Poster

IAMAS

M21 - Earth-Atmosphere interaction and Boundary Layer Processes

Temperature characteristics of ABL at Zhongshan Station, Antarctica observed by MTP

The atmosphere boundary layer (ABL), as the lowest atmospheric layer bridging the surface and free atmosphere, governs energy exchange, material transport, and climate feedback processes. Influenced by intense radiative cooling, katabatic winds, and complex terrain, the Antarctic ABL exhibits unique thermodynamic features, such as persistent near-surface temperature inversions (occurring year-round over inland regions) and shallow boundary layer depths (tens to hundreds of meters). Zhongshan Station (69��22��S, 76��22��E), located in the Larsemann Hills of East Antarctica, lies in a transition zone where katabatic winds intersect with marine air masses. Its heterogeneous glacial-rock terrain makes it an ideal site for studying coastal Antarctic ABL dynamics, offering representative insights into regional thermal and physical characteristics. Traditional ABL investigations in Antarctica have relied on meteorological stations, towers, and radiosondes, yet these methods lack the spatiotemporal resolution to resolve rapid ABL transitions, leading to uncertainties in polar boundary layer parameterization. The Microwave Temperature Profiler (MTP), a passive microwave radiometer, provides continuous, high temporal (a few minutes) and spatial (tens of meters) resolution, and uninterrupted temperature profiles covering the ABL through microwave radiometric scanning. Due to its portability, the MTP has been employed in various experimental fields and has been validated against radiosonde data, demonstrating strong reliability. This study utilizes 2 years of MTP observational data at Zhongshan station, with temporal resolution of 5 minutes, a maximum vertical observation height of 2000 m, and vertical resolutions of 10?100 m (increasing with height) to investigate the fundamental thermodynamic and dynamic characteristics of the ABL. Preliminary findings include: (1) The two-year mean temperature profile shows a decreasing trend with altitude, with the gradient first increasing and then decreasing, showing inflection points at 250 m and 600 m, where the temperature decreases most rapidly between these two heights. (2) Winter (JJA) temperature profiles exhibit surface-based inversions, transitioning to lapse conditions aloft, while summer (DJF) profiles display consistent temperature decreases with height. (3) Winter surface inversions lack diurnal variation, maintaining an average intensity of around 0.8��C. In summer, nocturnal surface inversions (0.2?0.4��C) weaken during daytime. The inversion strength is negatively correlated with 2 m air temperature and 10 m wind speed.