Microplastics in glaciers of the Tibetan Plateau: Evidence for the long-range transport of microplastics

Abstract. Long-range transport followed by deposition of black carbon on glaciers of Tibet is one of the key issues of climate research as it induces changes on radiative forcing and subsequently impacting the melting of glaciers. The transport mechanism, however, is not well understood. In this study, we use short-lived reactive aromatics as proxies to diagnose transport of pollutants to Tibet. In situ observations of short-lived reactive aromatics across the Tibetan Plateau are analyzed using a regional chemistry and transport model. The model performance using the current emission inventories over the region is poor due to problems in the inventories and model transport. Top-down emissions constrained by satellite observations of glyoxal are a factor of 2–6 higher than the a priori emissions over the industrialized Indo-Gangetic Plain. Using the top-down emissions, agreement between model simulations and surface observations of aromatics improves. We find enhancements of reactive aromatics over Tibet by a factor of 6 on average due to rapid transport from India and nearby regions during the presence of a high-altitude cut-off low system. Our results suggest that the cut-off low system is a major pathway for long-range transport of pollutants such as black carbon. The modeling analysis reveals that even the state-of-the-science high-resolution reanalysis cannot simulate this cut-off low system accurately, which probably explains in part the underestimation of black carbon deposition over Tibet in previous modeling studies. Another model deficiency of underestimating pollution transport from the south is due to the complexity of terrain, leading to enhanced transport. It is therefore challenging for coarse-resolution global climate models to properly represent the effects of long-range transport of pollutants on the Tibetan environment and the subsequent consequence for regional climate forcing.

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Enhanced Trans-Himalaya Pollution Transport to the Tibetan Plateau by the Cut-off Low System

10.5194/acp-2016-702 ◽

2016 ◽

Author(s):

Ruixiong Zhang ◽

Yuhang Wang ◽

Qiusheng He ◽

Laiguo Chen ◽

Yuzhong Zhang ◽

...

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

Long Range ◽

Radiative Forcing ◽

Long Range Transport ◽

The Tibetan Plateau ◽

Pollution Transport ◽

Top Down ◽

Gangetic Plain ◽

Range Transport

Abstract. Long-range transport and subsequent deposition of black carbon on glaciers of Tibet is one of the key issues of climate research inducing changes on radiative forcing and subsequently impacting on the melting of glaciers. The transport mechanism, however, is not well understood. In this study, we use short-lived reactive aromatics as proxies to diagnose transport of pollutants to Tibet. In situ observations of short-lived reactive aromatics across the Tibetan Plateau are analyzed using a regional chemistry and transport model. The model performance using the current emission inventories over the region is poor due to problems in the inventories and model transport. Top-down emissions constrained by satellite observations of glyoxal (CHOCHO) are a factor of 2–6 higher than the a priori emissions over the industrialized Indo-Gangetic Plain. Using the top-down emissions, agreement between model simulations and surface observations of aromatics improves. We find enhancements of reactive aromatics over Tibet by a factor of 6 on average due to rapid transport from India and nearby regions during the presence of a high-altitude cut-off low system. Our results suggest that the cut-off low system is a major pathway for long-range transport of pollutants such as black carbon. The modeling analysis reveals that even the state-of-the-science high-resolution reanalysis cannot simulate this cut-off low system accurately, which probably explains in part the underestimation of black carbon deposition over Tibet in previous modeling studies. Furthermore, another model deficiency of underestimating pollution transport from the south is due to the complexity of terrain, leading to enhanced transport. It is therefore challenging for coarse-resolution global climate models to properly represent the effects of long-range transport of pollutants on the Tibetan environment and the subsequent consequence for regional climate forcing.

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Spatiotemporal variation of aerosol and potential long-range transport impact over the Tibetan Plateau, China

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-14637-2019 ◽

2019 ◽

Vol 19 (23) ◽

pp. 14637-14656 ◽

Cited By ~ 6

Author(s):

Jun Zhu ◽

Xiangao Xia ◽

Huizheng Che ◽

Jun Wang ◽

Zhiyuan Cong ◽

...

Keyword(s):

Tibetan Plateau ◽

South Asia ◽

Long Range ◽

Long Range Transport ◽

Back Trajectory ◽

Taklimakan Desert ◽

The Tibetan Plateau ◽

The Taklimakan Desert ◽

Aerosol Pollution ◽

Range Transport

Abstract. The long-term temporal–spatial variations in the aerosol optical properties over the Tibetan Plateau (TP) and the potential long-range transport from surrounding areas to the TP were analyzed in this work, by using multiple years of sun photometer measurements (CE318) at five stations in the TP, satellite aerosol products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), back-trajectory analysis from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) and model simulations from the Goddard Earth Observing System (GEOS)-Chem chemistry transport model. The results from the ground-based observations showed that the annual aerosol optical depth (AOD) at 440 nm at most TP sites increased in recent decades with trends of 0.001±0.003 yr−1 at Lhasa, 0.013±0.003 yr−1 at Mt_WLG, 0.002±0.002 yr−1 at NAM_CO and 0.000±0.002 yr−1 at QOMS_CAS. The increasing trend was also found for the aerosol extinction Ångström exponent (EAE) at most sites with the exception of the Mt_WLG site. Spatially, the AOD at 550 nm observed from MODIS showed negative trends at the northwest edge close to the Taklimakan Desert and to the east of the Qaidam Basin and slightly positive trends in most of the other areas of the TP. Different aerosol types and sources contributed to a polluted day (with CE318 AOD at 440 nm > 0.4) at the five sites on the TP: dust was the dominant aerosol type in Lhasa, Mt_WLG and Muztagh with sources in the Taklimakan Desert, but fine-aerosol pollution was dominant at NAM_CO and QOMS_CAS with transport from South Asia. A case of aerosol pollution at Lhasa, NAM_CO and QOMS_CAS during 28 April–3 May 2016 revealed that the smoke aerosols from South Asia were lifted up to 10 km and transported to the TP, while the dust from the Taklimakan Desert could climb the north slope of the TP and then be transported to the central TP. The long-range transport of aerosol thereby seriously impacted the aerosol loading over the TP.

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Identification of Long-Range Transport Pathways and Potential Sources of PM10 in Tibetan Plateau Uplift Area: Case Study of Xining, China in 2014

Aerosol and Air Quality Research ◽

10.4209/aaqr.2015.05.0296 ◽

2016 ◽

Vol 16 (4) ◽

pp. 1044-1054 ◽

Cited By ~ 31

Author(s):

Yujie Xin ◽

Guochen Wang ◽

Li Chen

Keyword(s):

Tibetan Plateau ◽

Long Range ◽

Long Range Transport ◽

Transport Pathways ◽

Plateau Uplift ◽

Range Transport ◽

Potential Sources ◽

Tibetan Plateau Uplift

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Spatiotemporal variation of aerosol and potential long-range transport impact over Tibetan Plateau, China

10.5194/acp-2019-444 ◽

2019 ◽

Author(s):

Jun Zhu ◽

Xiangao Xia ◽

Huizheng Che ◽

Jun Wang ◽

Zhiyuan Cong ◽

...

Keyword(s):

Tibetan Plateau ◽

South Asia ◽

Long Range ◽

Long Range Transport ◽

Back Trajectory ◽

Orthogonal Polarization ◽

Taklimakan Desert ◽

The Taklimakan Desert ◽

Aerosol Pollution ◽

Range Transport

Abstract. The long-term temporal-spatial variations of aerosol optical properties in Tibetan Plateau (TP) and the potential long-range transport from surrounding areas to TP were analyzed in this work, by using multiple years of sunphotometer measurements (CE318) at five stations in TP, satellite aerosol productions from Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), back-trajectory analysis from the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) and model simulation of the Goddard Earth Observing System (GEOS)-Chem chemistry transport model. The results from ground-based observations show that the annual aerosol optical depth (AOD) at most TP sites increased in the past decades with trends of 0.001 ± 0.003/year at Lhasa, 0.013 ± 0.003/year at Mt_WLG, 0.002 ± 0.002/year at NAM_CO, and 0.000 ± 0.002/year at QOMS_CAS. The increasing trend is also found for the aerosol Extinction Ångstrom exponent (EAE) at most sites, except for Mt_WLG sites with an obvious decreasing trend. Spatially, the AOD observed from MODIS shows negative trends in the northwest edge closed to the Taklimakan Desert and east of the Qaidam Basin and slightly positive trends in most of the other area of TP. Different aerosol types and sources contribute to the polluted day (with CE318 AOD at 440 nm > 0.4) in the five sites of TP: dust dominant in Lhasa, Mt_WLG and Muztagh with sources from the Taklimakan Desert but fine aerosol pollution dominant at NAM_CO and QOMS_CAS with the transport from South Asia. A case of aerosol pollution at Lhasa, NAM_CO and QOMS_CAS during 28 April–3 May 2016 reveals that the smoke aerosols in South Asia were lifted up to 10 km and transported to TP, while the dust from Taklimakan Desert could climb the north slope of TP and then be transported to center TP. The long-range transport thereby seriously impact aerosol loading over the TP.

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