Aerosol Properties Over Tibetan Plateau From a Decade of AERONET Measurements: Baseline, Types, and Influencing Factors. Issue 23 (14th December 2019)

• Record Type: Journal Article
• Authors: Pokharel, Manisha; Guang, Jie; Liu, Bin; Kang, Shichang; Ma, Yaoming; Holben, Brent N.; Xia, Xiang'ao; Xin, Jinyuan; Ram, Kirpa; Rupakheti, Dipesh; Wan, Xin; Wu, Guangming; Bhattarai, Hemraj; Zhao, Chuanfeng; Cong, Zhiyuan
• Is Part Of: Journal of geophysical research. Volume 124:Issue 23(2019)
• Page Start: 13357
• Page End: 13374
• Publication Date: 2019-12-14
• Subjects: Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2019JD031293
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: In this study, a decade long measurement of aerosol optical properties at two AERONET stations (Nam Co during 2006–2016 and QOMS during 2009–2017) in the Tibetan Plateau (TP), a region sensitive to climate change and human perturbation, is presented. The baseline value of aerosol optical depth (AOD) was 0.029 and 0.027 at Nam Co and QOMS, respectively, which are comparable to or even lower than those at some Arctic and remote ocean locations. The seasonality of AOD values were the order of spring > summer > winter > autumn. Based on AOD and Ångström exponent ( α ), major aerosol types over the TP were further identified as continental background, biomass burning, and dust. Although continental background aerosol was the main feature in remote areas of TP, biomass burning plumes frequently occurred, especially during spring (March–April). In one of such biomass burning event in April 2014, MODIS observations demonstrated that intensive open fires occurred in South Asia, covering the foothills of Himalayas and Indo‐Gangetic Plain. The air mass back trajectories and CALIOP observations further revealed that biomass burning plume could be uplifted to higher altitudes and reach the Himalayas. Moreover, an occasional dust event detected in April 2008 over the TP demonstrated that the dust from Taklamakan Desert may impact the main body of TP episodically, although the local dust from the inside of TP cannot be excluded and warrants further study. Key Points: The baseline value of AOD in Tibetan Plateau is comparable to or even lower than that at Arctic and remote ocean locations Major aerosol types over the Tibetan Plateau were identified as continental background, biomass burning, and dust Biomass burning emissions in South Asia and dust from Taklamakan Desert could impact Tibetan Plateau episodically