.Sea ice erodes both from the top and the bottom. Atmospheric, oceanic and sea ice processes interact in nonlinear 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, at the same time, accelerates ice reduction. Knowledge of the mechanisms of sea ice decline grew during the 1990s and This article reviews recent progress in understanding the sea ice decline. Processes are revisited from atmospheric, oceanic and sea ice perspectives. There is strong evidence that decisive atmospheric changes are the major driver of sea ice change. Feedbacks due to reduced ice concentration, surface albedo, and ice thickness allow for additional local atmospheric and oceanic influences and self-supporting feedbacks. Large-scale ocean influences on 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. There is little indication of a direct and 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.

Arctic Sea Ice: Decadal Simulations and Future Scenarios Using BESM-OA

“…To remove the strong seasonal cycle, we again specifically focus on September since it shows the minimum annual of SIE. According to Doescher et al [5], the ability to identify real changes in the Arctic Climate System increases when we focus on individual seasons. In this context, Figure 5 shows the SIE time series of September averages from 1982 to 2014.…”

“…Sea ice formation, growth and decay are closely related to air temperature, ocean heat content, albedo and heat fluxes and hence can vary strongly from month to month [5] [40].…”

“…According to Holland and Bitz [3] and Curry et al [9], the range of simulated polar warming is from 1.5 to 4.5 times the global mean warming and is widely related to the sea ice-albedo feedback mechanism. Most of the climate models agree that the global air temperature will continue to rise, particularly in northern high latitudes and the Arctic will become ice free in the summer in approximately 30 years, as a response to an increase in atmospheric greenhouse gas concentrations [1] [5]. The impacts of melting sea ice in recent and future decades have not yet been fully understood and accurately quantified.…”

“…Notz and Marotzke [4] and Doescher et al [5], indicate that sea ice cover is a more robust indicator of climate change than temperature trends alone, because sea ice changes depend on integrated changes in atmospheric and ocean variables with non linear impacts, on various temporal and spatial scales under global climate forcing.…”

“…The BESM model, also aims to contribute to Program for Climate Model Diagnostics and Intercomparison (PCMDI) with short-term and long-term simulations, as well as to provide futures scenarios of climate change [18]. Based on several studies and reports [5] [14] [17] [19] and understanding the importance of sea ice in the global climate system and the global economy, BESM simulations are expected to contribute with, among other variables, sea ice short and long-term simulations. BESM simulations can also be useful for future studies on ocean-atmosphere-sea ice coupling processes and impacts of sea ice loss around the world.…”