Role of cloud liquid water in modulating the Arctic surface energy budget

Matthew Shupe (1,2), Ola Persson (1,2)

Abstract
The surface energy budget is of great important in the Arctic, where the surface consists largely of permafrost, sea-ice, and land ice. Perturbations to surface energy can lead to changes in surface and sub-surface temperatures and ultimately impact melting, thawing, and freezing processes. The fate of the Arctic cryosphere has profound regional and global implications related to climate-scale feedback processes (sea-ice changes), the potential release of greenhouse gases (thawing permafrost), changes in sea-level (melting land ice), and others. While the solar cycle and winter darkness largely control the seasonal evolution of the Arctic surface energy budget, clouds also play a critical role. Here we focus specifically on the important influences of liquid water clouds as they influence the surface energy budget in Barrow, Alaska. We show that these clouds lead to significant changes in surface radiation that elicit responses in surface turbulent fluxes. Over the annual cycle, liquid clouds increase the total atmospheric surface flux in all months of the year except for June and July, when they cool the surface. It is important to understand these processes in a changing Arctic where modified large-scale temperature and moisture structure might alter the occurrence of liquid water clouds.