The refreezing of melt ponds on Arctic sea ice. Issue 2 (5th February 2015)

• Record Type: Journal Article
• Authors: Flocco, Daniela; Feltham, Daniel L.; Bailey, Eleanor; Schroeder, David
• Is Part Of: Journal of geophysical research. Volume 120:Issue 2(2015:Feb.)
• Page Start: 647
• Page End: 659
• Publication Date: 2015-02-05
• Subjects: refreezing melt ponds -- sea ice -- global climate model; Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/2014JC010140
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: The presence of melt ponds on the surface of Arctic sea ice significantly reduces its albedo, inducing a positive feedback leading to sea ice thinning. While the role of melt ponds in enhancing the summer melt of sea ice is well known, their impact on suppressing winter freezing of sea ice has, hitherto, received less attention. Melt ponds freeze by forming an ice lid at the upper surface, which insulates them from the atmosphere and traps pond water between the underlying sea ice and the ice lid. The pond water is a store of latent heat, which is released during refreezing. Until a pond freezes completely, there can be minimal ice growth at the base of the underlying sea ice. In this work, we present a model of the refreezing of a melt pond that includes the heat and salt balances in the ice lid, trapped pond, and underlying sea ice. The model uses a two‐stream radiation model to account for radiative scattering at phase boundaries. Simulations and related sensitivity studies suggest that trapped pond water may survive for over a month. We focus on the role that pond salinity has on delaying the refreezing process and retarding basal sea ice growth. We estimate that for a typical sea ice pond coverage in autumn, excluding the impact of trapped ponds in models overestimates ice growth by up to 265 million km 3, an overestimate of 26%. Key Points: Salt release delays melt pond refreezing Pond refreezing prevents basal sea ice growth for some time Refreezing is increasingly important over thin ice