In-situ observation of warm atmospheric layer and the contribution of suspended dusts over the Tarim Basin

Abstract. Basing on the radiosonde observations in the spring and summer during 2016–2017, an anomalous warm atmospheric layer is verified and the contribution of suspended dusts over the Tarim Basin (TB) is quantified. The result indicates a warm atmospheric layer between 300 hPa and 500 hPa with an average intensity of 2.53 K and 1.39 K in the spring and summer, respectively. Over the TB, where the world’s second largest moving desert, the Taklimakan Desert (TD) is distributed, large amounts of dust particles are emitted from the TD and suspended over the TB. Using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data, we found the dusts can be lifted to the upper atmospheric layer between 2.5 and 5.5 km above mean sea level over the TB. Consequently, the suspended dusts can exert a maximum heating effect of approximately +0.45 K and +0.25 K in spring and summer, respectively. The contribution of dust heating to the anomalous warm atmospheric layer over the TB is 13.77 % and 10.25 % in spring and summer, respectively. In view of the topographical feature, the TB is adjacent to the Tibetan Plateau (TP) which acts as an elevated heat source in spring and summer. The warm atmospheric layer over the TB seems a northward extension of Tibet heat source, the concept of which is proposed in this study. Such a northward extension of the elevated heating by the Tibetan Plateau could induce some profound impacts on the regional climate, especially on the western section of the “Silk Road Economic Belt”, and therefore demands more attention.