Observations of the summer breakup of an Arctic sea ice cover

Abstract

The Arctic sea ice cover evolves dramatically through the summer melt season. Floe size distribution (FSD) is a critical parameter used to examine this change as the ice cover transitions from large rectilinear plates in spring to an ensemble of discrete rounded floes by midsummer. The FSD at a given time impacts the dynamic and thermodynamic behavior of the ice cover. Focusing on the seasonal marginal ice zone in the Beaufort and Chukchi Seas from May to September 2014, we present qualitative and quantitative results derived from National Technical Means high‐resolution imagery and supported by ice mass balance buoy data. Results indicate that as melt accelerates, floe breaking pattern, and therefore FSD, is heavily influenced by the distribution of melt ponds. Discrete element model results using morphological conditions derived from analyzed satellite imagery confirmed that breaking occurs along ponds and perpendicular to applied stress.

Mapping and assessing variability in the Antarctic marginal ice zone, pack ice and coastal polynyas in two sea ice algorithms with implications on breeding success of snow petrels

“…This will result in different proportions of MIZ and consolidated pack ice. In the Arctic, the MIZ is driven not only by wave mechanics and flow breaking (dynamic origin) but also by melt pond processes in summer (thermodynamic origin) (Arnsten et al, 2015). Thus, larger sensitivity of the NT algorithm to melt processes may be one reason for the larger discrepancy observed in the MIZ between the algorithms for the Arctic.…”

Simultaneous disintegration of outlet glaciers in Porpoise Bay (Wilkes Land), East Antarctica, driven by sea ice break-up

“…In the Arctic, sea ice melt-ponding along pre-existing weaknesses has been widely reported to precede sea ice break-up (Ehn et al, 2011;Petrich et al, 2012;Landy et al, 2014;Schroder et al, 2014;Arntsen et al, 2015). Despite its importance in the Arctic, it has yet to be considered as a possible factor in landfast sea ice break-up in coastal Antarctica.…”

Thin ice and storms: Sea ice deformation from buoy arrays deployed during N‐ICE2015

“…The wind and ocean driven sea ice drift are not uniform and the differential motion causes the ice to break and deform in features such as pressure ridges and leads. When the sea ice starts to melt in summer these features are the weak points along which the ice cover disintegrates [Perovich et al, 2001;Arntsen et al, 2015]. The summer sea ice extent can be additionally impacted by the storms and swell [Asplin et al, 2012;Zhang et al, 2013], but much of it is preconditioned by the sea ice dynamics during the cold season [e.g., Kauker et al, 2009;Kimura et al, 2013].…”