Climatic controls on active layer dynamics: Amsler Island, Antarctica

Abstract

AbstractVariations in atmospheric conditions can be important factors influencing temperature dynamics within the active layer of a soil. Solar radiation and air temperature can directly alter ground surface temperatures, while variations in wind and precipitation can control how quickly heat is carried through soil pores. The presence of seasonal snow cover can also create a thermal barrier between the atmosphere and ground surface. This study examines the relation between atmospheric conditions and ground temperature variations on a deglaciated island along the Western Antarctic Peninsula. Ground temperatures were most significantly influenced by incoming solar radiation, followed by air temperature variations. When winter months were included in the comparison, the influence of air temperature increased while solar radiation became less influential, indicating that snow cover reflected solar radiation inputs, but was not thick enough to insulate the ground. When ground temperatures were compared to atmospheric conditions of preceding weeks, seasonal temperature peaks 1.6 m below ground were best related to seasonal air temperature peaks from the previous two weeks. The same ground temperature peaks were best related to seasonal solar radiation peaks of seven weeks prior. This difference was a result of temperature lags within the atmosphere.