Drivers of the tropospheric ozone budget throughout the 21st century under the medium-high climate scenario RCP 6.0
Summary: We have examined the effects of ozone precursor emissions and climate change on the tropospheric ozone budget. Under RCP 6.0, ozone in the future is governed primarily by changes in nitrogen oxides (NOx). Methane is also important, and induces an increase in tropospheric ozone that is approximately one-third of that caused by NOx. This study highlights the critical role that emission policies globally have to play in determining tropospheric ozone evolution through the 21st century.
Atmos. Chem. Phys., 15, 5887-5902, doi:10.5194/acp-15-5887-2015, 2015
Turbulent structure and scaling of the inertial subrange in a stratocumulus-topped boundary layer observed by a Doppler lidar
Atmos. Chem. Phys., 15, 5873-5885, doi:10.5194/acp-15-5873-2015, 2015
Large eddy simulation of ship tracks in the collapsed marine boundary layer: a case study from the Monterey area ship track experiment
Atmos. Chem. Phys., 15, 5851-5871, doi:10.5194/acp-15-5851-2015, 2015
Wind extraction potential from ensemble Kalman filter assimilation of stratospheric ozone using a global shallow water model
Summary: While direct wind observations are routinely made in the troposphere (0-10km), in the stratosphere (above 10km) wind observations are sparse. This study examines the potential of using ozone observations to infer stratospheric wind. This novel approach is tested with a data assimilation system based on a simplified model of the atmosphere, the so-called "shallow water model". It is shown that assimilation of ozone observations significantly benefits winds, particularly in the tropics.
Atmos. Chem. Phys., 15, 5835-5850, doi:10.5194/acp-15-5835-2015, 2015
Ocean mediation of tropospheric response to reflecting and absorbing aerosols
Summary: Strong solar heating by absorbing aerosols (black carbon) is considered more effective in inducing atmospheric circulation change than reflecting aerosols (sulfate), which do not have direct atmospheric heating effect. Surprisingly, we show that reflecting aerosols induce tropospheric temperature and circulation response similar to that induced by absorbing aerosols. The common response is mediated by the ocean through SST gradient, a process overlooked so far in aerosol-climate connection.
Atmos. Chem. Phys., 15, 5827-5833, doi:10.5194/acp-15-5827-2015, 2015
Quantifying contributions to the recent temperature variability in the tropical tropopause layer
Atmos. Chem. Phys., 15, 5815-5826, doi:10.5194/acp-15-5815-2015, 2015
Modeling study of PM2.5 pollutant transport across cities in China's Jing–Jin–Ji region during a severe haze episode in December 2013
Atmos. Chem. Phys., 15, 5803-5814, doi:10.5194/acp-15-5803-2015, 2015
Modeling the formation and aging of secondary organic aerosols in Los Angeles during CalNex 2010
Summary: (1) Four different parameterizations for the formation and chemical evolution of secondary organic aerosol (SOA) are evaluated using a box model representing the Los Angeles region during the CalNex campaign. (2) The SOA formed only from the oxidation of VOCs is insufficient to explain the observed SOA concentrations. (3) The amount of SOA mass formed from diesel vehicle emissions is estimated to be 16-27%. (4) Modeled SOA depends strongly on the P-S/IVOC volatility distribution.
Atmos. Chem. Phys., 15, 5773-5801, doi:10.5194/acp-15-5773-2015, 2015
Diurnal variations of aerosol optical properties in the North China Plain and their influences on the estimates of direct aerosol radiative effect
Summary: In this paper, it is found that the diurnal variations of single scattering albedo (SSA) and asymmetry factor (g) for ambient aerosol are both evident and far different from those of dry state aerosol in the North China Plain (NCP. The diurnal changes of SSA and g have significant impacts on the estimation of daily average direct aerosol radiative effect (DARE) at the top of the atmosphere. In addition, several suggestions are proposed to improve the accurate prediction of DARE in the NCP.
Atmos. Chem. Phys., 15, 5761-5772, doi:10.5194/acp-15-5761-2015, 2015
Using the OMI aerosol index and absorption aerosol optical depth to evaluate the NASA MERRA Aerosol Reanalysis
Summary: MERRAero is an aerosol reanalysis based on the GEOS-5 earth system model that incorporates an online aerosol module and assimilation of AOD from MODIS sensors. This study assesses the quality of MERRAero absorption using independent OMI observations. In addition to comparisons to OMI absorption AOD, we have developed a radiative transfer interface to simulate the UV aerosol index from assimilated aerosol fields at OMI footprint. Also, we fully diagnose the model using MISR, AERONET and CALIPSO.
Atmos. Chem. Phys., 15, 5743-5760, doi:10.5194/acp-15-5743-2015, 2015
Photochemical aging of volatile organic compounds associated with oil and natural gas extraction in the Uintah Basin, UT, during a wintertime ozone formation event
Summary: Extraction of natural gas and oil is associated with a range of possible atmospheric environmental issues. Here we present an analysis of gas-phase hydrocarbon measurements taken in an oil and natural gas extraction area in Utah during a period of high wintertime ozone. We are able to constrain important chemical parameters related to emission sources and rates, hydrocarbon photochemistry, and VOC composition.
Atmos. Chem. Phys., 15, 5727-5741, doi:10.5194/acp-15-5727-2015, 2015
Long-term (2001–2012) concentrations of fine particulate matter (PM2.5) and the impact on human health in Beijing, China
Summary: The present study uses aerosol optical depth as proxy to estimate 12 years of PM2.5 data for the Beijing central area and calculate the yearly premature mortality by different diseases attributable to PM2.5. The estimated average total mortality due to PM2.5 is about 5100 individuals/year for the period 2001--2012 in the Beijing central area, and the per capita mortality for all ages due to PM2.5 is around 15 per 10,000 person-years for the period 2010--2012.
Atmos. Chem. Phys., 15, 5715-5725, doi:10.5194/acp-15-5715-2015, 2015
Measuring and modeling mercury in the atmosphere: a critical review
Summary: The Minamata Convention for mercury (Hg) has been signed by many nations and the primary objective is to protect human health and the environment from releases of Hg. A key challenge researchers is developing linkages between Hg in the atmosphere, deposition, and ecosystem contamination. Here we critically review where the science on measuring and modeling atmospheric Hg stands and offer suggestions for future research that will both advance understanding of Hg cycling and serve the convention.
Atmos. Chem. Phys., 15, 5697-5713, doi:10.5194/acp-15-5697-2015, 2015
Molecular composition of fresh and aged secondary organic aerosol from a mixture of biogenic volatile compounds: a high-resolution mass spectrometry study
Atmos. Chem. Phys., 15, 5683-5695, doi:10.5194/acp-15-5683-2015, 2015
OClO and BrO observations in the volcanic plume of Mt. Etna – implications on the chemistry of chlorine and bromine species in volcanic plumes
Atmos. Chem. Phys., 15, 5659-5681, doi:10.5194/acp-15-5659-2015, 2015
Precipitation effects of giant cloud condensation nuclei artificially introduced into stratocumulus clouds
Summary: To study the effect of giant cloud condensation nuclei (GCCN) on precipitation processes in stratocumulus clouds, 1-10 µm diameter salt particles were released from an aircraft while flying near the cloud top off the central coast of California. The analyses suggest that GCCN result in a four-fold increase in the cloud base rainfall rate and depletion of the cloud water due to rainout.
Atmos. Chem. Phys., 15, 5645-5658, doi:10.5194/acp-15-5645-2015, 2015
Development of a custom OMI NO2 data product for evaluating biases in a regional chemistry transport model
Summary: Regional NO2 distributions can be simulated by models or retrieved from satellite observations. We developed a custom OMI NO2 data product for the Pearl River delta region which reduces biases compared to the standard product. The product is used for the evaluation of a regional air quality model for which it is a useful addition to ground measurements. The unbiased NO2 data product can be very helpful for air pollution studies in urban areas.
Atmos. Chem. Phys., 15, 5627-5644, doi:10.5194/acp-15-5627-2015, 2015
Evaluation of a regional air quality model using satellite column NO2: treatment of observation errors and model boundary conditions and emissions
Atmos. Chem. Phys., 15, 5611-5626, doi:10.5194/acp-15-5611-2015, 2015
Iodine observed in new particle formation events in the Arctic atmosphere during ACCACIA
Summary: New particle formation (NPF) is an important contributor to aerosol number concentrations in the Arctic and thus has a major role in dictating cloud properties and climate in this region. Here we present direct evidence that the oxidation of iodine in the atmosphere causes NPF in the Greenland Sea. This is important because this is a NPF mechanism that has not previously been considered in modelling studies at these latitudes.
Atmos. Chem. Phys., 15, 5599-5609, doi:10.5194/acp-15-5599-2015, 2015
Compilation and evaluation of gas phase diffusion coefficients of reactive trace gases in the atmosphere: Volume 2. Diffusivities of organic compounds, pressure-normalised mean free paths, and average Knudsen numbers for gas uptake calculations
Atmos. Chem. Phys., 15, 5585-5598, doi:10.5194/acp-15-5585-2015, 2015
Quasi-biennial oscillation of the tropical stratospheric aerosol layer
Atmos. Chem. Phys., 15, 5557-5584, doi:10.5194/acp-15-5557-2015, 2015
Simulation of the isotopic composition of stratospheric water vapour – Part 1: Description and evaluation of the EMAC model
Atmos. Chem. Phys., 15, 5537-5555, doi:10.5194/acp-15-5537-2015, 2015
AOD trends during 2001–2010 from observations and model simulations
Summary: Thanks to numerical simulations and satellite observations, it is shown that aerosol optical depth (AOD) trends (2000--2010 period) over the US and Europe are due to emission decrease, while over the Sahara Desert and the Middle East they are due to meteorological changes. Over Southeast Asia, both meteorology and emission changes are important for the AOD trends. It is shown that soluble components strongly influence AOD, as their contribution is enhanced by the aerosol water content.
Atmos. Chem. Phys., 15, 5521-5535, doi:10.5194/acp-15-5521-2015, 2015
Impacts of emission reductions on aerosol radiative effects
Summary: The global aerosol--climate model ECHAM-HAMMOZ is used to study the aerosol burden and forcing changes in the coming decades. We show that aerosol burdens overall can have a decreasing trend leading to reductions in the direct aerosol effect being globally 0.06--0.4W/m2 by 2030, whereas the aerosol indirect radiative effect could decline 0.25--0.82W/m2. We also show that the targeted emission reduction measures can be a much better choice for the climate than overall high reductions globally.
Atmos. Chem. Phys., 15, 5501-5519, doi:10.5194/acp-15-5501-2015, 2015
Profiles of second- to fourth-order moments of turbulent temperature fluctuations in the convective boundary layer: first measurements with rotational Raman lidar
Summary: The exchange of energy between the Earth surface and the atmosphere is governed by turbulent processes which form the convective boundary layer (CBL) in daytime. The representation of the CBL in atmospheric models is critical, e.g., for the simulation of clouds and precipitation. We show that a new active remote-sensing technique, rotational Raman lidar, characterizes the turbulent temperature fluctuations in the CBL better than previous techniques and discuss the statistics of a typical case.
Atmos. Chem. Phys., 15, 5485-5500, doi:10.5194/acp-15-5485-2015, 2015
A novel methodology for large-scale daily assessment of the direct radiative forcing of smoke aerosols
Summary: A new methodology was developed for retrieving the daily direct radiative forcing of smoke aerosols (24h-DARF) using satellite remote sensing. This method was used to assess the DARF at high temporal resolution and over a large area in Amazonia. We showed that our methodology considerably reduces statistical sources of uncertainties in the estimate of the DARF. DARF assessments using the new methodology agree well with ground-based measurements and radiative transfer models.
Atmos. Chem. Phys., 15, 5471-5483, doi:10.5194/acp-15-5471-2015, 2015
Free amino acids in Antarctic aerosol: potential markers for the evolution and fate of marine aerosol
Atmos. Chem. Phys., 15, 5457-5469, doi:10.5194/acp-15-5457-2015, 2015
Assessment of China's virtual air pollution transport embodied in trade by using a consumption-based emission inventory
Atmos. Chem. Phys., 15, 5443-5456, doi:10.5194/acp-15-5443-2015, 2015
One year of Raman lidar observations of free-tropospheric aerosol layers over South Africa
Summary: In this study we summarize 1 year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps in the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type are available for this region. For the first time, we have been able to cover the full seasonal cycle on geometrical characteristics and optical properties of free tropospheric aerosol layers in the region.
Atmos. Chem. Phys., 15, 5429-5442, doi:10.5194/acp-15-5429-2015, 2015
Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)
Summary: We examine differences in the surface BC between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identify dominant sources of BC in South Asia during ICARB. Anthropogenic emissions were the main source of BC during ICARB and had about 5 times stronger influence on the BoB compared to the AS. Regional-scale transport contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions.
Atmos. Chem. Phys., 15, 5415-5428, doi:10.5194/acp-15-5415-2015, 2015
A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains
Summary: This paper investigates 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (CAM4/CLM4) with a 0.23°×0.31° resolution for simulations over 6 years. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations.
Atmos. Chem. Phys., 15, 5405-5413, doi:10.5194/acp-15-5405-2015, 2015
Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013
Summary: Sudden stratospheric warmings (SSWs) cause a rapid rise in lower stratospheric temperatures, terminating conditions favorable to chemical ozone loss. We show that although temperatures rose precipitously during the vortex split SSW in early Jan 2013, because the offspring vortices each remained isolated and in regions that received sunlight, chemical ozone loss continued for over 1 month after the SSW. Dec/Jan Arctic ozone loss was larger than any previously observed during that period.
Atmos. Chem. Phys., 15, 5381-5403, doi:10.5194/acp-15-5381-2015, 2015
General introduction to the DAMOCLES special issue
Atmos. Chem. Phys., 15, 5377-5379, doi:10.5194/acp-15-5377-2015, 2015
Mercury vapor air–surface exchange measured by collocated micrometeorological and enclosure methods – Part II: Bias and uncertainty analysis
Summary: Bias and uncertainty in Hg flux measured by micrometeorological methods (MM) and dynamic flux chambers (DFCs) are assessed from two field inter-comparison campaigns. DFC flux bias follows a diurnal cycle due to modified temperature and radiation balance inside the chamber. The precision in concentration difference measurements poses critical constraint on obtaining a larger fraction of significant MM flux. Asynchronous sampling impairs flux accuracy under varying atmospheric Hg concentration.
Atmos. Chem. Phys., 15, 5359-5376, doi:10.5194/acp-15-5359-2015, 2015
Data assimilation in atmospheric chemistry models: current status and future prospects for coupled chemistry meteorology models
Summary: Data assimilation is used in atmospheric chemistry models to improve air quality forecasts, construct re-analyses of concentrations, and perform inverse modeling. Coupled chemistry meteorology models (CCMM) are atmospheric chemistry models that simulate meteorological processes and chemical transformations jointly. We review here the current status of data assimilation in atmospheric chemistry models, with a particular focus on future prospects for data assimilation in CCMM.
Atmos. Chem. Phys., 15, 5325-5358, doi:10.5194/acp-15-5325-2015, 2015
CFD modeling of a vehicle exhaust laboratory sampling system: sulfur-driven nucleation and growth in diluting diesel exhaust
Summary: This article presents a new model that simulates particle formation in vehicle exhaust. The model is used to examine particle dynamics, such as nucleation, inside a diesel exhaust laboratory sampling system. The results suggest lower slope of nucleation rate versus sulfuric acid concentration than previously found.
Atmos. Chem. Phys., 15, 5305-5323, doi:10.5194/acp-15-5305-2015, 2015
Data assimilation of satellite-retrieved ozone, carbon monoxide and nitrogen dioxide with ECMWF's Composition-IFS
Summary: The paper presents results from data assimilation studies with the new Composition-IFS model developed in the MACC project. This system was used in MACC to produce daily analyses and 5-day forecasts of atmospheric composition and is now run daily in the EU’s Copernicus Atmosphere Monitoring Service. The paper looks at the quality of the CO, O3 and NO2 analysis fields obtained with this system, comparing them against observations, a control run and an older version of the model.
Atmos. Chem. Phys., 15, 5275-5303, doi:10.5194/acp-15-5275-2015, 2015
Greenhouse gas emissions from laboratory-scale fires in wildland fuels depend on fire spread mode and phase of combustion
Summary: By undertaking greenhouse gas emissions measurements (plus CO) in a combustion wind tunnel facility, we show that emissions from fire depend on how they spread relative to the wind. Statistically significant differences include fires spreading with the wind emitting twice as much CO as fires spreading perpendicular to or against the wind, and about 10-17% more carbon dioxide. Our results suggest that judicious use of ignition patterns could mitigate carbon emissions from forest fires.
Atmos. Chem. Phys., 15, 5259-5273, doi:10.5194/acp-15-5259-2015, 2015
Gas and aerosol carbon in California: comparison of measurements and model predictions in Pasadena and Bakersfield
Summary: This work details the evaluation of PM2.5 carbon, VOC precursors, and OH estimated by the CMAQ photochemical transport model using routine and special measurements from the 2010 CalNex field study. Here, CMAQ and most recent emissions inventory (2011 NEI) are used to generate model PM2.5 OC estimates that are examined in novel ways including primary vs. secondary formation, fossil vs. contemporary carbon, OH and HO2 evaluation, and the relationship between key VOC precursors and SOC tracers.
Atmos. Chem. Phys., 15, 5243-5258, doi:10.5194/acp-15-5243-2015, 2015
Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling
Summary: Measurements of SO2, NOx and particle emission factors of more than 400 individual ship passages in the Gulf of Finland are presented and discussed. The measurements were conducted during two campaigns in the years 2011 and 2012 from ground-based and helicopter-based platforms. It was found that a significant number of ships use fuel oil with a fuel sulfur content below the limit of 1%. Additionally, the results of modeled data for the same ships were compared to the measurements of this study.
Atmos. Chem. Phys., 15, 5229-5241, doi:10.5194/acp-15-5229-2015, 2015
Fine-particle water and pH in the southeastern United States
Summary: Particle pH can affect many aerosol processes, including gas-particle partitioning, SOA formation, and mobilization of toxic redox metals. pH is challenging to directly measure and often improperly characterized by proxies like ion balances or molar ratios of measured aerosol ionic species. We present a detailed analysis predicting pH with a thermodynamic model, verify the prediction, and test pH sensitivity to model inputs based on data from the SOAS field campaign.
Atmos. Chem. Phys., 15, 5211-5228, doi:10.5194/acp-15-5211-2015, 2015
Ice nucleation by combustion ash particles at conditions relevant to mixed-phase clouds
Summary: Combustion ash particles nucleate ice in the immersion mode at conditions relevant to mixed-phase clouds. Hence, combustion ashes could play an important role in primary ice formation in mixed-phase clouds, especially in clouds that are formed near the emission source of these aerosol particles. From this study, there is a need to quantify the atmospheric abundance of combustion ashes in order to quantitatively assess the impact of combustion ashes on mixed-phase clouds.
Atmos. Chem. Phys., 15, 5195-5210, doi:10.5194/acp-15-5195-2015, 2015
Characterization of thermal structure and conditions for overshooting of tropical and extratropical cyclones with GPS radio occultation
Atmos. Chem. Phys., 15, 5181-5193, doi:10.5194/acp-15-5181-2015, 2015
Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis
Summary: High ozone concentrations (up to 94.7ppbv) were frequently observed at an altitude of ~1.5--2km over Beijing during April--May 2005. Ozone due to Asian anthropogenic pollution made major contributions to the observed ozone enhancements. These enhancements typically occurred under southerly wind and warmer conditions. An earlier onset of the Asian summer monsoon would cause more ozone enhancement events in the lower troposphere over the North China Plain in late spring and early summer.
Atmos. Chem. Phys., 15, 5161-5179, doi:10.5194/acp-15-5161-2015, 2015
Relative humidity-dependent viscosities of isoprene-derived secondary organic material and atmospheric implications for isoprene-dominant forests
Atmos. Chem. Phys., 15, 5145-5159, doi:10.5194/acp-15-5145-2015, 2015
Influence of isoprene chemical mechanism on modelled changes in tropospheric ozone due to climate and land use over the 21st century
Atmos. Chem. Phys., 15, 5123-5143, doi:10.5194/acp-15-5123-2015, 2015
Ozone distributions over southern Lake Michigan: comparisons between ferry-based observations, shoreline-based DOAS observations and model forecasts
Summary: This study examines ozone mixing ratios over Lake Michigan as measured on the Lake Express ferry, by shoreline differential optical absorption spectroscopy (DOAS) observations in southeastern Wisconsin, and as predicted by the Community Multiscale Air Quality (CMAQ) model. Over water, ozone was determined to be an average of 3.8ppb higher than shoreline observations but overpredicted by the CMAQ model by as much as 11-16ppb midday.
Atmos. Chem. Phys., 15, 5109-5122, doi:10.5194/acp-15-5109-2015, 2015
Signatures of the 2-day wave and sudden stratospheric warmings in Arctic water vapour observed by ground-based microwave radiometry
Atmos. Chem. Phys., 15, 5099-5108, doi:10.5194/acp-15-5099-2015, 2015
Airborne determination of the temporo-spatial distribution of benzene, toluene, nitrogen oxides and ozone in the boundary layer across Greater London, UK
Summary: This paper presents the first highly spatially resolved simultaneous mixing ratios of VOCs, NOx and O3 in the atmospheric boundary layer above Greater London (UK) using an research aircraft. Average mixing ratios measured at 360±10 m agl over outer London were always lower than over inner London, indicative of strong local vehicular sources. The comparison of airborne mixing ratio with LAQN air quality ground monitoring stations suggests that the mixing ratios were characteristic of the surface.
Atmos. Chem. Phys., 15, 5083-5097, doi:10.5194/acp-15-5083-2015, 2015
Chemical composition and size distribution of summertime PM2.5 at a high altitude remote location in the northeast of the Qinghai–Xizang (Tibet) Plateau: insights into aerosol sources and processing in free troposphere
Atmos. Chem. Phys., 15, 5069-5081, doi:10.5194/acp-15-5069-2015, 2015
Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory: a case study with a long-range transported biomass burning plume
Summary: Aerosol was sampled at the Pico Mountain Observatory located at 2.2km amsl on Pico Island of the North Atlantic Azores archipelago. Two aerosol samples characterized by ultrahigh resolution mass spectrometry had biomass burning and marine emissions origins, as corroborated by collocated gas- and particle-phase measurements, air masses analyses and satellites. The paper presents the first molecular characterization of aged and processed aerosol intercepted at a remote lower free troposphere
Atmos. Chem. Phys., 15, 5047-5068, doi:10.5194/acp-15-5047-2015, 2015
Influence of particle-phase state on the hygroscopic behavior of mixed organic–inorganic aerosols
Atmos. Chem. Phys., 15, 5027-5045, doi:10.5194/acp-15-5027-2015, 2015
Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)
Summary: In June 2013, a ground-based mobile lidar performed the 10,000km ride from Paris to Ulan-Ude, near Lake Baikal. Aerosols have been characterized using two intensive properties: extinction-to-backscatter ratio and particle depolarization ratio. The results highlight spatial variations in the aerosol mix, with more terrigenous particles over Russia than Europe. Wildfire and desert dust plumes were also observed, offering the first optical characterization of dust from the Caspian–Aral region.
Atmos. Chem. Phys., 15, 5007-5026, doi:10.5194/acp-15-5007-2015, 2015
Observations of planetary waves in the mesosphere-lower thermosphere during stratospheric warming events
Summary: Planetary wave activity measured in the mesosphere to lower thermosphere is shown to increase drastically after strong stratospheric polar cap wind reversals associated with sudden stratospheric warmings. In addition, a moderate but significant correlation was found between planetary wave enhancement in the mesosphere to lower thermosphere and all stratospheric polar cap wind reversals, irrespective of the strength of the reversal.
Atmos. Chem. Phys., 15, 4997-5005, doi:10.5194/acp-15-4997-2015, 2015
Characterization of satellite-based proxies for estimating nucleation mode particles over South Africa
Atmos. Chem. Phys., 15, 4983-4996, doi:10.5194/acp-15-4983-2015, 2015
Compilation of Henry's law constants (version 4.0) for water as solvent
Atmos. Chem. Phys., 15, 4399-4981, doi:10.5194/acp-15-4399-2015, 2015
Seasonal variability of Saharan desert dust and ice nucleating particles over Europe
Summary: 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.
Atmos. Chem. Phys., 15, 4389-4397, doi:10.5194/acp-15-4389-2015, 2015
Near-highway aerosol and gas-phase measurements in a high-diesel environment
Summary: 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.
Atmos. Chem. Phys., 15, 4373-4387, doi:10.5194/acp-15-4373-2015, 2015
Impact of isoprene and HONO chemistry on ozone and OVOC formation in a semirural South Korean forest
Atmos. Chem. Phys., 15, 4357-4371, doi:10.5194/acp-15-4357-2015, 2015
Quantifying pyroconvective injection heights using observations of fire energy: sensitivity of spaceborne observations of carbon monoxide
Atmos. Chem. Phys., 15, 4339-4355, doi:10.5194/acp-15-4339-2015, 2015
Evaluating the effects of China's pollution controls on inter-annual trends and uncertainties of atmospheric mercury emissions
Summary: 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.
Atmos. Chem. Phys., 15, 4317-4337, doi:10.5194/acp-15-4317-2015, 2015
Hydroxy nitrate production in the OH-initiated oxidation of alkenes
Atmos. Chem. Phys., 15, 4297-4316, doi:10.5194/acp-15-4297-2015, 2015