Articles | Volume 19, issue 20
18 Oct 2019
Research article | 18 Oct 2019
Nepal emission inventory – Part I: Technologies and combustion sources (NEEMI-Tech) for 2001–2016
Pankaj Sadavarte et al.
Chandra Venkataraman, Michael Brauer, Kushal Tibrewal, Pankaj Sadavarte, Qiao Ma, Aaron Cohen, Sreelekha Chaliyakunnel, Joseph Frostad, Zbigniew Klimont, Randall V. Martin, Dylan B. Millet, Sajeev Philip, Katherine Walker, and Shuxiao Wang
Atmos. Chem. Phys., 18, 8017–8039,
Mukesh Rai, Shichang Kang, Junhua Yang, Maheswar Rupakheti, Dipesh Rupakheti, Lekhendra Tripathee, Yuling Hu, and Xintong Chen
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Our study revealed distinctive seasonality with the maximum and minimum aerosol concentrations during the winter and summer seasons respectively. However, interestingly summer high (AOD > 0.8) was observed over South Asia. The highest aerosols are laden over South Asia and East China within 1–2 km, however, aerosol overshooting found up to 10 km due to the deep convection process. Whereas, integrated aerosol transport for OC during spring was found to be 5 times higher than the annual mean.
Yifan Zhou, Benjamin F. Zaitchik, Sujay V. Kumar, Kristi R. Arsenault, Mir A. Matin, Faisal M. Qamer, Ryan A. Zamora, and Kiran Shakya
Hydrol. Earth Syst. Sci., 25, 41–61,Short summary
South and Southeast Asia face significant food insecurity and hydrological hazards. Here we introduce a South and Southeast Asia hydrological monitoring and sub-seasonal to seasonal forecasting system (SAHFS-S2S) to help local governments and decision-makers prepare for extreme hydroclimatic events. The monitoring system captures soil moisture variability well in most regions, and the forecasting system offers skillful prediction of soil moisture variability 2–3 months in advance, on average.
August Andersson, Elena N. Kirillova, Stefano Decesari, Langley DeWitt, Jimmy Gasore, Katherine E. Potter, Ronald G. Prinn, Maheswar Rupakheti, Jean de Dieu Ndikubwimana, Julius Nkusi, and Bonfils Safari
Atmos. Chem. Phys., 20, 4561–4573,Short summary
Large-scale biomass burning events seasonally cover sub-Saharan Africa with air particles. In this study, we find that the concentrations of these particles at a remote mountain site in Rwanda may increase by a factor of 10 during such dry biomass burning periods, with strong implications for the regional climate and human health. These results provide quantitative constraints that could contribute to reducing the large uncertainties regarding the environmental impact of these fires.
Md. Robiul Islam, Thilina Jayarathne, Isobel J. Simpson, Benjamin Werden, John Maben, Ashley Gilbert, Puppala S. Praveen, Sagar Adhikari, Arnico K. Panday, Maheswar Rupakheti, Donald R. Blake, Robert J. Yokelson, Peter F. DeCarlo, William C. Keene, and Elizabeth A. Stone
Atmos. Chem. Phys., 20, 2927–2951,Short summary
The Kathmandu Valley experiences high levels of air pollution. In this study, atmospheric gases and particulate matter were characterized by online and off-line measurements, with an emphasis on understanding their sources. The major sources of particulate matter and trace gases were identified as garbage burning, biomass burning, and vehicles. The majority of secondary organic aerosol was attributed to anthropogenic precursors, while a minority was attributed to biogenic gases.
Min Zhong, Eri Saikawa, Alexander Avramov, Chen Chen, Boya Sun, Wenlu Ye, William C. Keene, Robert J. Yokelson, Thilina Jayarathne, Elizabeth A. Stone, Maheswar Rupakheti, and Arnico K. Panday
Atmos. Chem. Phys., 19, 8209–8228,Short summary
Air pollution is one of the most pressing environmental issues in the Kathmandu Valley, the capital city of Nepal. We estimated emissions from two of the major source types in the valley (vehicles and brick kilns) and found that they have significant impacts on air quality surrounding the valley. Our results highlight the importance of improving local emissions estimates for air quality modeling.
Xin Wan, Shichang Kang, Maheswar Rupakheti, Qianggong Zhang, Lekhendra Tripathee, Junming Guo, Pengfei Chen, Dipesh Rupakheti, Arnico K. Panday, Mark G. Lawrence, Kimitaka Kawamura, and Zhiyuan Cong
Atmos. Chem. Phys., 19, 2725–2747,Short summary
The sources of primary and secondary aerosols in the Hindu Kush–Himalayan–Tibetan Plateau region are not well known. Organic molecular tracers are useful for aerosol source apportionment. The characterization of molecular tracers were first systemically investigated and the contribution from primary and secondary sources to carbonaceous aerosols was estimated in the Kathmandu Valley. Our results demonstrate that biomass burning contributed a significant fraction to OC in the Kathmandu Valley.
H. Langley DeWitt, Jimmy Gasore, Maheswar Rupakheti, Katherine E. Potter, Ronald G. Prinn, Jean de Dieu Ndikubwimana, Julius Nkusi, and Bonfils Safari
Atmos. Chem. Phys., 19, 2063–2078,Short summary
Air quality in rapidly developing East Africa is a growing but understudied concern. We analyzed long-term black carbon, carbon monoxide, and ozone measurements from the remote Rwanda Climate Observatory and found that seasonal regional biomass burning raised black carbon levels to above-urban concentrations 6 months out of the year. Additional local pollution could exacerbate this issue. More regional monitoring needs to be done to understand and reduce air pollution in this region.
Ashish Singh, Khadak S. Mahata, Maheswar Rupakheti, Wolfgang Junkermann, Arnico K. Panday, and Mark G. Lawrence
Atmos. Chem. Phys., 19, 245–258,Short summary
This paper reports the first airborne measurement campaign in the central Himalayan foothill region, one of the polluted but relatively poorly sampled regions of the world. The measurement campaign quantifies the vertical distribution of aerosols over a polluted mountain valley in the Himalayan foothills and investigates the extent of regional emission transport.
J. Douglas Goetz, Michael R. Giordano, Chelsea E. Stockwell, Ted J. Christian, Rashmi Maharjan, Sagar Adhikari, Prakash V. Bhave, Puppala S. Praveen, Arnico K. Panday, Thilina Jayarathne, Elizabeth A. Stone, Robert J. Yokelson, and Peter F. DeCarlo
Atmos. Chem. Phys., 18, 14653–14679,Short summary
Size distributions and emission factors of submicron aerosol were quantified using online techniques for a variety of common but under-sampled combustion sources in South Asia: wood and dung cooking fires, groundwater pumps, brick kilns, trash burning, and open burning of crop residues. Optical properties (brown carbon light absorption and the absorption Ångström exponent, AAE) of the emissions were also investigated. Contextual comparisons to the literature and other NAMaSTE results were made.
Khadak Singh Mahata, Maheswar Rupakheti, Arnico Kumar Panday, Piyush Bhardwaj, Manish Naja, Ashish Singh, Andrea Mues, Paolo Cristofanelli, Deepak Pudasainee, Paolo Bonasoni, and Mark G. Lawrence
Atmos. Chem. Phys., 18, 14113–14132,Short summary
This paper presents the first-time simultaneous measurement of CO and O3 at multiple sites in the Kathmandu Valley bottom, its mountain rim and a river outlet, providing their spatial, temporal and seasonal–diurnal variations. Our study reveals that high O3, especially during premonsoon, in observed sites is of high concern for human health and ecosystems in the region. We also estimated CO emission flux to be 2–14 times higher than widely used emission databases (EDGAR HTAP, REAS and INTEX-B).
Piyush Bhardwaj, Manish Naja, Maheswar Rupakheti, Aurelia Lupascu, Andrea Mues, Arnico Kumar Panday, Rajesh Kumar, Khadak Singh Mahata, Shyam Lal, Harish C. Chandola, and Mark G. Lawrence
Atmos. Chem. Phys., 18, 11949–11971,Short summary
This study provides information about the regional variabilities in some of the pollutants using observations in Nepal and India. It is shown that agricultural crop residue burning leads to a significant enhancement in ozone and CO over a wider region. Further, the wintertime higher ozone levels are shown to be largely due to local emissions, while regional transport could be important in spring and hence shows the role of regional sources versus local sources in the Kathmandu Valley.
Erika von Schneidemesser, Boris Bonn, Tim M. Butler, Christian Ehlers, Holger Gerwig, Hannele Hakola, Heidi Hellén, Andreas Kerschbaumer, Dieter Klemp, Claudia Kofahl, Jürgen Kura, Anja Lüdecke, Rainer Nothard, Axel Pietsch, Jörn Quedenau, Klaus Schäfer, James J. Schauer, Ashish Singh, Ana-Maria Villalobos, Matthias Wiegner, and Mark G. Lawrence
Atmos. Chem. Phys., 18, 8621–8645,Short summary
This paper provides an overview of the measurements done at an urban background site in Berlin from June-August of 2014. Results show that natural source contributions to ozone and particulate matter (PM) air pollutants are substantial. Large contributions of secondary aerosols formed in the atmosphere to PM10 concentrations were quantified. An analysis of the sources also identified contributions to PM from plant-based sources, vehicles, and a small contribution from wood burning.
Andrea Mues, Axel Lauer, Aurelia Lupascu, Maheswar Rupakheti, Friderike Kuik, and Mark G. Lawrence
Geosci. Model Dev., 11, 2067–2091,
Chandra Venkataraman, Michael Brauer, Kushal Tibrewal, Pankaj Sadavarte, Qiao Ma, Aaron Cohen, Sreelekha Chaliyakunnel, Joseph Frostad, Zbigniew Klimont, Randall V. Martin, Dylan B. Millet, Sajeev Philip, Katherine Walker, and Shuxiao Wang
Atmos. Chem. Phys., 18, 8017–8039,
D. Rupakheti, S. Kang, Z. Cong, M. Rupakheti, L. Tripathee, A. K. Panday, and B. Holben
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-3, 1493–1497,
Khadak Singh Mahata, Arnico Kumar Panday, Maheswar Rupakheti, Ashish Singh, Manish Naja, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 12573–12596,Short summary
The paper provides an overview of CH4, CO2, and CO mixing ratios, including diurnal and seasonal variation, and discusses the association of potential sources and meteorology with the observed temporal variation in the Kathmandu Valley. The study will provide an important dataset for a poorly studied region and will be useful for validating estimates from emission inventories, regional models, and satellite observations and assisting in the design of mitigation measures in the region.
Chaeyoon Cho, Sang-Woo Kim, Maheswar Rupakheti, Jin-Soo Park, Arnico Panday, Soon-Chang Yoon, Ji-Hyoung Kim, Hyunjae Kim, Haeun Jeon, Minyoung Sung, Bong Mann Kim, Seungkyu K. Hong, Rokjin J. Park, Dipesh Rupakheti, Khadak Singh Mahata, Puppala Siva Praveen, Mark G. Lawrence, and Brent Holben
Atmos. Chem. Phys., 17, 12617–12632,Short summary
We investigated the optical and chemical properties and direct radiative effects of aerosols in the Kathmandu Valley. We concluded that the ratio of light-absorbing to scattering aerosols as well as the concentration of light-absorbing aerosols is much higher at Kathmandu than other comparable regions, and it contributes to a great atmospheric absorption efficiency. This study provides unprecedented insights into aerosol optical properties and their radiative forcings in the Kathmandu Valley.
Dipesh Rupakheti, Bhupesh Adhikary, Puppala Siva Praveen, Maheswar Rupakheti, Shichang Kang, Khadak Singh Mahata, Manish Naja, Qianggong Zhang, Arnico Kumar Panday, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 11041–11063,Short summary
For the first time, atmospheric composition was monitored during pre-monsoon season of 2013 at Lumbini (UNESCO world heritage site as birthplace of the Buddha). PM and O3 frequently exceeded WHO guidelines. Pollution concentration, diurnal characteristics and influence of open burning on air quality in Lumbini were investigated. Potential source regions were also identified. Results show that air pollution at this site is of a great concern, requiring prompt attention for mitigation.
Heiko Bozem, Tim M. Butler, Mark G. Lawrence, Hartwig Harder, Monica Martinez, Dagmar Kubistin, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 17, 10565–10582,Short summary
We present airborne measurements and model simulations in the tropics and mid-latitudes during GABRIEL and HOOVER, respectively. Based only on in situ data net ozone formation/destruction tendencies (NOPR) are calculated and compared to a 3-D chemistry transport model. The NOPR is positive in the continental boundary layer and the upper troposphere above 6 km. In the marine boundary layer and the middle troposphere ozone destruction prevails. Fresh convection shows strong net ozone formation.
Xin Wan, Shichang Kang, Quanlian Li, Dipesh Rupakheti, Qianggong Zhang, Junming Guo, Pengfei Chen, Lekhendra Tripathee, Maheswar Rupakheti, Arnico K. Panday, Wu Wang, Kimitaka Kawamura, Shaopeng Gao, Guangming Wu, and Zhiyuan Cong
Atmos. Chem. Phys., 17, 8867–8885,Short summary
Biomass burning (BB) tracers in the aerosols in Lumbini, northern IGP, were studied for the first time. The levoglucosan was the predominant tracer and BB significantly contributed to the air quality in Lumbini. Mixed crop residues and hardwood were main burning materials. BB emissions constituted large fraction of OC, especially during the post-monsoon season. The sources of BB aerosols in Lumbini varies seasonally due to the influence of local emissions and long-range transport.
Andrea Mues, Maheswar Rupakheti, Christoph Münkel, Axel Lauer, Heiko Bozem, Peter Hoor, Tim Butler, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 8157–8176,Short summary
Ceilometer measurements taken in the Kathmandu Valley, Nepal, were used to study the temporal and spatial evolution of the mixing layer height in the valley. This provides important information on the vertical structure of the atmosphere and can thus also help to understand the mixing of air pollutants (e.g. black carbon) in the valley. The seasonal and diurnal cycles of the mixing layer were found to be highly dependent on meteorology and mainly anticorrelated to black carbon concentrations.
Chinmoy Sarkar, Vinayak Sinha, Baerbel Sinha, Arnico K. Panday, Maheswar Rupakheti, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 8129–8156,Short summary
This study provides quantitative information regarding the source contributions of the major non-methane volatile organic compound sources in the Kathmandu Valley. Combining high-resolution in situ NMVOC data and model analyses, we show that REAS v2.1 and EDGAR v4.2 emission inventories underestimate the contribution of traffic and do not take the contribution of brick kilns into account. Furthermore, REAS v2.1 overestimates the contribution of residential biofuel use and industries.
Kabindra M. Shakya, Maheswar Rupakheti, Anima Shahi, Rejina Maskey, Bidya Pradhan, Arnico Panday, Siva P. Puppala, Mark Lawrence, and Richard E. Peltier
Atmos. Chem. Phys., 17, 6503–6516,Short summary
Particulate matter levels were monitored at six major roadway intersections in the Kathmandu Valley during two seasons in 2014. The study documented distinct seasonal (dry season versus wet season) and diel variations in particulate matter levels. This study suggests traffic-related emissions, and soil–dust–construction materials were found to be a major source of particulate matter at these locations.
Boris Bonn, Erika von Schneidemesser, Dorota Andrich, Jörn Quedenau, Holger Gerwig, Anja Lüdecke, Jürgen Kura, Axel Pietsch, Christian Ehlers, Dieter Klemp, Claudia Kofahl, Rainer Nothard, Andreas Kerschbaumer, Wolfgang Junkermann, Rüdiger Grote, Tobias Pohl, Konradin Weber, Birgit Lode, Philipp Schönberger, Galina Churkina, Tim M. Butler, and Mark G. Lawrence
Atmos. Chem. Phys., 16, 7785–7811,Short summary
The distribution of air pollutants (gases and particles) have been investigated in different environments in Potsdam, Germany. Remarkable variations of the pollutants have been observed for distances of tens of meters by bicycles, vans and aircraft. Vegetated areas caused reductions depending on the pollutants, the vegetation type and dimensions. Our measurements show the pollutants to be of predominantly local origin, resulting in a huge challenge for common models to resolve.
Marje Prank, Mikhail Sofiev, Svetlana Tsyro, Carlijn Hendriks, Valiyaveetil Semeena, Xavier Vazhappilly Francis, Tim Butler, Hugo Denier van der Gon, Rainer Friedrich, Johannes Hendricks, Xin Kong, Mark Lawrence, Mattia Righi, Zissis Samaras, Robert Sausen, Jaakko Kukkonen, and Ranjeet Sokhi
Atmos. Chem. Phys., 16, 6041–6070,Short summary
Aerosol composition in Europe was simulated by four chemistry transport models and compared to observations to identify the most prominent areas for model improvement. Notable differences were found between the models' predictions, attributable to different treatment or omission of aerosol sources and processes. All models underestimated the observed concentrations by 10–60 %, mostly due to under-predicting the carbonaceous and mineral particles and omitting the aerosol-bound water.
Chinmoy Sarkar, Vinayak Sinha, Vinod Kumar, Maheswar Rupakheti, Arnico Panday, Khadak S. Mahata, Dipesh Rupakheti, Bhogendra Kathayat, and Mark G. Lawrence
Atmos. Chem. Phys., 16, 3979–4003,Short summary
First deployment of PTR-TOF-MS in South Asia. High acetaldehyde and biogenic isoprene concentrations detected even in winter in the Kathmandu Valley. Isocyanic acid, formamide, acetamide, naphthalene and nitromethane were detected for the first time in South Asian air. Oxygenated VOCs and isoprene-dominated OH reactivity and ozone production potentials (> 68 % OPP). Regulation of emissions from biomass co-fired brick kilns' by cleaner technology would improve air quality of the valley.
Peng Fei Chen, Chao Liu Li, Shi Chang Kang, Maheswar Rupakheti, Arnico K. Panday, Fang Ping Yan, Quan Lian Li, Qiang Gong Zhang, Jun Ming Guo, Dipesh Rupakheti, and Wei Luo
Atmos. Chem. Phys. Discuss.,
Revised manuscript not acceptedShort summary
PAHs were measured at six sites along two south-north transects across the central Himalayas. The annual average PAHs and their dry deposition fluxes decreased noticeably from the south to north sides, however, a similar compostion pattern was found at three remote sites, suggesting the northern slope of the Himalayas may be affected by anthropogenic emissions form Indo-Gangetic Plain. PAHs showed a clear seasonal variation at Nepal and they were mainly form biomass and fossil combustion .
E. W. Butt, A. Rap, A. Schmidt, C. E. Scott, K. J. Pringle, C. L. Reddington, N. A. D. Richards, M. T. Woodhouse, J. Ramirez-Villegas, H. Yang, V. Vakkari, E. A. Stone, M. Rupakheti, P. S. Praveen, P. G. van Zyl, J. P. Beukes, M. Josipovic, E. J. S. Mitchell, S. M. Sallu, P. M. Forster, and D. V. Spracklen
Atmos. Chem. Phys., 16, 873–905,Short summary
We estimate the impact of residential emissions (cooking and heating) on atmospheric aerosol, human health, and climate. We find large contributions to annual mean ambient PM2.5 in residential sources regions resulting in significant but uncertain global premature mortality when key uncertainties in emission flux are considered. We show that residential emissions exert an uncertain global radiative effect and suggest more work is needed to characterise residential emissions climate importance.
D. Putero, P. Cristofanelli, A. Marinoni, B. Adhikary, R. Duchi, S. D. Shrestha, G. P. Verza, T. C. Landi, F. Calzolari, M. Busetto, G. Agrillo, F. Biancofiore, P. Di Carlo, A. K. Panday, M. Rupakheti, and P. Bonasoni
Atmos. Chem. Phys., 15, 13957–13971,Short summary
The aim of this paper is to present a full-year analysis of simultaneous measurements of ozone, black carbon, and aerosol number concentration at Paknajol, in the Kathmandu Valley, one of the global “hot spots” in terms of air pollution. Results indicate persisting poor air quality conditions throughout the measurement period, and suggest that the pollutants' variability is mainly driven by local pollution source activity, local- and large-scale dynamics, photochemistry, and vegetation fires.
B. Kravitz, A. Robock, S. Tilmes, O. Boucher, J. M. English, P. J. Irvine, A. Jones, M. G. Lawrence, M. MacCracken, H. Muri, J. C. Moore, U. Niemeier, S. J. Phipps, J. Sillmann, T. Storelvmo, H. Wang, and S. Watanabe
Geosci. Model Dev., 8, 3379–3392,
M. Beekmann, A. S. H. Prévôt, F. Drewnick, J. Sciare, S. N. Pandis, H. A. C. Denier van der Gon, M. Crippa, F. Freutel, L. Poulain, V. Ghersi, E. Rodriguez, S. Beirle, P. Zotter, S.-L. von der Weiden-Reinmüller, M. Bressi, C. Fountoukis, H. Petetin, S. Szidat, J. Schneider, A. Rosso, I. El Haddad, A. Megaritis, Q. J. Zhang, V. Michoud, J. G. Slowik, S. Moukhtar, P. Kolmonen, A. Stohl, S. Eckhardt, A. Borbon, V. Gros, N. Marchand, J. L. Jaffrezo, A. Schwarzenboeck, A. Colomb, A. Wiedensohler, S. Borrmann, M. Lawrence, A. Baklanov, and U. Baltensperger
Atmos. Chem. Phys., 15, 9577–9591,Short summary
A detailed characterization of air quality in the Paris (France) agglomeration, a megacity, during two summer and winter intensive campaigns and from additional 1-year observations, revealed that about 70% of the fine particulate matter (PM) at urban background is transported into the megacity from upwind regions. Unexpectedly, a major part of organic PM is of modern origin (woodburning and cooking activities, secondary formation from biogenic VOC).
Z. L. Lüthi, B. Škerlak, S.-W. Kim, A. Lauer, A. Mues, M. Rupakheti, and S. Kang
Atmos. Chem. Phys., 15, 6007–6021,Short summary
The Himalayas and the Tibetan Plateau region (HTP) is regularly exposed to polluted air masses that might influence glaciers as well as climate on regional to global scales. We found that atmospheric brown clouds from South Asia reach the HTP by crossing the Himalayas not only through the major north--south river valleys but rather over large areas by being lifted and advected at mid-troposheric levels. The transport is enabled by a combination of synoptic and local meteorological settings.
L. Drinovec, G. Močnik, P. Zotter, A. S. H. Prévôt, C. Ruckstuhl, E. Coz, M. Rupakheti, J. Sciare, T. Müller, A. Wiedensohler, and A. D. A. Hansen
Atmos. Meas. Tech., 8, 1965–1979,Short summary
We present a new real-time algorithm for compensation of the filter-loading effect in filter photometers, based on a two parallel spot measurement of optical absorption. This algorithm has been incorporated into the new Aethalometer AE33. Intercomparison studies show excellent reproducibility of the AE33 measurements and very good agreement with post-processed data obtained using earlier aethalometer models and other filter-based absorption photometers.
C. Liu, S. Beirle, T. Butler, P. Hoor, C. Frankenberg, P. Jöckel, M. Penning de Vries, U. Platt, A. Pozzer, M. G. Lawrence, J. Lelieveld, H. Tost, and T. Wagner
Atmos. Chem. Phys., 14, 1717–1732,
Z. S. Stock, M. R. Russo, T. M. Butler, A. T. Archibald, M. G. Lawrence, P. J. Telford, N. L. Abraham, and J. A. Pyle
Atmos. Chem. Phys., 13, 12215–12231,
S. M. Burrows, P. J. Rayner, T. Butler, and M. G. Lawrence
Atmos. Chem. Phys., 13, 5473–5488,
D. Kunkel, H. Tost, and M. G. Lawrence
Atmos. Chem. Phys., 13, 4203–4222,
J. Lelieveld, M. G. Lawrence, and D. Kunkel
Atmos. Chem. Phys., 13, 31–34,
Related subject area
Subject: Aerosols | Research Activity: Atmospheric Modelling | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)Eurodelta multi-model simulated and observed particulate matter trends in Europe in the period of 1990–2010Elucidating the critical oligomeric steps in secondary organic aerosol and brown carbon formationFast climate responses to emission reductions in aerosol and ozone precursors in China during 2013–2017Secondary PM2.5 decreases significantly less than NO2 emission reductions during COVID lockdown in GermanyMolecular-level nucleation mechanism of iodic acid and methanesulfonic acidEstimation of secondary PM2.5 in China and the United States using a multi-tracer approachTwo-way coupled meteorology and air quality models in Asia: a systematic review and meta-analysis of impacts of aerosol feedbacks on meteorology and air qualityOCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) sea spray organic aerosol emissions – implementation in a global climate model and impacts on cloudsThe pathway of impacts of aerosol direct effects on secondary inorganic aerosol formationThe impact of molecular self-organisation on the atmospheric fate of a cooking aerosol proxyThe formation and mitigation of nitrate pollution: comparison between urban and suburban environmentsImpacts of aerosol–photolysis interaction and aerosol–radiation feedback on surface-layer ozone in North China during multi-pollutant air pollution episodesReducing future air-pollution-related premature mortality over Europe by mitigating emissions from the energy sector: assessing an 80 % renewable energies scenarioThe impact of chlorine chemistry combined with heterogeneous N2O5 reactions on air quality in ChinaOH-initiated atmospheric degradation of hydroxyalkyl hydroperoxides: mechanism, kinetics, and structure–activity relationshipA predictive viscosity model for aqueous electrolytes and mixed organic–inorganic aerosol phasesA new assessment of global and regional budgets, fluxes and lifetimes of atmospheric reactive N and S gases and aerosolsThe role of organic acids in new particle formation from methanesulfonic acid and methylamineThe number fraction of iron-containing particles affects OH, HO2 and H2O2 budgets in the atmospheric aqueous phaseSource-resolved variability of fine particulate matter and human exposure in an urban areaThe impact of atmospheric blocking on the compounding effect of ozone pollution and temperature: a copula-based approachExploring dimethyl sulfide (DMS) oxidation and implications for global aerosol radiative forcingModelling changes in secondary inorganic aerosol formation and nitrogen deposition in Europe from 2005 to 2030Extension of the AIOMFAC model by iodine and carbonate species: applications for aerosol acidity and cloud droplet activationA numerical framework for simulating the atmospheric variability of supermicron marine biogenic ice nucleating particlesPrediction of secondary organic aerosol from the multiphase reaction of gasoline vapor by using volatility–reactivity base lumpingModelling the gas–particle partitioning and water uptake of isoprene-derived secondary organic aerosol at high and low relative humidityLimitations in representation of physical processes prevent successful simulation of PM2.5 during KORUS-AQContrasting source contributions of Arctic black carbon to atmospheric concentrations, deposition flux, and atmospheric and snow radiative effectsModeling secondary organic aerosol formation from volatile chemical productsWhy is the city's responsibility for its air pollution often underestimated? A focus on PM2.5Quantifying the structural uncertainty of the aerosol mixing state representation in a modal modelChanges in PM2.5 concentrations and their sources in the US from 1990 to 2010A predictive thermodynamic framework of cloud droplet activation for chemically unresolved aerosol mixtures, including surface tension, non-ideality, and bulk–surface partitioningProcess-based and observation-constrained SOA simulations in China: the role of semivolatile and intermediate-volatility organic compounds and OH levelsImpacts of emission changes in China from 2010 to 2017 on domestic and intercontinental air quality and health effectExploring the sensitivity of atmospheric nitrate concentrations to nitric acid uptake rate using the Met Office's Unified ModelImproving the representation of HONO chemistry in CMAQ and examining its impact on haze over ChinaHow alkaline compounds control atmospheric aerosol particle acidityAerosol transport pathways and source attribution in China during the COVID-19 outbreakNonlinear responses of particulate nitrate to NOx emission controls in the megalopolises of ChinaInsight into PM2.5 sources by applying positive matrix factorization (PMF) at urban and rural sites of BeijingEvaluation and intercomparison of wildfire smoke forecasts from multiple modeling systems for the 2019 Williams Flats fireA comprehensive observation-based multiphase chemical model analysis of sulfur dioxide oxidations in both summer and winterPredicting gas–particle partitioning coefficients of atmospheric molecules with machine learningDevelopment of a new emission reallocation method for industrial sources in ChinaProjections of shipping emissions and the related impact on air pollution and human health in the Nordic regionA predictive model for salt nanoparticle formation using heterodimer stability calculationsUsing GECKO-A to derive mechanistic understanding of secondary organic aerosol formation from the ubiquitous but understudied campheneSeasonal distribution and drivers of surface fine particulate matter and organic aerosol over the Indo-Gangetic Plain
Svetlana Tsyro, Wenche Aas, Augustin Colette, Camilla Andersson, Bertrand Bessagnet, Giancarlo Ciarelli, Florian Couvidat, Kees Cuvelier, Astrid Manders, Kathleen Mar, Mihaela Mircea, Noelia Otero, Maria-Teresa Pay, Valentin Raffort, Yelva Roustan, Mark R. Theobald, Marta G. Vivanco, Hilde Fagerli, Peter Wind, Gino Briganti, Andrea Cappelletti, Massimo D'Isidoro, and Mario Adani
Atmos. Chem. Phys., 22, 7207–7257,Short summary
Particulate matter (PM) air pollution causes adverse health effects. In Europe, the emissions caused by anthropogenic activities have been reduced in the last decades. To assess the efficiency of emission reductions in improving air quality, we have studied the evolution of PM pollution in Europe. Simulations with six air quality models and observational data indicate a decrease in PM concentrations by 10 % to 30 % across Europe from 2000 to 2010, which is mainly a result of emission reductions.
Yuemeng Ji, Qiuju Shi, Xiaohui Ma, Lei Gao, Jiaxin Wang, Yixin Li, Yanpeng Gao, Guiying Li, Renyi Zhang, and Taicheng An
Atmos. Chem. Phys., 22, 7259–7271,Short summary
The formation mechanisms of secondary organic aerosol and brown carbon from small α-carbonyls are still unclear. Thus, the mechanisms and kinetics of aqueous-phase reactions of glyoxal were investigated using quantum chemical and kinetic rate calculations. Several essential isomeric processes were identified, including protonation to yield diol/tetrol and carbenium ions as well as nucleophilic addition of carbenium ions to diol/tetrol and free methylamine/ammonia.
Jiyuan Gao, Yang Yang, Hailong Wang, Pinya Wang, Huimin Li, Mengyun Li, Lili Ren, Xu Yue, and Hong Liao
Atmos. Chem. Phys., 22, 7131–7142,Short summary
China has been implementing a sequence of policies for clean air since the year 2013. The aerosol decline produced a 0.09 ± 0.10°C warming during 2013–2017 estimated in this study, and the increase in ozone in the lower troposphere during this time period accelerated the warming, leading to a total 0.16 ± 0.15°C temperature increase in eastern China. Residential emission reductions led to a cooling effect because of a substantial decrease in light-absorbing aerosols.
Vigneshkumar Balamurugan, Jia Chen, Zhen Qu, Xiao Bi, and Frank N. Keutsch
Atmos. Chem. Phys., 22, 7105–7129,Short summary
In this study, we investigated the response of secondary pollutants to changes in precursor emissions, focusing on the formation of secondary PM, during the COVID-19 lockdown period. We show that, due to the decrease in primary NOx emissions, atmospheric oxidizing capacity is increased. The nighttime increase in ozone, caused by less NO titration, results in higher NO3 radicals, which contribute significantly to the formation of PM nitrates. O3 should be limited in order to control PM pollution.
An Ning, Ling Liu, Lin Ji, and Xiuhui Zhang
Atmos. Chem. Phys., 22, 6103–6114,Short summary
Iodic acid (IA) and methanesulfonic acid (MSA) were previously proved to be significant nucleation precursors in marine areas. However, the nucleation process involved in IA and MSA remains unclear. We show the enhancement of MSA on IA cluster formation and reveal the IAM-SA nucleating mechanism using a theoretical approach. This study helps to understand the clustering process in which marine sulfur- and iodine-containing species are jointly involved and its impact on new particle formation.
Haoran Zhang, Nan Li, Keqin Tang, Hong Liao, Chong Shi, Cheng Huang, Hongli Wang, Song Guo, Min Hu, Xinlei Ge, Mindong Chen, Zhenxin Liu, Huan Yu, and Jianlin Hu
Atmos. Chem. Phys., 22, 5495–5514,Short summary
We developed a new algorithm with low economic/technique costs to identify primary and secondary components of PM2.5. Our model was shown to be reliable by comparison with different observation datasets. We systematically explored the patterns and changes in the secondary PM2.5 pollution in China at large spatial and time scales. We believe that this method is a promising tool for efficiently estimating primary and secondary PM2.5, and has huge potential for future PM mitigation.
Chao Gao, Aijun Xiu, Xuelei Zhang, Qingqing Tong, Hongmei Zhao, Shichun Zhang, Guangyi Yang, and Mengduo Zhang
Atmos. Chem. Phys., 22, 5265–5329,Short summary
With ever-growing applications of two-way coupled meteorology and air quality models in Asia over the past decade, this paper summarizes the current status and research focuses, as well as how aerosol effects impact model performance, meteorology, and air quality. These models enable investigations of ARI and ACI effects induced by natural and anthropogenic aerosols in Asia, which has serious air pollution problems. The current gaps and perspectives are also presented and discussed.
Susannah M. Burrows, Richard C. Easter, Xiaohong Liu, Po-Lun Ma, Hailong Wang, Scott M. Elliott, Balwinder Singh, Kai Zhang, and Philip J. Rasch
Atmos. Chem. Phys., 22, 5223–5251,Short summary
Sea spray particles are composed of a mixture of salts and organic substances from oceanic microorganisms. In prior work, our team developed an approach connecting sea spray chemistry to ocean biology, called OCEANFILMS. Here we describe its implementation within an Earth system model, E3SM. We show that simulated sea spray chemistry is consistent with observed seasonal cycles and that sunlight reflected by simulated Southern Ocean clouds increases, consistent with analysis of satellite data.
Jiandong Wang, Jia Xing, Shuxiao Wang, Rohit Mathur, Jiaping Wang, Yuqiang Zhang, Chao Liu, Jonathan Pleim, Dian Ding, Xing Chang, Jingkun Jiang, Peng Zhao, Shovan Kumar Sahu, Yuzhi Jin, David C. Wong, and Jiming Hao
Atmos. Chem. Phys., 22, 5147–5156,Short summary
Aerosols reduce surface solar radiation and change the photolysis rate and planetary boundary layer stability. In this study, the online coupled meteorological and chemistry model was used to explore the detailed pathway of how aerosol direct effects affect secondary inorganic aerosol. The effects through the dynamics pathway act as an equally or even more important route compared with the photolysis pathway in affecting secondary aerosol concentration in both summer and winter.
Adam Milsom, Adam M. Squires, Andrew D. Ward, and Christian Pfrang
Atmos. Chem. Phys., 22, 4895–4907,Short summary
Cooking emissions can self-organise into nanostructured lamellar bilayers, and this can influence reaction kinetics. We developed a kinetic multi-layer model-based description of decay data we obtained from laboratory experiments of the ozonolysis of coated films of such a self-organised system, demonstrating a decreased diffusivity for both oleic acid and ozone. Nanostructure formation can thus increase the reactive half-life of oleic acid by days under typical indoor and outdoor conditions.
Suxia Yang, Bin Yuan, Yuwen Peng, Shan Huang, Wei Chen, Weiwei Hu, Chenglei Pei, Jun Zhou, David D. Parrish, Wenjie Wang, Xianjun He, Chunlei Cheng, Xiao-Bing Li, Xiaoyun Yang, Yu Song, Haichao Wang, Jipeng Qi, Baolin Wang, Chen Wang, Chaomin Wang, Zelong Wang, Tiange Li, E Zheng, Sihang Wang, Caihong Wu, Mingfu Cai, Chenshuo Ye, Wei Song, Peng Cheng, Duohong Chen, Xinming Wang, Zhanyi Zhang, Xuemei Wang, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4539–4556,Short summary
We use a model constrained using observations to study the formation of nitrate aerosol in and downwind of a representative megacity. We found different contributions of various chemical reactions to ground-level nitrate concentrations between urban and suburban regions. We also show that controlling VOC emissions are effective for decreasing nitrate formation in both urban and regional environments, although VOCs are not direct precursors of nitrate aerosol.
Hao Yang, Lei Chen, Hong Liao, Jia Zhu, Wenjie Wang, and Xin Li
Atmos. Chem. Phys., 22, 4101–4116,Short summary
Aerosols can influence O3 through aerosol–radiation interactions, including aerosol–photolysis interaction (API) and aerosol–radiation feedback (ARF). The weakened photolysis rates and changed meteorological conditions reduce surface-layer O3 concentrations by up to 9.3–11.4 ppb, with API and ARF contributing 74.6 %–90.0 % and 10.0 %–25.4 % of the O3 decrease in three episodes, respectively, which indicates that API is the dominant way for O3 reduction related to aerosol–radiation interactions.
Patricia Tarín-Carrasco, Ulas Im, Camilla Geels, Laura Palacios-Peña, and Pedro Jiménez-Guerrero
Atmos. Chem. Phys., 22, 3945–3965,Short summary
The evidence of the effects of atmospheric pollution (and particularly fine particulate matter, PM2.5) on human mortality is now unquestionable. Here, 895 000 annual premature deaths (PD) are estimated for the present (1991–2010), which increases to 1 540 000 in the year 2050 due to the ageing of the European population. The implementation of a mitigation scenario (80 % of the energy production in Europe from renewable sources) could lead to a decrease of over 60 000 annual PD for the year 2050.
Xiajie Yang, Qiaoqiao Wang, Nan Ma, Weiwei Hu, Yang Gao, Zhijiong Huang, Junyu Zheng, Bin Yuan, Ning Yang, Jiangchuan Tao, Juan Hong, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 3743–3762,Short summary
We use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 ＋ Cl chemistry to investigate the impacts of chlorine chemistry on air quality in China. Our study not only significantly improves the model's performance but also demonstrates the importance of non-sea-salt chlorine sources as well as an appropriate parameterization for N2O5 ＋ Cl chemistry to the impact of chlorine chemistry in China.
Long Chen, Yu Huang, Yonggang Xue, Zhihui Jia, and Wenliang Wang
Atmos. Chem. Phys., 22, 3693–3711,Short summary
Quantum chemical methods are applied to gain insight into the detailed mechanisms of OH-initiated oxidation of distinct HHPs. The dominant pathway is H-abstraction from the -OOH group in the initiation reactions of the OH radical with HOCH2OOH and HOC(CH3)2OOH. H-abstraction from -CH group is competitive with that from the -OOH group in the reaction of the OH radical with HOCH(CH3)OOH. The barrier of H-abstraction from the -OOH group is slightly increased as the methyl group number increases.
Joseph Lilek and Andreas Zuend
Atmos. Chem. Phys., 22, 3203–3233,Short summary
Depending on temperature and chemical makeup, certain aerosols can be highly viscous or glassy, with atmospheric implications. We have therefore implemented two major upgrades to the predictive viscosity model AIOMFAC-VISC. First, we created a new viscosity model for aqueous electrolyte solutions containing an arbitrary number of ion species. Second, we integrated the electrolyte model within the existing AIOMFAC-VISC framework to enable viscosity predictions for organic–inorganic mixtures.
Yao Ge, Massimo Vieno, David Stevenson, Peter Wind, and Mathew Heal
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Reactive N and S gases and particle are critical determinants of air quality. We reports a comprehensive analysis of the concentrations, wet and dry deposition, fluxes and lifetimes of these species globally, and for 10 world regions. We used the EMEP MSC-W model coupled with WRF meteorology and 2015 global emissions. Our work demonstrates the substantial regional variation in these quantities and the need for modelling to simulate atmospheric responses to precursor emissions.
Rongjie Zhang, Jiewen Shen, Hong-Bin Xie, Jingwen Chen, and Jonas Elm
Atmos. Chem. Phys., 22, 2639–2650,Short summary
Formic acid is screened out as the species that can effectively catalyze the new particle formation (NPF) of the methanesulfonic acid (MSA)–methylamine system, indicating organic acids might be required to facilitate MSA-driven NPF in the atmosphere. The results are significant to comprehensively understand the MSA-driven NPF and expand current knowledge of the contribution of OAs to NPF.
Amina Khaled, Minghui Zhang, and Barbara Ervens
Atmos. Chem. Phys., 22, 1989–2009,Short summary
Chemical reactions with iron in clouds and aerosol form and cycle reactive oxygen species (ROS). Previous model studies assumed that all cloud droplets (particles) contain iron, while single-particle analyses showed otherwise. By means of a model, we explore the bias in predicted ROS budgets by distributing a given iron mass to either all or only a few droplets (particles). Implications for oxidation potential, radical loss and iron oxidation state are discussed.
Pablo Garcia Rivera, Brian T. Dinkelacker, Ioannis Kioutsioukis, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 22, 2011–2027,Short summary
The contribution of various pollution sources to the variability of fine PM in an urban area was examined using as an example the city of Pittsburgh. Biomass burning aerosol shows the largest variability during the winter with local maxima within the city and in the suburbs. During both periods the largest contributing source to the average PM2.5 is particles from outside the modeling domain. The average population-weighted PM2.5 concentration does not change significantly with resolution.
Noelia Otero, Oscar E. Jurado, Tim Butler, and Henning W. Rust
Atmos. Chem. Phys., 22, 1905–1919,Short summary
Surface ozone and temperature are strongly dependent and their extremes might be exacerbated by underlying climatological drivers, such as atmospheric blocking. Using an observational data set, we measure the dependence structure between ozone and temperature under the influence of atmospheric blocking. Blocks enhanced the probability of occurrence of compound ozone and temperature extremes over northwestern and central Europe, leading to greater health risks.
Ka Ming Fung, Colette L. Heald, Jesse H. Kroll, Siyuan Wang, Duseong S. Jo, Andrew Gettelman, Zheng Lu, Xiaohong Liu, Rahul A. Zaveri, Eric C. Apel, Donald R. Blake, Jose-Luis Jimenez, Pedro Campuzano-Jost, Patrick R. Veres, Timothy S. Bates, John E. Shilling, and Maria Zawadowicz
Atmos. Chem. Phys., 22, 1549–1573,Short summary
Understanding the natural aerosol burden in the preindustrial era is crucial for us to assess how atmospheric aerosols affect the Earth's radiative budgets. Our study explores how a detailed description of dimethyl sulfide (DMS) oxidation (implemented in the Community Atmospheric Model version 6 with chemistry, CAM6-chem) could help us better estimate the present-day and preindustrial concentrations of sulfate and other relevant chemicals, as well as the resulting aerosol radiative impacts.
Jan Eiof Jonson, Hilde Fagerli, Thomas Scheuschner, and Svetlana Tsyro
Atmos. Chem. Phys., 22, 1311–1331,Short summary
Ammonia emissions are expected to decrease less than SOx and NOx emissions between 2005 and 2030. As the formation of PM2.5 particles from ammonia depends on the ratio between ammonia on one hand and sulfate (from SOx) and HNO3 (from NOx) on the other hand, the efficiency of particle formation from ammonia is decreasing. Depositions of reduced nitrogen are decreasing much less than oxidized nitrogen. The critical loads for nitrogen deposition will also be exceeded in much of Europe in 2030.
Hang Yin, Jing Dou, Liviana Klein, Ulrich K. Krieger, Alison Bain, Brandon J. Wallace, Thomas C. Preston, and Andreas Zuend
Atmos. Chem. Phys., 22, 973–1013,Short summary
Iodine and carbonate species are important components in marine and dust aerosols, respectively. We introduce an extended version of the AIOMFAC thermodynamic mixing model, which includes the ions I−, IO3−, HCO3−, CO32−, OH−, and CO2(aq) as new species, and we discuss two methods for solving the carbonate dissociation equilibria numerically. We also present new experimental water activity data for aqueous iodide and iodate systems.
Isabelle Steinke, Paul J. DeMott, Grant B. Deane, Thomas C. J. Hill, Mathew Maltrud, Aishwarya Raman, and Susannah M. Burrows
Atmos. Chem. Phys., 22, 847–859,Short summary
Over the oceans, sea spray aerosol is an important source of particles that may initiate the formation of cloud ice, which then has implications for the radiative properties of marine clouds. In our study, we focus on marine biogenic particles that are emitted episodically and develop a numerical framework to describe these emissions. We find that further cloud-resolving model studies and targeted observations are needed to fully understand the climate impacts from marine biogenic particles.
Sanghee Han and Myoseon Jang
Atmos. Chem. Phys., 22, 625–639,Short summary
The gasoline SOA formation potential was simulated by using the UNIPAR model coupled with CB6r3 mechanism under varying NOx levels, aerosol acidity, humidity, temperature, and concentrations of aqueous salts and gasoline vapor. The model predicts SOA formation via multiphase reactions in the absence of wall bias. The simulation shows that both heterogeneous reactions in the aqueous phase and the implementation of model parameters corrected for GWP are critical to accurately predict SOA mass.
Dalrin Ampritta Amaladhasan, Claudia Heyn, Christopher R. Hoyle, Imad El Haddad, Miriam Elser, Simone M. Pieber, Jay G. Slowik, Antonio Amorim, Jonathan Duplissy, Sebastian Ehrhart, Vladimir Makhmutov, Ugo Molteni, Matti Rissanen, Yuri Stozhkov, Robert Wagner, Armin Hansel, Jasper Kirkby, Neil M. Donahue, Rainer Volkamer, Urs Baltensperger, Martin Gysel-Beer, and Andreas Zuend
Atmos. Chem. Phys., 22, 215–244,Short summary
We use a combination of models for gas-phase chemical reactions and equilibrium gas–particle partitioning of isoprene-derived secondary organic aerosols (SOAs) informed by dark ozonolysis experiments conducted in the CLOUD chamber. Our predictions cover high to low relative humidities (RHs) and quantify how SOA mass yields are enhanced at high RH as well as the impact of inorganic seeds of distinct hygroscopicities and acidities on the coupled partitioning of water and semi-volatile organics.
Katherine R. Travis, James H. Crawford, Gao Chen, Carolyn E. Jordan, Benjamin A. Nault, Hwajin Kim, Jose L. Jimenez, Pedro Campuzano-Jost, Jack E. Dibb, Jung-Hun Woo, Younha Kim, Shixian Zhai, Xuan Wang, Erin E. McDuffie, Gan Luo, Fangqun Yu, Saewung Kim, Isobel J. Simpson, Donald R. Blake, Limseok Chang, and Michelle J. Kim
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
The 2016 Korea United States-Air Quality (KORUS-AQ) field campaign provided a unique set of observations to improve our understanding of PM2.5 pollution in South Korea. Models typically have errors in simulating PM2.5 in this region, which is of concern for the development of control measures. We use KORUS-AQ observations to improve our understanding of the mechanisms driving PM2.5 and the implications of model errors for determining PM2.5 that is attributable to local or foreign sources.
Hitoshi Matsui, Tatsuhiro Mori, Sho Ohata, Nobuhiro Moteki, Naga Oshima, Kumiko Goto-Azuma, Makoto Koike, and Yutaka Kondo
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Using a global aerosol model, we find that the source contributions to radiative effects of black carbon (BC) in the Arctic are quite different from those to mass concentrations and deposition flux of BC in the Arctic. This is because microphysical properties (e.g., mixing state), altitudes, and seasonal variations of BC in the atmosphere differ among emissions sources. These differences need to be considered for accurate simulations of Arctic BC and its source contributions and climate impacts.
Elyse A. Pennington, Karl M. Seltzer, Benjamin N. Murphy, Momei Qin, John H. Seinfeld, and Havala O. T. Pye
Atmos. Chem. Phys., 21, 18247–18261,Short summary
Volatile chemical products (VCPs) are commonly used consumer and industrial items that contribute to the formation of atmospheric aerosol. We implemented the emissions and chemistry of VCPs in a regional-scale model and compared predictions with measurements made in Los Angeles. Our results reduced model bias and suggest that VCPs may contribute up to half of anthropogenic secondary organic aerosol in Los Angeles and are an important source of human-influenced particular matter in urban areas.
Philippe Thunis, Alain Clappier, Alexander de Meij, Enrico Pisoni, Bertrand Bessagnet, and Leonor Tarrason
Atmos. Chem. Phys., 21, 18195–18212,Short summary
Air pollution's origin in cities is still a point of discussion, and approaches to assess the city's responsibility for its pollution are not harmonized and thus not comparable, resulting in sometimes contradicting interpretations. We show that methodological choices can easily lead to differences of a factor of 2 in terms of responsibility outcome and stress that methodological choices and assumptions most often lead to a systematic and important underestimation of the city's responsibility.
Zhonghua Zheng, Matthew West, Lei Zhao, Po-Lun Ma, Xiaohong Liu, and Nicole Riemer
Atmos. Chem. Phys., 21, 17727–17741,Short summary
Aerosol mixing state is an important emergent property that affects aerosol radiative forcing and aerosol–cloud interactions, but it has not been easy to constrain this property globally. We present a framework for evaluating the error in aerosol mixing state induced by aerosol representation assumptions, which is one of the important contributors to structural uncertainty in aerosol models. Our study provides insights into potential improvements to model process representation for aerosols.
Ksakousti Skyllakou, Pablo Garcia Rivera, Brian Dinkelacker, Eleni Karnezi, Ioannis Kioutsioukis, Carlos Hernandez, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 17115–17132,Short summary
Significant reductions in pollutant emissions took place in the US from 1990 to 2010. The reductions in sulfur dioxide emissions from electric-generating units have dominated the reductions in fine particle mass. The reductions in transportation emissions have led to a 30 % reduction of elemental concentrations and of organic particulate matter by a factor of 3. On the other hand, changes in biomass burning and biogenic secondary organic aerosol have been modest.
Nønne L. Prisle
Atmos. Chem. Phys., 21, 16387–16411,Short summary
A mass-based Gibbs adsorption model is presented to enable predictive Köhler calculations of droplet growth and activation with considerations of surface partitioning, surface tension, and non-ideal water activity for chemically complex and unresolved surface active aerosol mixtures, including actual atmospheric samples. The model is used to calculate cloud condensation nuclei (CCN) activity of aerosol particles comprising strongly surface-active model atmospheric humic-like substances (HULIS).
Ruqian Miao, Qi Chen, Manish Shrivastava, Youfan Chen, Lin Zhang, Jianlin Hu, Yan Zheng, and Keren Liao
Atmos. Chem. Phys., 21, 16183–16201,Short summary
We apply process-based and observation-constrained schemes to simulate organic aerosol in China and conduct comprehensive model–observation comparisons. The results show that anthropogenic semivolatile and intermediate-volatility organic compounds (SVOCs and IVOCs) are the main sources of secondary organic aerosol (SOA) in polluted regions, for which the residential sector is perhaps the predominant contributor. The hydroxyl radical level is also important for SOA modeling in polluted regions.
Yuqiang Zhang, Drew Shindell, Karl Seltzer, Lu Shen, Jean-Francois Lamarque, Qiang Zhang, Bo Zheng, Jia Xing, Zhe Jiang, and Lei Zhang
Atmos. Chem. Phys., 21, 16051–16065,Short summary
In this study, we use a global chemical transport model to simulate the effects on global air quality and human health due to emission changes in China from 2010 to 2017. By performing sensitivity analysis, we found that the air pollution control policies not only decrease the air pollutant concentration but also bring significant co-benefits in air quality to downwind regions. The benefits for the improved air pollution are dominated by PM2.5.
Anthony C. Jones, Adrian Hill, Samuel Remy, N. Luke Abraham, Mohit Dalvi, Catherine Hardacre, Alan J. Hewitt, Ben Johnson, Jane P. Mulcahy, and Steven T. Turnock
Atmos. Chem. Phys., 21, 15901–15927,Short summary
Ammonium nitrate is hard to model because it forms and evaporates rapidly. One approach is to relate its equilibrium concentration to temperature, humidity, and the amount of nitric acid and ammonia gases. Using this approach, we limit the rate at which equilibrium is reached using various condensation rates in a climate model. We show that ammonium nitrate concentrations are highly sensitive to the condensation rate. Our results will help improve the representation of nitrate in climate models.
Shuping Zhang, Golam Sarwar, Jia Xing, Biwu Chu, Chaoyang Xue, Arunachalam Sarav, Dian Ding, Haotian Zheng, Yujing Mu, Fengkui Duan, Tao Ma, and Hong He
Atmos. Chem. Phys., 21, 15809–15826,Short summary
Six heterogeneous HONO chemistry updates in CMAQ significantly improve HONO concentration. HONO production is primarily controlled by the heterogeneous reactions on ground and aerosol surfaces during haze. Additional HONO chemistry updates increase OH and production of secondary aerosols: sulfate, nitrate, and SOA.
Vlassis A. Karydis, Alexandra P. Tsimpidi, Andrea Pozzer, and Jos Lelieveld
Atmos. Chem. Phys., 21, 14983–15001,Short summary
Aerosol particle pH is well-buffered by alkaline compounds, notably NH3 and crustal elements. NH3 is found to supply remarkable buffering capacity on a global scale, from the polluted continents to the remote oceans. Potential future changes in agricultural NH3 must be accompanied by strong reductions of SO2 and NOx to avoid particles becoming highly acidic, with implications for human health (aerosol toxicity), ecosystems (acid deposition), clouds, and climate (aerosol hygroscopicity).
Lili Ren, Yang Yang, Hailong Wang, Pinya Wang, Lei Chen, Jia Zhu, and Hong Liao
Atmos. Chem. Phys., 21, 15431–15445,Short summary
Due to the COVID-19 pandemic, human activities were strictly restricted in China. Even though anthropogenic aerosol emissions largely decreased, haze events still occurred. Our results shows that PM2.5 over the North China Plain is largely contributed by local sources. For other regions in China, PM2.5 is largely contributed from nonlocal sources. As emission reduction is a future goal, aerosol long-range transport and unfavorable meteorology are increasingly important to air quality.
Mengmeng Li, Zihan Zhang, Quan Yao, Tijian Wang, Min Xie, Shu Li, Bingliang Zhuang, and Yong Han
Atmos. Chem. Phys., 21, 15135–15152,Short summary
We establish the nonlinear responses between nitrate and NOx in China. Reduction of NOx results in linearly lower nitrate in summer–autumn whereas an increase of winter nitrate until an inflexion point at 40–50 % reduction due to the excess oxidants. NH3 and VOCs are effective in controlling nitrate pollution, whereas decreasing the SO2 and NOx emissions may have counterintuitive effects on nitrate aerosols. This paper helps understand the nonlinear aerosol and photochemistry feedback.
Deepchandra Srivastava, Jingsha Xu, Tuan V. Vu, Di Liu, Linjie Li, Pingqing Fu, Siqi Hou, Natalia Moreno Palmerola, Zongbo Shi, and Roy M. Harrison
Atmos. Chem. Phys., 21, 14703–14724,Short summary
This study presents the source apportionment of PM2.5 performed by positive matrix factorization (PMF) at urban and rural sites in Beijing. These factors are interpreted as traffic emissions, biomass burning, road and soil dust, coal and oil combustion, and secondary inorganics. PMF failed to resolve some sources identified by CMB and AMS and appears to overestimate the dust sources. Comparison with earlier PMF studies from the Beijing area highlights inconsistent findings using this method.
Xinxin Ye, Pargoal Arab, Ravan Ahmadov, Eric James, Georg A. Grell, Bradley Pierce, Aditya Kumar, Paul Makar, Jack Chen, Didier Davignon, Greg R. Carmichael, Gonzalo Ferrada, Jeff McQueen, Jianping Huang, Rajesh Kumar, Louisa Emmons, Farren L. Herron-Thorpe, Mark Parrington, Richard Engelen, Vincent-Henri Peuch, Arlindo da Silva, Amber Soja, Emily Gargulinski, Elizabeth Wiggins, Johnathan W. Hair, Marta Fenn, Taylor Shingler, Shobha Kondragunta, Alexei Lyapustin, Yujie Wang, Brent Holben, David M. Giles, and Pablo E. Saide
Atmos. Chem. Phys., 21, 14427–14469,Short summary
Wildfire smoke has crucial impacts on air quality, while uncertainties in the numerical forecasts remain significant. We present an evaluation of 12 real-time forecasting systems. Comparison of predicted smoke emissions suggests a large spread in magnitudes, with temporal patterns deviating from satellite detections. The performance for AOD and surface PM2.5 and their discrepancies highlighted the role of accurately represented spatiotemporal emission profiles in improving smoke forecasts.
Huan Song, Keding Lu, Can Ye, Huabin Dong, Shule Li, Shiyi Chen, Zhijun Wu, Mei Zheng, Limin Zeng, Min Hu, and Yuanhang Zhang
Atmos. Chem. Phys., 21, 13713–13727,Short summary
Secondary sulfate aerosols are an important component of fine particles in severe air pollution events. We calculated the sulfate formation rates via a state-of-the-art multiphase model constrained to the observed values. We showed that transition metals in urban aerosols contribute significantly to sulfate formation during haze periods and thus play an important role in mitigation strategies and public health measures in megacities worldwide.
Emma Lumiaro, Milica Todorović, Theo Kurten, Hanna Vehkamäki, and Patrick Rinke
Atmos. Chem. Phys., 21, 13227–13246,Short summary
The study of climate change relies on climate models, which require an understanding of aerosol formation. We train a machine-learning model to predict the partitioning coefficients of atmospheric molecules, which govern condensation into aerosols. The model can make instant predictions based on molecular structures with accuracy surpassing that of standard computational methods. This will allow the screening of low-volatility molecules that contribute most to aerosol formation.
Yun Fat Lam, Chi Chiu Cheung, Xuguo Zhang, Joshua S. Fu, and Jimmy Chi Hung Fung
Atmos. Chem. Phys., 21, 12895–12908,Short summary
In recent years, air pollution forecasting has become an important municipal service of the government. In this study, a new spatial allocation method based on satellite remote sensing and GIS techniques was developed to address the spatial deficiency of industrial source emissions in China, providing a substantial improvement on NO2 and PM2.5 forecast for the Pearl River Delta/Greater Bay Area.
Camilla Geels, Morten Winther, Camilla Andersson, Jukka-Pekka Jalkanen, Jørgen Brandt, Lise M. Frohn, Ulas Im, Wing Leung, and Jesper H. Christensen
Atmos. Chem. Phys., 21, 12495–12519,Short summary
In this study, we set up new shipping emissions scenarios and use two chemistry transport models and a health assessment model to assess the development of air quality and related health impacts in the Nordic region. Shipping alone is associated with about 850 premature deaths during present-day conditions, decreasing to approximately 550–600 cases in the 2050 scenarios.
Sabrina Chee, Kelley Barsanti, James N. Smith, and Nanna Myllys
Atmos. Chem. Phys., 21, 11637–11654,Short summary
We explored molecular properties affecting atmospheric particle formation efficiency and derived a parameterization between particle formation rate and heterodimer concentration, which showed good agreement to previously reported experimental data. Considering the simplicity of calculating heterodimer concentration, this approach has potential to improve estimates of global cloud condensation nuclei in models that are limited by the computational expense of calculating particle formation rate.
Isaac Kwadjo Afreh, Bernard Aumont, Marie Camredon, and Kelley Claire Barsanti
Atmos. Chem. Phys., 21, 11467–11487,Short summary
This is the first mechanistic modeling study of secondary organic aerosol (SOA) from the understudied monoterpene, camphene. The semi-explicit chemical model GECKO-A predicted camphene SOA yields that were ~2 times α-pinene. Using 50/50 α-pinene + limonene as a surrogate for camphene increased predicted SOA mass from biomass burning fuels by up to ~100 %. The accurate representation of camphene in air quality models can improve predictions of SOA when camphene is a dominant monoterpene.
Caterina Mogno, Paul I. Palmer, Christoph Knote, Fei Yao, and Timothy J. Wallington
Atmos. Chem. Phys., 21, 10881–10909,Short summary
We use a 3-D atmospheric chemistry model to investigate how seasonal emissions sources and meteorological conditions affect the surface distribution of fine particulate matter (PM2.5) and organic aerosol (OA) over the Indo-Gangetic Plain. We find that all seasonal mean values of PM2.5 still exceed safe air quality levels, with human emissions contributing to PM2.5 all year round, open fires during post- and pre-monsoon, and biogenic emissions during monsoon. OA contributes up to 30 % to PM2.5.
Adhikari, S., Mahapatra, P. S., Sapkota, V., and Puppala, S. P.: Characterizing Emissions from Agricultural Diesel Pumps in the Terai Region of Nepal, Atmosphere, 10, 1–12, https://doi.org/10.3390/atmos10020056, 2019.
AEPC: A Year in Review NYF 2069/70, Alternative Energy Promotion Centre, Ministry of Science, Technology and Environment, Government of Nepal, 1–74, 2012.
ARAI: Emission factor development for Indian vehicles, in: Air Quality Monitoring Project-Indian Clean Air Programme, The Automotive Research Association Of India, Pune, 1–94, 2007.
Baidya, S. and Borken-Kleefeld, J.: Atmospheric emissions from road transportation in India, Energ. Policy, 37, 3812–3822, https://doi.org/10.1016/j.enpol.2009.07.010, 2009.
Bajracharya, I. and Bhattarai, N.: Road Transportation Energy Demand and Environmental Emission: A Case of Kathmandu Valley, Hydro Nepal, J. Water Energ. Environ., 18, 30–40, https://doi.org/10.3126/hn.v18i0.14641, 2016.
Ban-Weiss, G. A., Lunden, M. M., Kirchstetter, T. W., and Harley, R. A.: Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks, Environ. Sci. Technol., 43, 1419–1424, 2009.
Bhari B.: Characterization of Roadside Air Pollution Levels in Kathmandu Valley, Master's Thesis, School of Environment, Resources and Development, Asian Institute of Technology, Thailand, 1–88, 2015.
Bhattarai, N. and Jha, A. K.: Commercial Sector Energy Demand Projections of Nepal for Sustainable Sectoral Energy Planning, J. Environ. Protect. Sustain. Dev., 1, 165–177, 2015.
Bond, T. C., Streets, D. G., Yarber, K. F., Nelson, S. M., Woo, J. H., and Klimont, Z.: A technology-based global inventory of black and organic carbon emissions from combustion, J. Geophys. Res., 109, D14203, https://doi.org/10.1029/2003JD003697, 2004.
Burney J. and Ramanathan V.: Recent climate and air pollution impacts on Indian agriculture, P. Natl. Acad. Sci. USA, 111, 16319–16324, https://doi.org/10.1073/pnas.1317275111, 2014.
CBS: National Census of Manufacturing Establishment (CME) 2006/07, National Planning Commission Secretariat, Central Bureau of Statistics, Kathmandu, 1–154, 2008.
CBS: National Population and Housing Census, 2011, National Report, National Planning Commission Secretariat, Central Bureau of Statistics, Kathmandu, 1–262, 2012.
CBS: National Census of Manufacturing Establishment (CME) 2011/12, National Planning Commission Secretariat, Central Bureau of Statistics, Kathmandu, 7–126, June 2014.
Collier J. C. and Zhang G. J.: Aerosol direct forcing of the summer Indian monsoon as simulated by the NCAR CAM3, Clim. Dynam., 32, 313–332, https://doi.org/10.1007/s00382-008-0464-9, 2009.
Crippa, M., Guizzardi, D., Muntean, M., Schaaf, E., Dentener, F., van Aardenne, J. A., Monni, S., Doering, U., Olivier, J. G. J., Pagliari, V., and Janssens-Maenhout, G.: Gridded emissions of air pollutants for the period 1970–2012 within EDGAR v4.3.2, Earth Syst. Sci. Data, 10, 1987–2013, https://doi.org/10.5194/essd-10-1987-2018, 2018.
DECP: District Climate and Energy Plan Reports, Multiscope Consultancy Pvt. Ltd., Kathmandu, 1–155, 2014.
Devakumar D., Semple, S., Osrin, D., Yadav, S. K., Kurmi, O. P., Saville, N. M., Shrestha, B., Manandhar, D. S., Costello, A., and Ayres, J. G.: Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal, Environ. Int., 66, 79–87, https://doi.org/10.1016/j.envint.2014.01.011, 2014.
Dhakal, S.: Implications of transportation policies on energy and environment in Kathmandu Valley, Nepal, Energ. Policy, 31, 1493–1507, https://doi.org/10.1016/S0301-4215(02)00205-7, 2003.
Dhital, H. C. and Shakya, S. R.: Implication of Sustainable Low Carbon Transportation Development Strategy in Emerging City: A case of Kathmandu Valley, Proceedings of IOE Graduate Conference, 215–224, 2014.
DoTM: Details of Registration of Transport up to Fiscal Year 2046/47-070/71, Department of Transport Management, Kathmandu, p. 1, 2013.
DoTM: Details of Registration of Transport up to Fiscal Year 2046/47-073/74, Department of Transport Management, Kathmandu, p. 1, 2016.
Fiore, A. M., Naik, V., and Leibensperger, E. M.: Air Quality and Climate Connections, J. Air Waste Manage., 65, 645–685, https://doi.org/10.1080/10962247.2015.1040526, 2015.
Forouzanfar, M. H., et al.: Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015, The Lancet, 388, 1659–1724, https://doi.org/10.1016/S0140-6736(16)31679-8, 2016.
Frenken K. and Gillet V.: Irrigation water requirement and water withdrawal by country, FAO AQUASTAT Reports, 1–263, 2012.
Gurung, A., Ghimeray, A. K., and Hassan, S. H. A.: The prospects of renewable energy technologies for rural electrification: a review from Nepal, Energ. Policy, 40, 374–380, https://doi.org/10.1016/j.enpol.2011.10.022, 2012.
Habib, G., Venkataraman, C., Shrivastava, M., Banerjee, R., Stehr, J. W., and Dickerson, R. R.: New methodology for estimating biofuel consumption for cooking: atmospheric emissions of black carbon and sulfur dioxide from India, Global Biogeochem. Cy., 18, GB3007, https://doi.org/10.1029/2003GB002157, 2004.
Habib, G., Venkataraman, C., Bond, T. C., and Schauer, J. J.: Chemical, microphysical and optical properties of primary particles from the combustion of biomass fuels, Environ. Sci. Technol., 42, 8829–8834, https://doi.org/10.1021/es800943f, 2008.
Hoesly, R. M., Smith, S. J., Feng, L., Klimont, Z., Janssens-Maenhout, G., Pitkanen, T., Seibert, J. J., Vu, L., Andres, R. J., Bolt, R. M., Bond, T. C., Dawidowski, L., Kholod, N., Kurokawa, J.-I., Li, M., Liu, L., Lu, Z., Moura, M. C. P., O'Rourke, P. R., and Zhang, Q.: Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS), Geosci. Model Dev., 11, 369–408, https://doi.org/10.5194/gmd-11-369-2018, 2018.
Jaiprakash, Gazala H., and Kumar S.: Evaluation of portable dilution system for aerosol measurement from stationary and mobile combustion sources, Aerosol Sci. Technol., 50, 717–731, https://doi.org/10.1080/02786826.2016.1178502, 2016.
Janssens-Maenhout, G., Crippa, M., Guizzardi, D., Muntean, M., Schaaf, E., Dentener, F., Bergamaschi, P., Pagliari, V., Olivier, J. G. J., Peters, J. A. H. W., van Aardenne, J. A., Monni, S., Doering, U., and Petrescu, A. M. R.: EDGAR v4.3.2 Global Atlas of the three major Greenhouse Gas Emissions for the period 1970–2012, Earth Syst. Sci. Data Discuss., 11, 959–1002, https://doi.org/10.5194/essd-11-959-2019, 2019.
Jayarathne, T., Stockwell, C. E., Bhave, P. V., Praveen, P. S., Rathnayake, C. M., Islam, Md. R., Panday, A. K., Adhikari, S., Maharjan, R., Goetz, J. D., DeCarlo, P. F., Saikawa, E., Yokelson, R. J., and Stone, E. A.: Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of particulate matter from wood- and dung-fueled cooking fires, garbage and crop residue burning, brick kilns, and other sources, Atmos. Chem. Phys., 18, 2259–2286, https://doi.org/10.5194/acp-18-2259-2018, 2018.
Klimont, Z., Kupiainen, K., Heyes, C., Purohit, P., Cofala, J., Rafaj, P., Borken-Kleefeld, J., and Schöpp, W.: Global anthropogenic emissions of particulate matter including black carbon, Atmos. Chem. Phys., 17, 8681–8723, https://doi.org/10.5194/acp-17-8681-2017, 2017.
Kurmi, O. P., Semple, S., Devereux, G. S., Gaihre, S., Lam, K. B., Sadhra, S., Steiner, M. F., Simkhada, P., Smith W. C., and Ayres, J. G.: The effect of exposure to biomass smoke on respiratory symptoms in adult rural and urban Nepalese populations, Environ. Health, 13, 1–8, https://doi.org/10.1186/1476-069X-13-92, 2014.
Kurokawa, J., Ohara, T., Morikawa, T., Hanayama, S., Janssens-Maenhout, G., Fukui, T., Kawashima, K., and Akimoto, H.: Emissions of air pollutants and greenhouse gases over Asian regions during 2000–2008: Regional Emission inventory in ASia (REAS) version 2, Atmos. Chem. Phys., 13, 11019–11058, https://doi.org/10.5194/acp-13-11019-2013, 2013.
Lam, N. L., Chen, Y., Weyant, C., Venkataraman, C., Sadavarte, P., Johnson, M. A., Smith, K. R., Brem, B. T., Arineitwe, J., Ellis, J. E., and Bond, T. C.: Household light makes global heat: high black carbon emissions from kerosene wick lamps, Environ. Sci. Technol., 46, 13531–13538, https://doi.org/10.1021/es302697h, 2012.
Li, M., Zhang, Q., Kurokawa, J.-I., Woo, J.-H., He, K., Lu, Z., Ohara, T., Song, Y., Streets, D. G., Carmichael, G. R., Cheng, Y., Hong, C., Huo, H., Jiang, X., Kang, S., Liu, F., Su, H., and Zheng, B.: MIX: a mosaic Asian anthropogenic emission inventory under the international collaboration framework of the MICS-Asia and HTAP, Atmos. Chem. Phys., 17, 935–963, https://doi.org/10.5194/acp-17-935-2017, 2017.
Malla, S.: Household energy consumption patterns and its environmental implications: Assessment of energy access and poverty in Nepal, Energ. Policy, 61, 990–1002, https://doi.org/10.1016/j.enpol.2013.06.023, 2013.
Mennis J.: Dasymetric Mapping for Estimating Population in Small Areas, Geography Compass, 3/2, 727–745, https://doi.org/10.1111/j.1749-8198.2009.00220.x, 2009.
MoAD: Statistical Information on Nepalese Agriculture 2011/12, Agri-Business Promotion and Statistics Division, Statistics Section, Ministry of Agricultural Development, Singha Durbar, Kathmandu, Nepal, 1–170, 2011.
MoCTCA: Nepal Tourism Statistics 2012, Ministry of Culture, Tourism and Civil Aviation, Planning and Evaluation Division, Statistical Section, Singha Darbar, Kathmandu, 1–117, 2013.
MoEST: Ambient Air Quality of Kathmandu Valley, Ministry of Environment, Science and Technology Singh Durbar, Kathmandu, 1–33, 2005.
MoF: Nepal Foreign Trade Statistics, Annual Report 2011/12, Ministry of Finance, Department of Customs, Kathmandu, available at: https://www.customs.gov.np/en/annual.html (last access: 27 April 2017), 2012.
MoF: Nepal Foreign Trade Statistics, Annual Report 2016/17, Ministry of Finance, Department of Customs, Kathmandu, 1–550, 2017.
Nepal, S., Mahapatra, P. S., Adhikari, S., Shrestha, S., Sharma, P., Shrestha, K. L., Pradhan, B. B., and Puppala, S. P.: A Comparative Study of Stack Emissions from Straight-Line and Zigzag Brick Kilns in Nepal, Atmosphere, 10, 1–19, https://doi.org/10.3390/atmos10030107, 2019.
NOC: Nepal Oil Corporation, available at: http://nepaloil.com.np/import?type=sales&offset=0&max=10, last access: 11 January 2019.
Notter, B. and Schmied, M.: Non-road energy consumption and pollutant emissions, Study for the period from 1980 to 2050, Federal Office for the Environment, Bern, Environmental studies no. 1519, 237 pp., 2015.
PACE Nepal: Baseline Study of Selected Sector Industries to Assess the Potentials for more Efficient use of Energy, PACE Nepal Pvt. Ltd., Kathmandu, 1–220, 2012.
Pandey, A. and Venkataraman, C.: Estimating emissions from the Indian transport sector with on-road fleet composition and traffic volume, Atmos. Environ., 98, 123–133, https://doi.org/10.1016/j.atmosenv.2014.08.039, 2014.
Pandey, A., Patel, S., Pervez, S., Tiwari, S., Yadama, G., Chow, J. C., Watson, J. G., Biswas, P., and Chakrabarty, R. K.: Aerosol emissions factors from traditional biomass cookstoves in India: insights from field measurements, Atmos. Chem. Phys., 17, 13721–13729, doi.org/10.5194/acp-17-13721-2017, 2017.
Pokharel, S.: Energy economics of cooking in households in Nepal, Energy, 29, 547–559, https://doi.org/10.1016/j.energy.2003.10.015, 2004.
Pokhrel, A. K., Bates, M. N., Acharya, J., Valentiner-Branth, P., Chandyo, R. K., Shrestha, P. S., Raut, A. K., and Smith, K. R.: PM2.5 in household kitchens of Bhaktapur, Nepal, using four different cooking fuels, Atmos. Environ., 113, 159–168, https://doi.org/10.1016/j.atmosenv.2015.04.060, 2015.
Pradhan, S., Alea, B. B., and Amatya, V. B.: Mitigation potential of greenhouse gas emission and implications on fuel consumption due to clean energy vehicles as public passenger transport in Kathmandu Valley of Nepal: A case study of trolley buses in Ring Road, Energy, 31, 1748–1760, https://doi.org/10.1016/j.energy.2005.10.013, 2006.
Sadavarte, P. and Venkataraman, C.: Trends in multi-pollutant emissions from a technology-linked inventory for India: I. Industry and transport sectors, Atmos. Environ., 99, 353–364, https://doi.org/10.1016/j.atmosenv.2014.09.081, 2014.
Shah, S. D., Cocker, D. R., Johnson, K. C., Lee, J. M., Soriano, B. L., Wayne and Miller, J.: Emissions of regulated pollutants from in-use diesel back-up generators, Atmos. Environ., 40, 4199–4209, https://doi.org/10.1016/j.atmosenv.2005.12.063, 2006.
Shakya, K. M., Rupakheti, M., Aryal, K., and Peltier, R.: Respiratory effects of high levels of particulate exposure in a cohort of traffic police in Nepal, J. Occup. Environ. Med., 58, 218–225, https://doi.org/10.1097/JOM.0000000000000753, 2016.
Shakya, K. M., Rupakheti, M., Shahi, A., Maskey, R., Pradhan, B., Panday, A., Puppala, S. P., Lawrence, M., and Peltier, R. E.: Near-road sampling of PM2.5, BC, and fine-particle chemical components in Kathmandu Valley, Nepal, Atmos. Chem. Phys., 17, 6503–6516, https://doi.org/10.5194/acp-17-6503-2017, 2017.
Shastri H., Barik, B., Ghosh, S., Venkataraman, C., and Sadavarte, P.: Flip flop of day-night and summer-winter surface urban heat island intensity in India, Sci. Rep., 7, 40178, https://doi.org/10.1038/srep40178, 2017.
Shrestha, R. M. and Rajbhandari, S.: Energy and environmental implications of carbon emission reduction targets: case of Kathmandu valley, Nepal, Energ. Policy, 38, 4818–4827, https://doi.org/10.1016/j.enpol.2009.11.088, 2010.
Singh, A., Tuladhar, B., Bajracharya, K., and Pillarisetti, A.: Assessment of effectiveness of improved cookstoves in reducing indoor air pollution and improving health in Nepal, Energy Sustain. Dev., 16, 406–414, https://doi.org/10.1016/j.esd.2012.09.004, 2012.
Smith, K. R: National burden of disease in India from indoor air pollution., P. Natl. Acad. Sci. USA, 97, 13286–13293, https://doi.org/10.1073/pnas.97.24.13286, 2000.
Stockwell, C. E., Christian, T. J., Goetz, J. D., Jayarathne, T., Bhave, P. V., Praveen, P. S., Adhikari, S., Maharjan, R., DeCarlo, P. F., Stone, E. A., Saikawa, E., Blake, D. R., Simpson, I. J., Yokelson, R. J., and Panday, A. K.: Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage and crop residue burning, brick kilns, and other sources, Atmos. Chem. Phys., 16, 11043–11081, https://doi.org/10.5194/acp-16-11043-2016, 2016.
Subramanian, R., Winijkul, E., Bond, T. C., Thiansathit, W., Kim Oanh, N. T., Paw-Armart, I., and Duleep, K. G.: Climate-relevant properties of diesel particulate emissions: results from a piggyback study in Bangkok, Thailand, Environ. Sci. Technol., 43, 4213–4218, https://doi.org/10.1021/es8032296, 2009.
WECS: Energy Sector Synopsis Report, Nepal, Water Energy Commission Secretariat, 1–115, 2010.
WECS: Energy Data Sheet, Water Energy Commission Secretariat, 1–16, 2014.
Weyant, C. L., Athalye, V., Ragavan, S., Rajarathnam, U., Lalchandani, D., Maithel, S., and Bond, T. C.: Emissions from South Asian brick production, Environ. Sci. Technol., 46, 13531–13538, https://doi.org/10.1021/es302697h, 2014.
World Bank: Diesel Power Generation: Inventories and Black Carbon Emissions in Kathmandu Valley, Nepal, The World Bank, 1–60, 2014.
Wu, B., Shen, X., Cao, X., Zhang, W., Wu, H., and Yao, Z.: Carbonaceous composition of PM2.5 emitted from on-road China III diesel trucks in Beijing, China, Atmos. Environ., 116, 216–224, https://doi.org/10.1016/j.atmosenv.2015.06.039, 2015.
Yan, F., Winijkul, E., Jung, S., Bond, T. C., and Streets, D. G.: Global emission projections of particulate matter (PM): I. Exhaust emissions from on-road vehicles, Atmos. Environ., 45, 4830–4844, https://doi.org/10.1016/j.atmosenv.2011.06.018, 2011.
Yang, H. H., Dhital, N. B., Wang, L. C., Hsieh, Y. S., Lee, K. T., Hsu, Y. T., and Huang, S. C.: Chemical Characterization of Fine Particulate Matter in Gasoline and Diesel Vehicle Exhaust, Aerosol Air Qual. Res., 19, 1439–1449, https://doi.org/10.4209/aaqr.2019.04.0191, 2019.
Zhang, J., Smith, K. R., Ma, Y., Ye, S., Jiang, F., Qi, W., and Thorneloe, S. A.: Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission factors, Atmos. Environ., 34, 4537–4549, https://doi.org/10.1016/S1352-2310(99)00450-1, 2000.
Zhang, Q., Streets, D. G., Carmichael, G. R., He, K. B., Huo, H., Kannari, A., Klimont, Z., Park, I. S., Reddy, S., Fu, J. S., Chen, D., Duan, L., Lei, Y., Wang, L. T., and Yao, Z. L.: Asian emissions in 2006 for the NASA INTEX-B mission, Atmos. Chem. Phys., 9, 5131–5153, https://doi.org/10.5194/acp-9-5131-2009, 2009.
Zhang, Y., Yao, Z., Shen, X., Liu, H., and He, K.: Chemical characterization of PM2.5 emitted from on-road heavy-duty diesel trucks in China, Atmos. Environ., 122, 885–891, https://doi.org/10.1016/j.atmosenv.2015.07.014, 2015.
Emission inventory studies are an important regulatory tool for quantifying the amount of pollutants released in the atmosphere using the fuel consumption and emission rates for different fuels. This study developed an emission inventory over Nepal for 2001–2016 that reveals the changing fuel consumption and subsequently the pollution across different sectors of industrial, transport, agricultural, commercial and residential uses with the use of spatial distribution of anthropogenic activities.
Emission inventory studies are an important regulatory tool for quantifying the amount of...