Lidar-observed enhancement of aerosols in the upper troposphere and lower stratosphere over the Tibetan Plateau induced by the Nabro volcano eruption
- 1Shanghai Meteorological Service, Shanghai, China
- 2Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
- 3Chinese Academy of Meteorological Sciences, Beijing, China
- 4College of Environmental Science and Engineering, Donghua University, Shanghai, China
- 5School of Computer and Software, Nanjing University of Information Science and Technology, Nanjing, China
- 6Germu Meteorological Bureau, Qinghai, China
Abstract. Vertical profiles of aerosol extinction coefficients were measured by a micro-pulse lidar at Naqu (31.5° N, 92.1° E; 4508 m a.m.s.l.), a meteorological station located on the central part of the Tibetan Plateau during summer 2011. Observations show a persistent maximum in aerosol extinction coefficients in the upper troposphere–lower stratosphere (UTLS). These aerosol layers were generally located at an altitude of 18–19 km a.m.s.l., 1–2 km higher than the tropopause, with broad layer depth ranging approximately 3–4 km and scattering ratio of 4–9. Daily averaged aerosol optical depths (AODs) of the enhanced aerosol layers in UTLS over the Tibetan Plateau varied from 0.007 to 0.030, in agreement with globally averaged levels of 0.018 ± 0.009 at 532 nm from previous observations, but the percentage contributions of the enhanced aerosol layers to the total AOD over the Tibetan Plateau are higher than those observed elsewhere. The aerosol layers in UTLS wore off gradually with the reducing intensity of the Asian monsoon over the Tibetan Plateau at the end of August. The eruption of Nabro volcano on 13 June 2011 is considered an important factor to explain the enhancement of tropopause aerosols observed this summer over the Tibetan Plateau.