Arctic Energy Budget in Relation to Sea Ice Variability on Monthly-to-Annual Time Scales

Abstract

The large decrease in Arctic sea ice in recent years has triggered a strong interest in Arctic sea ice predictions on seasonal-to-decadal time scales. Hence, it is important to understand physical processes that provide enhanced predictability beyond persistence of sea ice anomalies. This study analyzes the natural variability of Arctic sea ice from an energy budget perspective, using 15 climate models from phase 5 of CMIP (CMIP5), and compares these results to reanalysis data. The authors quantify the persistence of sea ice anomalies and the cross correlation with the surface and top-of-atmosphere energy budget components. The Arctic energy balance components primarily indicate the important role of the seasonal ice-albedo feedback, through which sea ice anomalies in the melt season reemerge in the growth season. This is a robust anomaly reemergence mechanism among all 15 climate models. The role of the ocean lies mainly in storing heat content anomalies in spring and releasing them in autumn. Ocean heat flux variations play only a minor role. Confirming a previous (observational) study, the authors demonstrate that there is no direct atmospheric response of clouds to spring sea ice anomalies, but a delayed response is evident in autumn. Hence, there is no cloud-ice feedback in late spring and summer, but there is a cloud-ice feedback in autumn, which strengthens the ice-albedo feedback. Anomalies in insolation are positively correlated with sea ice variability. This is primarily a result of reduced multiple reflection of insolation due to an albedo decrease. This effect counteracts the ice-albedo effect up to 50%. ERA-Interim and Ocean Reanalysis System 4 (ORAS4) confirm the main findings from the climate models.

Recent Advances in Arctic Cloud and Climate Research

“…In a warmer world with more open water and less sea ice, there is less multiple scattering between the bright clouds and the surface. As a result, there is less downwelling shortwave radiation in a warmer world with less sea ice (e.g., DeWeaver et al [52], Frikken and Hazeleger [53]). Importantly, because these downwelling shortwave radiation reductions are driven by surface albedo reductions, they occur even if the clouds remain identical (i.e., if there is no cloud response to summer sea ice loss as suggested by discovery no.…”

Magnitude and pattern of Arctic warming governed by the seasonality of radiative forcing

“…An important aspect of the seasonal response is the ice-albedo feedback, which operates mainly in the spring/summer seasons. However, this feedback contributes to winter warming20 through interacting with storage (in summer) and release (in winter) of heat in the Arctic Ocean2521. Arctic winter warming is further amplified by feedbacks that operate in wintertime, such as the lapse-rate feedback7.…”

Autumn Arctic Pacific Sea Ice Dipole as a Source of Predictability for Subsequent Spring Barents Sea Ice Condition

“…Multiple mechanisms have been investigated to understand the origin of the sea ice variability. Some studies attributed it to atmospheric dynamical and radiative drivers (e.g., Kay et al 2008;Graversen et al 2011;Herbaut et al 2015;Urrego-Blanco et al 2019), while others emphasized the roles of oceanic and sea ice processes (e.g., Shimada et al 2006;Yeager et al 2015;Zhang 2015;Årthun et al 2017;Oldenburg et al 2018) and their interactions (e.g., Nakanowatari et al 2014;Krikken and Hazeleger 2015). The interplay of natural variability and decreasing trend leads to spatial heterogeneity of the sea ice variability (Close et al 2015;Zhang 2015;Lee et al 2017;Onarheim and Årthun 2017).…”