In the scope of the AQMEII Phase 1 project the GEM-AQ model was run over Europe for the year 2006 with a resolution of 0.2 × 0.2 degrees. Spatial distribution and temporal variability of the GEM-AQ model results were analyzed for surface ozone and PM₁₀ concentrations in the context of regional climate characteristics. The GEM-AQ model performance was characterized for station types, European climatic regions, and seasons.

Atmospheric mineral dust from a MACC-II short reanalysis (2007-2008) has been evaluated over northern Africa and the Middle East using satellite aerosol products, AERONET data, in situ PM10 concentrations, and extinction vertical profiles. The MACC-II AOD spatial and temporal variability shows good agreement with satellite sensors and AERONET. We find a good agreement in averaged extinction vertical profiles between MACC-II and lidars. MACC correctly reproduces daily to interannual PM10.

Health- and vegetation-relevant ozone exposure metrics (SOMO10/SOMO35 and PODY/AOT40 respectively) are analysed between 1990 and 2013 using data from the UK EMEP supersites: Auchencorth Moss, southern Scotland and Harwell, south-east England. Analysis shows that for health-relevant ozone exposure, improvement has been achieved for SOMO35 but not for SOMO10 despite European mitigation strategies reducing precursor emissions. Vegetation impacts based on PODY have also not decreased.

This work describes an analysis of measurements of the influence of water uptake on the light-scattering properties of sub- and supermicron-sized particles as observed in the Sacramento, CA, USA region during the 2010 CARES field campaign. The observations are used to derive campaign-average effective hygroscopicity parameters for submicron oxygenated organic aerosol and for supermicron particles, and the influence of chloride displacement reactions on particle hygroscopicity is examined.

The manuscript provides insights into the calculation of new particle formation rates. Generally, formation rates are measured at a diameter which can be substantially larger than the critical size of the newly formed particles. In order to transform the formation rate to a smaller size, a correction needs to be applied. We present a new method to apply this correction which takes into account the effect of self-coagulation.

This paper describes the atmospheric modeling that underlies the science analysis for the NASA Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). Summary statistics of the WRF meteorological model performance on a 3.3 km grid indicate good overall agreement with surface and radiosonde observations. The high quality of the WRF meteorological fields inspires confidence in their use to drive the STILT transport model for the purpose of computing surface influence fields (“footprints”).

In this work, size distributions and chemical compositions of 36 PM metals emitted from traffic emissions are explored by tunnel experiments. Potential sources of tunnel PM are also identified. Importantly, fingerprinting ratios of wear debris and automotive catalysts are established. The ratios will be good tools for apportioning PM sources in the polluted urban atmosphere.

A green light sensor has been developed at KNMI to measure actinic flux profiles together with an ozonesonde. The impact of clouds on the actinic flux is clearly detected. Good agreement is found between the DAK-simulated actinic flux profiles and the observations for single-layer clouds in fully overcast scenes. The instrument is suitable for operational balloon measurements because of its simplicity and low cost.

Our study shows, based on data from three atmospheric pressure interface time-of-flight mass spectrometers measuring in parallel charged and neutral molecules and molecular clusters, how oxidised organic compounds bind to inorganic ions (e.g. bisulfate, nitrate, ammonium). This ionisation is selective for compounds with lower molar mass due to their limited amount and variety of functional groups. We also found that extremely low volatile organic compounds (ELVOCs) can be formed immediately.

This study presents an original method to evaluate the aerosol optical thickness, the single scattering albedo and the cloud optical thickness for aerosol above cloud scenes. It is based on multi-angle total and polarized radiances both provided by the A-train satellite instrument POLDER/PARASOL. This algorithm has been applied together with a radiative transfer code over the South East Atlantic Ocean. The mean direct radiative effect for August and September 2006 is found to be 33.5W.m−2.

We present an experimental protocol to constrain the nature of organic vapor--wall deposition in Teflon chambers and develop an empirical model to predict the wall-induced deposition rate of intermediate/semi/non-volatility organic vapors in chambers.

While global stratospheric O3 has begun to recover, there are localized regions where O3 has decreased since 1991. O3 in the mid-stratosphere is very sensitive to nitrogen chemistry, with increased NOy resulting in decreased O3. We show how the observed O3 changes in the tropical mid-stratosphere can be caused by long-term variations in dynamics. These variations result in a decrease in N2O, an increase in NOy, and a resulting decrease in O3.

We have observed the formation of colored organic surface films on solutions of propanal and sulfuric acid at acidities chosen to mimic the highly acidic aerosols in the upper troposphere and lower stratosphere. The films were found to be composed of aldol condensation products and polyacetals. If such species also form coatings on atmospheric aerosols, they could impact climate by changing the chemical, optical and cloud-forming properties of aerosols.

A decadal aerosol climatology of South Africa's major metropolitan areas is presented, utilizing data from multiple satellite platforms and 19 ground-monitoring sites. Remotely sensed data are dominated by a seasonal signal corresponding to transported biomass burning during austral spring, while ground data are dominated by domestic burning in low-income areas during austral winter. We report poor agreement between satellite- and ground-based aerosol measurements.

By using an online coupled meteorology and aerosol/chemistry model (WRF-Chem), the increase of surface PM2.5 concentration is estimated to be up to 30% during a severe fog--haze event (10--15 January 2013) over North China Plain owing to the aerosol-induced decreased surface temperature, wind speed and atmosphere boundary layer height, increased surface relative humidity, and more stable atmosphere. A mechanism of positive feedback exists and contributes to the formation of fog--haze events.

China’s atmospheric Hg emissions of anthropogenic origin have been effectively restrained through the national policy of air pollution control. Expansion of technologies with high energy efficiencies and air pollutant removal rates leads to a much slower growth of Hg emissions than that of energy and economy. However, increased uncertainties of Hg emissions are quantified from 2005 to 2012, attributed to the unclear operation status or small sample size of field tests on those technologies.

By performing source-apportionment modeling, the amount of primary and secondary organic emissions was resolved from a bulk aerosol data set measured adjacent to a major highway in France. Over 70% of vehicles on this highway were diesel, and a high concentration of BC and NOx were measured. Even close to a major highway, the bulk of the aerosol mass was secondary in nature. Radiocarbon data revealed that most of the fossil organic carbon was from primary vehicular emissions and not from SOA.

Dust is a significant aerosol on seasonal timescales. There are large differences in dust and INP concentrations between seasons. The INP concentrations have a different vertical distribution than other common parameterisations suggest. We provide a new formulation to estimate the INP particles formed on dust aerosols, for use in process studies and regional simulations over Europe. The new formulation captures a much more realistic seasonal variability and vertical profile.