Total sulfate vs. sulfuric acid monomer concenterations in nucleation studies
Summary: A discrepancy of 2 orders of magnitude was found between the measured sulfuric acid monomer concentration and total sulfate, when measured with independent methods (mass spectrometry and ion chromatography) with the same source of sulphuric acid vapor. The ion chromatography method produces the exact concentrations predicted by empirical equations, and the mass spectrometry method shows significantly lower values. The discrepancy is investigated thoroughly from different points of views.
Atmos. Chem. Phys., 15, 3429-3443, doi:10.5194/acp-15-3429-2015, 2015
Major contribution of neutral clusters to new particle formation at the interface between the boundary layer and the free troposphere
Atmos. Chem. Phys., 15, 3413-3428, doi:10.5194/acp-15-3413-2015, 2015
Using the chemical equilibrium partitioning space to explore factors influencing the phase distribution of compounds involved in secondary organic aerosol formation
Summary: The manuscript presents a new way to graphically illustrate some of the processes that occur when organic particles form in the atmosphere. In particular, this method makes it possible to see how factors such as the composition of the atmosphere and temperature affect these processes.
Atmos. Chem. Phys., 15, 3395-3412, doi:10.5194/acp-15-3395-2015, 2015
Hygroscopic properties of NaCl and NaNO3 mixture particles as reacted inorganic sea-salt aerosol surrogates
Summary: This work focuses on the hygroscopic behavior of NaCl-NaNO3 mixed particles as reacted sea-salt aerosol surrogates. The experimental phase diagrams for their deliquescence and efflorescence are determined, and the efflorescence process is explained. This study has high atmospheric implications, because the observed phases and chemical microstructures are expected to help in elucidating the complexity of real ambient sea salt aerosols, their hygroscopic properties, aqueous phase chemistry, etc.
Atmos. Chem. Phys., 15, 3379-3393, doi:10.5194/acp-15-3379-2015, 2015
Diel and seasonal changes of biogenic volatile organic compounds within and above an Amazonian rainforest
Atmos. Chem. Phys., 15, 3359-3378, doi:10.5194/acp-15-3359-2015, 2015
Relating hygroscopicity and optical properties to chemical composition and structure of secondary organic aerosol particles generated from the ozonolysis of α-pinene
Atmos. Chem. Phys., 15, 3339-3358, doi:10.5194/acp-15-3339-2015, 2015
Energetic particle induced intra-seasonal variability of ozone inside the Antarctic polar vortex observed in satellite data
Summary: Energetic particles from the sun produce NOx (=N+NO+NO2) in the mesosphere/lower thermosphere. The NOx can be transported downward in the stratosphere during polar winter where NOx eventually depletes O3. This entire chain is the so-called energetic particle precipitation (EPP) indirect effect. Here we show downward propagating negative stratospheric O3 anomalies during Antarctic polar winter. The O3 anomalies are caused by geomagnetic activity and show strong hints of the EPP indirect effect.
Atmos. Chem. Phys., 15, 3327-3338, doi:10.5194/acp-15-3327-2015, 2015
Dust aerosol radiative effects during summer 2012 simulated with a coupled regional aerosol–atmosphere–ocean model over the Mediterranean
Summary: This paper uses an original approach based on a coupled regional aerosol--atmosphere--ocean model to study the dust radiative effects over the Mediterranean in summer 2012. After an evaluation of the prognostic aerosol scheme, the dust aerosol daily variability is shown to improve the simulated surface radiation and temperature at the daily scale. It has also a significant impact on the summer average, thus highlighting the importance of a relevant representation of aerosols in climate models.
Atmos. Chem. Phys., 15, 3303-3326, doi:10.5194/acp-15-3303-2015, 2015
The influence of clouds on radical concentrations: observations and modelling studies of HOx during the Hill Cap Cloud Thuringia (HCCT) campaign in 2010
Atmos. Chem. Phys., 15, 3289-3301, doi:10.5194/acp-15-3289-2015, 2015
Mesoscale modelling study of the interactions between aerosols and PBL meteorology during a haze episode in China Jing–Jin–Ji and its near surrounding region – Part 2: Aerosols' radiative feedback effects
Summary: Solar radiation reaching the ground decreases about 15% in Chinese 3JNS region and by 20 to 25% in the region with the highest AOD. Aerosol cools the PBL atmosphere but warms the atmosphere above it, leading to a more stable atmosphere that causes a decrease in turbulence diffusion of about 52% and in PBL height of about 33%; this results in a positive feedback on the PM2.5 concentration within the PBL and the surface as well as the haze formation.
Atmos. Chem. Phys., 15, 3277-3287, doi:10.5194/acp-15-3277-2015, 2015
Mesoscale modeling study of the interactions between aerosols and PBL meteorology during a haze episode in Jing–Jin–Ji (China) and its nearby surrounding region – Part 1: Aerosol distributions and meteorological features
Atmos. Chem. Phys., 15, 3257-3275, doi:10.5194/acp-15-3257-2015, 2015
Spaceborne observations of the lidar ratio of marine aerosols
Atmos. Chem. Phys., 15, 3241-3255, doi:10.5194/acp-15-3241-2015, 2015
Seasonal changes in the tropospheric carbon monoxide profile over the remote Southern Hemisphere evaluated using multi-model simulations and aircraft observations
Summary: The Southern Hemisphere (SH) serves as an important test bed for evaluating our understanding of the processes that drive the composition of the clean background atmosphere. Using data from two aircraft campaigns, combined with four atmospheric chemistry models, we find a large sensitivity in the remote SH to biogenic emissions and their subsequent chemistry and transport. Future model evaluation and measurement campaigns should prioritize reducing uncertainties in these processes.
Atmos. Chem. Phys., 15, 3217-3239, doi:10.5194/acp-15-3217-2015, 2015
Aerosol physicochemical properties and implications for visibility during an intense haze episode during winter in Beijing
Atmos. Chem. Phys., 15, 3205-3215, doi:10.5194/acp-15-3205-2015, 2015
Interannual variability of isotopic composition in water vapor over western Africa and its relationship to ENSO
Atmos. Chem. Phys., 15, 3193-3204, doi:10.5194/acp-15-3193-2015, 2015
Explaining variance in black carbon's aging timescale
Summary: The timescale for particles containing black carbon to age from hydrophobic to hygroscopic strongly influences black carbon's atmospheric lifetime and climate impact. This paper identifies the minimal set of independent variables needed to explain variance in this aging timescale. This work distills the complex interactions captured by a particle-resolved aerosol model to a few input variables and is a first step toward developing physically based parameterizations of aerosol aging.
Atmos. Chem. Phys., 15, 3173-3191, doi:10.5194/acp-15-3173-2015, 2015
Sources and contributions of wood smoke during winter in London: assessing local and regional influences
Summary: Wood is a renewable fuel but its combustion for residential heating releases a number of locally acting air pollutants, most notably particulate matter known to have adverse effects on human health. This paper used chemical tracers for wood smoke to estimate the contribution that burning wood makes to concentrations of airborne particles in the atmosphere of southern England and most particularly in London.
Atmos. Chem. Phys., 15, 3149-3171, doi:10.5194/acp-15-3149-2015, 2015
Spatiotemporal variability of water vapor investigated using lidar and FTIR vertical soundings above the Zugspitze
Summary: We quantitatively analyzed the spatiotemporal variability (minutes to hours, 500m to 10km) of water vapor (IWV and profiles) in the free troposphere recorded at the Zugspitze (Germany) with lidar and solar FTIR. We found that long-range transport of heterogeneous air masses may cause relative short-term variations of the water-vapor density which exceed the impact of local convection by 1 order of magnitude. Our results could be useful for issues of model parametrization and co-location.
Atmos. Chem. Phys., 15, 3135-3148, doi:10.5194/acp-15-3135-2015, 2015
Comparison of mercury concentrations measured at several sites in the Southern Hemisphere
Summary: • Longer-term mercury measurement in the Southern Hemisphere is compared. • Mercury, in terms of monthly and annual medians and averages, is more evenly distributed than hitherto believed. • Consequently, trends observed at one or a few sites are likely to be representative of the whole hemisphere, and smaller trends can be detected in shorter time periods. • We report a change in the trend sign at Cape Point from decreasing mercury concentrations in 1996-2004 to increasing ones since 2007.
Atmos. Chem. Phys., 15, 3125-3133, doi:10.5194/acp-15-3125-2015, 2015
Dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls, fatty acids and benzoic acid in PM2.5 aerosol collected during CAREBeijing-2007: an effect of traffic restriction on air quality
Summary: The objective of this study is to identify the influence of traffic emissions and regional transport to the atmosphere in Beijing during the CAREBeijing-2007 in summer. This study demonstrates that even when primary exhaust was controlled by traffic restrictions, the contribution of secondary organic species formed from photochemical processes was critical with long-range atmospheric transport of pollutants.
Atmos. Chem. Phys., 15, 3111-3123, doi:10.5194/acp-15-3111-2015, 2015
Comment on "Observation and modelling of HOx radicals in a boreal forest" by Hens et al. (2014)
Atmos. Chem. Phys., 15, 3109-3110, doi:10.5194/acp-15-3109-2015, 2015
Chemical and stable carbon isotopic composition of PM2.5 from on-road vehicle emissions in the PRD region and implications for vehicle emission control policy
Atmos. Chem. Phys., 15, 3097-3108, doi:10.5194/acp-15-3097-2015, 2015
Properties and evolution of biomass burning organic aerosol from Canadian boreal forest fires
Summary: Particulate emissions in the form of organic aerosol from boreal forest fires in Canada have been measured during an aircraft measurement campaign. Ratios of the amount of aerosol emitted relative to gas species such as CO were calculated and show high levels of variability throughout the campaign. This variability is affected by both changes in fire conditions, as fires tended to die down later in the measurement period, and by changes to the aerosol due to chemical reactions in the atmosphere.
Atmos. Chem. Phys., 15, 3077-3095, doi:10.5194/acp-15-3077-2015, 2015
Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield
Summary: We compared the chemistry and yields of SOA generated from OH oxidation of gas-phase precursors in a flow reactor (high OH, short residence time) and environmental chambers (low OH, long residence time). We find that chemical composition of SOA produced in the flow reactor and in chambers is similar. SOA yields measured in the flow reactor are lower than in chambers. Seed particles increase the yield of SOA produced in the flow reactor and may account in part for higher SOA yields in chambers.
Atmos. Chem. Phys., 15, 3063-3075, doi:10.5194/acp-15-3063-2015, 2015
Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications
Atmos. Chem. Phys., 15, 3045-3062, doi:10.5194/acp-15-3045-2015, 2015
Intercomparison of vertically resolved merged satellite ozone data sets: interannual variability and long-term trends
Summary: Understanding ozone trends in the vertical is vital in terms of assessing the success of the Montreal Protocol. This paper compares and analyses the long-term trends in stratospheric ozone from seven new merged satellite data sets. The data sets largely agree well with each other, particularly for the negative trends seen in the early period 1984-1997. For the 1998-2011 period there is less agreement, but a clear shift from negative to mostly positive trends.
Atmos. Chem. Phys., 15, 3021-3043, doi:10.5194/acp-15-3021-2015, 2015
Gauss–Seidel limb scattering (GSLS) radiative transfer model development in support of the Ozone Mapping and Profiler Suite (OMPS) limb profiler mission
Summary: The Gauss--Seidel limb scattering (GSLS) radiative transfer model simulates the transfer of solar radiation through the atmosphere. Several recent changes have been added that improve the accuracy and flexibility of the GSLS radiance calculations. The single-scattered radiance errors have been reduced from 4% in earlier studies to 0.3%, while total radiance errors generally decline from 10% to 1-3%. In all cases, the tangent height dependence of the GSLS radiance error is greatly reduced.
Atmos. Chem. Phys., 15, 3007-3020, doi:10.5194/acp-15-3007-2015, 2015
Two years of near real-time chemical composition of submicron aerosols in the region of Paris using an Aerosol Chemical Speciation Monitor (ACSM) and a multi-wavelength Aethalometer
Atmos. Chem. Phys., 15, 2985-3005, doi:10.5194/acp-15-2985-2015, 2015
Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions
Atmos. Chem. Phys., 15, 2969-2983, doi:10.5194/acp-15-2969-2015, 2015
Gaseous products and secondary organic aerosol formation during long term oxidation of isoprene and methacrolein
Summary: First- and higher order -generation products formed from the oxidation of isoprene and methacrolein with OH radicals in the presence of NOx have been studied in a simulation chamber. Differences in light source are proposed to partially explain the discrepancies observed between different studies in the literature for both isoprene- and methacrolein-SOA mass yields. According to our results, these SOA yields in the atmosphere could be lower than suggested by most of the current chamber studies.
Atmos. Chem. Phys., 15, 2953-2968, doi:10.5194/acp-15-2953-2015, 2015
Long-term real-time chemical characterization of submicron aerosols at Montsec (southern Pyrenees, 1570 m a.s.l.)
Summary: Real-time measurements of inorganic (sulfate, nitrate, ammonium, chloride and black carbon (BC)) and organic submicron aerosols from a continental background site (Montsec, MSC, 1570m a.s.l.) in the western Mediterranean Basin (WMB) were conducted for 10 months (July 2011 - April 2012) with an aerosol chemical speciation monitor (ACSM). The ACSM was co-located with other online and offline PM1 measurements. Analyses of the hourly, diurnal, and seasonal variations are presented here.
Atmos. Chem. Phys., 15, 2935-2951, doi:10.5194/acp-15-2935-2015, 2015
Trends of ozone total columns and vertical distribution from FTIR observations at eight NDACC stations around the globe
Atmos. Chem. Phys., 15, 2915-2933, doi:10.5194/acp-15-2915-2015, 2015
Biases in atmospheric CO2 estimates from correlated meteorology modeling errors
Atmos. Chem. Phys., 15, 2903-2914, doi:10.5194/acp-15-2903-2015, 2015
Stratospheric and mesospheric HO2 observations from the Aura Microwave Limb Sounder
Atmos. Chem. Phys., 15, 2889-2902, doi:10.5194/acp-15-2889-2015, 2015
Standard climate models radiation codes underestimate black carbon radiative forcing
Summary: Radiative forcing (RF) of black carbon (BC) in the atmosphere is estimated using radiative transfer codes of various complexities. Here we show that the two-stream radiative transfer codes used most in climate models give overly strong forward scattering, leading to enhanced absorption at the surface and overly weak absorption by BC. Such calculations are found to underestimate RF in all sky conditions by 10% for global mean, relative to the more sophisticated multi-stream model.
Atmos. Chem. Phys., 15, 2883-2888, doi:10.5194/acp-15-2883-2015, 2015
Temperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)2 Observational Prototype Experiment
Summary: Measurements and upgrades of the rotational Raman lidar of the University of Hohenheim during the HD(CP)2 Observational Prototype Experiment are presented in this paper. This includes 25h long time series of temperature gradients and water vapor mixing ratio. Through simulation, optimum wavelengths for high- and low-background cases were identified and tested successfully. Low-elevation measurements were performed to measure temperature gradients at altitudes around 100m above ground level.
Atmos. Chem. Phys., 15, 2867-2881, doi:10.5194/acp-15-2867-2015, 2015
Uplifting of carbon monoxide from biomass burning and anthropogenic sources to the free troposphere in East Asia
Summary: 1. High CO abundances of 300-550 ppbv is shown in aircraft MOZAIC data between 700 and 300 hPa over East Asia in three episodes. Correspondingly, elevated CO is observed in satellite MOPITT data at similar altitudes. 2. GEOS-Chem and FLEXPART simulations reveal distinct uplifting processes for CO from fires and anthropogenic sources in the cases. 3. Topography in East Asia affects uplifting of CO in different ways. 4. The new version 5 MOPITT data can help diagnose vertical transport of CO.
Atmos. Chem. Phys., 15, 2843-2866, doi:10.5194/acp-15-2843-2015, 2015
Characterization of primary and secondary wood combustion products generated under different burner loads
Summary: Residential wood combustion contributes significantly to the total atmospheric particulate burden; however, uncertainties remain in the magnitude and characteristics of wood burning products. The effects of wood loading on freshly emitted and aged emissions were investigated. Polycyclic aromatic hydrocarbons, which negatively impact health, contributed more to the total organic aerosol under highly loaded burner conditions, which has significant implications for burner operation protocols.
Atmos. Chem. Phys., 15, 2825-2841, doi:10.5194/acp-15-2825-2015, 2015
How emissions, climate, and land use change will impact mid-century air quality over the United States: a focus on effects at national parks
Summary: We present for the first time the relative effect of climate, emissions, and land use change on ozone and PM25 over the United States, focusing on the national parks. Air quality in 2050 will likely be dominated by emission patterns, but climate and land use changes alone can lead to a substantial increase in air pollution over most of the US, with important implications for O3 air quality, visibility and ecosystem health degradation in the national parks.
Atmos. Chem. Phys., 15, 2805-2823, doi:10.5194/acp-15-2805-2015, 2015
Biomass burning related ozone damage on vegetation over the Amazon forest: a model sensitivity study
Atmos. Chem. Phys., 15, 2791-2804, doi:10.5194/acp-15-2791-2015, 2015
A critical evaluation of proxy methods used to estimate the acidity of atmospheric particles
Summary: We show that the ion balance and molar ratio methods are unsuitable for use as aerosol pH proxies. Our recommendation is that 1) thermodynamic equilibrium models constrained by both gas and aerosol inputs run in the forward (open) mode, and 2) the phase partitioning of ammonia provides the best predictions of aerosol pH. Given the significance of acidity for numerous chemical processes in the atmosphere, the implications of this study are important and far reaching.
Atmos. Chem. Phys., 15, 2775-2790, doi:10.5194/acp-15-2775-2015, 2015
Sources and fluxes of organic nitrogen in precipitation over the southern East Sea/Sea of Japan
Atmos. Chem. Phys., 15, 2761-2774, doi:10.5194/acp-15-2761-2015, 2015
Competition between core and periphery-based processes in warm convective clouds – from invigoration to suppression
Atmos. Chem. Phys., 15, 2749-2760, doi:10.5194/acp-15-2749-2015, 2015
Observations and modeling of air quality trends over 1990–2010 across the Northern Hemisphere: China, the United States and Europe
Summary: Model-simulated air quality trends over the past 2 decades largely agree with those derived from observations. In the relative amounts of VOC and NOx emission controls in different regions across the northern hemisphere have led to significantly different trends in tropospheric O3. Differences in the historical changes in the relative amounts of NH3, NOx and SO2 emissions also impact the trends in inorganic particulate matter amounts and composition in China, the U.S. and Europe.
Atmos. Chem. Phys., 15, 2723-2747, doi:10.5194/acp-15-2723-2015, 2015
Evidence for tropospheric wind shear excitation of high-phase-speed gravity waves reaching the mesosphere using the ray-tracing technique
Summary: Sources and propagation characteristics of high-frequency gravity waves observed in the mesosphere using airglow emissions from Gadanki and Hyderabad, India, are investigated using reverse ray tracing. Wave amplitudes are also traced back, including both radiative and diffusive damping. Interestingly, large vertical shears in the horizontal wind are noticed near the ray terminal points (at 10-12km altitude) and are thus identified to be the source for generating the observed gravity waves.
Atmos. Chem. Phys., 15, 2709-2721, doi:10.5194/acp-15-2709-2015, 2015
Analysis of the ozone profile specifications in the WRF-ARW model and their impact on the simulation of direct solar radiation
Atmos. Chem. Phys., 15, 2693-2707, doi:10.5194/acp-15-2693-2015, 2015
Assessment of small-scale integrated water vapour variability during HOPE
Atmos. Chem. Phys., 15, 2675-2692, doi:10.5194/acp-15-2675-2015, 2015
Air quality monitoring in communities of the Canadian Arctic during the high shipping season with a focus on local and marine pollution
Summary: In an effort to characterize the effect of shipping on Arctic air quality during the 2013 shipping season, air-quality monitoring stations were installed in Cape Dorset and Resolute, Nunavut, Canada, to measure NOx, SO2, PM2.5, O3, and BC. Results indicate that on the order of 5--25% of local cumulative exposure to these pollutants is due to ship emissions. This approach is complementary to pollution measurements at the source and has wider applications for the impact of traffic on air quality.
Atmos. Chem. Phys., 15, 2651-2673, doi:10.5194/acp-15-2651-2015, 2015
How much is particulate matter near the ground influenced by upper-level processes within and above the PBL? A summertime case study in Milan (Italy) evidences the distinctive role of nitrate
Summary: Particulate matter (PM) at ground level is of primary concern for the quality of the air we breathe. Most direct sources of PM are near the ground, but an important fraction of PM is produced by photochemical processes happening also in the upper atmospheric layers. We investigated the contribution of those layers to the PM near the ground and found a significant impact. Nitrate is a major player in the “vertical direction”, owing to its sensitivity to ambient temperature and relative humidity.
Atmos. Chem. Phys., 15, 2629-2649, doi:10.5194/acp-15-2629-2015, 2015
Quantification of the depletion of ozone in the plume of Mount Etna
Summary: We investigate the atmospheric chemistry that occurs in the plume of Mt. Etna shortly after emission. We measured O3 destruction in the plume. Using simultaneous measurements of SO2 and wind speed, we approximate the rate of this destruction. BrO, expected to be an indicator of ozone-destructive chemistry, is also detected. A computer model is able to approximately reproduce these results and is used to make inferences about the chemistry occurring that cannot be directly observed.
Atmos. Chem. Phys., 15, 2613-2628, doi:10.5194/acp-15-2613-2015, 2015
Variations in global methane sources and sinks during 1910–2010
Summary: Atmospheric CH4 increased from 900ppb to 1800ppb during the period 1900–2010 at a rate unprecedented in any observational records. We use bottom-up emissions and a chemistry-transport model to simulate CH4. The optimized global total CH4 emission, estimated from the model–observation differences, increased at fastest rate during 1940–1990. Using δ13C of CH4 measurements we attribute this emission increase to biomass burning. Total CH4 lifetime is shortened by 4% over the simulation period.
Atmos. Chem. Phys., 15, 2595-2612, doi:10.5194/acp-15-2595-2015, 2015
Theory of the norm-induced metric in atmospheric dynamics
Summary: A metric measures the difference between two system states. So far, there is arbitrariness in its definition in terms of wind, temperature and surface pressure of the atmosphere. The choice of definition affects many applications: e.g. predictability studies, error growth analyses and ensemble forecasts. We construct a new metric based on vector space theory and energy conservation, and apply it to analytic models and atmospheric data. We discuss its advantages over a widely used older metric.
Atmos. Chem. Phys., 15, 2571-2594, doi:10.5194/acp-15-2571-2015, 2015
Corrigendum to "SO2 photolysis as a source for sulfur mass-independent isotope signatures in stratospheric aerosols" published in Atmos. Chem. Phys., 15, 1843–1864, 2015
Atmos. Chem. Phys., 15, 2569-2569, doi:10.5194/acp-15-2569-2015, 2015
Importance of aerosol composition and mixing state for cloud droplet activation over the Arctic pack ice in summer
Summary: In the Arctic clouds are very important for determining the melting of the sea ice. The radiative properties of the optically thin Arctic clouds strongly depend on the number of particles available for water uptake. This study argues that the Köhler equation commonly used for simulating cloud droplet activation is not fully complete for describing the condensational growth of the interaction of the hydrophilic and hydrophobic entities on the structures of the airborne polymer gels present.
Atmos. Chem. Phys., 15, 2545-2568, doi:10.5194/acp-15-2545-2015, 2015
A science-based use of ensembles of opportunities for assessment and scenario studies
Summary: Ensembles of results from multiple models require systematic screening according to well-defined and analytical principles described in the paper. The screening guarantees more robust conclusions especially in the case of scenario analysis.
Atmos. Chem. Phys., 15, 2535-2544, doi:10.5194/acp-15-2535-2015, 2015
Corrigendum to "Development towards a global operational aerosol consensus: basic climatological characteristics of the International Cooperative for Aerosol Prediction Multi-Model Ensemble (ICAP-MME)" published in Atmos. Chem. Phys., 15, 335–362, 2015
Atmos. Chem. Phys., 15, 2533-2534, doi:10.5194/acp-15-2533-2015, 2015
A new method for measuring the imaginary part of the atmospheric refractive index structure parameter in the urban surface layer
Summary: This study developed a theoretical framework to analyse the contribution of absorption to scintillation, which can be used to derive the imaginary part of the ARISP in the urban atmospheric boundary layer from scintillation measurements. In this study, a simple expression for the imaginary part of the ARISP is obtained, which can be conveniently used to determine the imaginary part of the ARISP from LAS measurements. The experimental results showed good agreement with the presented theory.
Atmos. Chem. Phys., 15, 2521-2531, doi:10.5194/acp-15-2521-2015, 2015
Corrigendum to "High-resolution mapping of vehicle emissions in China in 2008" published in Atmos. Chem. Phys., 14, 9787–9805, 2014
Atmos. Chem. Phys., 15, 2519-2519, doi:10.5194/acp-15-2519-2015, 2015
A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques
Summary: Seventeen ice nucleation measurement techniques contributed to investigate the immersion freezing behavior of illite NX. All data showed a similar temperature trend, but the measured ice nucleation activity was on average smaller for the wet suspended samples and higher for the dry-dispersed aerosol samples at high temperatures. A continued investigation and collaboration is necessary to obtain further insights into consistency or diversity of ice nucleation measurements.
Atmos. Chem. Phys., 15, 2489-2518, doi:10.5194/acp-15-2489-2015, 2015
Corrigendum to "Seasonal and interannual variations of HCN amounts in the upper troposphere and lower stratosphere observed by MIPAS" published in Atmos. Chem. Phys., 15, 563–582, 2015
Atmos. Chem. Phys., 15, 2487-2488, doi:10.5194/acp-15-2487-2015, 2015
Aerosol properties over the western Mediterranean basin: temporal and spatial variability
Summary: High aerosol loads over Alborán were mainly associated with desert dust transport and occasional advection from central European urban-industrial areas. The fine particle load observed over Alborán was surprisingly similar to that obtained over the other three nearest AERONET stations, suggesting homogeneous spatial distribution of fine particle loads over the four studied sites in spite of the large differences in local sources.
Atmos. Chem. Phys., 15, 2473-2486, doi:10.5194/acp-15-2473-2015, 2015
First quasi-Lagrangian in situ measurements of Antarctic Polar springtime ozone: observed ozone loss rates from the Concordiasi long-duration balloon campaign
Summary: Ozone measurements onboard three Concordiasi balloons flown in the stratosphere in the Antarctic spring of 2010 are presented. These measurements are the first long-duration in situ measurements of Antarctic springtime stratospheric ozone. By matching air parcels, ozone loss rates where derived. Downwind of the Antarctic Peninsula, very large ozone losses of up to 230 ppb per day or 16 ppbv per sunlit hour were observed. These high rates are consistent with almost complete chlorine activation.
Atmos. Chem. Phys., 15, 2463-2472, doi:10.5194/acp-15-2463-2015, 2015
Variability of mixed-phase clouds in the Arctic with a focus on the Svalbard region: a study based on spaceborne active remote sensing
Summary: The study presents a characterization of the vertical, spatial and seasonal variability of Arctic clouds and mixed-phase clouds (MPCs) over the entire Arctic region. MPC properties in the region of the Svalbard archipelago (78°N, 15°E) are also investigated. The occurrence frequency of clouds and MPCs are determined from CALIPSO/CLOUDSAT measurements processed with the DARDAR retrieval algorithm which allows for a reliable cloud thermodynamic phase classification.
Atmos. Chem. Phys., 15, 2445-2461, doi:10.5194/acp-15-2445-2015, 2015
Investigating a two-component model of solid fuel organic aerosol in London: processes, PM1 contributions, and seasonality
Summary: Two solid fuel organic aerosol (SFOA) factors, both associated with domestic space heating activities, were derived from positive matrix factorisation (PMF) applied to organic aerosol data from an aerosol mass spectrometer (AMS) deployed at an urban background site in London during winter 2012. The factors controlling the split between the two SFOA factors were assessed, and it is concluded the split is likely governed predominantly by differences in burn conditions.
Atmos. Chem. Phys., 15, 2429-2443, doi:10.5194/acp-15-2429-2015, 2015
Estimating sources of elemental and organic carbon and their temporal emission patterns using a least squares inverse model and hourly measurements from the St. Louis–Midwest supersite
Summary: Elemental carbon and organic carbon are components of fine particulate matter that are harmful to health. We use computer simulations of wind patterns and pollution dispersion to analyze a year-long time series of hourly measurements made at the St. Louis-Midwest supersite. The inverse method produced improved estimates of emissions of these pollutants by different types of sources such as on-road and off-road emissions and open burning.
Atmos. Chem. Phys., 15, 2405-2427, doi:10.5194/acp-15-2405-2015, 2015
Simulating aerosol–radiation–cloud feedbacks on meteorology and air quality over eastern China under severe haze conditionsin winter
Atmos. Chem. Phys., 15, 2387-2404, doi:10.5194/acp-15-2387-2015, 2015
Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012
Summary: Ambient concentrations of trace elements with 2h time resolution were measured in three size ranges (PM10–2.5, PM2.5–1.0, PM1.0–0.3) at kerbside, urban background and rural sites in London during the ClearfLo (Clean Air for London) field campaign. Quantification of kerb and urban increments, and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure.
Atmos. Chem. Phys., 15, 2367-2386, doi:10.5194/acp-15-2367-2015, 2015
Ensemble simulations of the role of the stratosphere in the attribution of northern extratropical tropospheric ozone variability
Summary: Using a series of model simulations, we find that at widespread NH extratropical locations, interannual tropospheric ozone variability is largely determined by the transport of ozone from the stratosphere. This has implications in the interpretation of measured tropospheric ozone variability in light of changes in the emissions of ozone precursors and in the response of tropospheric ozone to climate change.
Atmos. Chem. Phys., 15, 2341-2365, doi:10.5194/acp-15-2341-2015, 2015
Oxidant production from source-oriented particulate matter – Part 1: Oxidative potential using the dithiothreitol (DTT) assay
Summary: We measured the oxidative potential of airborne particles – a property that has been linked to health problems caused by particles – from different emission source mixtures in Fresno, CA. Copper was responsible for the majority of the oxidative potential (as measured by the DTT assay), followed by unknown species (likely organics) and manganese. Sources of copper-rich particles, including vehicles, had higher oxidative potentials.
Atmos. Chem. Phys., 15, 2327-2340, doi:10.5194/acp-15-2327-2015, 2015
Persistent after-effects of heavy rain on concentrations of ice nuclei and rainfall suggest a biological cause
Summary: We show that atmospheric load of ice nuclei is enhanced for up to 20 days after key rainfall events. The rate of enhancement decreases exponentially with time. Rainfall quantity and frequency are increased for a similar duration and with similar exponential decreases thereby supporting the notion of rainfall feedback. We reveal series of significant feedback in rainfall patterns across Australia over the past century and marked changes in feedback patterns, and we indicate their locations.
Atmos. Chem. Phys., 15, 2313-2326, doi:10.5194/acp-15-2313-2015, 2015
A new model for the global biogeochemical cycle of carbonyl sulfide – Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model
Atmos. Chem. Phys., 15, 2295-2312, doi:10.5194/acp-15-2295-2015, 2015
Copernicus stratospheric ozone service, 2009–2012: validation, system intercomparison and roles of input data sets
Summary: We validate and discuss the analyses of stratospheric ozone delivered in near-real time between 2009 and 2012 by four different data assimilation systems: IFS-MOZART, BASCOE, SACADA and TM3DAM. It is shown that the characteristics of the assimilation systems are much less important than those of the assimilated data sets. A correct representation of the vertical distribution of ozone requires satellite observations which are well resolved vertically and extend into the lowermost stratosphere.
Atmos. Chem. Phys., 15, 2269-2293, doi:10.5194/acp-15-2269-2015, 2015
Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation
Summary: We use modeled estimates of BVOCs from the years 1000 to 2000 to test the effect of anthropogenic BVOC emission changes on SOA formation, aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS model. Changes of >25% in the number of particles with diameters >80nm are predicted regionally due to extensive land-use changes, leading to increases in combined radiative effect of >0.5 Wm-2. This change in radiative forcing could be an overlooked anthropogenic effect on climate.
Atmos. Chem. Phys., 15, 2247-2268, doi:10.5194/acp-15-2247-2015, 2015
Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models
Summary: Seven tropospheric species (CO, HCN, C2H6, C2H2, CH3OH, HCOOH, and H2CO) released by biomass burning events transported to the high Arctic were monitored with two sets of FTIR measurements, located at Eureka (Nunavut, Canada) and Thule (Greenland), from 2008 to 2012. We compared these data sets with the MOZART-4 chemical transport model to help improve its simulations in the Arctic. Emission factors of these biomass burning products were derived and compared to the literature.
Atmos. Chem. Phys., 15, 2227-2246, doi:10.5194/acp-15-2227-2015, 2015
Corrigendum to "Use of a global model to understand speciated atmospheric mercury observations at five high-elevation sites" published in Atmos. Chem. Phys., 15, 1161–1173, 2015
Atmos. Chem. Phys., 15, 2225-2225, doi:10.5194/acp-15-2225-2015, 2015
A negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine
Atmos. Chem. Phys., 15, 2215-2224, doi:10.5194/acp-15-2215-2015, 2015
Northern Hemisphere stratospheric winds in higher midlatitudes: longitudinal distribution and long-term trends
Summary: The main goal of this paper is to show the geographical distribution of meridional wind for several reanalyses and to analyse the wind trends in different areas. We show two areas (100°E-160°E and 140°W-80°W) where the meridional wind is as strong as zonal wind (which is normally dominant in the stratosphere). The trends of meridional wind are significant mostly at 99% level in these areas and insignificant outside. The problem with zonal averages could affect the results.
Atmos. Chem. Phys., 15, 2203-2213, doi:10.5194/acp-15-2203-2015, 2015
Real-case simulations of aerosol–cloud interactions in ship tracks over the Bay of Biscay
Summary: For the first time, real-case simulations of ship tracks are performed at the 2km scale and evaluated against observations. Simulations show that ship tracks are quantitatively and qualitatively captured by the model. Therefore, this approach could be used to evaluate the interplay between parameterisations for aerosol–cloud interactions which occur, in the case of ship tracks, in spatially defined regions and under constrained environmental conditions.
Atmos. Chem. Phys., 15, 2185-2201, doi:10.5194/acp-15-2185-2015, 2015
The impacts of firework burning at the Chinese Spring Festival on air quality: insights of tracers, source evolution and aging processes
Atmos. Chem. Phys., 15, 2167-2184, doi:10.5194/acp-15-2167-2015, 2015
Comparing turbulent parameters obtained from LITOS and radiosonde measurements
Summary: Stratospheric turbulence is essential for the atmospheric energy budget. We compare in situ observations with our LITOS method based on spectral analysis of mm-scale wind fluctuations with the Thorpe method applied to standard radiosondes. Energy dissipations rates from both methods differ by up to 3 orders of magnitude. Nevertheless, mean values are in good agreement. We present case studies on both methods and examine the applicability of the Thorpe method for calculation of dissipation rates.
Atmos. Chem. Phys., 15, 2159-2166, doi:10.5194/acp-15-2159-2015, 2015
Receptor modelling of fine particles in southern England using CMB including comparison with AMS-PMF factors
Summary: Breathing particles from polluted air is known to cause increased health complaints and higher death rates. Airborne particles come from a range of sources; in order to implement cost-effective control measures, it is necessary to understand the amount contributed by each. In this paper, two advanced procedures for estimating the contributions of particle sources in London are compared with one another, revealing a wide range of sources including traffic, woodsmoke and cooking particles.
Atmos. Chem. Phys., 15, 2139-2158, doi:10.5194/acp-15-2139-2015, 2015
Dependence of the vertical distribution of bromine monoxide in the lower troposphere on meteorological factors such as wind speed and stability
Summary: We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.
Atmos. Chem. Phys., 15, 2119-2137, doi:10.5194/acp-15-2119-2015, 2015
Characterization of road freight transportation and its impact on the national emission inventory in China
Atmos. Chem. Phys., 15, 2105-2118, doi:10.5194/acp-15-2105-2015, 2015
Estimating surface fluxes using eddy covariance and numerical ogive optimization
Atmos. Chem. Phys., 15, 2081-2103, doi:10.5194/acp-15-2081-2015, 2015