Atmospheric Structure Observed over the Antarctic Plateau and Its Response to a Prominent Blocking High Event

Studies on the atmospheric structure over the Antarctic Plateau are important for better understanding the weather and climate systems of polar regions. In the summer of 2017, an observational experiment was conducted at Dome-A, the highest station in Antarctica, with a total of 32 profiles obtained from global positioning system (GPS) radiosondes. Based on observational data, the atmospheric temperature, humidity and wind structures and their variations are investigated, and compared with those from four other stations inside the Antarctic circle. Distinguished thermal and dynamic structures were revealed over Dome-A, characterized by the lowest temperature, the highest tropopause, the largest lapse rate and the most frequent temperature and humidity inversion. During the experiment, a prominent blocking event was identified, with great influence on the atmospheric structure over Dome-A. The blocking high produced a strong anticyclone that brought warm and moist air to the hinterland of the Antarctic Plateau, causing a much warmer, wetter and windier troposphere over the Dome-A station. Meanwhile, a polar air mass was forced out of the Antarctic, formed a cold surge extending as far as Southern New Zealand and affected the weather there. Our results proved that there would be a direct interaction between the atmosphere over the hinterland of the Antarctic Plateau and middle latitudes with the action of a blocking high. Further studies are needed to explore the interaction between the atmospheric systems over the Antarctic and middle latitudes under intense synoptic disturbance, with long-term data and numerical modeling.