Air Moisture Climatology and Related Physical Processes in the Antarctic on the Basis of ERA5 Reanalysis

Abstract Atmospheric moisture is a key component in the water cycle and radiative transfer. In this study, comprehensive picture of air climatology related physical processes presented for first time circumpolar area south 50°S. The results are based on most modern global reanalysis, ERA5, which manages reasonably well to close Antarctic budget. We show that over ocean transient cyclones have dominant role determining conditions, whereas continent conditions largely affected by mean circulation. Over open sea, transport from lower latitudes an equally important source compared local evaporation, but practically all precipitating plateau provided horizontal transport. continental slopes, southward brings warm moist masses latitudes, notably increasing atmospheric vapor cloud water, simultaneously decreasing evaporation sea. On plateau, cooling leads high relative humidity causes condensation especially near surface, causing nearly permanent specific inversion layer. As consequence, dry with extremely low formed. These transported downward katabatic winds, experiencing adiabatic warming. This decrease downward-directed sensible heat flux, enable efficient surface coastal slopes farther polynyas leads.