Effect of atmosphere-wave-ocean/ice interactions on a polar low simulation over the Barents Sea

The impact of atmosphere-wave-ocean/ice interactions on the development of a hurricane-like polar low (PL) over the Barents Sea during 18-21 December 2002 is investigated using a fully coupled atmosphere-wave-ocean/ice model with five model settings. The atmosphere-wave-ocean/ice interactions have a marginal influence on the PL development when the baroclinic instability is a dominating factor. However, they do have an influence on the PL development when the role of baroclinic instability vanishes. The atmosphere-wave interactions have a limited influence on the PL intensity but they extend the size of the anticyclonic loop of the PL track. In contrast, the atmosphere-ocean interactions reduce the size of the track loop since the ice coverage is increased due to the atmosphere-ocean coupling which limits the northward movement of the PL. Besides, the increase of the ice coverage reduces the PL precipitation, in contrast, the wave coupling processes increase the PL precipitation. The atmosphere-ocean coupling processes enhance the PL intensity in term of the minimum sea level pressure which differs from previous studies that the atmosphere-ocean coupling has a negative feedback on the development of cyclones. The positive feedback from atmosphere-ocean coupling is more significant when the wave coupling processes are added into the model. The feedback from atmosphere-ocean coupling processes are determined by two processes: (1) heat flux induced sea surface cooling which has a negative feedback on the PL development, and (2) the strong wind-induced sea surface warming caused by the upper-ocean mixing when the temperature inversion exists in the ocean close to the ice edge. In this PL case, the wave coupling processes enhance the upper-ocean mixing and bring warm water to the surface in the area with ocean temperature inversions. Besides, the atmosphere-ocean coupling processes enhance the thermal wind of the PL and alter the vertical structure of the PL.