第一届未来大气科学论坛

Dust in the upper tropopause plays an important role in the microphysics and radiative energy budget. Some satellite observations and simulations have identified the transport of dust to the upper troposphere, but in–situ observation with particle vertical distribution remain lacking, which affects the accuracy of dust simulation and atmospheric radiation evaluation. For the first time, the vertical transport of dust into the stratosphere was captured through balloon-borne in-situ observations in this study. On April 19, 2023, a large amount of dust surged into the northern Tibetan Plateau (TP), causing the number concentration of particles with a diameter larger than 0.416 μm below 5 km altitude to increase over 10 times compared to April 17. Even near the tropopause (12–13 km altitude), the concentration still showed a 1–fold increase. During this vertical transport event, dust mainly originated from the Taklamakan Desert (TKD) and the Thar Desert (TD). Under the control of weather troughs, the TKD and the TD emitted abundant dust. Below 5 km altitude, the dust primarily came from the TKD, which was transported through the flow surrounding the TP. The dust in the stratosphere (12–13 km altitude) mainly came from TD, which underwent two uplift processes: convective lifting in the trough region and forced uplift due to the high terrain of the TP. Simulations indicated that following the dust transport process, significant dust presented the tropopause layer over northern TP, there was a high–value region of dust mass concentration (4 cm^-3) and number concentration (0.75 μg cm^-3) at 200 hPa. And dust radiative effect notably promoted the vertical transport of both dust and non–dust aerosols, resulting in more than 40 % of dust mass column concentration and the total aerosols mass column concentration over the northern TP at the upper–level (from an altitude of 2 km below the lapse–rate tropopause to 30 hPa), as well as more than 30 % of dust number column concentration and more than 10 % of the total aerosols number column concentration.
 

Balloon-borne Measurement,dust,Numerical simulation