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1] Type II polar stratospheric clouds (PSCs) were observed by micropulse lidar (MPL) at Syowa Station in the Antarctic on 30 June and on 1 July 2001. The vertical profiles of the PSCs had a wavy structure that was synchronized with the temperature fluctuations. A wave analysis using radiosonde data shows that the wavy fluctuations were associated with an inertia gravity wave that was not forced by ground topography, but probably by a spontaneous adjustment in association with synoptic-scale wave-breaking processes in the upper troposphere. It is suggested that the observed PSCs were generated under the low-temperature conditions induced by these waves and that such gravity waves generated by spontaneous adjustment of large-scale fields can be more important to the formation of PSC particles, in both the Antarctic and Arctic stratosphere, than topographically forced gravity waves, because the former are not fixed to the ground topography.Citation: Shibata, T., K. Sato, H. Kobayashi, M. Yabuki, and M. Shiobara, Antarctic polar stratospheric clouds under temperature perturbation by nonorographic inertia gravity waves observed by micropulse lidar at Syowa Station,

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Natural mineral dust and heavy anthropogenic pollution and its complex interactions cause significant environmental problems in East Asia. Due to restrictions of observing technique, real-time morphological change in Asian dust particles owing to coating process of anthropogenic pollutants is still statistically unclear. Here, we first used a newly developed, single-particle polarization detector and quantitatively investigate the evolution of the polarization property of backscattering light reflected from dust particle as they were mixing with anthropogenic pollutants in North China. The decrease in observed depolarization ratio is mainly attributed to the decrease of aspect ratio of the dust particles as a result of continuous coating processes. Hygroscopic growth of Calcium nitrate (Ca(NO3)2) on the surface of the dust particles played a vital role, particularly when they are stagnant in the polluted region with high RH conditions. Reliable statistics highlight the significant importance of internally mixed, ‘quasi-spherical’ Asian dust particles, which markedly act as cloud condensation nuclei and exert regional climate change.

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