Observations of flooding and snow‐ice formation in a thinner Arctic sea‐ice regime during the N‐ICE2015 campaign: Influence of basal ice melt and storms

• DOI: 10.1002/2016jc012011
• Publication Date: 2017-02-14T08:37:11Z
• Authors: Christine Provost; Nathalie Sennéchael; Jonas Miguet; Polona Itkin; Anja Rösel; Zoé Koenig; Nicolas Villacier...; Mats A. Granskog
• Keywords: Slush; Pancake ice; Clear ice; Melt pond; Ice divide; Fast ice

Abstract Seven ice mass balance instruments deployed near 83°N on different first‐year and second‐year floes, representing variable snow conditions, documented the evolution of conditions in Arctic Ocean north Svalbard January–March 2015. Frequent profiles temperature thermal diffusivity proxy were recorded to distinguish changes depth thickness with 2 cm vertical resolution. Four flooding ‐ formation. Flooding was clearly detectable simultaneous proxy, increased temperature, heat propagation through underlying ice. Slush then progressively transformed into snow‐ice. resulted from two processes: (i) after storm‐induced breakup snow‐loaded floes (ii) loss buoyancy due basal melt. In case breakup, when cold not permeable, rapid flooding, probably lateral intrusion seawater, led slush snow‐ice layers at ocean freezing (−1.88°C). After storm, sea‐ice melt over warm Atlantic waters ocean‐to‐ice flux peaked up 400 W m −2 . The permeable more gradual involving brines colder (−3°C). N‐ICE2015 campaign provided first documentation significant formation pack as partially refroze. Snow‐ice may become a frequently observed process thinner Arctic.