Impact of sea ice initialization on sea ice and atmosphere prediction skill on seasonal timescales. Issue 8 (21st April 2016)

• Record Type: Journal Article
• Authors: Guemas, V.; Chevallier, M.; Déqué, M.; Bellprat, O.; Doblas‐Reyes, F.
• Is Part Of: Geophysical research letters. Volume 43:Issue 8(2016)
• Page Start: 3889
• Page End: 3896
• Publication Date: 2016-04-21
• Subjects: Arctic -- initialization -- Antarctic -- sea ice -- seasonal forecast -- climate prediction; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL066626
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We present a robust assessment of the impact of sea ice initialization from reconstructions of the real state on the sea ice and atmosphere prediction skill. We ran two ensemble seasonal prediction experiments from 1979 to 2012 : one using realistic sea ice initial conditions and another where sea ice is initialized from a climatology, with two forecast systems. During the melting season in the Arctic Ocean, sea ice forecasts become skilful with sea ice initialization until 3–5 months ahead, thanks to the memory held by sea ice thickness. During the freezing season in both the Arctic and Antarctic Oceans, sea ice forecasts are skilful for 7 and 2 months, respectively, with negligible differences between the two experiments, the memory being held by the ocean heat content. A weak impact on the atmosphere prediction skill is obtained. Key Points: Initializing sea ice from a realistic state in May allows for skillful summer Arctic sea ice forecasts The skill in predicting winter sea ice conditions one season ahead arises from the ocean memory The atmosphere seasonal forecast skill over continents is not affected by sea ice initialization