Land-atmosphere coupling characteristics in summer based on microwave radiometer data at Nagqu site of Tibetan Plateau

Abstract

The energy transfer within the planetary boundary layer (PBL) is a crucial variable influencing weather processes both on the Tibetan Plateau (TP) and in its downstream areas. This paper assesses the accuracy of ground-based microwave radiometer (MWR) in comparison with radiosonde data in different weather conditions. The effects of surface heat flux and precipitation on the atmosphere in different weather conditions are quantified to facilitate the study of land- atmosphere coupling in the Nagqu region. The findings indicate that microwave radiometer can provide accurate measurements of air temperature within 4 km height and specific humidity below cloud cover. The variation in surface sensible heat aligns with changes in the convective boundary layer (CBL) height, whereas latent heat shows no significant correlation during the diurnal cycle. Furthermore, daily precipitation process influences the lower atmosphere in the Nagqu region, with the impact scaling with precipitation intensity. The MWR observations indicate that precipitation generated by the Tibetan Plateau vortex (TPV) has the most significant impact on the land-atmosphere energy exchange.