Feedbacks and Interactions: From the Arctic Cryosphere to the Climate System

Abstract

Changes in the Arctic's climate are a result of complex interactions between the cryosphere, atmosphere, ocean, and biosphere. More feedbacks from the cryosphere to climate warming are positive and result in further warming than are negative, resulting in a reduced rate of warming or cooling. Feedbacks operate at different spatial scales; many, such as those operating through albedo and evapotranspiration, will have significant local effects that together could result in global impacts. Some processes, such as changes in carbon dioxide (CO 2 ) emissions, are likely to have very small global effects but uncertainty is high whereas others, such as subsea methane (CH 4 ) emissions, could have large global effects. Some cryospheric processes in the Arctic have teleconnections with other regions and major changes in the cryosphere have been largely a result of large-scale processes, particularly atmospheric and oceanic circulation. With continued climate warming it is highly likely that the cryospheric components will play an increasingly important climatic role. However, the net effect of all the feedbacks is difficult to assess because of the variability in spatial and temporal scales over which they operate. Furthermore, general circulation models (GCMs) do not include all major feedbacks while those included may not be accurately parameterized. The lack of full coupling between surface dynamics and the atmosphere is a major gap in current GCMs.

Exchange of CO<sub>2</sub> in Arctic tundra: impacts of meteorological variations and biological disturbance

“…5) followed analogous patterns compared to other years. This evidence agrees with the literature (Callaghan et al, 2012b;Lund et al, 2017) on the fact that tundra systems can fluctuate in sink strength influenced by factors such as episodic disturbances or species shifts, events which are very difficult to predict.…”

“…With continued warming temperature and longer growing seasons, tundra systems will likely have enhanced GPP and R eco rates, but long-term data with which to investigate and quantify these responses are rare. Further, the effects on net CO 2 sequestration are not known, and may be altered by long-term processes such as vegetation shifts and short-term disturbances like insect pest outbreaks, complicating the prognostic forecast of upcoming C states (Callaghan et al, 2012b;McGuire et al, 2012). Consequently, there is a need to understand how the C cycle behaves over timescales from days to years and the links to environmental drivers.…”

Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system: a review

“…The present level of uncertainty is characterized by the fact that recent improvements in the ECMWF land snow scheme have resulted in a doubling of the snow-albedo feedback (Dutra et al, 2012). Further, the net effect of all the feedbacks taking place in the Arctic is difficult to assess because they operate on different spatial and temporal scales (Callaghan et al, 2012).…”

A Framework for Prioritization, Design and Coordination of Arctic Long-term Observing Networks: A Perspective from the U.S. SEARCH Program

“…Initial synthesis of individual research findings and results from programs focusing on specific aspects of change led the scientific community, through programs such as SEARCH, ScanNet, DAMOCLES and others, to articulate overarching science questions selected to improve understanding and responses to Arctic environmental change (e.g., Dickson, 1999;Overpeck et al, 2005;Callaghan et al, 2011b). However, these science questions evolved somewhat separately from the concerns raised by Arctic residents and others affected by socioeconomic change (Krupnik et al, 2011;Alessa et al, 2013;Johnson et al, 2015).…”