scholarly journals Long-range transport of mutagens and other air pollutants from mainland East Asia to western Japan

2015 ◽  
Vol 37 (1) ◽  
Author(s):  
Souleymane Coulibaly ◽  
Hiroki Minami ◽  
Maho Abe ◽  
Tomohiro Hasei ◽  
Tadashi Oro ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Air Pollutants ◽  
Long Range Transport ◽  
Range Transport ◽  
Western Japan

New particle formation under the influence of the long-range transport of air pollutants in East Asia

2016 ◽  
Vol 141 ◽  
pp. 30-40 ◽  
Author(s):  
Indra Chandra ◽  
Seyoung Kim ◽  
Takafumi Seto ◽  
Yoshio Otani ◽  
Akinori Takami ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Air Pollutants ◽  
Particle Formation ◽  
Long Range Transport ◽  
New Particle Formation ◽  
Range Transport

scholarly journals Long-range transport of anthropogenic air pollutants into the marine air: insight into fine particle transport and chloride depletion on sea salts

2021 ◽  
Vol 21 (23) ◽  
pp. 17715-17726
Author(s):  
Liang Xu ◽  
Xiaohuan Liu ◽  
Huiwang Gao ◽  
Xiaohong Yao ◽  
Daizhou Zhang ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Air Pollutants ◽  
Radiative Forcing ◽  
Eastern China ◽  
Long Range Transport ◽  
Anthropogenic Aerosols ◽  
Range Transport ◽  
Anthropogenic Air Pollutants ◽  
Marine Air

Abstract. Long-range transport of anthropogenic air pollutants from East Asia can affect the downwind marine air quality during spring and winter. Long-range transport of continental air pollutants and their interaction with sea salt aerosol (SSA) significantly modify the radiative forcing of marine aerosols and influence ocean biogeochemical cycling. Previous studies poorly characterize variations of aerosol particles along with air mass transport from the continental edge to the remote ocean. Here, the research ship R/V Dongfanghong 2 traveled from the eastern China seas (ECS) to the northwestern Pacific Ocean (NWPO) to understand what and how air pollutants were transported from the highly polluted continental air to clean marine air in spring. A transmission electron microscope (TEM) was used to find the long-range transported anthropogenic particles and the possible Cl-depletion phenomenon of SSA in marine air. Anthropogenic aerosols (e.g., sulfur (S)-rich, S-soot, S-metal/fly ash, organic matter (OM)-S, and OM coating particles) were identified and dramatically declined from 87 % to 8 % by number from the ECS to remote NWPO. For the SSA aging, 87 % of SSA particles in the ECS were identified as fully aged, while the proportion of fully aged SSA particles in the NWPO decreased to 29 %. Our results highlight that anthropogenic acidic gases in the troposphere (e.g., SO2, NOx, and volatile organic compounds) could be transported to remote marine air and exert a significant impact on aging of SSA particles in the NWPO. The study shows that anthropogenic particles and gases from East Asia significantly perturb different aerosol chemistry from coastal to remote marine air. More attention should be given to the modification of SSA particles in remote marine areas due to the influence of anthropogenic gaseous pollutants.

scholarly journals Long-range transport of anthropogenic air pollutants into the marine air: Insight into fine particle transport and chloride depletion on sea salts

2021 ◽  
Author(s):  
Liang Xu ◽  
Xiaohuan Liu ◽  
Huiwang Gao ◽  
Xiaohong Yao ◽  
Daizhou Zhang ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Air Pollutants ◽  
Eastern China ◽  
Long Range Transport ◽  
Marine Aerosols ◽  
Anthropogenic Aerosols ◽  
Range Transport ◽  
Anthropogenic Air Pollutants ◽  
Marine Air

Abstract. Long-range transport of anthropogenic air pollutants from East Asia can affect the downwind marine air quality during spring and winter. Long-range transport of continental air pollutants and their interaction with sea salt aerosols (SSA) significantly modify the radiative forcing of marine aerosols and influence ocean biogeochemical cycling. Previous studies poorly characterize variations of aerosol particles along with air mass transport from the continental edge to the remote ocean. Here, the research ship R/V Dongfanghong 2 traveled from the eastern China seas (ECS) to the northwestern Pacific Ocean (NWPO) to understand what and how air pollutants were transported from the highly polluted continental air to clean marine air in spring. A transmission electron microscope (TEM) was used to find the long-range transported anthropogenic particles and the possible Cl-depletion phenomenon of SSA in marine air. Primary and secondary anthropogenic aerosols were identified and dramatically declined from 87 % to 8 % by number from the ECS to remote NWPO. For the SSA aging, 86 % of SSA particles in the ECS were identified as fully aged, while the proportion of fully aged SSA particles in the NWPO decreased to 31 %. The result highlights that anthropogenic acidic gases in the troposphere (e.g., SO2, NOx, and volatile organic compounds) were transported longer distances compared to the anthropogenic aerosol and could exert a significant impact on marine aerosols in the NWPO. These results show that anthropogenic particles and gases from East Asia significantly perturb aerosol chemistry in marine air. The optical properties and cloud condensation nucleation of the modified SSA particles should be incorporated into the more accurately modeling of clouds in the ECS and NWPO in spring and winter.

scholarly journals Atmospheric pollution over the eastern Mediterranean during summer – a review

2017 ◽  
Vol 17 (21) ◽  
pp. 13233-13263 ◽  
Author(s):  
Uri Dayan ◽  
Philippe Ricaud ◽  
Régina Zbinden ◽  
François Dulac
Keyword(s):  
Boundary Layer ◽  
Carbon Monoxide ◽  
Long Range ◽  
Mixed Layer ◽  
Air Pollutants ◽  
Asian Monsoon ◽  
Eastern Mediterranean ◽  
Long Range Transport ◽  
Range Transport ◽  
Ventilation Rates

Abstract. The eastern Mediterranean (EM) is one of the regions in the world where elevated concentrations of primary and secondary gaseous air pollutants have been reported frequently, mainly in summer. This review discusses published studies of the atmospheric dispersion and transport conditions characterizing this region during the summer, followed by a description of some essential studies dealing with the corresponding concentrations of air pollutants such as ozone, carbon monoxide, total reactive nitrogen, methane, and sulfate aerosols observed there. The interlaced relationship between the downward motion of the subsiding air aloft induced by global circulation systems affecting the EM and the depth of the Persian Trough, a low-pressure trough that extends from the Asian monsoon at the surface controlling the spatiotemporal distribution of the mixed boundary layer during summer, is discussed. The strength of the wind flow within the mixed layer and its depth affect much the amount of pollutants transported and determine the potential of the atmosphere to disperse contaminants off their origins in the EM. The reduced mixed layer and the accompanying weak westerlies, characterizing the summer in this region, led to reduced ventilation rates, preventing an effective dilution of the contaminants. Several studies pointing at specific local (e.g., ventilation rates) and regional peculiarities (long-range transport) enhancing the build-up of air pollutant concentrations are presented. Tropospheric ozone (O3) concentrations observed in the summer over the EM are among the highest over the Northern Hemisphere. The three essential processes controlling its formation (i.e., long-range transport of polluted air masses, dynamic subsidence at mid-tropospheric levels, and stratosphere-to-troposphere exchange) are reviewed. Airborne campaigns and satellite-borne initiatives have indicated that the concentration values of reactive nitrogen identified as precursors in the formation of O3 over the EM were found to be 2 to 10 times higher than in the hemispheric background troposphere. Several factors favor sulfate particulate abundance over the EM. Models, aircraft measurements, and satellite-derived data have clearly shown that sulfate has a maximum during spring and summer over the EM. The carbon monoxide (CO) seasonal cycle, as obtained from global background monitoring sites in the EM, is mostly controlled by the tropospheric concentration of the hydroxyl radical (OH) and therefore demonstrates high concentrations over winter months and the lowest concentrations during summer when photochemistry is active. Modeling studies have shown that the diurnal variations in CO concentration during the summer result from long-range CO transport from European anthropogenic sources, contributing 60 to 80 % of the boundary-layer CO over the EM. The values retrieved from satellite data enable us to derive the spatial distribution of methane (CH4), identifying August as the month with the highest levels over the EM. The outcomes of a recent extensive examination of the distribution of methane over the tropospheric Mediterranean Basin, as part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) program, using model simulations and satellite measurements, are coherent with other previous studies. Moreover, this methane study provides some insight into the role of the Asian monsoon anticyclone in controlling the variability of CH4 pollutant within mid-to-upper tropospheric levels above the EM in summer.

scholarly journals Tropospheric CO vertical profiles measured by IAGOS aircraft in 2002–2017 and the role of biomass burning

2018 ◽  
pp. 1-41
Author(s):  
Hervé Petetin ◽  
Bastien Sauvage ◽  
Mark Parrington ◽  
Hannah Clark ◽  
Alain Fontaine ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Biomass Burning ◽  
South India ◽  
Long Range Transport ◽  
Anthropogenic Emissions ◽  
South East Asia ◽  
Vertical Profiles ◽  
Range Transport

<p><strong>Abstract.</strong> This study investigates the role of biomass burning and long-range transport in the anomalies of carbon monoxide (CO) regularly observed along the tropospheric vertical profiles measured in the framework of IAGOS. Considering the high interannual variability of biomass burning emissions and the episodic nature of pollution long-range transport, one strength of this study is the amount of data taken into account, namely 30,000 vertical profiles at 9 clusters of airports in Europe, North America, Asia, India and southern Africa over the period 2002&amp;ndash;2017. </p> <p> As a preliminary, a brief overview of the spatio-temporal variability, latitudinal distribution, interannual variability and trends of biomass burning CO emissions from 14 regions is provided. The distribution of CO mixing ratios at different levels of the troposphere is also provided based on the entire IAGOS database (125 million CO observations). </p> <p> This study focuses on the free troposphere (altitudes above 2<span class="thinspace"></span>km) where the long-range transport of pollution is favoured. Anomalies at a given airport cluster are here defined as departures from the local seasonally-averaged climatological vertical profile. The intensity of these anomalies varies significantly depending on the airport, with maximum (minimum) CO anomalies of 110&amp;ndash;150 (48)<span class="thinspace"></span>ppbv in Asia (Europe). Looking at the seasonal variation of the frequency of occurrence, the 25<span class="thinspace"></span>% strongest CO anomalies appears reasonably well distributed along the year, in contrast to the 5<span class="thinspace"></span>% or 1<span class="thinspace"></span>% strongest anomalies that exhibit a strong seasonality with for instance more frequent anomalies during summertime in northern United-States, during winter/spring in Japan, during spring in South-east China, during the non-monsoon seasons in south-east Asia and south India, and during summer/fall at Windhoek, Namibia. Depending on the location, these strong anomalies are observed in different parts of the free troposphere. </p> <p> In order to investigate the role of biomass burning emissions in these anomalies, we used the SOFT-IO v1.0 IAGOS added-value products that consist of FLEXPART 20-days backward simulations along all IAGOS aircraft trajectories, coupled with anthropogenic (MACCity) and biomass burning (GFAS) CO emission inventories and vertical injections. SOFT-IO estimates the contribution (in ppbv) of the recent (less than 20 days) primary worldwide CO emissions, tagged per source region. Biomass burning emissions are found to play an important role in the strongest CO anomalies observed at most airport clusters. The regional tags indicate a large contribution from boreal regions at airport clusters in Europe and North America during summer season. In both Japan and south India, the anthropogenic emissions dominate all along the year, except for the strongest summertime anomalies observed in Japan that are due to Siberian fires. The strongest CO anomalies at airport clusters located in south-east Asia are induced by fires burning during spring in south-east Asia and during fall in equatorial Asia. In southern Africa, the Windhoek airport was mainly impacted by fires in southern hemisphere Africa and South America. </p> <p> To our knowledge, no other studies have used such a large dataset of in situ vertical profiles for deriving a climatology of the impact of biomass burning versus anthropogenic emissions on the strongest CO anomalies observed in the troposphere, in combination with information on the source regions. This study therefore provides both qualitative and quantitative information for interpreting the highly variable CO vertical distribution in several regions of interest.</p>

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