Forecasting the North African dust outbreak towards Europe in April 2011: a model intercomparison
Summary: Five dust models are evaluated in their performance to predict an intense Saharan dust outbreak affecting Western and Northern Europe. Models predict the onset and evolution of the event for all analysed lead-times. On average, differences among the models are larger than differences among lead-times for each model. They tend to underestimate the long-range transport towards Northern Europe. This is partly due to difficulties simulating the vertical dust distribution and horizontal wind.
Atmos. Chem. Phys. Discuss., 15, 26661-26710, doi:10.5194/acpd-15-26661-2015, 2015
Observations of surface momentum exchange over the marginal-ice-zone and recommendations for its parameterization
Summary: Rare aircraft observations of surface momentum flux over the Arctic marginal ice zone provide the best means yet to constrain model representation of MIZ surface roughness. The sensitivity of surface roughness to ice concentration over the Arctic MIZ is presented; these results do not support the values used in many models. However, a leading parameterization scheme (that of Lupkes et al., 2012) is found to provide a good representation of form drag, after some parameter alterations.
Atmos. Chem. Phys. Discuss., 15, 26609-26660, doi:10.5194/acpd-15-26609-2015, 2015
Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2014
Summary: We examine changes in SO2 and NO2 over the world’s most polluted regions during the first decade of Aura OMI observations. Over the eastern US, both NO2 and SO2 levels decreased by 40% and 80%, respectively. OMI confirmed large reductions in SO2 over eastern Europe’s largest coal power plants. The North China Plain has the world’s most severe SO2 pollution, but a decreasing trend been observed since 2011, with a 50% reduction in 2012-2014. India’s SO2 and NO2 levels are growing at a fast pace. S
Atmos. Chem. Phys. Discuss., 15, 26555-26607, doi:10.5194/acpd-15-26555-2015, 2015
Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes
Atmos. Chem. Phys. Discuss., 15, 26509-26554, doi:10.5194/acpd-15-26509-2015, 2015
Can we use modelling methodologies to assess airborne benzo[a]pyrene from biomonitors? A comprehensive evaluation approach
Summary: This original interpretation and application of environmental databases combines biomonitoring and atmospheric field data and state-of-the-art chemistry transport models to study one of the most carcinogenic atmospheric pollutants, benzo(a)pyrene (BaP). A comparison of ways to estimate air concentrations of BaP from its levels in vegetation is also a strong asset of this study. The whole methodology proposed here is versatile and can easily be applied to other regions and chemicals of interest.
Atmos. Chem. Phys. Discuss., 15, 26481-26507, doi:10.5194/acpd-15-26481-2015, 2015
Meteorological-gaseous influences on seasonal PM2.5 variability in the Klang Valley urban-industrial environment
Summary: This study investigate the PM2.5 variability in the Klang Valley urban-industrial environment. Source apportionment analysis reveal two major contributors of PM2.5 in the study area i.e. secondary inorganic aerosols and biomass burning. The chemical constituents and sources of PM2.5 in this study area were greatly influenced and characterised by meteorological and gaseous parameters which largely varies with season.
Atmos. Chem. Phys. Discuss., 15, 26423-26479, doi:10.5194/acpd-15-26423-2015, 2015
Shortwave direct radiative effects of above cloud aerosols over global oceans derived from eight years of CALIOP and MODIS observations
Summary: The frequency of occurrence and shortwave direct radiative effects (DRE) of above-cloud aerosols (ACAs) over global oceans are investigated using eight years of collocated CALIOP and MODIS observations. We estimated that ACAs have a global ocean annual mean diurnally averaged cloudy-sky DRE of 0.015 W/m2 (range of −0.03 to 0.06 W/m2) at TOA. The DREs at surface and within atmosphere are −0.15 W/m2 (range of −0.09 to −0.21 W/m2), and 0.17 W/m2 (range of 0.11 to 0.24 W/m2), respectively.
Atmos. Chem. Phys. Discuss., 15, 26357-26421, doi:10.5194/acpd-15-26357-2015, 2015
Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe
Summary: In early spring the Baltic region is frequently affected by high pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires.
Atmos. Chem. Phys. Discuss., 15, 26315-26355, doi:10.5194/acpd-15-26315-2015, 2015
Ability of the 4-D-Var analysis of the GOSAT BESD XCO2 retrievals to characterize atmospheric CO2 at large and synoptic scales
Atmos. Chem. Phys. Discuss., 15, 26273-26313, doi:10.5194/acpd-15-26273-2015, 2015
Transport across the tropical tropopause layer and convection
Summary: Transit properties across the TTL are studied using forward and backward Lagrangian trajectories between cloud tops and the reference surface 380K. The tropical domain is subdivided into 11 sub-regions according to the distribution of land and convection. Due to the good agreement between forward and backward statistics, we estimate the contribution of each region to the upward mass flux across the 380K surface, the vertical distribution of convective sources and of transit times over 2005-2008.
Atmos. Chem. Phys. Discuss., 15, 26231-26271, doi:10.5194/acpd-15-26231-2015, 2015
The importance of temporal collocation for the evaluation of aerosol models with observations
Summary: When comparing models against observations, researchers often use long-term averages without due regard for the temporal sampling of the underlying datasets. We study the errors introduced by this practice and show they are often larger than observational errors and comparable to model errors. We further analyse what causes these errors and suggest best practices for eliminating them.
Atmos. Chem. Phys. Discuss., 15, 26191-26230, doi:10.5194/acpd-15-26191-2015, 2015
Using beryllium-7 to assess cross-tropopause transport in global models
Summary: We assess the utility of cosmogenic beryllium-7, a natural aerosol tracer, for evaluating cross-tropopause transport in global models. We show that model excessive cross-tropopause transport of beryllium-7 corresponds to overestimated stratospheric contribution to tropospheric ozone. We conclude that the observational constraints for beryllium-7 and observed beryllium-7 total deposition fluxes can be used routinely as a first-order assessment of cross-tropopause transport in global models.
Atmos. Chem. Phys. Discuss., 15, 26131-26189, doi:10.5194/acpd-15-26131-2015, 2015
Multimodel emission metrics for regional emissions of short lived climate forcers
Atmos. Chem. Phys. Discuss., 15, 26089-26130, doi:10.5194/acpd-15-26089-2015, 2015
Observations of fluorescent aerosol–cloud interactions in the free troposphere at the Sphinx high Alpine research station, Jungfraujoch
Summary: In this manuscript we discuss observations of fluorescent aerosol and their interactions with cloud at a high alpine site in the wintertime under background conditions. We find the majority of the fluorescent aerosol to be consistent in nature to mineral dust and no apparent trend was observed between the fluorescent aerosol fraction and meteorological or cloud microphysical parameters, suggesting that particle fluorescence does not impact cloud evolution or formation at the site.
Atmos. Chem. Phys. Discuss., 15, 26067-26088, doi:10.5194/acpd-15-26067-2015, 2015
Towards understanding the variability in biospheric CO2 fluxes: using FTIR spectrometry and a chemical transport model to investigate the sources and sinks of carbonyl sulfide and its link to CO2
Summary: OCS could provide an additional constraint on carbon cycle. The FTIR networks have been existing for more than 20 years. For the first time, we used FTIR measurements of OCS and CO2 to study their relationship. We put the coupled CO2 and OCS land fluxes from the Simple Biosphere Model (SiB) into a transport model, and compared the simulations to the measurements. Looking at OCS and CO2 together inspires some new thoughts in how the biospheric models reproduce the carbon cycle in the real world.
Atmos. Chem. Phys. Discuss., 15, 26025-26065, doi:10.5194/acpd-15-26025-2015, 2015
Transport pathways from the Asian monsoon anticyclone to the stratosphere
Atmos. Chem. Phys. Discuss., 15, 25981-26023, doi:10.5194/acpd-15-25981-2015, 2015
What controls the vertical distribution of aerosol? Relationships between process sensitivity in HadGEM3–UKCA and inter-model variation from AeroCom Phase II
Summary: The vertical distribution of atmospheric aerosol is an important factor in its effects on climate. In this study we use a sophisticated model of the many interacting processes affecting aerosol in the atmosphere to show that the vertical distribution is typically dominated by only a few of these processes. Constraining these physical processes may help to reduce the large differences between models. However, the important processes are not always the same for different types of aerosol.
Atmos. Chem. Phys. Discuss., 15, 25933-25980, doi:10.5194/acpd-15-25933-2015, 2015
Simultaneous Retrievals of Polar Mesospheric Clouds (PMCs) with Ozone from OMI UV measurements
Summary: This work demonstrated the interference of tenuous PMCs on OMI ozone profile retrievals above 6hPa. The presence of PMCs leads to the systematic biases of -2% at 2hPa and -20% at 0.5hPa in OMI retrievals, which are significantly correlated with brightness of PMCs. We perform simultaneous retrievals of PMC optical depth with ozone using optimal estimation technique, to reduce the interference on ozone profile retrievals. As a result, the negative OMI biases are reduced to within ±10%.
Atmos. Chem. Phys. Discuss., 15, 25907-25932, doi:10.5194/acpd-15-25907-2015, 2015
Water vapour variability in the high-latitude upper troposphere – Part 2: Impact of volcanic emissions
Atmos. Chem. Phys. Discuss., 15, 25873-25905, doi:10.5194/acpd-15-25873-2015, 2015
Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 1: Assessing the influence of constrained multi-generational ageing
Summary: Multi-generational chemistry schemes applied in regional models do not increase SOA mass production relative to traditional "2-product" schemes when both models are fitted to the same chamber data. The multi-generational chemistry schemes do change the predicted composition of SOA and the source-attribution of SOA.
Atmos. Chem. Phys. Discuss., 15, 25837-25872, doi:10.5194/acpd-15-25837-2015, 2015
Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system
Summary: We use a newly built two-way coupling system of the GEOS-Chem CTM to simulate the global tropospheric O3 in 2009. It significantly improves the simulation upon the global model by comparisons with a suite of ground, aircraft, and satellite measurements, also reduces the global OH by 5% with enhancements by 5% in the lifetimes of MCF and methane. Therefore improving model representations of small-scale processes are a critical step forward to understanding the global tropospheric chemistry.
Atmos. Chem. Phys. Discuss., 15, 25789-25836, doi:10.5194/acpd-15-25789-2015, 2015
Sensitivity of nitrate aerosols to ammonia emissions and to nitrate chemistry: implications for present and future nitrate optical depth
Summary: We characterize the sensitivity of NO3 optical depth (OD) to both the sources of its precursors (NH3 and HNO3) and to its surface sinks. Uncertainties in the heterogeneous chemistry of HNO3 and the near-surface volatilization of NH4NO3 can cause up to 25% difference in the global NO3 OD. Simulated NO3 OD increases little (<30%) in response to changes in emissions (2010 to 2050). Better constraints on the tropical flux of NH3 into the free troposphere are needed to improve estimates of NO3 OD.
Atmos. Chem. Phys. Discuss., 15, 25739-25788, doi:10.5194/acpd-15-25739-2015, 2015
Aerosol optical properties in the southeastern United States in summer – Part 1: Hygroscopic growth
Atmos. Chem. Phys. Discuss., 15, 25695-25738, doi:10.5194/acpd-15-25695-2015, 2015
Comparing model and measured ice crystal concentrations in orographic clouds during the INUPIAQ campaign
Summary: This paper assesses the reasons for high ice number concentrations observed in orographic clouds by comparing observations with model simulations over Jungfraujoch, Switzerland. The results suggest that ice nuclei do not significantly contribute to the high concentrations, and suggest that a surface source of ice crystals is responsible for the witnessed ice number concentrations.
Atmos. Chem. Phys. Discuss., 15, 25647-25694, doi:10.5194/acpd-15-25647-2015, 2015
Stratospheric sulfate geoengineering enhances terrestrial gross primary productivity
Summary: Climate model simulations show that stratospheric sulfate geoengineering could impact the terrestrial carbon cycle by enhancing the carbon sink. Enhanced downward diffuse radiation, combined with cooling, could stimulate plants to grow more and absorb more carbon dioxide. This beneficial impact of stratospheric sulfate geoengineering would need to be balanced by a large number of potential risks in any future decisions about implementation of geoengineering.
Atmos. Chem. Phys. Discuss., 15, 25627-25645, doi:10.5194/acpd-15-25627-2015, 2015
Nitrogen speciation in various types of aerosol in spring over the northwestern Pacific Ocean
Atmos. Chem. Phys. Discuss., 15, 25583-25625, doi:10.5194/acpd-15-25583-2015, 2015
Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the MEGAPOLI summer and winter campaigns
Summary: We use PMCAMx with high grid resolution over Paris to simulate carbonaceous aerosol during the summer and winter MEGAPOLI campaigns. PMCAMx reproduces BC observations well. Addition of cooking organic aerosol emissions of 80 mg per day per capita is needed to reproduce the corresponding observations. While the oxygenated organic aerosol predictions during the summer are encouraging a major wintertime source appears to be missing.
Atmos. Chem. Phys. Discuss., 15, 25547-25582, doi:10.5194/acpd-15-25547-2015, 2015
Observations of high droplet number concentrations in Southern Ocean boundary layer clouds
Atmos. Chem. Phys. Discuss., 15, 25503-25545, doi:10.5194/acpd-15-25503-2015, 2015
Atmospheric constraints on the methane emissions from the East Siberian Shelf
Atmos. Chem. Phys. Discuss., 15, 25477-25501, doi:10.5194/acpd-15-25477-2015, 2015
Potential sensitivity of photosynthesis and isoprene emission to direct radiative effects of atmospheric aerosol pollution
Summary: We apply a global Earth system model to quantify the direct impacts of anthropogenic aerosols on gross primary productivity (GPP) and isoprene emission. On the global scale, GPP and isoprene emission are not sensitive to pollution aerosols, while at the regional scale they show a robust but opposite sensitivity to pollution aerosols. We posit that anthropogenic aerosols affect land carbon fluxes (GPP and isoprene emission) via radiative and thermal mechanisms that vary across regions.
Atmos. Chem. Phys. Discuss., 15, 25433-25475, doi:10.5194/acpd-15-25433-2015, 2015
What do correlations tell us about anthropogenic–biogenic interactions and SOA formation in the Sacramento Plume during CARES?
Summary: Atmospheric measurements of total organic aerosol (OA) and tracers of anthropogenic and biogenic emissions are used to quantify synergistic effects (A-B interactions) between two classes of precursors in the formation of OA. Regressions are consistent with the Sacramento plume composed mainly of modern carbon, and OA correlating best with an anthropogenic tracer. It is found that meteorological conditions during a pollution episode can mimic effects of A-B interactions.
Atmos. Chem. Phys. Discuss., 15, 25381-25431, doi:10.5194/acpd-15-25381-2015, 2015
Exploring the uncertainty associated with satellite-based estimates of premature mortality due to exposure to fine particulate matter
Summary: As motivation for air quality research, many studies cite the fact that exposure to particulate matter is associated with premature mortality. Recently, more studies have also tried to quantify this burden; however, there are many data sets that can be used and many different methodological choices to be made. In this paper, we seek to explain the different sources of uncertainty in health impact assessments through the example of using model and satellite-based PM2.5 concentrations.
Atmos. Chem. Phys. Discuss., 15, 25329-25380, doi:10.5194/acpd-15-25329-2015, 2015
High resolution inventory of re-estimating ammonia emissions from agricultural fertilizer in China from 1978 to 2008
Summary: A 1 x 1 km gridded map on the county level was developed for 2008; a combined bottom-up and top-down method was used for the local correction of emission factors and parameters; the spatial and temporal patterns of historical time trends for 1978-2008 were estimated and the uncertainties were quantified for the inventories; and a sensitivity test was performed in which a province-level disaggregated map was compared with Chinese agricultural fertilizer NH3 emissions for 2008.
Atmos. Chem. Phys. Discuss., 15, 25299-25327, doi:10.5194/acpd-15-25299-2015, 2015
Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China
Summary: We present the first volatility tandem differential mobility analyzer (VTDMA) measurements in Pearl River Delta region, China for aerosols at 40 to 300 nm in mobility diameter. The measured volatility characteristics reflect the difference of freshly emitted 40 nm particles and aged bigger ones (80 to 300 nm). Mass closure of the VTDMA data and data from an organic carbon/elemental carbon analyzer suggests that the non-volatile residuals at 300°C observed in VTDMA may contain less volatile OC.
Atmos. Chem. Phys. Discuss., 15, 25269-25298, doi:10.5194/acpd-15-25269-2015, 2015
Towards a first classification of aerosol shrinkage events
Atmos. Chem. Phys. Discuss., 15, 25231-25267, doi:10.5194/acpd-15-25231-2015, 2015
Stratospheric ozone change and related climate impacts over 1850–2100 as modelled by the ACCMIP ensemble
Atmos. Chem. Phys. Discuss., 15, 25175-25229, doi:10.5194/acpd-15-25175-2015, 2015
Speciation of 127I and 129I in atmospheric aerosols at Risø, Denmark: insight into sources of iodine isotopes and their species transformations
Summary: Speciation analysis of long-lived anthropogenic iodine isotopes (129I) in time series Danish aerosols shows that secondary emission from heavily 129I-contaminated seawater is a major source of 129I in the Atmosphere, at least in North Europe. Iodide is the major form of water-soluble iodine, while NaOH-soluble iodine is the dominant species of iodine in aerosol, which is likely bound with organic substances. The contribution of Fukushima-derived 129I is estimated to be negligible in the Europe.
Atmos. Chem. Phys. Discuss., 15, 25139-25173, doi:10.5194/acpd-15-25139-2015, 2015
Light absorption and morphological properties of soot-containing aerosols observed at an East Asian outflow site, Noto Peninsula, Japan
Summary: Detailed understandings of light absorption property of black carbon (BC) particles and its relation to the mixing state and morphology are important. In this study, the enhancement of light absorption of BC due to coating (lensing effect) in a well-aged air mass was observed at an East Asian outflow site in Japan using a photoacoustic spectrometer and its relation with mixing state and morphology of individual particles was examined based on transmission electron microscope analyses.
Atmos. Chem. Phys. Discuss., 15, 25089-25138, doi:10.5194/acpd-15-25089-2015, 2015
Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley
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 & isoprene dominated OH reactivity and ozone production potentials (>68% OPP). Mitigation of emissions from biomass co-fired brick kilns' by cleaner technology would improve air quality of the Valley.
Atmos. Chem. Phys. Discuss., 15, 25021-25087, doi:10.5194/acpd-15-25021-2015, 2015
Large XCH4 anomaly in summer 2013 over Northeast Asia observed by GOSAT
Summary: Greenhouse gases Observing SATellite (GOSAT) was launched to monitor CO2 and CH4 concentrations from the space. This paper analyses an extremely high XCH4 event over Northeast Asia observed by GOSAT in the summer of 2013. Model analysis indicates that anomalies of high-pressure systems over East Asia caused the fast transport of CH4-rich air from the East China to Japan. This analysis demonstrates the capability of GOSAT with 3-day recurrence to monitor an XCH4 event on a synoptic scale.
Atmos. Chem. Phys. Discuss., 15, 24995-25020, doi:10.5194/acpd-15-24995-2015, 2015
An exemplary case of a bromine explosion event linked to cyclone development in the Arctic
Atmos. Chem. Phys. Discuss., 15, 24955-24993, doi:10.5194/acpd-15-24955-2015, 2015
The millennium water vapour drop in chemistry-climate model simulations
Atmos. Chem. Phys. Discuss., 15, 24909-24953, doi:10.5194/acpd-15-24909-2015, 2015
Fog composition at Baengnyeong Island in the Eastern Yellow Sea: detecting markers of aqueous atmospheric oxidations
Summary: Samples of fog water collected in the Yellow Sea during summer 2014 represent fog downwind of polluted regions and provide new insight into the fate of regional emissions. Organic and inorganic components reveal contributions from urban, biogenic, marine and biomass burning emissions, as well as evidence of aqueous organic processing reactions. Many fog components are products of extensive photochemical aging during multiday transport, including oxidation within wet aerosols and fogs.
Atmos. Chem. Phys. Discuss., 15, 24871-24908, doi:10.5194/acpd-15-24871-2015, 2015
Top-down estimates of benzene and toluene emissions in Pearl River Delta and Hong Kong, China
Summary: This is the first study reporting top-down estimates of benzene and toluene emissions in southern China using atmospheric measurement data from a rural site in the area, an atmospheric transport model and an inverse modeling method. This study shows in detail the temporal and spatial differences between the inversion estimate and four different bottom-up emission inventories (RCP, REAS, MEIC, Yin et al. (2015)). We propose that more observations are urgently needed in future.
Atmos. Chem. Phys. Discuss., 15, 24839-24870, doi:10.5194/acpd-15-24839-2015, 2015
Source attribution of aerosol size distributions and model evaluation using Whistler Mountain measurements and GEOS-Chem-TOMAS simulations
Summary: We evaluate aerosol size distributions predicted by GEOS-Chem-TOMAS using measurements from the peak of Whistler Mountain. We improve model-measurement comparisons of aerosol number, size and composition during periods of free tropospheric and boundary-layer influence by developing simple filtering techniques, and determine the influence of Asian anthropogenic and biomass burning emissions. The low-cost filtering techniques and source apportionment methods can be used for other mountain sites.
Atmos. Chem. Phys. Discuss., 15, 24805-24838, doi:10.5194/acpd-15-24805-2015, 2015
Observations of the spectral dependence of particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar
Summary: The manuscript describes measurements of particle depolarization ratio from the NASA airborne HSRL-2, for two dust cases and a smoke case. Differences in the spectral dependence of particle depolarization ratio are due to the sizes of the non-spherical particles, large for dust and small for smoke. The large depolarization at 355nm for smoke has not been previously reported and has possible implications for the upcoming EarthCARE satellite, which will measure depolarization only at 355nm.
Atmos. Chem. Phys. Discuss., 15, 24751-24803, doi:10.5194/acpd-15-24751-2015, 2015
Spatial evaluation of volcanic ash forecasts using satellite observations
Atmos. Chem. Phys. Discuss., 15, 24727-24749, doi:10.5194/acpd-15-24727-2015, 2015
Observational evidence of temperature trends at two levels in the surface layer
Atmos. Chem. Phys. Discuss., 15, 24695-24726, doi:10.5194/acpd-15-24695-2015, 2015
The vertical distribution of volcanic SO2 plumes measured by IASI
Atmos. Chem. Phys. Discuss., 15, 24643-24693, doi:10.5194/acpd-15-24643-2015, 2015
Why does surface ozone peak before a typhoon landing in southeast China?
Summary: An O3 episode with high nighttime O3 was observed before typhoon landing over southeastern China. Variations in the observed O3, NO2, CO and meteorology during Typhoon Hagibis event clearly suggest a substantial impact of the peripheral downdrafts in the tropical cyclone on the high O3 episode. This study provides observational evidence of typhoon-driven intrusion of O3 from the upper troposphere and lower stratosphere to surface air threatening to ambient air quality.
Atmos. Chem. Phys. Discuss., 15, 24623-24642, doi:10.5194/acpd-15-24623-2015, 2015
Comparisons of urban and rural PM10−2.5 and PM2.5 mass concentrations and semi-volatile fractions in Northeastern Colorado
Atmos. Chem. Phys. Discuss., 15, 24587-24622, doi:10.5194/acpd-15-24587-2015, 2015
Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models
Atmos. Chem. Phys. Discuss., 15, 24513-24585, doi:10.5194/acpd-15-24513-2015, 2015
Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?
Summary: New data of water diffusivity in secondary organic aerosol (SOA) material and organic/inorganic model mixtures is presented over an extensive temperature range. Our data suggest that water diffusion in SOA is sufficiently fast so that it is unlikely to have significant consequences on the direct climatic effect under tropospheric conditions. Glass formation in SOA is unlikely to restrict homogeneous ice nucleation.
Atmos. Chem. Phys. Discuss., 15, 24473-24511, doi:10.5194/acpd-15-24473-2015, 2015
Aerosol properties, source identification, and cloud processing in orographic clouds measured by single particle mass spectrometry on a Central European mountain site during HCCT-2010
Summary: This paper reports on single-particle measurements of ambient aerosol particles and cloud residues sampled from orographic clouds on a mountain site in central Germany. The results show that soot particles can get efficiently activated in cloud droplets when they are mixed with or coated by sulfate and nitrate. Cloud processing leads to addition of nitrate and sulfate to the particles, thereby increasing the hygroscopicity of these particles when the remain in the air after cloud evaporation.
Atmos. Chem. Phys. Discuss., 15, 24419-24472, doi:10.5194/acpd-15-24419-2015, 2015
The latitudinal structure of recent changes in the boreal Brewer–Dobson circulation
Summary: The latitudinal structure of recent changes in the boreal Brewer-Dobson Circulation presented the reduction of the tropical upwelling and the local strengthening of the mid-latitude downwelling. The acceleration of downwelling in the mid-latitudes is caused by the branch narrowing equatorward which is related to the weaker planetary wave activity and the stronger polar vortex.
Atmos. Chem. Phys. Discuss., 15, 24403-24417, doi:10.5194/acpd-15-24403-2015, 2015
Mixing state, composition, and sources of fine aerosol particles in the Qinghai-Tibetan Plateau and the influence of agricultural biomass burning
Summary: We found that anthropogenic refractory aerosols (e.g., soot, fly ash, and visible organic particles) likely adhere to the surface of SIA particles larger than 200 nm due to coagulation. Biomass burning and coal combustion both constantly contribute to anthropogenic particles in the QTP background atmosphere. Organic coating and soot on surface of the aged particles could have different impacts on their hygroscopic and optical properties in the QTP compared to the urban aerosols in East China.
Atmos. Chem. Phys. Discuss., 15, 24369-24401, doi:10.5194/acpd-15-24369-2015, 2015
Cloud water composition during HCCT-2010: Scavenging efficiencies, solute concentrations, and droplet size dependence of inorganic ions and dissolved organic carbon
Atmos. Chem. Phys. Discuss., 15, 24311-24368, doi:10.5194/acpd-15-24311-2015, 2015
Isoprene chemistry in pristine and polluted Amazon environments: Eulerian and Lagrangian model frameworks and the strong bearing they have on our understanding of surface ozone and predictions of rainforest exposure to this priority pollutant
Summary: This study explores our ability to simulate atmospheric chemistry stemming from isoprene emissions—a reactive gas emitted from vegetation—in pristine and polluted regions of the Amazon basin. We explore how two contrasting models fare in reproducing recent airborne measurements in the region. Their differing treatments of transport and mixing are found to: profoundly affect their performance; and yield very different pictures of the exposure of the rainforest to harmful ozone concentrations.
Atmos. Chem. Phys. Discuss., 15, 24251-24310, doi:10.5194/acpd-15-24251-2015, 2015
Solubility and reactivity of HNCO in water: insights into HNCO's fate in the atmosphere
Summary: HNCO is a toxic molecule and can cause cardiovascular and cataract problems through protein carbamylation. Recently reported ambient measurements of HNCO in North America raise concerns for human exposure. To better understand HNCO’s loss processes and behavior in the atmosphere, we provide thermochemical data on HNCO. Our measurements allow for more accurate predictions of its lifetime in the atmosphere and consequently help define exposure of this toxic molecule.
Atmos. Chem. Phys. Discuss., 15, 24217-24249, doi:10.5194/acpd-15-24217-2015, 2015
NOx lifetimes and emissions of hotspots in polluted background estimated by satellite observations
Summary: We present a new method to quantify NOx emissions and corresponding atmospheric lifetimes from OMI NO2 observations together with ECMWF wind fields without further model input for sources located in polluted background. The derived NOx emissions show generally good agreement with bottom-up inventories for power plants and cities. Global inventory significantly underestimated NOx emissions in Chinese cities, most likely due to uncertainties associated with downscaling approaches.
Atmos. Chem. Phys. Discuss., 15, 24179-24215, doi:10.5194/acpd-15-24179-2015, 2015
Drizzle formation in stratocumulus clouds: effects of turbulent mixing
Summary: The mechanism of drizzle formation in shallow stratocumulus clouds and the effect of turbulent mixing on this process are investigated using a Lagrangian-Eularian model of the cloud-topped boundary layer. It was found that first large drops form in volumes that are closest to adiabatic with extended residence near cloud top, and maximum values of LWC. Turbulent mixing was found able to delay the process of drizzle initiation but is essential for the further development of drizzle in the cloud.
Atmos. Chem. Phys. Discuss., 15, 24131-24177, doi:10.5194/acpd-15-24131-2015, 2015
Global and zonal tropospheric ozone variations from 2003–2011 as seen by SCIAMACHY
Summary: The goal of this study is to determine the global and zonal changes in the tropospheric ozone data product derived from SCIAMACHY limb-nadir-matching (LNM) observations during the period 2003-2011. Tropospheric O3 shows statistically significant increases over some regions of South Asia, the South American continent, Alaska and around Congo in Africa and over some continental outflows. Significant decrease in TOC is observed over some continents and Oceans.
Atmos. Chem. Phys. Discuss., 15, 24085-24130, doi:10.5194/acpd-15-24085-2015, 2015
Oxygen isotope mass balance of atmospheric nitrate at Dome C, East Antarctica, during the OPALE campaign
Atmos. Chem. Phys. Discuss., 15, 24041-24083, doi:10.5194/acpd-15-24041-2015, 2015
AIRUSE-LIFE+: a harmonized PM speciation and source apportionment in 5 Southern European cities
Summary: PM10/PM2.5 source apportionment at 5 EU cities (Barcelona, Florence, Milan, Athens and Porto) reveals that vehicle exhaust (excluding nitrate) and non-exhaust contributes 16-32% to PM10 and 15-36% to PM2.5. Secondary PM represents 37-82% of PM2.5. Biomass burning varies from <2 to 24% of PM10, depending on the residential heating fuel. Other sources are local dust (7-19% of PM10), industries (4-11% of PM10, 5-12% of PM2.5), shipping, sea salt and Saharan dust.
Atmos. Chem. Phys. Discuss., 15, 23989-24039, doi:10.5194/acpd-15-23989-2015, 2015
Equatorial middle atmospheric chemical composition changes during sudden stratospheric warming events
Summary: Chemical composition changes over equator during SSW events are investigated using MLS and MIPAS data sets. It is found that the O3 VMR increases whereas H2O VMR decreases. In the upper stratosphere, the source of water vapor is oxidation of CH4 by OH or O. But, OH does not vary during SSW. The temperature decrease over equator during SSW increases the reaction rate of ozone production to shift the O/O3 ratio towards O3, resulting in decrease of CH4 oxidation and consequent decrease in H2O.
Atmos. Chem. Phys. Discuss., 15, 23969-23988, doi:10.5194/acpd-15-23969-2015, 2015
Sensitivity of modelled sulfate radiative forcing to DMS concentration and air-sea flux formulation
Summary: A global atmosphere model with explicit representation of aerosol processes is used to assess uncertainties in climate impact of ocean DMS efflux and the role of spatial and temporal variability of DMS flux in climate forcing. Radiative forcing is nearly linearly related to global total DMS flux. Removing the spatial or temporal variability of DMS flux changes radiative forcing, but the response is of second order importance relative to the global mean flux.
Atmos. Chem. Phys. Discuss., 15, 23931-23968, doi:10.5194/acpd-15-23931-2015, 2015
Impact of chamber wall loss of gaseous organic compounds on secondary organic aerosol formation: explicit modeling of SOA formation from alkane and alkene oxidation
Summary: The potential impact of chamber walls on the loss of gaseous organic species and secondary organic aerosol (SOA) formation has been explored using the GECKO-A modeling tool which explicitly represents SOA formation and gas/wall partitioning. The model was compared with 41 smog chamber experiments of SOA formation under OH oxidation of alkane and alkene serie. The loss of organic vapors to the chamber walls is found to affect SOA yields as well as the composition of the gas and the particle phase
Atmos. Chem. Phys. Discuss., 15, 23893-23930, doi:10.5194/acpd-15-23893-2015, 2015
Characterizing tropospheric ozone and CO around Frankfurt between 1994–2012 based on MOZAIC-IAGOS aircraft measurements
Atmos. Chem. Phys. Discuss., 15, 23841-23891, doi:10.5194/acpd-15-23841-2015, 2015
Charging and coagulation of radioactive and nonradioactive particles in the atmosphere
Summary: Three microphysical approaches are proposed to incorporate mutual effects of particle charging and coagulation in predictions of transient charge and size distributions of atmospheric particles, including radioactive aerosols. The three approaches have different levels of complexities and are applicable to various laboratory and field atmospheric studies. Also, these approaches can be easily incorporated into aerosol transport models at different scales to account for particle charging effects.
Atmos. Chem. Phys. Discuss., 15, 23795-23840, doi:10.5194/acpd-15-23795-2015, 2015
Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model
Summary: This paper presents the first combined measurements of both ammonium nitrate aerosols and their gaseous precursors (HNO3, NH3) in the Paris megacity, obtained during the FRANCIPOL and PARTICULES campaigns. This dataset is used to investigate the nitrate formation regime within the city, which is particularly important considering the high contribution of nitrates in the fine aerosol pollution of Paris. In addition, it is also used to evaluate the CHIMERE chemistry-transport model.
Atmos. Chem. Phys. Discuss., 15, 23731-23794, doi:10.5194/acpd-15-23731-2015, 2015
On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models
Summary: The variation of aerosol indirect effects (AIE) in several climate models is investigated across different dynamical regimes. Regimes with strong large-scale ascend are shown to be as important as stratocumulus regimes in studying AIE. AIE over regions with high monthly large-scale surface precipitation rate contributes the most to the total aerosol indirect forcing. These results point to the need to reduce the uncertainty in AIE in different dynamical regimes.
Atmos. Chem. Phys. Discuss., 15, 23683-23729, doi:10.5194/acpd-15-23683-2015, 2015
Pesticides in the atmosphere: a comparison of gas-particle partitioning and particle size distribution of legacy and current-use pesticides
Summary: We examined gas-particle partitioning and size-fraction specific particle phase distributions for 27 current use pesticides, identifying seasonal and source-related trends, and contrasting with legacy organochlorine pesticides. The timing of pesticide use, seasonal air concentration trends, and particle size distributions were related. This informs our understanding of the atmospheric fate and transport of current use pesticides.
Atmos. Chem. Phys. Discuss., 15, 23651-23681, doi:10.5194/acpd-15-23651-2015, 2015
Formation of secondary aerosols from gasoline vehicle exhausts when mixing with SO2
Summary: The formation of SOA and sulfate aerosols from the photooxidation of gasoline vehicles exhausts (GVE) when mixing with SO2 was investigated in a smog chamber. We found that the presence of GVE enhanced the conversion of SO2 to sulfate predominantly through reactions with stabilized Criegee intermediates. On the other hand, the elevated particle acidity enhanced the SOA production from GVE. This study indicated that SO2 and GVE could enhance each other in forming secondary aerosols.
Atmos. Chem. Phys. Discuss., 15, 23613-23649, doi:10.5194/acpd-15-23613-2015, 2015
A new method for estimating emission ratios in the urban atmosphere: examples of ratios to CO2, CO and volatile organic compounds in Paris
Summary: We propose a new approach to estimate urban emission ratios that takes advantage of the enhanced local urban signal in the atmosphere at low wind speed. We apply it to estimate monthly ratios between CO2, CO and some VOCs from atmospheric measurement datasets acquired in the centre of Paris between 2010 and 2014. We find that this approach is little sensitive to the regional background level definition. With this new method, we may reveal spatial and seasonal variability in the ratios in Paris.
Atmos. Chem. Phys. Discuss., 15, 23587-23612, doi:10.5194/acpd-15-23587-2015, 2015
Non-OH chemistry in oxidation flow reactors for the study of atmospheric chemistry systematically examined by modeling
Summary: Oxidation flow reactors (OFRs) are promising tools of studying atmospheric oxidation processes. Elevated concentrations of both OH and non-OH oxidants in OFRs leave room for speculation that non-OH chemistry can play a major role. Through systematic modeling, we find conditions where non-OH VOC fate is significant and show that in most field studies of SOA using OFRs, non-OH VOC fate in OFRs was insignificant. We also provide guidelines helping OFR users avoid significant non-OH VOC oxidation.
Atmos. Chem. Phys. Discuss., 15, 23543-23586, doi:10.5194/acpd-15-23543-2015, 2015
Emissions factors for gaseous and particulate pollutants from offshore diesel engine vessels in China
Summary: In this study, on-board test of three offshore vessels in China have been carried out for the first time. Emission factors for gaseous species, PM and relevant chemical components (OC, EC, metal elements and water soluble ions) in different operating modes are given which means a lot for estimating contribution of ships to atmosphere and calculating emission inventories of ships. Besides, impacts of engine speed on NOx emission factors also have been discussed for the first time.
Atmos. Chem. Phys. Discuss., 15, 23507-23541, doi:10.5194/acpd-15-23507-2015, 2015
Isotopic signatures of production and uptake of H2 by soil
Summary: We investigated soil production and uptake of H2 and associated isotope effects. Uptake and emission of H2 occurred simultaneously at all sampling sites, with strongest emission where N2 fixing legume was present. The fractionation constant during soil uptake was about 0.945 and it did not show positive correlation with deposition velocity. The isotopic composition of H2 emitted from soil with legume was about -530‰, which is less deuterium-depleted than isotope equilibrium between H2O and H2.
Atmos. Chem. Phys. Discuss., 15, 23457-23506, doi:10.5194/acpd-15-23457-2015, 2015
Aerosol composition, oxidative properties, and sources in Beijing: results from the 2014 Asia-Pacific Economic Cooperation Summit study
Summary: We have investigated the response of aerosol composition, size distributions, and oxidative properties to emission controls during the 2014 Asia- Pacific Economic Cooperation (APEC) summit in Beijing. Our results showed substantial changes of aerosol bulk composition during APEC with the most reductions in secondary aerosols in large accumulation modes, demonstrating that that emission controls over regional scales can substantially reduce secondary particulates.
Atmos. Chem. Phys. Discuss., 15, 23407-23455, doi:10.5194/acpd-15-23407-2015, 2015
Hygroscopic behavior of multicomponent organic aerosols and their internal mixtures with ammonium sulfate
Atmos. Chem. Phys. Discuss., 15, 23357-23405, doi:10.5194/acpd-15-23357-2015, 2015
Aerosol composition and variability in the Baltimore–Washington, DC region
Summary: Airborne measurements in Baltimore–Washington, DC allow for an understanding of the relationship between aerosol extinction which can be measured by satellites and mass which is used for air quality monitoring. Extinction was found to be driven to first-order by aerosol loadings; however, humidity-driven aerosol hydration plays an important secondary role. Spatial and diurnal variability in aerosol composition were small, but day-to-day variability aerosol hygroscopicity must be accounted for.
Atmos. Chem. Phys. Discuss., 15, 23317-23355, doi:10.5194/acpd-15-23317-2015, 2015
Retrieval of ammonia from ground-based FTIR solar spectra
Summary: We present a new retrieval method for ammonia(NH3) concentrations and total columns from ground based Fourier Transform InfraRed(FTIR) observations. Observations from Bremen, Lauder , Reunion and Jungfraujoch are used to show the capabilities of the new retrieval. The developed retrieval provides a new way to obtain time-resolved measurements and will be usefull for understanding the dynamics of ammonia concentrations in the atmosphere and for satellite and model validation.
Atmos. Chem. Phys. Discuss., 15, 23279-23315, doi:10.5194/acpd-15-23279-2015, 2015
Limited effect of anthropogenic nitrogen oxides on Secondary Organic Aerosol formation
Summary: Nitrogen oxides (NOx) play an important but complex role in secondary organic aerosol (SOA) formation. In this study we update the SOA scheme in a global 3D chemistry-climate model by implementing a 4-product volatility basis set (VBS) framework with NOx-dependent yields and simplified aging parameterizations. We find that the SOA decrease in response to a 50% reduction in anthropogenic NOx emissions is limited due to the buffering in different chemical pathways.
Atmos. Chem. Phys. Discuss., 15, 23231-23277, doi:10.5194/acpd-15-23231-2015, 2015
Wintertime aerosol chemical composition, volatility, and spatial variability in the greater London area
Summary: We investigate the spatial distribution of submicron aerosol in the greater London area as part of the Clean Air for London (ClearfLo) project in winter 2012. Although the concentrations of organic aerosol (OA) are similar between a rural and an urban site, the OA sources are different. We also examine the volatility of submicron aerosol at the rural site and find that the non-volatile organics have similar sources or have undergone similar chemical processing as refractory black carbon.
Atmos. Chem. Phys. Discuss., 15, 23173-23229, doi:10.5194/acpd-15-23173-2015, 2015
The impact of atmospheric mineral aerosol deposition on the albedo of snow and sea ice: are snow and sea ice optical properties more important than mineral aerosol optical properties?
Summary: The decrease in reflectivity (albedo) of sea ice and snow containing mineral dusts and volcanic ashes is calculated. The type of snow and sea ice, the thickness and the layering of mineral aerosol deposits are varied. The results show that the response of the albedo of snow and sea ice to mineral aerosol deposits is more sensitive to the type of snow or sea ice than to the properties of the mineral aerosol deposits themselves.
Atmos. Chem. Phys. Discuss., 15, 23131-23172, doi:10.5194/acpd-15-23131-2015, 2015
Sources of nitrogen deposition in Federal Class I areas in the US
Summary: Sources of nitrogen deposition (Ndep) in Federal Class I areas in the US are investigated, identifying unique features in contributions from different species, sectors and locations. Ndep in many parks is impacted by emissions several hundred km away; the role of oxidized vs reduced sources varies regionally. Emissions reductions in the western US most effectively reduce the extent of areas in critical load exceedance, while reductions in the east most effectively reduce exceedance magnitudes.
Atmos. Chem. Phys. Discuss., 15, 23089-23130, doi:10.5194/acpd-15-23089-2015, 2015
Delivery of anthropogenic bioavailable iron from mineral dust and combustion aerosols to the ocean
Summary: A new Fe dissolution scheme is developed and is applied to atmospheric chemistry transport model to estimate the anthropogenic Fe deposition. Our improved model successfully captured the inverse relationship of Fe solubility and total Fe loading. Our model estimated low end of Fe solubility, compared to that estimated by the previous studies. Our model results suggest that human activities contribute to more than half of the bioavailable Fe supply to significant portions of the oceans.
Atmos. Chem. Phys. Discuss., 15, 23051-23088, doi:10.5194/acpd-15-23051-2015, 2015
Urban stress-induced biogenic VOC emissions impact secondary aerosol formation in Beijing
Atmos. Chem. Phys. Discuss., 15, 23005-23049, doi:10.5194/acpd-15-23005-2015, 2015
Role of radiatively forced temperature changes in enhanced semi-arid warming over East Asia
Atmos. Chem. Phys. Discuss., 15, 22975-23004, doi:10.5194/acpd-15-22975-2015, 2015
Spatial, temporal and vertical distribution of ammonia concentrations over Europe – comparing a static and dynamic approach with WRF-Chem
Summary: In our study we aim at improving the basic understanding of ammonia in the atmosphere. We have also identified current limitations in relation to the governing processes that cause ammonia emissions and initial dispersion due to meteorological parameters. For this purpose we have implemented the emission from a dynamical ammonia model into the atmospheric transport model WRF-Chem and evaluated the model results against a static approach for describing the emissions and against measurements.
Atmos. Chem. Phys. Discuss., 15, 22935-22973, doi:10.5194/acpd-15-22935-2015, 2015
Characteristics and sources of submicron aerosols above the urban canopy (260 m) in Beijing, China during 2014 APEC summit
Summary: We have a comprehensive characterization of submicron aerosol composition and sources at 260 m in urban Beijing during APEC 2014. Aerosol species were shown to have substantial decreases of 40–80% during APEC, whereas the bulk composition was relatively similar as a result of synergetic controls of secondary precursors. Our results elucidated that the good air quality during APEC was the combined result of emission controls and meteorological effects, with the former playing the dominant role.
Atmos. Chem. Phys. Discuss., 15, 22889-22934, doi:10.5194/acpd-15-22889-2015, 2015
Aircraft-measured indirect cloud effects from biomass burning smoke in the Arctic and subarctic
Summary: Based on extensive aircraft campaigns, we quantify how biomass burning smoke affects subarctic and Arctic liquid cloud microphysical properties. Enhanced cloud albedo may decrease shortwave radiative flux by 2-4 W m-2 or more in some subarctic conditions. Smoke halved average cloud droplet diameter, and in one case study, it also appeared to limit droplet formation. Numerous Arctic background Aitken particles can also interact with combustion particles, perhaps affecting their properties.
Atmos. Chem. Phys. Discuss., 15, 22823-22887, doi:10.5194/acpd-15-22823-2015, 2015
Modeling study of the 2010 regional haze event in the North China Plain
Atmos. Chem. Phys. Discuss., 15, 22781-22822, doi:10.5194/acpd-15-22781-2015, 2015
Investigation of error sources in regional inverse estimates of greenhouse gas emissions in Canada
Summary: This paper uses synthetic data experiments to investigate the impacts of different error sources associated with prior flux, transport model and optimisation method on the atmospheric greenhouse gas inverse estimates. Results indicate that estimation errors are dominated by the transport model error and can propagate to the flux estimates non-linearly. It is necessary to obtain stable and realistic results in synthetic data experiments before a real observation-based inversion is performed.
Atmos. Chem. Phys. Discuss., 15, 22715-22779, doi:10.5194/acpd-15-22715-2015, 2015
Observation of a tidal effect on the Polar Jet Stream
Summary: This paper demonstrates for the first time a direct link between atmospheric tides and the Polar Jet Stream flow. The authors have identified an anti-correlation of the Arctic Oscillation with the horizontal (‘tractional’) tidal force acting at high latitudes, particularly during winter months. The tractional force varies strongly during the lunar month and with the 18.6 year precession cycle of the lunar orbit. Changes in Jet Stream flow have a large effect on winter weather.
Atmos. Chem. Phys. Discuss., 15, 22701-22713, doi:10.5194/acpd-15-22701-2015, 2015
Investigations of boundary layer structure, cloud characteristics and vertical mixing of aerosols at Barbados with large eddy simulations
Summary: Large eddy simulations (LES) are performed for the area of the Caribbean island Barbados to investigate island effects on boundary layer modification, cloud generation and vertical mixing of aerosols. Incoming Saharan dust layers are analyzed and effects of layer thinning, subsidence and turbulent downward transport become apparent, which are sensitive to atmospheric stability and wind shear. Comparisons of LES model output with Doppler wind lidar data are made to validate the modeling results.
Atmos. Chem. Phys. Discuss., 15, 22637-22699, doi:10.5194/acpd-15-22637-2015, 2015
New insight into the spatiotemporal variability and source apportionments of C1–C4 alkyl nitrates in Hong Kong
Atmos. Chem. Phys. Discuss., 15, 22597-22636, doi:10.5194/acpd-15-22597-2015, 2015
Introduction: The Pan-Eurasian Experiment (PEEX) – multi-disciplinary, multi-scale and multi-component research and capacity building initiative
Atmos. Chem. Phys. Discuss., 15, 22567-22596, doi:10.5194/acpd-15-22567-2015, 2015
Seasonal variation of ozone and black carbon observed at Paknajol, an urban site in the Kathmandu Valley, Nepal
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 all the measurement period, and suggest that the pollutants variability is mainly driven by local pollution sources activity, local and large-scale dynamics, photochemistry and vegetation fires.
Atmos. Chem. Phys. Discuss., 15, 22527-22566, doi:10.5194/acpd-15-22527-2015, 2015
Possible influence of atmospheric circulations on winter hazy pollution in Beijing-Tianjin-Hebei region, northern China
Atmos. Chem. Phys. Discuss., 15, 22493-22526, doi:10.5194/acpd-15-22493-2015, 2015
The radiative impact of desert dust on orographic rain in the Cevennes–Vivarais area: a case study from HyMeX
Summary: We analyze the direct radiative impact of an intense African dust plume on orographic precipitation in the Western Mediterranean in the fall of 2012 using high resolution simulations from a convection permitting mesoscale model validated against measurements acquired during the first special observation period of HyMeX. We show that the dust direct radiative effect in such a dynamical environment is not sufficient to impact 24-h accumulated rainfall in the dusty simulation.
Atmos. Chem. Phys. Discuss., 15, 22451-22492, doi:10.5194/acpd-15-22451-2015, 2015
Annual variations of carbonaceous PM2.5 in Malaysia: influence by Indonesian peatland fires
Atmos. Chem. Phys. Discuss., 15, 22419-22449, doi:10.5194/acpd-15-22419-2015, 2015
Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia and Look Rock, Tennessee
Atmos. Chem. Phys. Discuss., 15, 22379-22417, doi:10.5194/acpd-15-22379-2015, 2015
Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011
Summary: Using a novel instrument, we have made measurements of organic compounds that can existing as a gas or particle in the rural atmosphere. Through hourly measurements, we have identified the sources and atmospheric processes of these compounds, which are important for modeling the climate and health impact of these emissions.
Atmos. Chem. Phys. Discuss., 15, 22331-22377, doi:10.5194/acpd-15-22331-2015, 2015
Upper tropospheric water vapour variability at high latitudes – Part 1: Influence of the annular modes
Atmos. Chem. Phys. Discuss., 15, 22291-22329, doi:10.5194/acpd-15-22291-2015, 2015
Volatility of organic aerosol and its components in the Megacity of Paris
Atmos. Chem. Phys. Discuss., 15, 22263-22289, doi:10.5194/acpd-15-22263-2015, 2015
Fine particulate matter associated with monsoonal effect and the responses of biomass fire hotspots in the tropical environment
Summary: Trans-boundary haze pollution is a major health and environmental concern during south-west and north-east monsoon in the South East Asian (SEA) regions. The concentration of PM2.5 exceeds the tolerable limits (WHO; USA EPA) during the summer monsoon. The novelty of this study is the source characterization of PM2.5 and source-specific risk assessment during intense haze pollution which are yet to be addressed in this region. The outcomes of this study will give an insight about future implicati
Atmos. Chem. Phys. Discuss., 15, 22215-22261, doi:10.5194/acpd-15-22215-2015, 2015
A sub-decadal trend of diacids in atmospheric aerosols in East Asia
Summary: The chemistry-transport models have predicted the change of secondary organic aerosols (SOA) in the future atmosphere with a large uncertainty. This study measures the change of diacids, major water-soluble surrogates of SOA, over a sub-decadal scale in atmospheric aerosols in East Asia. Diacids are observed to increase by 3.9 – 47.4% per year. If the increases continued, the water-soluble fraction of SOA would increase significantly in the future atmosphere in East Asia.
Atmos. Chem. Phys. Discuss., 15, 22183-22213, doi:10.5194/acpd-15-22183-2015, 2015
Polar Stratospheric Cloud evolution and chlorine activation measured by CALIPSO and MLS, and modelled by ATLAS
Summary: This paper presents the first trial of analyzing amount of chlorine activation on different PSC compositions by using match analysis on trajectories initiated from PSC locations identified by CALIPSO/CALIOP measurements. The measured minor species such as HCl and ClO by MLS are compared with ATLAS chemistry-transport model (CTM) results. PSC growth to NAT, NAT/STS mixture, and ice were identified by different temperature decrease histories on trajectories.
Atmos. Chem. Phys. Discuss., 15, 22141-22182, doi:10.5194/acpd-15-22141-2015, 2015
Detailed budget analysis of HONO in central London reveals a missing daytime source
Summary: This paper presents field measurements of HONO and a range of other gas phase and particulate species from an urban background site in London. The measured daytime HONO cannot be reproduced with a simple box model and thus a significant daytime missing source of HONO is present. We show that this missing source could be responsible for 40% of the OH radical source and 57% of the OH initiation, hence it's potential importance for atmospheric oxidation and ozone production.
Atmos. Chem. Phys. Discuss., 15, 22097-22139, doi:10.5194/acpd-15-22097-2015, 2015
OH reactivity and concentrations of Biogenic Volatile Organic Compounds in a Mediterranean forest of downy oak trees
Summary: Our manuscript shows results of OH reactivity and Biogenic Volatile Organic Compounds (BVOCs) concentration during a field experiment conducted in late spring 2014 at the Observatoire de Haute Provence (OHP) site. We found that OH reactivity is among the highest measured in forests globally (69s-1) and it is mainly due to isoprene. No missing reactivity was present during daytime inside or above the canopy, while 50% missing reactivity was found by night at both heights.
Atmos. Chem. Phys. Discuss., 15, 22047-22095, doi:10.5194/acpd-15-22047-2015, 2015
Variability of water vapour in the Arctic stratosphere
Atmos. Chem. Phys. Discuss., 15, 22013-22045, doi:10.5194/acpd-15-22013-2015, 2015
Viscosity controls humidity dependence of N2O5 uptake to citric acid aerosol
Summary: The heterogeneous loss of N2O5 to citric acid aerosol, a proxy for highly oxygenated secondary organic aerosol, is shown to be substantially lower than to other aqueous organic aerosol proxies investigated previously. This is attributed to the widely changing viscosity within the atmospherically relevant humidity range. It may explain some of the unexpectedly low loss rates of N2O5 to aerosol particles derived from in field studies.
Atmos. Chem. Phys. Discuss., 15, 21983-22011, doi:10.5194/acpd-15-21983-2015, 2015
A method to retrieve super-thin cloud optical depth over ocean background with polarized sunlight
Atmos. Chem. Phys. Discuss., 15, 21959-21982, doi:10.5194/acpd-15-21959-2015, 2015
Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area
Summary: An Oxidation Flow Reactor (OFR) was deployed to study secondary organic aerosol (SOA) formation and aging of urban emissions at a wide range of OH exposures during the CalNex campaign in Pasadena, CA, in 2010. Results include linking SOA formation to short-lived reactive compounds, similar elemental composition of reactor-aged emissions to atmospheric aging, changes in OA mass due to condensation of oxidized gas-phase species and heterogeneous oxidation of particle-phase species.
Atmos. Chem. Phys. Discuss., 15, 21907-21958, doi:10.5194/acpd-15-21907-2015, 2015
An adsorption theory of heterogeneous nucleation of water vapour on nanoparticles
Summary: Heterogeneous nucleation is a phenomenon that starts the condensation of supersaturated vapors on solid surfaces. An example is the formation of cirrus clouds in the atmosphere: their formation is often triggered at relative humidities clearly above 100%. We derive a new theory that can be used to calculate the threshold supersaturation of heterogeneous nucleation of water vapor on nanoparticles, and show that it performs significantly better than older theories when compared to lab experiments.
Atmos. Chem. Phys. Discuss., 15, 21883-21906, doi:10.5194/acpd-15-21883-2015, 2015
Radiative and climate impacts of a large volcanic eruption during stratospheric sulfur geoengineering
Summary: We have studied the impacts of a volcanic eruption during solar radiation management (SRM) using an aerosol-climate model ECHAM5-HAM-SALSA and an Earth system model MPI-ESM. A volcanic eruption during stratospheric sulfur geoengineering would lead to larger particles and smaller amount of new particles than if volcano erupts in normal atmospheric conditions. Thus, volcanic eruption during SRM would lead to only a small additional cooling which would last for a significantly shorter period.
Atmos. Chem. Phys. Discuss., 15, 21837-21881, doi:10.5194/acpd-15-21837-2015, 2015
Seasonality of ultrafine and sub-micron aerosols and the inferences on particle formation processes
Summary: This study investigated the properties of ultrafine (UFPs) and submicron particles (PM1) in an East-Asian urban area. The results indicate that the concentration of PM1 was elevated during cold seasons, whereas the highest UFPs concentration was measured in summer. Moreover, UFPs were composed mostly of organics, whereas ammonium and sulfate were the major constituents in PM1. This study underlines the significance of secondary organic aerosols in UFPs.
Atmos. Chem. Phys. Discuss., 15, 21803-21835, doi:10.5194/acpd-15-21803-2015, 2015
Validation of farm-scale methane emissions using nocturnal boundary layer budgets
Atmos. Chem. Phys. Discuss., 15, 21765-21802, doi:10.5194/acpd-15-21765-2015, 2015
Biomass burning emissions and potential air quality impacts of volatile organic compounds and other trace gases from temperate fuels common in the United States
Summary: A comprehensive suite of instruments was used to quantify the emissions of over 200 organic and inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the Southeastern, Southwestern, or Northern United States. Emission ratios relative to carbon monoxide (CO) are used to characterize the composition of gases emitted by mass; OH reactivity; and potential secondary organic aerosol (SOA) precursors for the 3 different U.S. fuel regions presented here.
Atmos. Chem. Phys. Discuss., 15, 21713-21763, doi:10.5194/acpd-15-21713-2015, 2015
Understanding cirrus ice crystal number variability for different heterogeneous ice nucleation spectra
Summary: We use the adjoint model of a cirrus parameterization to quantify sources of crystal variability for various ice-nucleating spectra and output from CAM5. The sensitivities can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, owing to aerosol surface properties. The sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters.
Atmos. Chem. Phys. Discuss., 15, 21671-21711, doi:10.5194/acpd-15-21671-2015, 2015
Size distribution and optical properties of mineral dust aerosols transported in the western Mediterranean
Summary: This study investigates the size distribution, chemical composition and optical properties of Saharan mineral dust transported over the Western Mediterranean using in-situ measurements collected from aircraft. Their variability due to altitude, time of transport and mixing rate with pollution particles are discussed. We found a moderate light absorption of the dust plumes even in presence of pollution particles and the persistence of large dust particles after transport in the Mediterranean.
Atmos. Chem. Phys. Discuss., 15, 21607-21669, doi:10.5194/acpd-15-21607-2015, 2015
Measurement-based direct radiative effect by brown carbon over Indo-Gangetic Plain
Summary: There are relatively few measurement-based estimates for the direct radiative effect of brown carbon so far. This is first time that the direct radiative effect of brown carbon is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in Indo-Gangetic Plain: Karachi, Lahore, Kanpur and Gandhi College.
Atmos. Chem. Phys. Discuss., 15, 21583-21606, doi:10.5194/acpd-15-21583-2015, 2015
Influence of biomass burning on CCN number and hygroscopicity during summertime in the eastern Mediterranean
Summary: BBOA from long-range transport exhibits increased CCN concentrations for particles larger than 100 nm. At the same time the hygroscopicity parameter decreased for all particle sizes, as sub-100 nm particles appear to be richer in less hygroscopic, organic material while larger particles become less hygroscopic due to condensation of less hygroscopic gaseous compounds. Finally, atmospheric processing of freshly-emitted BBOA to more oxidized organic aerosol can result in a 2-fold increase of κ_org
Atmos. Chem. Phys. Discuss., 15, 21539-21582, doi:10.5194/acpd-15-21539-2015, 2015
The tropopause inversion layer in baroclinic life cycles experiments: the role of diabatic and mixing processes
Summary: By conducting various simulations of dry and moist baroclinic life cycles we aimed to improve the understanding whether dynamical or diabatic processes are more relevant to form a tropopause inversion layer at midlatitudes. Most importantly, our experiments highlighted the role of different moisture related processes for the formation and evolution of the tropopause inversion layer with varying relevance and strength in different phases of the baroclinic life cycles.
Atmos. Chem. Phys. Discuss., 15, 21495-21537, doi:10.5194/acpd-15-21495-2015, 2015
Distinguishing the drivers of trends in land carbon fluxes and plant volatile emissions over the past three decades
Summary: We estimate decadal trends in land carbon fluxes and emissions of biogenic volatile organic compounds (BVOCs) during 1982-2011, with a focus on the feedback from biosphere (such as tree growth and phenology). Increases of LAI at peak season accounts for ~25% of the trends in GPP and isoprene emissions at the northern lands. However, phenological change alone does not promote regional carbon uptake and BVOC emissions.
Atmos. Chem. Phys. Discuss., 15, 21449-21494, doi:10.5194/acpd-15-21449-2015, 2015
Identification of particulate organosulfates in three megacities at the middle and lower reaches of the Yangtze River
Atmos. Chem. Phys. Discuss., 15, 21415-21448, doi:10.5194/acpd-15-21415-2015, 2015
Reactive nitrogen partitioning and its relationship to winter ozone events in Utah
Summary: High wintertime ozone levels have been observed in the Uintah Basin, Utah, a sparsely populated rural region with intensive oil and gas operations. The reactive nitrogen budget plays an important role in tropospheric ozone formation, and we find that nighttime chemistry has a large effect on its partitioning. Much of the oxidation of reactive nitrogen during a high-ozone year occurred via heterogeneous uptake onto aerosol at night, keeping NOx at concentrations comparable to a low-ozone year.
Atmos. Chem. Phys. Discuss., 15, 21383-21413, doi:10.5194/acpd-15-21383-2015, 2015
Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations
Summary: We report regional and global emissions estimates of HFC-152a using high frequency measurements from 11 observing sites and archived air samples dating back to 1978 together with atmospheric transport models. The ‘bottom up’ emissions of HFC-152a reported to the UNFCCC appear to significantly underestimate those reported here from observations. This discrepancy we suggest arises from largely underestimated USA and undeclared Asian emissions.
Atmos. Chem. Phys. Discuss., 15, 21335-21381, doi:10.5194/acpd-15-21335-2015, 2015
Spring and summer contrast in new particle formation over nine forest areas in North America
Summary: Role of low volatility organics in new particle formation (NPF) in the atmosphere is assessed. An empirical formulation in which formation rate is a function of the concentrations of sulfuric acid and low volatility organics significantly overpredicts NPF in the summer. Two different schemes predict quite different nucleation rates (including their spatial patterns), concentrations of cloud condensation nuclei, and aerosol first indirect radiative forcing in North America.
Atmos. Chem. Phys. Discuss., 15, 21271-21298, doi:10.5194/acpd-15-21271-2015, 2015
Conceptual design of a measurement network of the global change
Atmos. Chem. Phys. Discuss., 15, 21063-21093, doi:10.5194/acpd-15-21063-2015, 2015
Iodine's impact on tropospheric oxidants: a global model study in GEOS-Chem
Summary: Using a global chemical transport model (GEOS-Chem) with additional iodine emissions, chemistry and deposition we show that iodine is responsible for ~9% of global ozone loss but has negligible impacts on global OH. Uncertainties are large in the chemistry and emissions and future research is needed in both. Measurements of iodine species (especially HOI) would be useful. We believe iodine chemistry should be considered in future chemistry-climate and in air quality modeling.
Atmos. Chem. Phys. Discuss., 15, 20957-21023, doi:10.5194/acpd-15-20957-2015, 2015
Remote sensing of soot carbon – Part 2: Understanding the absorption Angstrom exponent
Atmos. Chem. Phys. Discuss., 15, 20911-20956, doi:10.5194/acpd-15-20911-2015, 2015
Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition
Atmos. Chem. Phys. Discuss., 15, 20811-20850, doi:10.5194/acpd-15-20811-2015, 2015
Hydrolysis and gas-particle partitioning of organic nitrates formed from the oxidation of α-pinene in environmental chamber experiments
Summary: The fate of organic nitrates influences their role as sinks and sources of NOx and their effects on the formation of tropospheric ozone and organic aerosol. Organic nitrates were formed from the photo-oxidation of α-pinene in environmental chamber experiments. Results on partitioning and hydrolysis of organic nitrates from this work could be implemented in chemical transport models to more accurately represent the fate of NOx and the formation of ozone and particulate matter.
Atmos. Chem. Phys. Discuss., 15, 20629-20653, doi:10.5194/acpd-15-20629-2015, 2015
Meteorological constraints on oceanic halocarbons above the Peruvian Upwelling
Atmos. Chem. Phys. Discuss., 15, 20597-20628, doi:10.5194/acpd-15-20597-2015, 2015
The imprint of stratospheric transport on column-averaged methane
Summary: We find that stratospheric model-transport errors are common for chemical transport models that are used for inverse estimates of CH4 emissions. These model-transport errors cause latitudinal as well as seasonal biases in simulated stratospheric and, hence, column-averaged CH4 mixing ratios (XCH4). Such a model bias corresponds to an overestimation of arctic and mid-latitude CH4 emissions if inversion studies do not apply an ad hoc bias correction before inverting fluxes from XCH4 observations.
Atmos. Chem. Phys. Discuss., 15, 20395-20447, doi:10.5194/acpd-15-20395-2015, 2015
Change in turbopause altitude at 52 and 70° N
Summary: Turbulent energy dissipation rates are calculated using MF-radar signals from 70°N and 52°N for the period 2001-2014 inclusive, and are used to estimate turbopause altitudes. A positive trend in turbopause altitude is identified for 70°N in summer, but not in winter and not at 52°N. The turbopause altitude change between 2001 and 2014 can be used to hypothesize a corresponding change in atomic oxygen concentration.
Atmos. Chem. Phys. Discuss., 15, 20287-20304, doi:10.5194/acpd-15-20287-2015, 2015
Development of an atmospheric N2O isotopocule model and optimization procedure, and application to source estimation
Summary: We developed an atmospheric N2O isotopocule model based on a chemistry-coupled atmospheric general circulation model and a simple method to optimize the model, and estimated the isotopic signatures of surface sources at the hemispheric scale. Data obtained from ground-based observations, measurements of firn air, and balloon and aircraft flights were used to optimize the long-term trends, interhemispheric gradients, and photolytic fractionation, respectively, in the model.
Atmos. Chem. Phys. Discuss., 15, 19947-20011, doi:10.5194/acpd-15-19947-2015, 2015
Cloud condensation nuclei activity, droplet growth kinetics and hygroscopicity of biogenic and anthropogenic Secondary Organic Aerosol (SOA)
Summary: This study investigated the cloud droplet activation behavior and hygroscopic growth of mixed anthropogenic and biogenic SOA (ABSOA) compared to pure biogenic SOA (BSOA) and pure anthropogenic SOA (ASOA). Cloud droplet activation behaviors of different types of SOA were similar. In contrast, the hygroscopicity of ASOA was higher than BSOA and ABSOA. ASOA components enhanced the hygroscopicity of the ABSOA. Yet this enhancement cannot be described by a linear mixing of pure SOA systems.
Atmos. Chem. Phys. Discuss., 15, 19903-19945, doi:10.5194/acpd-15-19903-2015, 2015
The contrasting roles of water and dust in controlling daily variations in radiative heating of the summertime Saharan Heat Low
Atmos. Chem. Phys. Discuss., 15, 19447-19476, doi:10.5194/acpd-15-19447-2015, 2015
Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition
Atmos. Chem. Phys. Discuss., 15, 19367-19403, doi:10.5194/acpd-15-19367-2015, 2015
Observed high-altitude warming and snow cover retreat over Tibet and the Himalayas enhanced by black carbon aerosols
Summary: We show that black carbon aerosol pollution is likely the dominating factor in causing the accelerated retreat of snow pack. The simulated snow fraction and surface albedo change at the surface, as well as the enhanced warming at higher elevations, are remarkably similar to observations. The fundamental reason for the model’s ability to simulate the observed trends is that in this study, we replace the model simulated black carbon forcing with one that is constrained by observations.
Atmos. Chem. Phys. Discuss., 15, 19079-19109, doi:10.5194/acpd-15-19079-2015, 2015
Impacts of aviation fuel sulfur content on climate and human health
Summary: Using a coupled tropospheric chemistry-aerosol microphysics model this research paper investigates the effect of variations in aviation fuel sulfur content (FSC) on surface PM2.5 concentrations, increases in aviation-induced premature mortalities, low-level cloud condensation nuclei and radiative effect. When investigating the climatic impact of variations in FSC the ozone direct radiative effect, aerosol direct radiative effect and aerosol cloud albedo effect are quantified.
Atmos. Chem. Phys. Discuss., 15, 18921-18961, doi:10.5194/acpd-15-18921-2015, 2015
High-resolution inventory of technologies, activities, and emissions of coal-fired power plants in China from 1990 to 2010
Summary: This is the first study that emissions from China’s coal-fired power plants were estimated at unit level for a 20-yr period. This new emission inventory is constructed from a unit-based database compiled in this work, named the China coal-fired Power plant Emissions Database (CPED), which includes detailed information on the technologies, activity data, operation situation, emission factors, and locations of individual units.
Atmos. Chem. Phys. Discuss., 15, 18787-18837, doi:10.5194/acpd-15-18787-2015, 2015
Atmospheric polarimetric effects on GNSS Radio Occultations: the ROHP-PAZ field campaign
Atmos. Chem. Phys. Discuss., 15, 18747-18785, doi:10.5194/acpd-15-18747-2015, 2015
Chemical characterization of fine organic aerosol for source apportionment at Monterrey, Mexico
Summary: The identified organic compound classes demonstrated that anthropogenic sources were dominant. Gasoline- and diesel-powered vehicles are the main emission sources (CMB = 64%) of this class of organic compounds in PM2.5. Other pyrogenic sources such as coal, grass, and wood combustion as well as meat cooking operations were also identified as contributors to the fine OA. Aging of primary emissions and the SOA from biogenic volatile organic compounds due to photochemical activity and transport.
Atmos. Chem. Phys. Discuss., 15, 17967-18010, doi:10.5194/acpd-15-17967-2015, 2015
Light absorption properties of laboratory generated tar ball particles
Summary: Tar balls (TBs) are a specific particle type which is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC) which can absorb light in the visible range of the solar spectrum. The refractive index of TBs falls closer to those of soot than to other light-absorbing species such as humic-like substances. These findings may have substantial influence on the understanding of global radiative energy fluxes.
Atmos. Chem. Phys. Discuss., 15, 16215-16234, doi:10.5194/acpd-15-16215-2015, 2015
Challenges of parameterizing CCN due to changes in particle physicochemical properties: implications from observations at a suburban site in China
Atmos. Chem. Phys. Discuss., 15, 16141-16174, doi:10.5194/acpd-15-16141-2015, 2015
Vertical variations of aerosols and the effects responded to the emission control: application of lidar ceilometer in Beijing during APEC, 2014
Summary: The manuscript is the first paper to validate and discuss the high resolution vertical profiles of aerosols using Ceilometer in Beijing, China. We introduce the contribution to aerosols during the different air pollution episode in Beijing. Also, we seize the opportunity of emission reduction during APEC to study the contribution to aerosols. The results are helpful to provide guidance of redefining coordinated emission control strategies to control the regional pollution over Northern China.
Atmos. Chem. Phys. Discuss., 15, 13173-13209, doi:10.5194/acpd-15-13173-2015, 2015
Effects of mineral dust on global atmospheric nitrate concentrations
Summary: We provide an assessment of the chemical composition and global aerosol load of aerosol nitrate and determine the effect of mineral dust on its formation due to thermodynamical interactions. For this purpose we used an explicit geographical representation of the emitted soil particle size distribution and chemical composition. We conclude that mineral dust aerosol chemistry is important for nitrate aerosol formation and significantly affects its global distribution, especially in the coarse mode
Atmos. Chem. Phys. Discuss., 15, 11525-11572, doi:10.5194/acpd-15-11525-2015, 2015
PLAM – a meteorological pollution index for air quality and its applications in fog-haze forecasts in north China
Summary: On the basis of parameterized meteorological condition principle method, this paper discussed the mutual impact of emission and meteorological condition, and studied the structure and function of meteorological conditions PLAM index in quantitatively identifying, diagnosing and forecasting large scope of fog-haze weather. A new model of PLAM/h – the meteorological pollution Index for air quality has been developed and used in NRT air quality forecasts, by considering both meteorology and polluta
Atmos. Chem. Phys. Discuss., 15, 9077-9106, doi:10.5194/acpd-15-9077-2015, 2015
A comprehensive inventory of ship traffic exhaust emissions in the European sea areas in 2011
Summary: This manuscript describes the emissions from shipping in European sea areas. The work is based on automatic position reports (AIS) sent by ships and reflects realistic activity patterns of ships. The work demonstrates that it is feasible to construct a full bottom-up emission inventories based on large-volume activity data sets.
Atmos. Chem. Phys. Discuss., 15, 7459-7491, doi:10.5194/acpd-15-7459-2015, 2015