Parameterization of atmosphere–surface exchange of CO₂ over sea ice

Abstract. We suggest the application of a flux parameterization commonly used over terrestrial areas for calculation of CO₂ fluxes over sea ice surfaces. The parameterization is based on resistance analogy. We present a concept for parameterization of the CO₂ fluxes over sea ice suggesting to use properties of the atmosphere and sea ice surface that can be measured or calculated on a routine basis. Parameters, which can be used in the conceptual model, are analysed based on data sampled from a seasonal fast-ice area, and the different variables influencing the exchange of CO₂ between the atmosphere and ice are discussed. We found the flux to be small during the late winter with fluxes in both directions. Not surprisingly we find that the resistance across the surface controls the fluxes and detailed knowledge of the brine volume and carbon chemistry within the brines as well as knowledge of snow cover and carbon chemistry in the ice are essential to estimate the partial pressure of pCO₂ and CO₂ flux. Further investigations of surface structure and snow cover and driving parameters such as heat flux, radiation, ice temperature and brine processes are required to adequately parameterize the surface resistance.