Sea ice extent, concentration, and seasonality [in 'State of the Climate in 2019']

• Published in: Bulletin of the American Meteorological Society
• Main Authors: Reid, P, Stammerjohn, S, Massom, RA, Barreira, S, Scambos, T, Lieser, JL
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Meteorological Soc 2020
• Subjects: Earth Sciences; Physical geography and environmental geoscience; Glaciology; Antarctic; Antarc*; Ice Shelf; Sea ice
• Online Access: https://doi.org/10.1175/2020BAMSStateoftheClimate.1; https://doi.org/10.1175/BAMS-D-20-0090.1; http://ecite.utas.edu.au/140557

Antarctic sea ice plays a pivotal role in the global climate system. Forming a highly reflective,dynamic, and insulative blanket that varies seasonally in its areal coverage from ~3 106 km 2 to ~1920 106 km 2 , sea ice and its snow cover strongly modifies oceanatmosphere fluxes andinteraction processes (Bourassa et al. 2013). Moreover, brine rejection into the underlying oceanduring sea ice formation onsome continental shelf areasleads to the formationof Antarctic Bottom Waterthat contributes to the globalocean overturning circulation(Johnson 2008). Antarcticsea ice also acts as a protectivebuffer for ice shelvesagainst destructive oceanswells (Massom et al. 2018)and modulates the interactionof warm ocean waterswith ice shelf basal cavitiesto affect basal melt there(Timmermann and Hellmer2013). Finally, it also formsa key habitat for a myriad ofbiotaranging from microorganismsto whales (Thomas2017)that are strongly affectedby changes in the presenceand seasonal rhythms ofthe sea ice cover (e.g., Massomand Stammerjohn 2010).