| Autor: |
Zhang X; Northwest Normal University, Lanzhou, 730070, China., Ming J; Biogeo/Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128, Mainz, Germany. jing.ming@mpic.de.; State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou, 730000, China. jing.ming@mpic.de., Li Z; State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou, 730000, China., Wang F; State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou, 730000, China., Zhang G; Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China. |
| Abstrakt: |
Equivalent black carbon (eBC) mass concentrations were measured by an aethalometer (AE-31) in the Nam Co, central Tibet from 2010 to 2014. Different from previous filter-sampling studies (Ming et al., J Environ Sci 22(11):1748-1756, 2010; Zhao et al., Environ Sci Pollut Res 20:5827-5838, 2013), the first high-resolution online eBC measurement conducted in central Tibet is reported here, allowing to discuss the diurnal variations as well as seasonal variabilities of eBC. Average daily eBC concentration was 74 ± 50 ng/m 3 , reflecting a global background level. Meteorological conditions influenced eBC concentrations largely at seasonal scale, which are higher in February-May but lower in June-January. The highest eBC concentrations (greater than 210 ng/m 3 ) were more associated with the W and WSW winds smaller than 6 m/s. The diurnal variations of eBC showed plateaus from 10:00 to 15:00 with seasonal variations, associated with local anthropogenic activities, such as indigenous Tibetan burning animal waste and tourism traffic. The PBLHs showed a co-variance with eBC concentrations, implicating close sources. The aerosol optical depths derived from the MODIS data over the Nam Co Observatory Station (NCOS)-included sub-area (30° N-40° N, 90° E-100° E) showed significant relationship with eBC concentrations. This suggests that nearby or short-distance sources other than long-distance transported pollutants could be important contributors to eBC concentrations at the NCOS, different from the conclusions suggested by previous studies. |
Full text from SpringerLink