Secondary Organic Aerosol (SOA) formation from the β-pinene + NO3 system: effect of humidity and peroxy radical fate
Summary: Laboratory chamber studies were conducted to investigate the formation of secondary organic aerosol from β-pinene oxidation by nitrate radicals. These experiments probed the effects of peroxy radical fate and relative humidity on the mass and chemical composition of secondary organic aerosol formed from nighttime chemistry. Results from this study were used to evaluate the contributions of NO3+monoterpene reaction to ambient organic aerosol recently measured in the southeastern United States.
Multi-model simulation of CO and HCHO in the Southern Hemisphere: biogenic emissions and model uncertainties
Summary: We assess the impact of biogenic emissions on CO and HCHO in the Southern Hemisphere (SH), with simulations using different emission inventories. Differences in biogenic emissions result in large differences on modelled CO in the source and the remote regions. Substantial inter-model differences exist. Models significantly underestimate observed HCHO columns in the SH, suggesting missing sources in the models. Differences in the CO/OH/CH4 chemistry lead to differences in HCHO in remote regions.
G. Zeng, J. E. Williams, J. A. Fisher, L. K. Emmons, N. B. Jones, O. Morgenstern, J. Robinson, D. Smale, C. Paton-Walsh, and D. W. T. Griffith Atmos. Chem. Phys. Discuss., 15, 2615-2678, 2015 AbstractDiscussion Paper (PDF, 6581 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
27 Jan 2015
An ecosystem-scale perspective of the net land methanol flux: synthesis of micrometeorological flux measurements
Summary: Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of plants as the major source and the reaction with OH as the major sink, global methanol budgets diverge considerably in terms of source/sink estimates. Here we present micrometeorological methanol flux data from eight 8 sites in order to provide a first cross-site synthesis of the terrestrial methanol exchange.
G. Wohlfahrt, C. Amelynck, C. Ammann, A. Arneth, I. Bamberger, A. H. Goldstein, L. Gu, A. Guenther, A. Hansel, B. Heinesch, T. Holst, L. Hörtnagl, T. Karl, Q. Laffineur, A. Neftel, K. McKinney, J. W. Munger, S. G. Pallardy, G. W. Schade, R. Seco, and N. Schoon Atmos. Chem. Phys. Discuss., 15, 2577-2613, 2015 AbstractDiscussion Paper (PDF, 2317 KB)Supplement (570 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
27 Jan 2015
Stratosphere–troposphere exchange (STE) in the vicinity of North Atlantic cyclones
Summary: In this manuscript, we investigate the exchange of air masses across the dynamical tropopause (stratosphere-troposphere exchange, STE) in the vicinity of North Atlantic cyclones. By using two 6-hourly resolved ERA-Interim climatologies of STE and cyclones from 1979 to 2011, we are able to directly compute the amount of STE in the vicinity of every individual cyclone in this time period. This enables us to provide a robust and consistent quantification of STE near North Atlantic cyclones.
Assessment of crop yield losses in Punjab and Haryana using two years of continuous in-situ ozone measurements
Summary: We use ozone measurements at a suburban site in Punjab to estimated ozone related crop yield losses for wheat, rice, cotton and maize for the states Punjab and Haryana for the years 2011-2013. Crop production losses amount to 10.3-20.8 Mt y-1 for wheat & 3.2-5.4 Mt y-1 for rice enough to feed 225-437 million of India’s poor. The lower limit for the ozone related economic losses is 3.7-6.5 billion USD (Punjab & Haryana), while the upper limit amounts to 3.5%-20% of the Indian GDP (entire India).
Evolution of gaseous precursors and meteorological parameters during new particle formation events in the Central European boundary layer
Summary: This paper revisits the atmospheric new particle formation (NPF) process in the polluted troposphere. Novel aspects include a new NPF classification, which aims at more objectivity, and a long-term collection of Neutral Cluster and Air Ion Spectrometer data. Intense NPF events were associated with enhanced sulphur dioxide precursor concentrations while no exclusive correlations were observed with the condensation sink, surface-measured turbulence parameters or ammonia.
J. Größ, W. Birmili, A. Hamed, A. Sonntag, A. Wiedensohler, G. Spindler, H. E. Maninnen, T. Nieminen, M. Kulmala, U. Hõrrak, and C. Plass-Dülmer Atmos. Chem. Phys. Discuss., 15, 2305-2353, 2015 AbstractDiscussion Paper (PDF, 2592 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
23 Jan 2015
LIVAS: a 3-D multi-wavelength aerosol/cloud climatology based on CALIPSO and EARLINET
V. Amiridis, E. Marinou, A. Tsekeri, U. Wandinger, A. Schwarz, E. Giannakaki, R. Mamouri, P. Kokkalis, I. Binietoglou, S. Solomos, T. Herekakis, S. Kazadzis, E. Gerasopoulos, D. Balis, A. Papayannis, C. Kontoes, K. Kourtidis, N. Papagiannopoulos, L. Mona, G. Pappalardo, O. Le Rille, and A. Ansmann Atmos. Chem. Phys. Discuss., 15, 2247-2304, 2015 AbstractDiscussion Paper (PDF, 9642 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
23 Jan 2015
Uncertainties in isoprene photochemistry and emissions: implications for the oxidative capacity of past and present atmospheres and for trends in climate forcing agents
Summary: The atmosphere’s oxidative capacity determines the lifetime of many trace gases important to climate, chemistry, and human health. Yet uncertainties remain about its past variations, its controlling factors, and the radiative forcing of short-lived species it influences. To reduce these uncertainties, we must better quantify the natural emissions and chemical reaction mechanisms of organic compounds in the atmosphere, which play a role in governing the oxidative capacity.
P. Achakulwisut, L. J. Mickley, L. T. Murray, A. P. K. Tai, J. O. Kaplan, and B. Alexander Atmos. Chem. Phys. Discuss., 15, 2197-2246, 2015 AbstractDiscussion Paper (PDF, 573 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
23 Jan 2015
Temporal and spatial scaling impacts on extreme precipitation
A comparison of measured HONO uptake and release with calculated source strengths in a heterogeneous forest environment
Summary: We measured near surface (< 2 m) profiles of HONO in a clearing and on a forest floor. Both HONO deposition and emission were observed. By comparing three postulated sources to observed daytime emissions, we made several important findings: ● conversion of NO2 is mostly independent of light due to light saturation ● HONO emissions from a very acidic soil were low ● photolysis of adsorbed HNO3 could serve as HONO source based on empirical parameters but unlikely via the proposed reaction pathway
Separating refractory and non-refractory particulate chloride and estimating chloride depletion by aerosol mass spectrometry in a marine environment
Summary: In this paper, we focus on the measurement and reporting of mass concentrations of particulate chloride and sea salt in a marine area off the coast of California using a High Resolution Aerosol Mass Spectrometer. We outline a method of deconvolving the total aerosol chloride mass into refractory and non-refractory components, previously not reported in the literature. This can be important in regions where refractory sea salt aerosols can contribute to the aerosol chloride signal measured with t
I. Nuaaman, S.-M. Li, K. L. Hayden, T. B. Onasch, P. Massoli, D. Sueper, D. R. Worsnop, T. S. Bates, P. K. Quinn, and R. McLaren Atmos. Chem. Phys. Discuss., 15, 2085-2118, 2015 AbstractDiscussion Paper (PDF, 2905 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
22 Jan 2015
Understanding atmospheric peroxyformic acid chemistry: observation, modeling and implication
Summary: The present field measurements have provided strong evidence for the existence of peroxyformic acid (HC(O)OOH) in the atmosphere for the first time. Moreover, the potential impact of peroxyformic acid chemistry on the formic acid production and the radical budget has been evaluated on the basis of model calculations. Our findings are of importance for a full understanding of the cycling of oxidants and the source of organic acids in the atmosphere.
Elevated uptake of CO2 over Europe inferred from GOSAT XCO2 retrievals: a real phenomenon or an artefact of the analysis?
Summary: There is an on-going debate on the larger European biospheric uptake inferred from GOSAT XCO2 retrievals than those inferred from in situ data. Using a set of 15 experiments, we found that the elevated uptake over Europe could largely be explained by mis-fitting data due to regional XCO2 biases: 50-80% of the elevated European uptake is due to retrievals outside the immediate European; and a varying monthly bias of upto 0.5 ppm for XCO2 retrievals over Europe could explain most of the remainder.
L. Feng, P. I. Palmer, R. J. Parker, N. M. Deutscher, D. G. Feist, R. Kivi, I. Morino, and R. Sussmann Atmos. Chem. Phys. Discuss., 15, 1989-2011, 2015 AbstractDiscussion Paper (PDF, 339 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
21 Jan 2015
Observations and analysis of organic aerosol evolution in some prescribed fire smoke plumes
Summary: Smoke plumes from some prescribed fires in the Southeastern United States were sampled via aircraft to observe changes in organic aerosol (OA) with atmospheric transport. These plumes underwent rapid mixing, and hence, substantial dilution with background air occurred. Dilution-driven evaporation appears to be the primary driver of OA transformations within the sampled plumes rather than photochemistry.
A. A. May, T. Lee, G. R. McMeeking, S. Akagi, A. P. Sullivan, S. Urbanski, R. J. Yokelson, and S. M. Kreidenweis Atmos. Chem. Phys. Discuss., 15, 1953-1988, 2015 AbstractDiscussion Paper (PDF, 682 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
21 Jan 2015
On the ability of a global atmospheric inversion to constrain variations of CO2 fluxes over Amazonia
L. Molina, G. Broquet, P. Imbach, F. Chevallier, B. Poulter, D. Bonal, B. Burban, M. Ramonet, L. V. Gatti, S. C. Wofsy, J. W. Munger, E. Dlugokencky, and P. Ciais Atmos. Chem. Phys. Discuss., 15, 1915-1952, 2015 AbstractDiscussion Paper (PDF, 3066 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACPSpecial Issue
21 Jan 2015
Trends and drivers of ozone human health and vegetation impact metrics from UK EMEP supersite measurements (1990–2013)
Summary: Health and vegetation relevant ozone exposure metrics (SOMO10/SOMO35 and PODY/AOT40 respectively) are analysed between 1990-2013 using data from the UK EMEP supersites: Auchencorth Moss, southern Scotland and Harwell, south-east England. Analysis shows 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.
Effects of global change during the 21st century on the nitrogen cycle
D. Fowler, C. E. Steadman, D. Stevenson, M. Coyle, R. M. Rees, U. M. Skiba, M. A. Sutton, J. N. Cape, A. J. Dore, M. Vieno, D. Simpson, S. Zaehle, B. D. Stocker, M. Rinaldi, M. C. Facchini, C. R. Flechard, E. Nemitz, M. Twigg, J. W. Erisman, and J. N. Galloway Atmos. Chem. Phys. Discuss., 15, 1747-1868, 2015 AbstractDiscussion Paper (PDF, 3689 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACPSpecial Issue
20 Jan 2015
Deuterium excess in atmospheric water vapor of a Mediterranean coastal wetland: regional versus local signatures
Summary: Based on summer measurements of δ18O and δD in atmospheric vapor of a Mediterranean coastal wetland, this paper explores the main drivers of isotopic signal variability at different time scales. The daily time scale is related to regional air mass trajectories, while diurnal variations are discussed with regards to the contribution of local evapotranspiration to the water budget of the Planetary Boundary Layer.
Mapping gas-phase organic reactivity and concomitant secondary organic aerosol formation: chemometric dimension reduction techniques for the deconvolution of complex atmospheric datasets
Summary: This paper describes a new ensemble methodology for the statistical analysis of atmospheric gas- & particle-phase composition data sets. The methodology reduces the huge amount of data derived from many chamber experiments to show that organic reactivity & resultant particle formation can be mapped into unique clusters in statistical space. The model generated is used to map more realistic plant mesocosm oxidation data, the projection of which gives insight into reactive pathways & precursors.
K. P. Wyche, P. S. Monks, K. L. Smallbone, J. F. Hamilton, M. R. Alfarra, A. R. Rickard, G. B. McFiggans, M. E. Jenkin, W. J. Bloss, A. C. Ryan, C. N Hewitt, and A. R MacKenzie Atmos. Chem. Phys. Discuss., 15, 1651-1702, 2015 AbstractDiscussion Paper (PDF, 4972 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
20 Jan 2015
An objective determination of optimal site locations for detecting expected trends in upper-air temperature and total column ozone
Summary: This manuscript aims to answer the following question: Which of the existing sites engaged in upper-air temperature measurements are best located to detect expected future trends within the shortest time possible. To do so, we explore one objective method for selecting the optimal locations for detecting projected 21st century trends and then demonstrate a similar technique for objectively selecting optimal locations for detecting expected future trends in total column ozone.
Ice phase in altocumulus clouds over Leipzig: remote sensing observations and detailed modelling
Summary: The paper combines remote sensing observations and detailed cloud modeling. It was shown that the main features of the observations could be captured which allows to perform sensitivity studies. Those show that the liquid phase is mainly determined by the dynamical parameters of the model whereas the ice phase is dominated by microphysical parameters such as ice nuclei number and ice particle shape.
The climatology of dust aerosol over the arabian peninsula
Summary: Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. AERONET, MODIS, MISR, OMI datasets have been analyzed to study atmospheric dust over Arabia also a 13 years simulation has been performed to study the dust climatology. The study showed how dust aerosol climatology changes from northern Arabia to southern Arabia and how this may impact the region climatology.
Evaluation of the GEM-AQ model in the context of the AQMEII Phase 1 project
Summary: In the scope of the AQMEII Phase 1 project the GEM-AQ model was run over Europe with the resolution of 0.2ox0.2o, for the year 2006. Spatial distribution and temporal variability of the GEM-AQ model results were analysed for surface ozone and PM10 concentrations in the context of regional climate characteristics. The GEM-AQ model performance was characterised for station types, European climatic regions, and seasons.
J. Struzewska, M. Zdunek, J. W. Kaminski, L. Lobocki, M. Porebska, M. Jefimow, and L. Gawuc Atmos. Chem. Phys. Discuss., 15, 1471-1522, 2015 AbstractDiscussion Paper (PDF, 11666 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
19 Jan 2015
Observations and simulations of three-dimensional radiative interactions between Arctic boundary layer clouds and ice floes
Deposition and immersion mode nucleation of ice by three distinct samples of volcanic ash using Raman spectroscopy
Summary: Fine volcanic ash can influence cloud glaciation and, therefore, global climate. In this work we examined the heterogeneous ice nucleation properties of three distinct types of volcanic ash. We find that, in contrast to previous studies, these volcanic ash samples have different ice nucleation properties in the immersion mode. In the deposition mode, however, they nucleate ice with similar efficiency. We show that this behavior may be due to their mineralogy.
One year of Raman lidar observations of free tropospheric aerosol layers over South Africa
Summary: In this study we summarize one year of Raman lidar observations over South Africa. The analyses of lidar measurements presented here could assist in bridging existing gaps on the knowledge of vertical distribution of aerosols above South Africa, since limited long-term data of this type is 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.
E. Giannakaki, A. Pfüller, K. Korhonen, T. Mielonen, L. Laakso, V. Vakkari, H. Baars, R. Engelmann, J. P. Beukes, P. G. Van Zyl, M. Josipovic, P. Tiitta, K. Chiloane, S. Piketh, H. Lihavainen, K. E. J. Lehtinen, and M. Komppula Atmos. Chem. Phys. Discuss., 15, 1343-1384, 2015 AbstractDiscussion Paper (PDF, 2322 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
16 Jan 2015
Insights into the chemical composition of summertime PM2.5 at the northeast of the Qinghai-Xizang (Tibet) Plateau
Free amino acids in Antarctic aerosol: potential markers for the evolution and fate of marine aerosol
E. Barbaro, R. Zangrando, M. Vecchiato, R. Piazza, W. R. L. Cairns, G. Capodaglio, C. Barbante, and A. Gambaro Atmos. Chem. Phys. Discuss., 15, 1269-1305, 2015 AbstractDiscussion Paper (PDF, 3072 KB)Supplement (110761 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
15 Jan 2015
Step changes in persistent organic pollutants over the Arctic and their implications
Summary: After several decades declining of persistent organic pollutants in the arctic environment due to their global use restriction, some of these toxic chemicals increased in the mid-2000s and undertook statistically significant step changes which coincided with arctic sea ice melting. Results provide statistical evidence for the releasing of toxic chemicals from their reservoirs in the Arctic due to the rapid change in the arctic environment.
Lidar observations of Nabro volcano aerosol layers in the stratosphere over Gwangju, Korea
Summary: We present for the first time results of Raman lidar observations of the temporal evolution of a stratospheric aerosol layer observed in the upper troposphere and lower stratosphere over Korea. We find what non-spherical particles may have been present in the lower stratosphere for at least six months after the eruption on the volcano. Our study adds to the limited information on volcanic aerosols over East Asia.
D. Shin, D. Müller, K. Lee, S. Shin, Y. J. Kim, C. K. Song, and Y. M. Noh Atmos. Chem. Phys. Discuss., 15, 1171-1191, 2015 AbstractDiscussion Paper (PDF, 3925 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
14 Jan 2015
Relative humidity-dependent viscosities of isoprene-derived secondary organic material and atmospheric implications for isoprene-dominant forests
Modeling the feedback between aerosol and meteorological variables in the atmospheric boundary layer during a severe fog-haze event over the North China Plain
Summary: By using a online coupled meteorology and aerosol/chemistry model (WRF-Chem), the increase of surface PM2.5 concentration is estimated up to be 30% during a severe fog-haze event (10~15 January 2013) over North China Plain owing to the aerosol-induced decrease surface temperature, wind speed and atmosphere boundary layer height, increase surface relative humidity, and more stable atmosphere. A mechanism of positive feedback exists and contributes to the formation of fog-haze events.
The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS)
Summary: This study examines the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection to a deep convective system, using the WRF model. Passive tracers are initialised to study the impact of the deep convection on the tracers and water vapour. We use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.
W. Frey, R. Schofield, P. Hoor, D. Kunkel, F. Ravegnani, A. Ulanovsky, S. Viciani, F. D'Amato, and T. P. Lane Atmos. Chem. Phys. Discuss., 15, 1041-1091, 2015 AbstractDiscussion Paper (PDF, 7449 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
14 Jan 2015
Technical Note: A novel parameterization of the transmissivity due to ozone absorption in the k-distribution method and correlated-k approximation of Kato et al. (1999) over the UV band
Summary: A novel model of the absorption of radiation by ozone in the UV bands [283, 307] nm and [307, 328] nm yields improvements in the modelling of the transmissivity in these bands. This model is faster than detailed spectral calculations and is as accurate with maximum error of respectively 0.0006 and 0.0041. How to practically implement this new parameterization in a radiative transfer model is discussed for the case of libRadtran.
W. Wandji Nyamsi, A. Arola, P. Blanc, A. V. Lindfors, V. Cesnulyte, M. R. A. Pitkänen, and L. Wald Atmos. Chem. Phys. Discuss., 15, 1027-1040, 2015 AbstractDiscussion Paper (PDF, 1588 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
13 Jan 2015
Balancing aggregation and smoothing errors in inverse models
Chemical characterization of submicron regional background aerosols in the Western Mediterranean using an Aerosol Chemical Speciation Monitor
Summary: The study focuses on the aerosol variations taking place in the regional background of the Western Mediterranean Basin and their relation with atmospheric conditions and scenarios. An Aerosol Chemical Speciation Monitor (ACSM) was deployed for one year and the results were validated with co-located PM1 measurements. The organic sources were investigated and the local secondary organic aerosol (SOA) formation was estimated.
Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada
Summary: Aerosols impact how clouds and precipitation form. In the California Sierra Nevada, we found that the formation and resulting amount of rain and snow were impacted by mineral dust, bioparticles such as bacteria, and biomass burning and pollution particles during three winter seasons. Dust and bioparticles from distant sources impacted high altitude clouds by forming ice, leading to more precipitation, whereas local biomass burning and pollution entered the base of clouds leading to less rain.
J. M. Creamean, A. P. Ault, A. B. White, P. J. Neiman, F. M. Ralph, P. Minnis, and K. A. Prather Atmos. Chem. Phys. Discuss., 15, 931-964, 2015 AbstractDiscussion Paper (PDF, 3456 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
12 Jan 2015
Investigating the discrepancy between wet-suspension and dry-dispersion derived ice nucleation efficiency of mineral particles
Quantifying methane and nitrous oxide emissions from the UK using a dense monitoring network
Summary: The UK is one of several countries to enact legislation to reduce greenhouse gas emissions. We present top-down emissions of methane and nitrous oxide for the UK and Ireland. We inferred average UK emissions of 2.08 Tg/yr CH4 and 0.105 Tg/yr N2O and used sectoral distributions to determine whether these discrepancies can be attributed to specific source sectors. We found the agricultural sector likely to be overestimated in the bottom-up emissions inventory of both gases.
A. L. Ganesan, A. J. Manning, A. Grant, D. Young, D. E. Oram, W. T. Sturges, J. B. Moncrieff, and S. O'Doherty Atmos. Chem. Phys. Discuss., 15, 857-886, 2015 AbstractDiscussion Paper (PDF, 873 KB)Supplement (2090 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
09 Jan 2015
Comment on "Observation and modelling of HOx radicals in a boreal forest" by Hens et al. (2014)
Impacts of an unknown daytime nitrous acid source on its daytime concentration and budget, as well as those of hydroxyl, hydroperoxyl, and organic peroxy radicals, in the coastal regions of China
Summary: High daytime HONO mixing ratios in field experiments suggest that an unknown daytime HONO source (Punknown) could exist.Punknown≈19.60×NO2×J(NO2) was obtained using observed data from 13 field experiments across the globe,then coupled into the WRF-Chem model. Simulations indicated that elevated Punknown were found in the coastal regions of China; the additional HONO sources,especially the Punknown produced significant increases of radicals in the major cities,and accelerated the radical cycles.
A modified micrometeorological gradient method for estimating O3 dry deposition over a forest canopy
Summary: In this study, we have developed a modified micrometeorological gradient method (MGM), although based on existing micrometeorological theory, to estimate O3 dry deposition fluxes over a forest canopy using concentration gradients between a level above and a level below the canopy top. The new method provides an alternative approach in monitoring/estimating long-term deposition fluxes of similar pollutants over tall canopies and is expected to be useful for the scientific community.
Estimating NH3 emissions from agricultural fertilizer application in China using the bi-directional CMAQ model coupled to an agro-ecosystem model
Summary: In this study, we estimate, for the first time, the NH3 emission from the agricultural fertilizer application in China online using the bi-directional CMAQ model coupled to an agro-ecosystem model. Compared with previous researches, this method considers more influencing factors, such as meteorological fields, soil and the fertilizer application, and provides improved NH3 emission with higher spatial and temporal resolution.
Particulate matter, air quality and climate: lessons learned and future needs
Summary: Particulate matter (PM) constitutes one of the most challenging problems both for air quality and climate change policies. This paper reviews the most recent scientific results on the issue, and the policy needs that have driven much of the increase in monitoring and mechanistic research over the last two decades. The synthesis reveals many new processes and developments in the science underpinning climate-PM interactions and effects of PM on human health and the environment.
S. Fuzzi, U. Baltensperger, K. Carslaw, S. Decesari, H. Denier van der Gon, M. C. Facchini, D. Fowler, I. Koren, B. Langford, U. Lohmann, E. Nemitz, S. Pandis, I. Riipinen, Y. Rudich, M. Schaap, J. Slowik, D. V. Spracklen, E. Vignati, M. Wild, M. Williams, and S. Gilardoni Atmos. Chem. Phys. Discuss., 15, 521-744, 2015 AbstractDiscussion Paper (PDF, 5565 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACPSpecial Issue
08 Jan 2015
Drivers of the tropospheric ozone budget throughout the 21st century under the medium-high climate scenario RCP 6.0
L. E. Revell, F. Tummon, A. Stenke, T. Sukhodolov, A. Coulon, E. Rozanov, H. Garny, V. Grewe, and T. Peter Atmos. Chem. Phys. Discuss., 15, 481-519, 2015 AbstractDiscussion Paper (PDF, 2760 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
07 Jan 2015
The decrease in mid-stratospheric tropical ozone since 1991
Summary: 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 which result in a decrease in N2O, an increase in NOy, and a resulting decrease in O3.
Observations of PW activity in the MLT during SSW events using a chain of SuperDARN radars and SD-WACCM
Summary: Planetary wave activity measured in the mesosphere 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 lower thermosphere and all stratospheric polar cap wind reversals, irrespective of the strength of the reversal.
N. H. Stray, Y. J. Orsolini, P. J. Espy, V. Limpasuvan, and R. E. Hibbins Atmos. Chem. Phys. Discuss., 15, 393-413, 2015 AbstractDiscussion Paper (PDF, 1150 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
07 Jan 2015
Signatures of the two day wave and sudden stratospheric warmings in Arctic water vapour observed by ground-based microwave radiometry
Diurnal variations of aerosol optical properties in the North China Plain and their influences on the estimates of direct aerosol radiative forcing
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 forcing (DARF) at the top of the atmosphere. In addition, several suggestions are proposed to improve the accurate prediction of DARF in the NCP.
Enhanced extinction of visible radiation due to hydrated aerosols in mist and fog
T. Elias, J.-C. Dupont, E. Hammer, C. R. Hoyle, M. Haeffelin, F. Burnet, and D. Jolivet Atmos. Chem. Phys. Discuss., 15, 291-337, 2015 AbstractDiscussion Paper (PDF, 1390 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
07 Jan 2015
Advances in understanding mineral dust and boundary layer processes over the Sahara from Fennec aircraft observations
Summary: Measurements of the Saharan atmosphere and of atmospheric mineral dust are lacking but are vital for understanding the climate of this region and its impacts further afield. Novel observations were made by the Fennec climate program during June 2011 and 2012 using ground-based, remote sensing and airborne platforms. Here we describe the airborne observations and the contributions they have made to furthering our understanding of the Saharan climate system.
C. L. Ryder, J. B. McQuaid, C. Flamant, R. Washington, H. E. Brindley, E. J. Highwood, J. H. Marsham, D. J. Parker, M. C. Todd, J. R. Banks, J. K. Brooke, S. Engelstaedter, V. Estellés, P. Formenti, L. Garcia-Carreras, C. Kocha, F. Marenco, P. Rosenberg, H. Sodemann, C. J. T. Allen, A. Bourdon, M. Bart, C. Cavazos-Guerra, S. Chevaillier, J. Crosier, E. Darbyshire, A. R. Dean, J. R. Dorsey, J. Kent, D. O'Sullivan, K. Schepanski, K. Szpek, and A. Woolley Atmos. Chem. Phys. Discuss., 15, 199-290, 2015 AbstractDiscussion Paper (PDF, 6462 KB)Supplement (706 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
07 Jan 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 relationship between key VOC precursors and SOC tracers.
K. R. Baker, A. G. Carlton, T. E. Kleindienst, J. H. Offenberg, M. R. Beaver, D. R. Gentner, A. H. Goldstein, P. L. Hayes, J. L. Jimenez, J. B. Gilman, J. A. de Gouw, M. C. Woody, H. O. T. Pye, J. T. Kelly, M. Lewandowski, M. Jaoui, P. S. Stevens, W. H. Brune, Y.-H. Lin, C. L. Rubitschun, and J. D. Surratt Atmos. Chem. Phys. Discuss., 15, 157-198, 2015 AbstractDiscussion Paper (PDF, 2360 KB)Supplement (4067 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
07 Jan 2015
High spatial resolution aerosol retrievals used for daily particulate matter monitoring over Po valley, northern Italy
Summary: The manuscript compares 10km Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5.1 and new 1 km Multi-Angle Implementation of Atmospheric Correction (MAIAC) Aerosol Optical Depth (AOD) retrievals to small (<10 micron) particulate matter (PM10) surface measurements from monitoring stations within the Po Valley in Northern Italy during 2012. When the depth of the planetary boundary layer (PBL) is used to normalize the AOD, we find PM – AOD correlations of 0.98 for both retrievals.
B. Arvani, R. B. Pierce, A. I. Lyapustin, Y. Wang, G. Ghermandi, and S. Teggi Atmos. Chem. Phys. Discuss., 15, 123-155, 2015 AbstractDiscussion Paper (PDF, 3305 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
07 Jan 2015
Quantifying sources, transport, deposition and radiative forcing of black carbon over the Himalayas and Tibetan Plateau
Summary: We use the CAM5 model with a novel source tagging technique to characterize the fate of BC particles emitted from various geographical regions and sectors and their transport pathways to the Himalayas and Tibetan Plateau (HTP). We show a comprehensive picture of the seasonal and regional dependence of BC source attributions, and find strong seasonal and spatial variations of BC-in-snow radiative forcing in HTP that can be quantitatively attributed to the various regional and sectoral sources.
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 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.
E. Jung, B. A. Albrecht, H. H. Jonsson, Y.-C. Chen, J. H. Seinfeld, A. Sorooshian, A. R. Metcalf, S. Song, M. Fang, and L. M. Russell Atmos. Chem. Phys. Discuss., 15, 47-76, 2015 AbstractDiscussion Paper (PDF, 1085 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
07 Jan 2015
Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: the case of Antalya in 2008
Summary: We investigate the quality of fire emission estimates derived from SEVIRI FRP for air quality simulations with the Community Multiscale Air Quality (CMAQ) model, by comparing them with available MODIS FRP based ones.
We demonstrate that geostationary observations allow refining biomass burning emissions, which can subsequently be used in regional scale air quality models in order to improve the prediction of chemical composition of the atmosphere in presence of large fire episodes.
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 SSAs, their hygroscopic properties, aqueous phase chemistry, etc.
Black carbon reduction will weaken the aerosol net cooling effect
Summary: In this study, we estimate that the global annual mean aerosol net cooling effect at the TOA will be significantly weakened relative to present-day conditions if emissions of BC and co-emitted sulfur dioxide and organic carbon are simultaneously reduced to the level projected for 2100 in different ways, because there are no effective ways to remove the BC exclusively without influencing the other co-emitted components.
Characterization of the boundary layer at Dome C (East Antarctica) during the OPALE summer campaign
H. Gallée, S. Preunkert, S. Argentini, M. M. Frey, C. Genthon, B. Jourdain, I. Pietroni, G. Casasanta, H. Barral, E. Vignon, and M. Legrand Atmos. Chem. Phys. Discuss., 14, 33089-33116, 2014 AbstractDiscussion Paper (PDF, 433 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
23 Dec 2014
Isotopic effects of nitrate photochemistry in snow: a field study at Dome C, Antarctica
OH populations and temperatures from simultaneous spectroscopic observations of 25 bands
Summary: We discuss a high-quality data set of simultaneous observations of 25 OH bands with an astronomical echelle spectrograph. These data allowed us to analyse band-dependent OH populations and temperatures. In particular, we could find different non-LTE contributions to OH rotational temperatures depending on band, line set, and observing time. This is critical for mesopause studies that use these temperatures as a proxy of the true temperatures.
Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer
Summary: Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a by-product of the very oxidation chemistry it largely initiates. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models.
P. S. Monks, A. T. Archibald, A. Colette, O. Cooper, M. Coyle, R. Derwent, D. Fowler, C. Granier, K. S. Law, D. S. Stevenson, O. Tarasova, V. Thouret, E. von Schneidemesser, R. Sommariva, O. Wild, and M. L. Williams Atmos. Chem. Phys. Discuss., 14, 32709-32933, 2014 AbstractDiscussion Paper (PDF, 11503 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACPSpecial Issue
22 Dec 2014
The diurnal variation in stratospheric ozone from the MACC reanalysis, the ERA-Interim reanalysis, WACCM and Earth observation data: characteristics and intercomparison
Summary: The manuscript describes novel findings in the diurnal variation of stratospheric ozone by means of the MACC reanalysis, the ERA-Interim reanalysis and the WACCM model. The diurnal variation in ozone has dynamical and photochemical origins which lead to substantial amplitudes especially in the polar, stratospheric regions. The unprecedented, global view on diurnal ozone variation strengthens the implication to correct diurnally sampled satellite observations used for ozone trend estimates.
Lagrangian analysis of microphysical and chemical processes in the Antarctic stratosphere: a case study
Summary: We investigated chemical and microphysical processes in the late winter Antarctic stratosphere, for the first time (to our knowledge) coupling a detailed microphysical box model with a chemistry model.
Model results have been compared with in situ and remote sensing measurements of particles along trajectories.
Our goal is to contribute to the most recent discussion of the relative role of PSC and liquid (background) aerosol in the ozone depletion.
L. Di Liberto, R. Lehmann, I. Tritscher, F. Fierli, J. L. Mercer, M. Snels, G. Di Donfrancesco, T. Deshler, B. P. Luo, J-U. Grooß, E. Arnone, B. M. Dinelli, and F. Cairo Atmos. Chem. Phys. Discuss., 14, 32629-32665, 2014 AbstractDiscussion Paper (PDF, 4492 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP
22 Dec 2014
Origin of springtime ozone enhancements in the lower troposphere over Beijing: in situ measurements and model analysis
Summary: High ozone concentrations (up to 94.7 ppbv) were frequently observed at the 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.
J. Huang, H. Liu, J. H. Crawford, C. Chan, D. B. Considine, Y. Zhang, X. Zheng, C. Zhao, V. Thouret, S. J. Oltmans, S. C. Liu, D. B. A. Jones, S. D. Steenrod, and M. R. Damon Atmos. Chem. Phys. Discuss., 14, 32583-32627, 2014 AbstractDiscussion Paper (PDF, 1369 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
22 Dec 2014
Ash iron mobilization in volcanic eruption plumes
Summary: Iron released from volcanic ash can perturb the biogeochemical cycles in the ocean. But knowing the fact that the emitted ash from volcano contains insoluble iron, which processes solubilise the ash iron while it is airborne? To answer this question, a numerical model is developed in this study to simulate the gas-ash-aerosol interactions within the eruption plume. Results show that the dissolution of the ash mediated by halogen acids exert the key control on ash iron mobilisation.
Turbulence vertical structure of the boundary layer during the afternoon transition
Summary: A case study of the BLLAST experiment is considered to explore the decay of turbulence that occurs in the convective boundary layer over land during the afternoon. Based on observations and on a Large Eddy Simulation, the analysis reveals two phases in the afternoon: a first quasi-stationary phase when the turbulent kinetic energy slowly decays without significant change of the turbulence structure, and a second phase of more rapid decay with a change in spectral turbulence characteristics.
C. Darbieu, F. Lohou, M. Lothon, J. Vilà-Guerau de Arellano, F. Couvreux, P. Durand, D. Pino, E. G. Patton, E. Nilsson, E. Blay-Carreras, and B. Gioli Atmos. Chem. Phys. Discuss., 14, 32491-32533, 2014 AbstractDiscussion Paper (PDF, 1022 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
22 Dec 2014
Investigating the links between ozone and organic aerosol chemistry in a biomass burning plume from a prescribed fire in California chaparral
Summary: Being able to understand and simulate the chemical evolution of biomass burning smoke plumes under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use an improved model of this chemistry to simulate the evolution of O3 and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, which was sampled over California in November 2009.
M. J. Alvarado, C. R. Lonsdale, R. J. Yokelson, S. K. Akagi, H. Coe, J. S. Craven, E. V. Fischer, G. R. McMeeking, J. H. Seinfeld, T. Soni, J. W. Taylor, D. R. Weise, and C. E. Wold Atmos. Chem. Phys. Discuss., 14, 32427-32489, 2014 AbstractDiscussion Paper (PDF, 1856 KB)Supplement (67 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
21 Dec 2014
Climate extremes in multi-model simulations of stratospheric aerosol and marine cloud brightening climate engineering
Summary: Simulations conducted in the GeoMIP and IMPLICC model intercomparison studies for climate engineering by stratospheric sulfate injection and marine cloud brightening via sea salt are analysed and compared to the reference scenario RCP4.5 for 2020 - 2060. The focus is on extremes in surface temperature and precipitation. It is found that mostly the extreme changes follow the mean changes and that extremes are also in general well mitigated, except for polar regions.
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 Metropolitan 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%.
P. L. Hayes, A. G. Carlton, K. R. Baker, R. Ahmadov, R. A. Washenfelder, S. Alvarez, B. Rappenglück, J. B. Gilman, W. C. Kuster, J. A. de Gouw, P. Zotter, A. S. H. Prévôt, S. Szidat, T. E. Kleindienst, J. H. Offenberg, and J. L. Jimenez Atmos. Chem. Phys. Discuss., 14, 32325-32391, 2014 AbstractDiscussion Paper (PDF, 2055 KB)Supplement (1075 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
20 Dec 2014
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.
M. Bocquet, H. Elbern, H. Eskes, M. Hirtl, R. Žabkar, G. R. Carmichael, J. Flemming, A. Inness, M. Pagowski, J. L. Pérez Camaño, P. E. Saide, R. San Jose, M. Sofiev, J. Vira, A. Baklanov, C. Carnevale, G. Grell, and C. Seigneur Atmos. Chem. Phys. Discuss., 14, 32233-32323, 2014 AbstractDiscussion Paper (PDF, 6740 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
20 Dec 2014
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 assess 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 (AI) from assimilated aerosol fields at OMI footprint. Also, we fully diagnose the model using MISR, AERONET and CALIPSO
V. Buchard, A. M. da Silva, P. R. Colarco, A. Darmenov, C. A. Randles, R. Govindaraju, O. Torres, J. Campbell, and R. Spurr Atmos. Chem. Phys. Discuss., 14, 32177-32231, 2014 AbstractDiscussion Paper (PDF, 9370 KB)Supplement (4893 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
19 Dec 2014
Volatile organic compounds over Eastern Himalaya, India: temporal variation and source characterization using Positive Matrix Factorization
C. Sarkar, A. Chatterjee, D. Majumdar, S. K. Ghosh, A. Srivastava, and S. Raha Atmos. Chem. Phys. Discuss., 14, 32133-32175, 2014 AbstractDiscussion Paper (PDF, 2852 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
19 Dec 2014
A next generation sequencing of Arctic bacteria in snow and frost flowers: identification, abundance and freezing nucleation
Summary: Next Generation Sequencing revealed the existence of diverse community of bacteria in the Arctic samples with many originating from distinct ecological environments. The observed varied range in ice nucleation of cultivable bacteria and in the whole melted samples further revealed the existence of the heterogeneous pool of bacteria. Changes in the microbial pool and its impact on the freezing and melting process may potentially lead into changing the Arctic environment and thus global climate.
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 is captures a much more realistic seasonal variability and vertical profile.
Formaldehyde (HCHO) in air, snow and interstitial air at Concordia (East Antarctic plateau) in summer
Summary: During two austral summers HCHO was investigated in air, snow, and interstitial air at the Concordia site located on the East Antarctic plateau. Snow emission fluxes were estimated to be around 1 to 2 and 3 to 5 x 1012 molecules m-2 s-1 at night and at noon, respectively. Shading experiments suggest that the photochemical HCHO production in the snowpack at Concordia remains negligible. The mean HCHO level of 130 pptv observed at 1 m above the surface, is quite well reproduced by 1-D simulations.
Investigation of post-depositional processing of nitrate in East Antarctic snow: isotopic constraints on photolytic loss, re-oxidation, and source inputs
Summary: We evaluate isotopic composition of NO3- in different environments across East Antarctica. At high snow accumulation sites, isotopic ratios are suggestive of preservation of NO3- deposition. At low accumulation sites, isotopes are sensitive to both the loss of NO3- due to photolysis and secondary formation of NO3- within the snowpack. The imprint of post-depositional alteration is not uniform with depth, however, raising the possibility that additional NO3- chemistry occurs deeper in snowpack.
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 0.06-0.4 W/m2 by 2030, whereas the cloud radiative effect could decline 0.25-0.82 W/m2. We also show that the targeted emission reduction measures can be a much better choice for the climate than overall high reductions globally.
J.-P. Pietikäinen, K. Kupiainen, Z. Klimont, R. Makkonen, H. Korhonen, R. Karinkanta, A.-P. Hyvärinen, N. Karvosenoja, A. Laaksonen, H. Lihavainen, and V.-M. Kerminen Atmos. Chem. Phys. Discuss., 14, 31899-31942, 2014 AbstractDiscussion Paper (PDF, 4189 KB)Supplement (9278 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
17 Dec 2014
The effects of global change upon United States air quality
R. Gonzalez-Abraham, J. Avise, S. H. Chung, B. Lamb, E. P. Salathé Jr., C. G. Nolte, D. Loughlin, A. Guenther, C. Wiedinmyer, T. Duhl, Y. Zhang, and D. G. Streets Atmos. Chem. Phys. Discuss., 14, 31843-31897, 2014 AbstractDiscussion Paper (PDF, 6695 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP
17 Dec 2014
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air
Summary: Stratospheric ozone protects life on Earth from harmful UV-B radiation. Chlorofluorocarbons (CFCs) are man-made compounds which act to destroy this barrier.
This paper represents:
• The first measurements of the stratospheric δ(37Cl) of CFCs -11 and -113.
• The first quantification of long-term trends in the tropospheric δ(37Cl) of CFCs -11, -12 and -113.
This study provides a better understanding of source and sink processes associated with these destructive compounds.
S. J. Allin, J. C. Laube, E. Witrant, J. Kaiser, E. McKenna, P. Dennis, R. Mulvaney, E. Capron, P. Martinerie, T. Röckmann, T. Blunier, J. Schwander, P. J. Fraser, R. L. Langenfelds, and W. T. Sturges Atmos. Chem. Phys. Discuss., 14, 31813-31841, 2014 AbstractDiscussion Paper (PDF, 1149 KB)Supplement (272 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
17 Dec 2014
Spatial and temporal variation of CO over Alberta using measurements from satellite, aircrafts, and ground stations
Summary: This study demonstrated the potential use of MOPITT CO measurements to better understand the CO sources over Alberta.The climatological time curtain plot and spatial maps for CO over northern Alberta indicate the signatures of transported CO for two distinct biomass burning seasons, summer and spring.Northern Alberta shows stronger upward lifting motion which leads to larger CO total column values while the poor dispersion in central and south Alberta exacerbates the surface CO pollution.
Particulate emissions from residential wood combustion in Europe – revised estimates and an evaluation
Summary: Residential wood combustion (RWC) is increasing in Europe but may cause high emissions of particulate matter (PM). A new bottom-up emission inventory for RWC was made which included the semi-volatile components. The new RWC emissions are 2-3 times higher than the previous inventory. It significantly improved the modeling of PM and comparison with observations. Our results suggest primary PM2.5 emission from RWC as reported in Europe is underestimated and emission inventories need to be revised.
H. A. C. Denier van der Gon, R. Bergström, C. Fountoukis, C. Johansson, S. N. Pandis, D. Simpson, and A. Visschedijk Atmos. Chem. Phys. Discuss., 14, 31719-31765, 2014 AbstractDiscussion Paper (PDF, 4808 KB)Supplement (346 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
16 Dec 2014
Mesoscale modeling study of the interactions between aerosols and PBL meteorology during a haze episode in China Jing–Jin–Ji and its near surrounding region – Part 1: Aerosol distributions and meteorological features
Impact of planetary boundary layer turbulence on model climate and tracer transport
Summary: PBL processes are important for weather, climate, and tracer transport and concentration. In the GEOS-5 AGCM, the PBL depth is used in the calculation of turbulent mixing. This study analyzes the impact of using different PBL depth definitions in this calculation. Near surface wind speed differences modify Saharan dust on the order of 1e-4 kg m-2. CO surface concentrations are modified by up to 20 ppb over biomass burning regions. Instantaneous CO2 differences are on the order of 10 ppm.
A global model simulation for 3-D radiative transfer impact on surface hydrology over 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 Sierra Nevada using CCSM4 (CAM4/CLM4) global model with a 0.23°×0.31° resolution for simulations over 6 years. We show that deviations of 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.
Estimating CO2 emissions from point sources: a case study of an isolated power station
Summary: A methodology to estimate CO2 emissions from an isolated power plant
is presented and illustrated for a power station in South Australia. It involves measurement of in-situ and column-averaged CO2 near the power plant, forward modelling of the observed signals (using WRF-Chem) and inverse modelling to obtain an estimate of the power plant fluxes. Better simulation is obtained for column data giving better estimates of fluxes. Our estimated emissions are within 6% of the reported values.
S. R. Utembe, N. Jones, P. J. Rayner, I. Genkova, D. W. T. Griffith, D. M. O'Brien, C. Lunney, and A. J. Clark Atmos. Chem. Phys. Discuss., 14, 31551-31601, 2014 AbstractDiscussion Paper (PDF, 4414 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
15 Dec 2014
A novel methodology using MODIS and CERES for assessing the daily radiative forcing of smoke aerosols in large scale over the Amazonia
Summary: A new methodology was developed for obtaining daily retrievals of the direct radiative forcing of aerosols (24h-DARF) at the top of the atmosphere (TOA) using satellite remote sensing. There was a very good agreement between satellite remote sensing, ground-based and radiative transfer evaluated DARF, demonstrating the robustness of the new proposed methodology for calculated radiative forcing for biomass burning aerosols.
A comprehensive investigation on afternoon–evening transition of the atmospheric boundary layer over a tropical rural site
Summary: The afternoon-evening transition (AET) in the atmospheric boundary layer has been studied in an integrated approach using 3 years of tower, sodar and wind profiler measurements. Such a long-term dataset has been used for the first time to understand the behavior of AET. It allowed us to study the seasonal variation. In contrast to common belief that the transition evolves from bottom-to-top, the present study clearly brought out the start time of transition follows top-to-bottom evolution.
Aging of secondary organic aerosol from small aromatic VOCs: changes in chemical composition, mass yield, volatility and hygroscopicity
Summary: Secondary organic aerosol (SOA) is transformed after its initial formation. We explored the effects of this chemical aging on the composition, mass yield, volatility and hygroscopicity of SOA formed from the photo-oxidation of small aromatic volatile organic compounds. Higher exposure to the hydroxyl radical resulted in different SOA composition, average carbon oxidation state and mass yield, and the vapor pressure of SOA formed under different conditions varied by as much as a factor of 30.
Comparisons of polar processing diagnostics from 34 years of the ERA-Interim and MERRA reanalyses
Summary: We use a comprehensive set of diagnostics to investigate how two widely-used modern reanalysis datasets might affect studies of lower stratospheric polar processing and ozone loss. Our results show that the agreement in temperature diagnostics between the two reanalyses improves over time in both hemispheres with increasing assimilation model inputs. This suggests that both datasets are appropriate choices for studies of polar processing in recent winters.
Z. D. Lawrence, G. L. Manney, K. Minschwaner, M. L. Santee, and A. Lambert Atmos. Chem. Phys. Discuss., 14, 31361-31408, 2014 AbstractDiscussion Paper (PDF, 3930 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
12 Dec 2014
A chamber study of the influence of boreal BVOC emissions and sulphuric acid on nanoparticle formation rates at ambient concentrations
Summary: In this paper, we present the first direct laboratory observations of nanoparticle formation from sulphuric acid and realistic BVOC precursor vapor mixtures performed at atmospherically relevant concentration levels. We found that the formation rate was proportional to the product of sulphuric acid and biogenic VOC emission strength, and that the formation rates were consistent with a mechanism in which nucleating BVOC oxidation products are rapidly formed and activate with sulphuric acid.
M. Dal Maso, L. Liao, J. Wildt, A. Kiendler-Scharr, E. Kleist, R. Tillmann, M. Sipilä, J. Hakala, K. Lehtipalo, M. Ehn, V.-M. Kerminen, M. Kulmala, D. Worsnop, and T. Mentel Atmos. Chem. Phys. Discuss., 14, 31319-31360, 2014 AbstractDiscussion Paper (PDF, 1715 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACPSpecial Issue
11 Dec 2014
Atmospheric nitrogen oxides (NO and NO2) at Dome C, East Antarctica, during the OPALE campaign
Summary: Surprisingly large concentrations and flux of atmospheric nitrogen oxides were measured at Dome C, East Antarctica. It was found that the surface snow holds a significant reservoir of photochemically produced NOx and is a sink of gas phase ozone. Main drivers of NOx snow emissions were large snow nitrate concentrations, with contributions from increased UV from decreases in stratospheric ozone. Observed halogen and hydroxyl radical concentrations were too low to explain large NO2:NO ratios.
Energetic particle induced inter-annual 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.
T. Fytterer, M. G. Mlynczak, H. Nieder, K. Pérot, M. Sinnhuber, G. Stiller, and J. Urban Atmos. Chem. Phys. Discuss., 14, 31249-31279, 2014 AbstractDiscussion Paper (PDF, 2719 KB)Interactive Discussion (Open, 4 Comments)Manuscript under review for ACP
11 Dec 2014
Aerosol optical hygroscopicity measurements during the 2010 CARES Campaign
Summary: 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.
Dimensions and aspect ratios of natural ice crystals
Summary: Dimensions of ice crystals increased with an increase in temperature and the L-W relationships of crystals with a given L depended heavily on temperature, whereas the aspect ratio depended only weakly on temperature. The relative frequency of occurrence of plates was much larger in anvil clouds compared to that of columnar crystals (i.e., columns and bullet rosettes), whereas the relative occurrence frequency of columnar crystals was much larger in non-anvil clouds.
J. Um, G. M. McFarquhar, Y. P. Hong, S.-S. Lee, C. H. Jung, R. P. Lawson, and Q. Mo Atmos. Chem. Phys. Discuss., 14, 31111-31167, 2014 AbstractDiscussion Paper (PDF, 10772 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP
10 Dec 2014
A case study of a low level jet during OPALE
Summary: This is the first time that a low level jet observed above the East-Antarctic Plateau is simulated by a regional climate model.
This paper illustrates in a 3-D simulation the respective influences of the large scale pressure gradient force and turbulence on the onset of the Low Level Jet.
As atmospheric turbulence plays a key role in explaining the behaviour of chemical tracers during the OPALE campain, this paper also increases our confidence in using the outputs of the model for this purpose.
Evaluation of a regional chemistry transport model using a newly developed regional OMI NO2 retrieval
Summary: Air pollutants can be simulated using models and measured by satellites. We present an improved OMI NO2 retrieval for the Pearl River Delta region which reduces the bias between satellite and ground measurements. The satellite retrieval is used to evaluate a regional air pollution model for which it can form a useful addition to ground measurements. To conclude, we show that our retrieval reduces the bias of satellite measurements which can be very useful for air pollution studies.
Aerosols over Continental Portugal (1978–1993): their sources and an impact on the regional climate
Summary: The aerosols sources (volcanoes, mineral dust, wildfires, pollution) in the
Continental Portugal were studied using ground and satellite measurements. The influence of the each source changes with the season and environment. Concerning the effect that aerosols have over the local climate variations change, the strongest influence was found for the less urbanized site and for the summer months. It consists in dependence of the maximum daily temperature variations on the absorbing aerosol content.
The oxidation capacity of the boreal forest: first simulated reactivities of O3 and NO3
D. Mogensen, R. Gierens, J. N. Crowley, P. Keronen, S. Smolander, A. Sogachev, A. C. Nölscher, L. Zhou, M. Kulmala, M. J. Tang, J. Williams, and M. Boy Atmos. Chem. Phys. Discuss., 14, 30947-31007, 2014 AbstractDiscussion Paper (PDF, 2409 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACPSpecial Issue
09 Dec 2014
Examining the major contributors and controlling factors of ozone production in a rural area of the Yangtze River Delta region during harvest season
X. Pan, Y. Kanaya, H. Tanimoto, S. Inomata, Z. Wang, S. Kudo, and I. Uno Atmos. Chem. Phys. Discuss., 14, 30913-30945, 2014 AbstractDiscussion Paper (PDF, 6326 KB)Interactive Discussion (Open, 3 Comments)Manuscript under review for ACP
09 Dec 2014
Solar cycle in current reanalyses: (non)linear attribution study
On the link between hygroscopicity, volatility, and oxidation state of ambient and water-soluble aerosol in the Southeastern United States
Summary: The hygroscopicity of SE US aerosol is mostly water-soluble, with a hygroscopicity that is insensitive to partial volatilization in a thermodenuder.
The most and least oxidized components of the aerosol are the most hygroscopic of organic constituents.
No clear relationship was found between organic aerosol hygroscopicity and oxygen-to-carbon ratio.
The aerosol factors covary in a way that induces the observed diurnal invariance in total organic hygroscopicity.
K. M. Cerully, A. Bougiatioti, J. R. Hite Jr., H. Guo, L. Xu, N. L. Ng, R. Weber, and A. Nenes Atmos. Chem. Phys. Discuss., 14, 30835-30877, 2014 AbstractDiscussion Paper (PDF, 2782 KB)Interactive Discussion (Open, 0 Comments)Manuscript under review for ACP
09 Dec 2014
Elemental composition and clustering of α-pinene oxidation products for different oxidation conditions
Summary: 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.
A. P. Praplan, S. Schobesberger, F. Bianchi, M. P. Rissanen, M. Ehn, T. Jokinen, H. Junninen, A. Adamov, A. Amorim, J. Dommen, J. Duplissy, J. Hakala, A. Hansel, M. Heinritzi, J. Kangasluoma, J. Kirkby, M. Krapf, A. Kürten, K. Lehtipalo, F. Riccobono, L. Rondo, N. Sarnela, M. Simon, A. Tomé, J. Tröstl, P. M. Winkler, C. Williamson, P. Ye, J. Curtius, U. Baltensperger, N. M. Donahue, M. Kulmala, and D. R. Worsnop Atmos. Chem. Phys. Discuss., 14, 30799-30833, 2014 AbstractDiscussion Paper (PDF, 1388 KB)Interactive Discussion (Open, 3 Comments)Manuscript under review for ACPSpecial Issue
09 Dec 2014
The role of organic condensation on ultrafine particle growth during nucleation events
Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)
Summary: This study introduces source, sector and region specific tracers in WRF-Chem to identify most important sources of black carbon aerosols in South Asia during ICARB. We find anthropogenic emissions from residential and industrial sectors were the most important sources of BC in South Asia during ICARB. Regional transport is also found to play an important role in distributing BC over this region.
Rapid transport of East Asian pollution to the deep tropics
M. J. Ashfold, J. A. Pyle, A. D. Robinson, M. S. M. Nadzir, S. M. Phang, A. A. Samah, S. Ong, H. E. Ung, L. K. Peng, S. E. Yong, and N. R. P. Harris Atmos. Chem. Phys. Discuss., 14, 30705-30726, 2014 AbstractDiscussion Paper (PDF, 1697 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP
05 Dec 2014
Estimates of non-traditional secondary organic aerosols from aircraft SVOC and IVOC emissions using CMAQ
Summary: Utilizing an aircraft-specific parameterization based on smog chamber data in a regional AQM, contributions of non-traditional secondary organic aerosols (NTSOA) from aircraft emissions of semi-volatile and intermediate volatility organic compounds were assessed. NTSOA, a previously unaccounted component of PM2.5 in most AQMs, contributed up to 7.4% of aviation-attributable PM2.5 at the airport, and rose to 17.9% downwind, suggesting its significance in aviation-attributed PM2.5 at all scales.
Comparison of mercury concentrations measured at several sites in the Southern Hemisphere
Summary: • Longer term mercury measurement in southern hemisphere are 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 for the whole hemisphere, and smaller trends can be detected in shorter time periods
• We report a change of the trend sign at Cape Point from decreasing mercury concentrations in 1996 - 2004 to increasing ones since 2007
F. Slemr, H. Angot, A. Dommergue, O. Magand, M. Barret, A. Weigelt, R. Ebinghaus, E.-G. Brunke, K. Pfaffhuber, G. Edwards, D. Howard, J. Powell, M. Keywood, and F. Wang Atmos. Chem. Phys. Discuss., 14, 30611-30637, 2014 AbstractDiscussion Paper (PDF, 664 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP
03 Dec 2014
Hydrogen peroxide in the marine boundary layer over the southern Atlantic during the OOMPH cruise in March 2007
H. Fischer, A. Pozzer, T. Schmitt, P. Jöckel, T. Klippel, D. Taraborrelli, and J. Lelieveld Atmos. Chem. Phys. Discuss., 14, 30547-30573, 2014 AbstractDiscussion Paper (PDF, 1308 KB)Interactive Discussion (Open, 3 Comments)Manuscript under review for ACP
02 Dec 2014
Evaluating BC and NOx emission inventories for the Paris region from MEGAPOLI aircraft measurements
H. Petetin, M. Beekmann, A. Colomb, H. A. C. Denier van der Gon, J.-C. Dupont, C. Honoré, V. Michoud, Y. Morille, O. Perrussel, A. Schwarzenboeck, J. Sciare, A. Wiedensohler, and Q. J. Zhang Atmos. Chem. Phys. Discuss., 14, 29237-29304, 2014 AbstractDiscussion Paper (PDF, 2711 KB)Supplement (782 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACPSpecial Issue
24 Nov 2014
The impact of temperature resolution on trajectory modeling of stratospheric water vapour
Summary: We investigated the impacts of temperatures of different vertical resolutions on trajectory simulations of stratospheric water vapour by comparing results using 1) MERRA temperatures on model levels; 2) GPS temperatures in finer vertical resolutions; and 3) MERRA temperatures incorporating enhanced waves in finer vertical resolutions. It shows that using GPS and MERRA-wave temperatures tend to dry air by 0.1 and 0.2-0.3 ppmv, respectively, but the interannual variability is essentially the same.
T. Wang, A. E. Dessler, M. R. Schoeberl, W. J. Randel, and J.-E. Kim Atmos. Chem. Phys. Discuss., 14, 29209-29236, 2014 AbstractDiscussion Paper (PDF, 3281 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
24 Nov 2014
First and second derivative atmospheric CO2, global surface temperature and ENSO
Summary: The previously expected linear relationship between atmospheric CO2 and climate variables including temperature is showing an increasing mismatch. This paper nonetheless provides fresh and possibly definitive support for a major relationship between CO2 and climate. Granger causality analysis provides evidence that rate of change not level of CO2 primarily influences both global temperature and the El Niño–Southern Oscillation. The results may contribute to the prediction of future climate.
Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska
C. R. Thompson, P. B. Shepson, J. Liao, L. G. Huey, E. C. Apel, C. A. Cantrell, F. Flocke, J. Orlando, A. Fried, S. R. Hall, R. S. Hornbrook, D. J. Knapp, R. L. Mauldin III, D. D. Montzka, B. C. Sive, K. Ullmann, P. Weibring, and A. Weinheimer Atmos. Chem. Phys. Discuss., 14, 28685-28755, 2014 AbstractDiscussion Paper (PDF, 1913 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
19 Nov 2014
Long-term (2001–2012) fine particulate matter (PM2.5) and the impact on human health in Beijing, China
Summary: The present study uses Aerosol Optical Depth (AOD) 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 6,100 individuals/yr for the period 2001-2012 in the Beijing central area, and for the period 2010-2012 the per capita mortality for all ages due to PM2.5 is around 17.9 per 10,000 person-year.
Connecting the solubility and CCN activation of complex organic aerosols: a theoretical study using the Solubility Basis Set (SBS)
Summary: Atmospheric organic aerosol is complex and thus a challenge to models. We introduce a theoretical framework (the Solubility Basis Set, SBS) to represent the solubility of multi-component mixtures. Using the SBS, we evaluate the commonly made assumptions about the cloud condensation nucleus (CCN) activity of organic mixtures. We find that material with water-solubilities larger than 1-10 g/L can usually be treated as completely soluble, which simplifies the treatment of organic CCN considerably
Positive feedback of dust aerosol via its impact on atmospheric stability during dust storms in the Eastern Mediterranean
Summary: In this paper we report on a new mechanism whereby the radiative effect of dust aerosol on surface fluxes acts to increase the dust loading of the atmosphere via modification of boundary-layer stability, thereby acting to enhance the radiative aerosol effect. This positive feedback between dust aerosol and boundary layer stability occurred during a series of dust storms in the Eastern Mediterranean in April 2012, which were studied using a global atmospheric composition forecast system.
Investigation into chemistry of new particle formation and growth in subtropical urban environment
F. Salimi, L. R. Crilley, S. Stevanovic, Z. Ristovski, M. Mazaheri, C. He, G. R Johnson, G. Ayoko, and L. Morawska Atmos. Chem. Phys. Discuss., 14, 27945-27971, 2014 AbstractDiscussion Paper (PDF, 4163 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
11 Nov 2014
The MACC-II 2007–2008 reanalysis: atmospheric dust evaluation and characterization over Northern Africa and Middle East
E. Cuevas, C. Camino, A. Benedetti, S. Basart, E. Terradellas, J. M. Baldasano, J.-J. Morcrette, B. Marticorena, P. Goloub, A. Mortier, A. Berjón, Y. Hernández, M. Gil-Ojeda, and M. Schulz Atmos. Chem. Phys. Discuss., 14, 27797-27879, 2014 AbstractDiscussion Paper (PDF, 10527 KB)Supplement (882 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
11 Nov 2014
A new model of the global biogeochemical cycle of carbonyl sulfide – Part 2: Use of ocs to constrain gross primary productivity of current vegetation models
A multi-year study of lower tropospheric aerosol variability and systematic relationships from four North American regions
Summary: Variability in aerosol optical properties relevant to radiative forcing were studied on several timescales at four continental North American NOAA-ESRL sites. Light scattering and intensive properties varied most on seasonal scales while absorption variability on weekly and diurnal timescales was comparable to its seasonal variability. Large reductions in light scattering were observed at the two long-term sites (relative to late 1990’s), along with a smaller contribution by sub-1µm particles.
Modulation of Saharan dust export by the North African dipole
Summary: Long term - 25 years - inter-annual variability of Saharan dust export to the subtropics is correlated with variability in Harmattan wind speeds in central Sahara and with monsoon-rainfalls in the tropics and in the Sahel. This variability is modulated by the intensity of the low-high dipole like pattern we so-called North African Dipole, whose variability may be connected with global oscillations in the climate of the tropics and subtropics.
S. Rodríguez, E. Cuevas, J. M. Prospero, A. Alastuey, X. Querol, J. López-Solano, M. I. García, and S. Alonso-Pérez Atmos. Chem. Phys. Discuss., 14, 26689-26719, 2014 AbstractDiscussion Paper (PDF, 1824 KB)Supplement (3319 KB)Interactive Discussion (Open, 1 Comment)Manuscript under review for ACP
24 Oct 2014
Primary marine aerosol emissions from the Mediterranean Sea during pre-bloom and oligotrophic conditions: correlations to seawater chlorophyll a from a mesocosm study
A. N. Schwier, C. Rose, E. Asmi, A. M. Ebling, W. M. Landing, S. Marro, M.-L. Pedrotti, A. Sallon, F. Iuculano, S. Agusti, A. Tsiola, P. Pitta, J. Louis, C. Guieu, F. Gazeau, and K. Sellegri Atmos. Chem. Phys. Discuss., 14, 26187-26230, 2014 AbstractDiscussion Paper (PDF, 1541 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACPSpecial Issue
20 Oct 2014
Influence of oil and gas field operations on spatial and temporal distributions of atmospheric non-methane hydrocarbons and their effect on ozone formation in winter
Marine submicron aerosol sources, sinks and chemical fluxes
D. Ceburnis, M. Rinaldi, J. Keane-Brennan, J. Ovadnevaite, G. Martucci, L. Giulianelli, and C. D. O'Dowd Atmos. Chem. Phys. Discuss., 14, 23847-23889, 2014 AbstractDiscussion Paper (PDF, 2969 KB)Interactive Discussion (Open, 2 Comments)Manuscript under review for ACP