Relative role of horizontal and vertical processes in the physical mechanism of wintertime Arctic amplification

The physical mechanism of Arctic amplification is still controversial. Specifically, relative role of vertical processes resulting from the reduction of sea ice in the Barents-Kara Seas is not clearly understood in comparison with the horizontal heat and moisture advection. Energy and moisture budgets are analyzed over the region of sea ice reduction in order to delineate the relative roles of horizontal and vertical processes. A detailed analysis of energy and moisture budgets in the atmospheric column indicates that both the vertical source from the release of heat flux and moisture due to sea ice reduction and the horizontal advection of heat and moisture are essential for explaining the variation of temperature and specific humidity over the Barents-Kara Seas. The vertical flux term explains a slightly larger fraction of the mean increase in temperature and specific humidity, while the horizontal advection is a major source of variability in temperature and specific humidity in the atmospheric column.