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

2019 ◽  
Vol 19 (23) ◽  
pp. 14637-14656 ◽  
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.

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

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.

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

2021 ◽  
Vol 758 ◽  
pp. 143634
Author(s):  
Yulan Zhang ◽  
Tanguang Gao ◽  
Shichang Kang ◽  
Steve Allen ◽  
Xi Luo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Long Range ◽  
Long Range Transport ◽  
The Tibetan Plateau ◽  
Range Transport

scholarly journals Enhanced trans-Himalaya pollution transport to the Tibetan Plateau by cut-off low systems

2017 ◽  
Vol 17 (4) ◽  
pp. 3083-3095 ◽  
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 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.

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

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.

Contamination of Antarctic snow by polycyclic aromatic hydrocarbons dominated by combustion sources in the polar region

2010 ◽  
Vol 7 (6) ◽  
pp. 504 ◽  
Author(s):  
Petr Kukučka ◽  
Gerhard Lammel ◽  
Alice Dvorská ◽  
Jana Klánová ◽  
Andrea Möller ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Long Range ◽  
Aromatic Hydrocarbons ◽  
Solid Phase ◽  
Weddell Sea ◽  
Long Range Transport ◽  
Back Trajectory ◽  
Range Transport ◽  
Polycyclic Aromatic ◽  
Combustion Sources

Environmental context Is long-range transport from populated and industrialised areas to blame for pollution of remote regions? We report that, for the world's most remote region, Antarctica, and one prominent class of global pollutants, polycyclic aromatic hydrocarbons, long-range transport from other continents has not contributed significantly to recent snow contamination. Rather, the major sources are regional scientific stations and ocean transport, mostly tourism. Abstract Firn samples attributed to the period between 2002 and 2005 were collected from a snow pit on the Ekström Shelf Ice in the Weddell Sea (70°43.8′S, 8°25.1′W). Low-volume meltwater samples (5 mL) were extracted by solid-phase microextraction (SPME) and analysed for polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrometry. The recovery of the analytical method for the 4–6 ring PAHs was low. PAH concentrations in snow were found within the range of 26–197 ng L–1. The most prevailing substances were determined to be naphthalene, 1- and 2-methylnaphthalene, acenaphthylene, acenaphthene and phenanthrene, with naphthalene accounting for an overall mean of 82% of total PAH. Potential emission sources of PAHs in snow were studied using back-trajectory statistics and available emission data of combustion sources in and around Antarctica. The distance to the sources (ships and research stations) in this region was found to control the snow PAH concentrations. There was no indication for intercontinental transport or marine sources.

scholarly journals Asian Long-Range Transport in Relation to Atmospheric Rivers in Northern California

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 313
Author(s):  
Catherine N. Liu ◽  
Sen Chiao ◽  
Ju-Mee Ryoo
Keyword(s):  
Long Range ◽  
Cold Season ◽  
Asian Dust ◽  
Long Range Transport ◽  
Back Trajectory ◽  
Northern California ◽  
Atmospheric Rivers ◽  
Back Trajectory Analysis ◽  
Range Transport ◽  
Moderate Resolution Imaging Spectroradiometer

The study investigates the effect of aerosol long-range transport on precipitation over Northern California during atmospheric river (AR) events in the 2017 cold season (January–April). ARs in 2017 were one of the strongest to date, and the intense precipitation associated with the ARs resulted in flooding, destruction of property, and contamination of water supplies. The Aerosol Optical Depth (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data shows Asian dust traveling across the Northern Pacific Ocean along with AR events. Aerosol measurements in California, provided by the Interagency Monitoring of Protected Visual Environments (IMPROVE), show that more Asian dust tends to be observed over the coast, while non-Asian/localized dust is observed inland. A mixture of Asian and localized dust is observed over the mountains, although higher amounts of both are observed in the spring (March–April). Back trajectory analysis confirms that Asian aerosols are transported along the air parcels, and each AR event has its own transport pattern in terms of horizontal advection and vertical lifting. Correlation between precipitation and aerosols is low. This suggests that aerosols contribute little to the decrease of local precipitation during the 2017 AR events.

scholarly journals Impact of transatlantic transport episodes on summertime ozone in Europe

2006 ◽  
Vol 6 (8) ◽  
pp. 2057-2072 ◽  
Author(s):  
G. Guerova ◽  
I. Bey ◽  
J.-L. Attié ◽  
R. V. Martin ◽  
J. Cui ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Long Range ◽  
North American ◽  
Tropospheric Chemistry ◽  
Long Range Transport ◽  
Back Trajectory ◽  
Pollution Transport ◽  
Upper Troposphere ◽  
Range Transport ◽  
The Impact

Abstract. This paper reports on the transport of ozone (O3) and related species over the North Atlantic ocean and its impact on Europe. Measurements of nitrogen dioxide (NO2) and carbon monoxide (CO) columns from the GOME and MOPITT satellite instruments, respectively, are used in conjunction with the GEOS-CHEM global model of transport and tropospheric chemistry to identify the major events of long range transport that reach Europe over the course of summer 2000. Sensitivity model simulations are used to analyse observed O3 distributions with respect to the impact of long range transport events. For that purpose, we used in-situ O3 observations taken at the mountain site of Jungfraujoch as well as O3 vertical profiles taken in the vicinity of central European cities. Over the course of summer 2000, we identified 9 major episodes of transatlantic pollution transport; 7 events are associated with transient cyclones while 2 events occur through zonal transport (e.g. by advection in the strong low-level westerly winds established in summer between the Azores anticyclone and transient cyclones). We find that on average three episodes occur per month with the strongest ones being in June. The number and frequency of long range transport events that reach Europe are driven by the position and strength of the Azores anticyclone. Model sensitivity simulations indicate that the summer mean North American O3 contribution ranges from 3 to 5 ppb (7–11%) in the planetary boundary layer and 10 to 13 ppb (18–23%) in the middle and upper troposphere. During particular episodes, North American sources can result in O3 enhancements up to 25–28 ppb in the layer between 800–600 hPa and 10–12 ppb in the boundary layer. The impact of the zonal transport events on O3 distribution over Europe is more clearly seen below 700 hPa as they tend to transport pollution at lower levels while the events associated with transient cyclones are more likely to have an impact on the middle and upper troposphere (i.e. above 600 hPa). The air mass origins found in the GEOS-CHEM model are clearly confirmed by back trajectory analyses. During most of the 9 events, a strong contribution in North American O3 is in general associated with only little European O3 and vice-versa (in particular at the Jungfraujoch). A substantial North American contribution (e.g., 30% or higher) to O3 over Europe does not always result in pronounced O3 enhancements in the observations during our period of study.

scholarly journals Seasonal changes of airborne bacterial communities over Tokyo and influence of local meteorology

2019 ◽  
Author(s):  
Jun Uetake ◽  
Yutaka Tobo ◽  
Yasushi Uji ◽  
Thomas C. J. Hill ◽  
Paul J. DeMott ◽  
...  
Keyword(s):  
Long Range ◽  
Community Dynamics ◽  
Microbial Community Composition ◽  
Local Source ◽  
Long Range Transport ◽  
Back Trajectory ◽  
Airborne Microorganisms ◽  
Short Period ◽  
Range Transport ◽  
Local Meteorology

AbstractRecent progress in Next Generation Sequencing allows us to explore the diversity of airborne microorganisms across time and space. However, few studies have used consecutive short-period samples to explore correlations between the seasonal variation of the microbiota and meteorology. In order to understand airborne bacterial community dynamics over Tokyo, including fine-scale correlations between airborne microorganisms and meteorological conditions, and the influence of local versus long-range transport of microbes, air samples were continuously taken from a platform at the 458-m level of the Tokyo Skytree (a 634-m-high broadcasting tower in Tokyo) from August 2016 to February 2017. Predicted source regions of airborne particles, from back trajectory analyses, changed abruptly from the Pacific Ocean to the Eurasian Continent in the beginning of October. However, microbial community composition and alpha and beta diversities were not affected by this meteorological regime shift, suggesting that long-range transport from ocean or continent was not the principal determinant controlling the local airborne microbiome. By contrast, local meteorology, especially relative humidity and wind speed, had significant relationships with both alpha diversities and beta diversity. Among four potential local source categories (soil, bay seawater, river, and pond), bay seawater and soil were constant and predominant sources. Statistical analyses suggest humidity is the most influential meteorological factor, most likely because it is correlated with soil moisture and hence negatively correlated with the dispersal of particles from the land surface.

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