Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005–2014
Summary: Using an exponentially-modified Gaussian method and taking into account the effect of wind on NO2 distributions, we estimate three-year moving-average emissions of summertime NOx from 35 U.S. urban areas directly from NO2 retrievals of the OMI during 2005−2014. Total OMI-derived NOx emissions over U.S. urban areas decreased by 49%, consistent with reductions of 43%, 49%, and 44% in the bottom-up NOx emissions, the weak-wind OMI NO2 burdens, and the averaged NO2 concentrations, respectively.
Atmos. Chem. Phys. Discuss., 15, 14961-15003, doi:10.5194/acpd-15-14961-2015, 2015
A comparison of secondary organic aerosol (SOA) yields and composition from ozonolysis of monoterpenes at varying concentrations of NO2
Summary: The addition of NO2 to atmospheric particle formation simulations based on ozone reactions with tree-emitted monoterpenes results in changing particle composition and mass yields, with effects that vary across the range of studied monoterpenes. For alpha-pinene, a dominantly emitted terpene in the United States, NO2 addition suppresses particle formation, while for others, particle yields remain high.
Atmos. Chem. Phys. Discuss., 15, 14923-14960, doi:10.5194/acpd-15-14923-2015, 2015
Evaluation of regional background particulate matter concentration based on vertical distribution characteristics
Summary: It is crucial for studying regional-scale PM pollution and for the development of efficient joint control policy to improve understanding of the regional background PM concentration. Based on the spectrum analysis of vertical variation of the atmospheric boundary layer structure and particle mass concentration, as well as the vertical distribution of particle size, chemical composition and pollution source apportionment, a method to estimate regional background PM concentration is proposed.
Atmos. Chem. Phys. Discuss., 15, 14889-14921, doi:10.5194/acpd-15-14889-2015, 2015
The importance of Asia as a source of black carbon to the European Arctic during springtime 2013
Summary: We show that during the springtime of 2013, the anthropogenic pollution particularly from sources in Asia, contributed significantly to black carbon across the European Arctic free troposphere. In contrast to previous studies, the contribution from open wildfires was minimal. Given that Asian pollution is likely to continue to rise over the coming years, it is likely that the radiative forcing in the Arctic will also continue to increase.
Atmos. Chem. Phys. Discuss., 15, 14843-14887, doi:10.5194/acpd-15-14843-2015, 2015
Global HCFC-22 measurements with MIPAS: retrieval, validation, climatologies and trends
Summary: HCFC-22 global distributions from MIPAS measurements for 2005 to 2012 are presented. Tropospheric trends are in good agreement with ground-based observations. A layer of enhanced HCFC-22 in the upper tropospheric tropics and Northern subtropics is identified to come from Asian sources uplifted in the Asian monsoon. Stratospheric distributions provide show seasonal, semi-annual, and QBO-related variations. Hemispheric asymmetries of trends hint towards a change in the stratospheric circulation.
Atmos. Chem. Phys. Discuss., 15, 14783-14841, doi:10.5194/acpd-15-14783-2015, 2015
Advanced source apportionment of size-resolved trace elements at multiple sites in London during winter
Summary: Trace element measurements in three particle size ranges (PM10-2.5, PM2.5-1.0 and PM1.0-0.3) were performed with 2h time resolution at kerbside, urban background and rural sites during the ClearfLo winter 2012 campaign in London. The environment-dependent variability of emissions was characterized using the Multilinear Engine implementation of the Positive Matrix Factorization model. A total of nine different factors was resolved from local, regional and natural origin.
Atmos. Chem. Phys. Discuss., 15, 14733-14781, doi:10.5194/acpd-15-14733-2015, 2015
Reassessment of MIPAS age of air trends and variability
Summary: Stratospheric circulation is thought to change as a consequence of climate change. Empirical evidence, however, is sparse. In this paper we present latitude- and altitude-resolved trends of the mean age of stratospheric air as derived from SF6 measurements performed by the MIPAS satellite instrument. The mean of the age of stratospheric air is a measure of the intensity of the Brewer-Dobson circulation. In this paper we discuss differences with respect to a preceding analysis by Stiller et al.
Atmos. Chem. Phys. Discuss., 15, 14685-14732, doi:10.5194/acpd-15-14685-2015, 2015
Oceanic bromine emissions weighted by their ozone depletion potential
Atmos. Chem. Phys. Discuss., 15, 14643-14684, doi:10.5194/acpd-15-14643-2015, 2015
Sources of long-lived atmospheric VOCs at the rural boreal forest site, SMEAR II
Summary: In this study main source areas for long-lived VOCs at the boreal forest in SMEAR II were determined. Air masses arriving from eastern and western directions were more polluted than those arriving from northern direction. Biogenic and anthropogenic influence of in three different source profiles were determined. The elevated trace gas concentrations from forest fire episodes were observed clearly in the trajectory analysis.
Atmos. Chem. Phys. Discuss., 15, 14593-14641, doi:10.5194/acpd-15-14593-2015, 2015
Long-term real-time measurements of aerosol particle composition in Beijing, China: seasonal variations, meteorological effects, and source analysis
Summary: We conducted the first long-term real-time measurement of submicron aerosol composition in Beijing using an ACSM for 1 year. The seasonal variations of mass concentrations and chemical composition of submicron aerosol were investigated in detail, and the meteorological effects particularly temperature and relative humidity on aerosol chemistry were elucidated. Finally, the potential source areas of aerosol species during four seasons were identified.
Atmos. Chem. Phys. Discuss., 15, 14549-14591, doi:10.5194/acpd-15-14549-2015, 2015
Decadal trends in global CO emissions as seen by MOPITT
Summary: We studied the global CO concentration decline over the recent decade with a sophisticated atmospheric inversion system assimilating MOPITT CO retrievals, surface methane and surface methyl-chloroform in-situ measurements. The inversion interprets the CO concentration decline as a 17% decrease in the CO emissions from 2002 to 2011, twice the negative trend estimated by emission inventories. In contrast to bottom-up inventories, we find negative trends in China and positive trends in Africa.
Atmos. Chem. Phys. Discuss., 15, 14505-14547, doi:10.5194/acpd-15-14505-2015, 2015
NO2 seasonal evolution in the North Subtropical free troposphere
Summary: The NO2 seasonal evolution in the free troposphere (FT) has been established for first time based on remote sensing technique (MAXDOAS) thus avoiding the problems of local pollution of in situ instruments. A clear seasonality has been found with background levels of 20-40pptv. Evidence has been found on fast direct injection of surface air into the free troposphere. This result might have implications on the FT distribution of halogens and other species with marine sources.
Atmos. Chem. Phys. Discuss., 15, 14473-14504, doi:10.5194/acpd-15-14473-2015, 2015
Simultaneous monitoring of stable oxygen isotope composition in water vapour and precipitation over the central Tibetan Plateau
Atmos. Chem. Phys. Discuss., 15, 14445-14472, doi:10.5194/acpd-15-14445-2015, 2015
Organic aerosol evolution and transport observed at Mt. Cimone (2165 m a.s.l.), Italy, during the PEGASOS campaign
Summary: This work highlights the important contribution of organic aerosols to the composition of submicron particles at remote mountain sites. Moreover, it confirms the importance of regional scale physical and chemical processes and of transboundary transport in determining the background aerosol composition at rural European sites.
Atmos. Chem. Phys. Discuss., 15, 14403-14443, doi:10.5194/acpd-15-14403-2015, 2015
Acetylene (C2H2) and hydrogen cyanide (HCN) from IASI satellite observations: global distributions, validation, and comparison with model
Summary: We present global distributions of acetylene (C2H2) and hydrogen cyanide (HCN) total columns derived from the Infrared Atmospheric Sounding Interferometer (IASI). C2H2 and HCN are ubiquitous atmospheric trace gases with medium tropospheric lifetime, which are frequently used as indicators of combustion sources and as tracers for atmospheric transport and chemistry. We show that there is an overall agreement between ground-based and space measurements, as well as model simulations.
Atmos. Chem. Phys. Discuss., 15, 14357-14401, doi:10.5194/acpd-15-14357-2015, 2015
The impact of embedded valleys on daytime pollution transport over a mountain range
Atmos. Chem. Phys. Discuss., 15, 14315-14356, doi:10.5194/acpd-15-14315-2015, 2015
The impact of volcanic aerosols on stratospheric ozone and the Northern Hemisphere polar vortex: separating radiative from chemical effects under different climate conditions
Summary: After volcanic eruptions different radiative and chemical processes take place in the stratosphere which perturb the ozone layer and cause pronounced dynamical changes. In idealized chemistry-climate model simulations the importance of these processes and the modulating role of the climate state is analysed. The chemical effect strongly differs between a preindustrial and present day climate, but the effect on the dynamics is weak. Radiative processes dominate the dynamics in all climate states.
Atmos. Chem. Phys. Discuss., 15, 14275-14314, doi:10.5194/acpd-15-14275-2015, 2015
On the potential of ICOS atmospheric CO2 measurement network for the estimation of the biogenic CO2 budget of Europe
Summary: We study the potential of the European Integrated Carbon Observing System (ICOS) atmospheric network for estimating European CO2 ecosystem fluxes. Regional atmospheric inversions with synthetic data are used to derive it in terms of statistical uncertainty. This potential is high in Western Europe and future extensions of the network will increase it in Eastern Europe. Future improvements of the models underlying the inversion should also significantly decrease uncertainties at high resolution.
Atmos. Chem. Phys. Discuss., 15, 14221-14273, doi:10.5194/acpd-15-14221-2015, 2015
Impact of vehicular emissions on the formation of fine particles in the Sao Paulo Metropolitan Area: a numerical study with the WRF-Chem model
Summary: This study provides a first step to understand the impact of vehicular emissions on the formation of secondary particles as well as the feedback between these particles and meteorology in the Sao Paulo Metropolitan Area (SPMA). Among the main research findings are: - The emissions of primary gases from vehicles led to a production between 20 and 30% due to new particles formation in relation to the total mass concentration PM2.5 in the downtown SPMA.
Atmos. Chem. Phys. Discuss., 15, 14171-14219, doi:10.5194/acpd-15-14171-2015, 2015
Black carbon aerosol in winter northeastern Qinghai-Tibetan Plateau, China: the effects from South Asia pollution
Summary: An intensive measurement campaign was conducted at the Qinghai-Tibetan Plateau using a ground-based single particle soot photometer (SP2) and a photoacoustic extinctiometer (PAX). Significant enhancements of BC loadings and number fraction of coated BC were observed during pollution episode. Backward trajectory, fire counts map and potential source contribution function model studies suggest that the biomass burning air masses from North India contributed to the increased BC loadings.
Atmos. Chem. Phys. Discuss., 15, 14141-14169, doi:10.5194/acpd-15-14141-2015, 2015
Impacts of historical climate and land cover changes on tropospheric ozone air quality and public health in East Asia over 1980–2010
Summary: Historical land cover and land use change alone over 1980-2010 could lead to reduced summertime surface ozone by up to 4ppbv in East Asia. Climate change alone could lead to an increase in summertime ozone by 2-10ppbv in most of East Asia. Land cover change could offset part of the climate effect and lead to a previously unknown public health benefit. The sensitivity of surface ozone to land cover change is more dependent on dry deposition than isoprene emission in most of East Asia.
Atmos. Chem. Phys. Discuss., 15, 14111-14139, doi:10.5194/acpd-15-14111-2015, 2015
Investigating the observed sensitivities of air quality extremes to meteorological drivers via quantile regression
Atmos. Chem. Phys. Discuss., 15, 14075-14109, doi:10.5194/acpd-15-14075-2015, 2015
Can a coupled meteorology-chemistry model reproduce the historical trend in aerosol direct radiative effects over the Northern Hemisphere?
Summary: The ability of a coupled meteorology-chemistry model (WRF-CMAQ) in reproducing the historical trend in AOD and clear-sky SWR over the N-Hemisphere has been evaluated through a comparison of 21-year simulated results with observation-derived records from 1990-2010. Questions of How well does the model represent the regional and temporal variability of aerosol burden and DRE, and Is the model able to capture past trends in aerosol loading and associated radiatiation effects will be addressed.
Atmos. Chem. Phys. Discuss., 15, 14027-14073, doi:10.5194/acpd-15-14027-2015, 2015
A study of the impact of synoptic weather conditions and water vapor on aerosol-cloud relationships over major urban clusters of China
Summary: The impact of aerosols on cloud cover (CC) under the influence of water vapor is studied using a decade of satellite observations. Water vapor is found to have a stronger impact on CC than aerosols. The water vapour impact shows that the hydrological cycle interferes with the aerosol climatic impact and we need to improve our understanding of this interference.
Atmos. Chem. Phys. Discuss., 15, 14007-14026, doi:10.5194/acpd-15-14007-2015, 2015
Thermodynamics of the formation of sulfuric acid dimers in the binary (H2SO4-H2O) and ternary (H2SO4-H2O-NH3) system
Summary: New particle formation (NPF) is an important atmospheric process. At cold temperatures in the upper troposphere the binary (H2SO4-H2O) and ternary (H2SO4-H2O-NH3) system are thought to be important for NPF. Sulfuric acid monomer (H2SO4) and sulfuric acid dimer ((H2SO4)2) concentrations were measured between 208 and 248K for these systems and dimer evaporation rates were derived. These data will help to better understand and predict binary and ternary nucleation at low temperatures.
Atmos. Chem. Phys. Discuss., 15, 13957-14006, doi:10.5194/acpd-15-13957-2015, 2015
A better understanding of hydroxyl radical photochemical sources in cloud waters collected at the puy de Dôme station: experimental vs. modeled formation rates
Atmos. Chem. Phys. Discuss., 15, 13923-13955, doi:10.5194/acpd-15-13923-2015, 2015
Impact of 2050 climate change on North American wildfire: consequences for ozone air quality
Summary: Based on simulated meteorology from 13 GCMs, we projected future wildfire activity in Alaskan and Canadian ecoregions by the midcentury. The most robust change is the increases of 150-390% in area burned over Alaska and western Canada. The models also predict increases of 45-90% in the central and southern Canadian ecoregions, but a decrease of up to 50% in northern Canada. We further quantify how the changes in wildfire emissions may affect ozone concentrations in North America.
Atmos. Chem. Phys. Discuss., 15, 13867-13921, doi:10.5194/acpd-15-13867-2015, 2015
Influence of mineral dust and sea spray supermicron particle concentrations and acidity on inorganic NO3− aerosol during the 2013 Southern Oxidant and Aerosol Study
Summary: We report ion chromatographic measurements of gas- and aerosol-phase inorganic species at the SOAS 2013 field study. Our particular focus is on inorganic nitrate aerosol formation via HNO3 uptake onto coarse-mode dust and sea-salt particles, which we find to be the dominant source of episodic inorganic nitrate at this site, due to the high acidity of the particles preventing formation of NH4NO3. We calculate a production rate of inorganic nitrate aerosol.
Atmos. Chem. Phys. Discuss., 15, 13827-13865, doi:10.5194/acpd-15-13827-2015, 2015
An empirically derived inorganic sea spray source function incorporating sea surface temperature
Summary: We have developed an inorganic sea spray source function that is based upon state-of-the-art measurements of sea spray aerosol production using a temperature-controlled plunging jet sea spray aerosol chamber. The sea spray sea spray source function was implemented in a Lagrangian particle dispersion model and showed good skill in predicting measurements of Na+ concentration at a number of field sites, underlining its validity.
Atmos. Chem. Phys. Discuss., 15, 13783-13826, doi:10.5194/acpd-15-13783-2015, 2015
Historic records of organic aerosols from a high Alpine glacier: implications of biomass burning, anthropogenic emissions, and dust transport
Summary: The paper focuses on the determination and interpretation of historic records of organic aerosol constituents in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. The resulting long-term records of aerosol compounds were found to be influenced by the forest fire history in southern Switzerland, anthropogenic emissions, as well as changing mineral dust transport to the drilling site.
Atmos. Chem. Phys. Discuss., 15, 13747-13781, doi:10.5194/acpd-15-13747-2015, 2015
The ENSO signal in atmospheric composition fields: emission driven vs. dynamically induced changes
Atmos. Chem. Phys. Discuss., 15, 13705-13745, doi:10.5194/acpd-15-13705-2015, 2015
Atmospheric nitrogen deposition to the northwestern Pacific: seasonal variation and source attribution
Summary: Rapid Asian industrialization has led to increased atmospheric nitrogen deposition downwind. This work analyzes the sources and processes controlling atmospheric nitrogen deposition to the northwestern Pacific. Both nitrogen emissions and meteorology largely controlled by the East Asian Monsoon determine the seasonality of nitrogen deposition. Ascribing deposition over the marginal seas to nitrogen sources from different regions and sectors shows important contribution from fertilizer use.
Atmos. Chem. Phys. Discuss., 15, 13657-13703, doi:10.5194/acpd-15-13657-2015, 2015
Remote sensing of soot carbon – Part 1: Distinguishing different absorbing aerosol species
Atmos. Chem. Phys. Discuss., 15, 13607-13656, doi:10.5194/acpd-15-13607-2015, 2015
A global aerosol classification algorithm incorporating multiple satellite data sets of aerosol and trace gas abundances
Atmos. Chem. Phys. Discuss., 15, 13551-13605, doi:10.5194/acpd-15-13551-2015, 2015
Chemical characterization of submicron aerosol and particle growth events at a national background site (3295 m a.s.l.) in the Tibetan Plateau
Summary: An autumn field campaign was conducted at a national background site (3295m a.s.l.) in the Tibetan Plateau. The submicron aerosol was dominated by organics (43%) and sulfate (28%). Secondary organic aerosol (SOA) dominated OA (85%) with 17% being aged biomass burning OA. New particle formation and growth events were frequently observed with an average particle growth rate of 2.0nm hr-1. The important role of organics in particle growth in the Tibetan Plateau was also demonstrated.
Atmos. Chem. Phys. Discuss., 15, 13515-13550, doi:10.5194/acpd-15-13515-2015, 2015
Modelled and observed changes in aerosols and surface solar radiation over Europe between 1960 and 2009
Summary: We evaluate a coupled chemistry climate model over Europe for the period 1960-2009 against observations of aerosol mass, aerosol optical depth (AOD) and surface solar radiation (SSR). The model underestimates aerosol mass but is less biased when compared to AOD and SSR. Observed trends in aerosols are well simulated by the model and necessary for reproducing the observed increase in SSR since 1990. European all-sky top of atmosphere aerosol radiative forcing increased by 3Wm-2 from 1970-2009.
Atmos. Chem. Phys. Discuss., 15, 13457-13513, doi:10.5194/acpd-15-13457-2015, 2015
Modeling organic aerosol composition at the puy de Dôme mountain (France) for two contrasted air masses with the WRF-Chem model
Atmos. Chem. Phys. Discuss., 15, 13395-13455, doi:10.5194/acpd-15-13395-2015, 2015
Composition, size distribution, optical properties and radiative effects of re-suspended local mineral dust of Rome area by individual-particle microanalysis and radiative transfer modelling
Summary: New information is given here on mineralogy, microphysical and optical properties, and radiative effects, of PM10 types from surface rocks at a non-desert site (Rome area, Italy). A large data set was built, by SEM XEDS microanalysis, of mineral particles (silicates, quartz and calcite, depending on rocks). Dust types show different size distribution, optical properties, and radiative effects. Radiative transfer modelling (6SV) based on SEM XEDS data is a further original feature of this work.
Atmos. Chem. Phys. Discuss., 15, 13347-13393, doi:10.5194/acpd-15-13347-2015, 2015
Global temperature response to the major volcanic eruptions in multiple reanalysis datasets
Summary: This paper evaluates the temperature response in the troposphere and the stratosphere to the three major and three smaller-scale volcanic eruptions between the 1960s and the 1990s. This paper provides intercomparison results for 9 reanalysis datasets for the volcanic temperature response and other naturally induced variabilities. It was found that the volcanic temperature response patterns differ not only between the major and smaller-scale eruptions but also among the major eruptions.
Atmos. Chem. Phys. Discuss., 15, 13315-13346, doi:10.5194/acpd-15-13315-2015, 2015
Elevated ozone in boreal fire plumes – the 2013 smoke season
Atmos. Chem. Phys. Discuss., 15, 13263-13313, doi:10.5194/acpd-15-13263-2015, 2015
Trends in concentrations of atmospheric gaseous and particulate species in rural eastern Tennessee as related to primary emissions reductions
Atmos. Chem. Phys. Discuss., 15, 13211-13262, doi:10.5194/acpd-15-13211-2015, 2015
Vertical variations of aerosols and the effects responded to the emission control: application of lidar ceilometer in Beijing during APEC, 2014
Summary: The manuscript is the first paper to validate and discuss the high resolution vertical profiles of aerosols using Ceilometer in Beijing, China. We introduce the contribution to aerosols during the different air pollution episode in Beijing. Also, we seize the opportunity of emission reduction during APEC to study the contribution to aerosols. The results are helpful to provide guidance of redefining coordinated emission control strategies to control the regional pollution over Northern China.
Atmos. Chem. Phys. Discuss., 15, 13173-13209, doi:10.5194/acpd-15-13173-2015, 2015
X-ray computed microtomography of sea ice – comment on "A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow", by Bartels-Rausch et al. (2014)
Summary: This paper, "X-ray computed microtomography of sea ice" is a comment on a recent paper, "A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow (Atmos. Chem. Phys., 14, 1587–1633, 2014)". Our paper corrects a part of the review paper which was inaccurate, regarding the capabilities of X-ray computed microtomography to reveal liquid brine inclusions in sea ice.
Atmos. Chem. Phys. Discuss., 15, 13167-13171, doi:10.5194/acpd-15-13167-2015, 2015
Analysis of isothermal and cooling rate dependent immersion freezing by a unifying stochastic ice nucleation model
Summary: A stochastic immersion freezing model is introduced capable of reproducing laboratory data for a variety of experimental methods using a time and surface area dependent ice nucleation process. The assumption that droplets contain identical surface area is evaluated. A quantitative uncertainty analysis of the laboratory observed freezing process is presented. Our results imply that ice nuclei surface area assumptions are crucial for interpretation of experimental immersion freezing results.
Atmos. Chem. Phys. Discuss., 15, 13109-13166, doi:10.5194/acpd-15-13109-2015, 2015
Influence of synoptic patterns on surface ozone variability over the Eastern United States from 1980 to 2012
Summary: In this study, we have examined the effect of polar jet and Bermuda High on ozone air quality in the eastern United States. In the Midwest and Northeast, the poleward shift of jet wind leads to reduced polar jet frequency, resulting in increased ozone there. In the Southeast, the influence of Bermuda High on ozone variability depends on the location of its west edge. Westward movement increases the ozone only when the JJA Bermuda High west edge is located west of 85.4°W.
Atmos. Chem. Phys. Discuss., 15, 13073-13108, doi:10.5194/acpd-15-13073-2015, 2015
Effect of tropical cyclones on the tropical tropopause parameters observed using COSMIC GPS RO data
Summary: 1. Quantified the effect of tropical cyclones (TCs) that occurred over North Indian Ocean in the last decade on the tropical tropopause parameters for the first time. 2. Vertical structure of temperature and tropopause parameters within the 5º radius away from the cyclone centre during TC period is also presented. 3. The water vapour variability in the vicinity of TC is also investigated. 4. Demonstrated that the TCs can significantly affect the tropical tropopause and thus STE processes.
Atmos. Chem. Phys. Discuss., 15, 13043-13071, doi:10.5194/acpd-15-13043-2015, 2015
Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing
Summary: Chemical characteristics of 12 trace elements in fine particles and clouds at a mountain site in southern China were investigated. Four major emission sources were classified. Long-range transport and regional air pollution contributed the most to elements concentration. Trace elements solubility within local area were found much higher. Cloud processing enhanced elements solubility in fine particles via altering metal particles morphology in cloud residues.
Atmos. Chem. Phys. Discuss., 15, 13001-13042, doi:10.5194/acpd-15-13001-2015, 2015
Quantifying sources of black carbon in Western North America using observationally based analysis and an emission tagging technique in the Community Atmosphere Model
Summary: We use a global climate model with an explicit source tagging technique to quantify contributions of emissions from various geographical regions and sectors to BC in North America. Model results are evaluated against measurements of near-surface and in-snow BC. We found strong spatial variations of BC and its radiative forcing that can be quantitatively attributed to the various source origins, and also identified a significant source of BC in snow that is likely missing in most climate models.
Atmos. Chem. Phys. Discuss., 15, 12957-13000, doi:10.5194/acpd-15-12957-2015, 2015
The CarboCount CH sites: characterization of a dense greenhouse gas observation network
Summary: We present a detailed analysis of a new greenhouse gas measurement network in the Swiss Plateau, situated between the Jura mountains and the Alps. We find the network's measurements to be information rich and suitable for studying surface carbon fluxes of the study region. However, we are limited by the high-resolution (2km) atmospheric transport model's ability to simulate meteorology at the individual measurement stations, especially at those situated in rough terrain.
Atmos. Chem. Phys. Discuss., 15, 12911-12956, doi:10.5194/acpd-15-12911-2015, 2015
HTAP_v2: a mosaic of regional and global emission gridmaps for 2008 and 2010 to study hemispheric transport of air pollution
Summary: This paper provides monthly emission gridmaps at 0.1deg x 0.1deg resolution with global coverage for air pollutants and aerosols anthropogenic emissions in 2008 and 2010. All world countries are consistently inter-compared with sector-specific implied emission factors, per capita emissions and emissions per unit of GDP. The emission gridmaps compose the reference emissions dataset for the community modeling hemispheric transport of air pollution (HTAP).
Atmos. Chem. Phys. Discuss., 15, 12867-12909, doi:10.5194/acpd-15-12867-2015, 2015
Interactions among drainage flows, gravity waves and turbulence: a BLLAST case study
Summary: Stable-boundary-layer processes have been analysed using BLLAST data. Shallow drainage flows were formed at some locations after the near calm stage of the late afternoon. This stage ended with the arrival of a deeper wind associated with the mountain-plain circulation. At the same time, gravity waves were detected with an array of microbarometers. The interaction of these processes with turbulence was studied through Multi-Resolution Flux Decomposition at different sites and heights.
Atmos. Chem. Phys. Discuss., 15, 12821-12865, doi:10.5194/acpd-15-12821-2015, 2015
Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments
Summary: We use water vapor profiles from ground-based microwave radiometers at five locations distributed over the northern hemisphere and operated in the frame of NDACC (Network for the Detection of Atmospheric Composition Change) to generate hemispheric water vapor maps based on the so called trajectory mapping technique. The novelty is to show that a mini-network of instruments is capable to provide information about the hemispheric distribution of water vapor under most conditions.
Atmos. Chem. Phys. Discuss., 15, 12777-12819, doi:10.5194/acpd-15-12777-2015, 2015
Ground-based aerosol climatology of China: aerosol optical depths from the China Aerosol Remote Sensing Network (CARSNET) 2002–2013
Atmos. Chem. Phys. Discuss., 15, 12715-12776, doi:10.5194/acpd-15-12715-2015, 2015
Influence of aerosols and surface reflectance on satellite NO2 retrieval: seasonal and spatial characteristics and implications for NOx emission constraints
Atmos. Chem. Phys. Discuss., 15, 12653-12714, doi:10.5194/acpd-15-12653-2015, 2015
Atmospheric chemistry of nitrogenous aerosols in Northeast Asia: biological sources and secondary formation
Atmos. Chem. Phys. Discuss., 15, 12617-12652, doi:10.5194/acpd-15-12617-2015, 2015
Four-year long-path monitoring of ambient aerosol extinction at a central European urban site: dependence on relative humidity
Atmos. Chem. Phys. Discuss., 15, 12583-12616, doi:10.5194/acpd-15-12583-2015, 2015
Seasonal trends in black carbon properties and co-pollutants in Mexico City
Summary: Extended measurements have been made of equivalent black carbon (eBC) derived from light absorption measurements made with a PAX over a 13 month period. The daily trends in eBC and other co-pollutants are evaluated with respect to season. The primary factors that led to large changes between the wet and dry seasons are the accelerated vertical mixing of boundary layer and free tropospheric air by the formation of clouds and decreased actinic flux that reduces the production of ozone.
Atmos. Chem. Phys. Discuss., 15, 12539-12582, doi:10.5194/acpd-15-12539-2015, 2015
Aerosol size distribution and new particle formation in western Yangtze River Delta of China: two-year measurement at the SORPES station
Atmos. Chem. Phys. Discuss., 15, 12491-12537, doi:10.5194/acpd-15-12491-2015, 2015
Characterization of ambient volatile organic compounds and their sources in Beijing, before, during, and after Asia-Pacific Economic Cooperation China 2014
Summary: Ambient VOCs were measured at an urban site in Beijing before, during and after APEC China 2014, when air quality control measures were implemented. PMF was applied to identify the major VOCs sources and their temporal variations. SOAP approach was used to estimate variations of precursor source contributions to SOA formation. Our results indicate that the stringent air quality restrictions have been successful, and controls on vehicles were the most important measures to VOCs.
Atmos. Chem. Phys. Discuss., 15, 12453-12490, doi:10.5194/acpd-15-12453-2015, 2015
Observations of new particle formation in enhanced UV irradiance zones near cumulus clouds
Summary: During the CARRIBA-campaign on Barbados 91 cases with increased aerosol particle number concentrations near clouds were detected from helicopter-borne measurements. Most of these cases are correlated with enhanced irradiance in the ultraviolet range. The events have a mean length of 100m corresponding to a lifetime of 300s, meaning a growth of several nm/h. Such high values cannot be explained by sulfuric acid alone thus probably extremely low volatile organic compounds are involved here.
Atmos. Chem. Phys. Discuss., 15, 12423-12452, doi:10.5194/acpd-15-12423-2015, 2015
A comparison of chemical mechanisms using Tagged Ozone Production Potential (TOPP) analysis
Summary: We show that simplified chemical mechanisms break down VOC into smaller sized degradation products on the first day faster than the near-explicit MCM chemical mechanism which would lead to an underprediction of ozone levels downwind of VOC emissions, and an underestimation of the VOC contribution to tropospheric background ozone when using simplified chemical mechanisms in regional or global modelling studies.
Atmos. Chem. Phys. Discuss., 15, 12389-12422, doi:10.5194/acpd-15-12389-2015, 2015
A solar signal in lower stratospheric water vapour?
Summary: A merged data set of HALOE and MIPAS lower stratospheric water vapour has been constructed. Multivariate linear regression yields that the merged time series can best be explained if a proxy for the 11-year solar cycle is considered. The amplitude of the solar cycle signal in water vapour is slightly higher than that which can be explained by the known solar cycle variation of cold-point temperatures.
Atmos. Chem. Phys. Discuss., 15, 12353-12387, doi:10.5194/acpd-15-12353-2015, 2015
Diurnal cycle of the dust instantaneous direct radiative forcing over the Arabian Peninsula
Summary: Calculate radiative effect of dust over different surfaces and for different optical depth, and test it using satellite and ground-based observations
Atmos. Chem. Phys. Discuss., 15, 12301-12352, doi:10.5194/acpd-15-12301-2015, 2015
Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations
Summary: We present the new version of the BIRA-IASB algorithm for the retrieval of H2CO columns from OMI and GOME-2A and B measurements. Validation results at seven stations in Europe, China and Africa confirm the capacity of the satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in Beijing and in Bujumbura are used for a more detailed validation exercise. Finally trends are estimated using 10 years of OMI observations.
Atmos. Chem. Phys. Discuss., 15, 12241-12300, doi:10.5194/acpd-15-12241-2015, 2015
An algorithm for the numerical solution of the multivariate master equation for stochastic coalescence
Summary: The mathematical description of finite volume coalescing systems relies on the multivariate master equation. However, due to its complexity, it has analytical solutions only for a limited number of kernels and initial conditions. In this paper, in an effort to solve this problem, we have introduced a novel numerical approach to calculate the solution of the multivariate coalescence master equation that works for any type of kernels and initial conditions.
Atmos. Chem. Phys. Discuss., 15, 12213-12240, doi:10.5194/acpd-15-12213-2015, 2015
Estimating collision efficiencies from contact freezing experiments
Summary: We determined experimentally collision efficiencies of cloud droplets with aerosol particles and found that they were around one order of magnitude higher than theoretical formulations that include Brownian diffusion, impaction, interception, thermophoretic, diffusiophoretic and electric forces, most probably due to uncertainties and inaccuracies in the theoretical formulations of thermophoretic and diffusiophoretic processes.
Atmos. Chem. Phys. Discuss., 15, 12167-12212, doi:10.5194/acpd-15-12167-2015, 2015
Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial variation distribution, uncertainties and control policies
Summary: For the first time, with S-shaped curves, the best available representation of time-varying emission factors of 12 heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) from primary anthropogenic sources of China are determined on accounting of economic transitions and pollution control technology improvement, and the temporal and spatial variation characteristics of these heavy metals emissions during the period of 1949−2012 are calculated and evaluated with uncertainty analysis.
Atmos. Chem. Phys. Discuss., 15, 12107-12166, doi:10.5194/acpd-15-12107-2015, 2015
Use of criteria pollutants, active and passive mercury sampling, and receptor modeling to understand the chemical forms of gaseous oxidized mercury in Florida
Summary: Gaseous oxidized Hg (GOM) is a major contributor to Hg in wet and dry deposition. Recent work has indicated that the concentrations of GOM as measured are too low by 3-to-12 times; and that compounds vary across space and time. Data collected in Florida indicate five potential GOM compounds, including HgBr2, HgO, Hg(NO3)2, HgSO4, and an unknown compound. Sources include local combustion (cars and power plants), the marine boundary layer, and long range transport from Asia.
Atmos. Chem. Phys. Discuss., 15, 12069-12105, doi:10.5194/acpd-15-12069-2015, 2015
How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?
Atmos. Chem. Phys. Discuss., 15, 12007-12067, doi:10.5194/acpd-15-12007-2015, 2015
The role of blowing snow in the activation of bromine over first-year Antarctic sea ice
Summary: This work analyzes the chemical composition of blowing snow collected over 1st-year Antarctic sea ice to assess its role in bromine activation during the polar sunrise. We found lofted snow to be depleted in Br- relative to Cl- by proportionally increasing amounts with height. This is the first study to use field data to substantiate modeling results implicating blowing snow as the location for initial halogen activation. We also found lofted snow to be depleted in SO4 and enriched in NO3.
Atmos. Chem. Phys. Discuss., 15, 11985-12005, doi:10.5194/acpd-15-11985-2015, 2015
Observations of atmospheric mercury in China: a critical review
Atmos. Chem. Phys. Discuss., 15, 11925-11983, doi:10.5194/acpd-15-11925-2015, 2015
On the statistical optimality of CO2 atmospheric inversions assimilating CO2 column retrievals
Summary: We demonstrate that a two-step approach to infer the CO2 surface fluxes from satellite measured radiances, with CO2 retrievals as an intermediate product, cannot be optimal. This suboptimality corrupts the 4D information flow from the radiance measurements to the surface flux estimates. It is amplified by current retrieval strategies where prior errors are much larger than the performance of prior CO2 simulations used in atmospheric inversions. We use the ACOS-GOSAT retrievals as an example and
Atmos. Chem. Phys. Discuss., 15, 11889-11923, doi:10.5194/acpd-15-11889-2015, 2015
Sensitivity of the recent methane budget to LMDz sub-grid scale physical parameterizations
Atmos. Chem. Phys. Discuss., 15, 11853-11888, doi:10.5194/acpd-15-11853-2015, 2015
Solar geoengineering using solid aerosol in the stratosphere
Summary: We investigate stratospheric aerosol geoengineering with solid particle injection by modeling the fractal structure of alumina aerosols and their interaction with background sulfate. We analyze the efficacy (W m^-2 of radiative forcing per megaton of injection) and risks (ozone loss) for both alumina and diamond particles as a function of injected monomer radius, finding 240 nm alumina and 160 nm diamond optimal. We discuss the limitations of our 2-D model study and associated uncertainties.
Atmos. Chem. Phys. Discuss., 15, 11799-11851, doi:10.5194/acpd-15-11799-2015, 2015
Relationships between photosynthesis and formaldehyde as a probe of isoprene emission
Summary: We apply two global observational datasets: gross primary productivity (GPP) and tropospheric formaldehyde column variability (HCHOv) to probe isoprene emission variability on large spatiotemporal scales. GPP and HCHOv are decoupled or weakly anti-correlated in regions and seasons when isoprene emission is high. Isoprene emission models that include soil moisture dependence demonstrate greater skill in reproducing observed seasonal GPP-HCHOv correlations in the southeast US and the Amazon.
Atmos. Chem. Phys. Discuss., 15, 11763-11797, doi:10.5194/acpd-15-11763-2015, 2015
The role of ice nuclei recycling in the maintenance of cloud ice in Arctic mixed-phase stratocumulus
Atmos. Chem. Phys. Discuss., 15, 11727-11761, doi:10.5194/acpd-15-11727-2015, 2015
The Amazon Tall Tower Observatory (ATTO) in the remote Amazon Basin: overview of first results from ecosystem ecology, meteorology, trace gas, and aerosol measurements
Summary: This paper describes the Amazon Tall Tower Observatory (ATTO), a new atmosphere-biosphere observatory located in the remote Amazon Basin. It presents results from ecosystem ecology, meteorology, trace gas, and aerosol measurements collected at the ATTO site during the first three years of operation.
Atmos. Chem. Phys. Discuss., 15, 11599-11726, doi:10.5194/acpd-15-11599-2015, 2015
Impact of ozone observations on the structure of a tropical cyclone using coupled atmosphere–chemistry data assimilation
Summary: In this study, the impact of O3 observations on the tropical cyclone (TC) structure is examined using the WRF-Chem with an ensemble-based data assimilation (DA) system. For a TC case that occurred over the East Asia, the ensemble forecast is reasonable and the O3 assimilation affects both chemical and atmospheric variables near the TC area. All measures indicate a positive impact of DA on the analysis – the cost function and root mean square error have decreased by 16.9% and 8.87%, respectively.
Atmos. Chem. Phys. Discuss., 15, 11573-11597, doi:10.5194/acpd-15-11573-2015, 2015
Effects of mineral dust on global atmospheric nitrate concentrations
Summary: We provide an assessment of the chemical composition and global aerosol load of aerosol nitrate and determine the effect of mineral dust on its formation due to thermodynamical interactions. For this purpose we used an explicit geographical representation of the emitted soil particle size distribution and chemical composition. We conclude that mineral dust aerosol chemistry is important for nitrate aerosol formation and significantly affects its global distribution, especially in the coarse mode
Atmos. Chem. Phys. Discuss., 15, 11525-11572, doi:10.5194/acpd-15-11525-2015, 2015
Particle hygroscopicity and its link to chemical composition in the urban atmosphere of Beijing, China during summertime
Atmos. Chem. Phys. Discuss., 15, 11495-11524, doi:10.5194/acpd-15-11495-2015, 2015
Atmospheric black carbon and sulfate concentrations in Northeast Greenland
Summary: Aerosols particles reach via long-range transport the high Arctic and have significant impacts on Arctic climate. This article demonstrates the comparison of measured and modelled aerosol mass concentrations for black carbon and sulfate particles at a high Arctic site. Based on the findings aging processes during transport seem to prolong the lifetimes of the two species and favor the possibility for their transport to the high Arctic.
Atmos. Chem. Phys. Discuss., 15, 11465-11493, doi:10.5194/acpd-15-11465-2015, 2015
Quantifying the contribution of long-range transport to Particulate Matter (PM) mass loadings at a suburban site in the North-Western Indo Gangetic Plain (IGP)
Summary: We quantify the contribution of long range transport to PM levels in the NW-IGP through back trajectory climatology analysis. Transport from the west significantly enhanced coarse and fine mode PM mass loadings during all seasons. Local pollution episodes enhanced coarse mode PM only during winter and fine mode PM during winter and summer season. South easterly air masses (Source region: SE-IGP) were associated with significantly lower fine and coarse mode PM mass loadings during all seasons.
Atmos. Chem. Phys. Discuss., 15, 11409-11464, doi:10.5194/acpd-15-11409-2015, 2015
Use of North American and European air quality networks to evaluate global chemistry-climate modeling of surface ozone
Summary: We test global-chemistry-climate models in their ability to simulate present-day surface ozone. Models are tested against observed hourly ozone from 4,217 stations in N. America and Europe that are averaged over 1°x1° grid cells. Using novel metrics, we find most models match the shape but not the amplitude of regional summertime diurnal and annual cycles and match the pattern but not the magnitude of summer ozone enhancement. Most also match the observed distribution of extreme episode sizes.
Atmos. Chem. Phys. Discuss., 15, 11369-11407, doi:10.5194/acpd-15-11369-2015, 2015
The impact of shipping emissions on air pollution in the Greater North Sea region – Part 2: Scenarios for 2030
Summary: Scenarios for future shipping emissions in the North Sea were developed. Compared to today, the contribution of shipping to the nitrogen dioxide and ozone concentrations will increase due to the expected enhanced traffic by more than 20% and 5%, respectively, by 2030 if no regulation for further emission reductions will be implemented. PM2.5 will decrease slightly because the sulphur contents in ship fuels will be reduced.
Atmos. Chem. Phys. Discuss., 15, 11325-11368, doi:10.5194/acpd-15-11325-2015, 2015
The impact of shipping emissions on air pollution in the Greater North Sea region – Part 1: Current emissions and concentrations
Summary: A multi-model approach consisting of a bottom-up ship emissions model and a chemistry transport model was used to evaluate the impact of shipping on air quality in North Sea bordering countries. As an example, the results of the simulations indicated that the relative contribution of ships to NO2 concentration levels ashore close to the sea can reach up to 25% in summer and 15% in winter. Some hundred kilometers away from the sea the contribution was about 6% in summer and 4% in winter.
Atmos. Chem. Phys. Discuss., 15, 11277-11323, doi:10.5194/acpd-15-11277-2015, 2015
Characterization of a real-time tracer for Isoprene Epoxydiols-derived Secondary Organic Aerosol (IEPOX-SOA) from aerosol mass spectrometer measurements
Atmos. Chem. Phys. Discuss., 15, 11223-11276, doi:10.5194/acpd-15-11223-2015, 2015
Comparison of the CMAM30 data set with ACE-FTS and OSIRIS: polar regions
Summary: The CMAM30 data set takes a chemistry-climate model and relaxes the dynamics to reanalysis, which can then provide chemistry fields not available from the reanalysis data set. This paper addresses this gap by comparing temperature, water vapour, ozone and methane to satellite data to determine and document any biases in the model fields. The lack of ozone destruction and dehydration in the SH polar vortex is shown to be due to the treatment of polar stratosphere clouds in the model.
Atmos. Chem. Phys. Discuss., 15, 11179-11221, doi:10.5194/acpd-15-11179-2015, 2015
Atmospheric new particle formation as source of CCN in the Eastern Mediterranean marine boundary layer
Summary: Cloud Condensation Nuclei (CCN) production associated with atmospheric new particle formation (NPF) is presented and this is the first direct evidence on CCN production resulting from NPF in the Eastern Mediterranean atmosphere. We show that condensation of both gaseous sulfuric acid and organic compounds from multiple sources leads to the rapid growth of nucleated particles. Sub-100nm particles were found to be substantially less hygroscopic than larger particles during the active NPF period
Atmos. Chem. Phys. Discuss., 15, 11143-11178, doi:10.5194/acpd-15-11143-2015, 2015
Heavy air pollution episodes in Beijing during January 2013: inorganic ion chemistry and source analysis using Highly Time-Resolved Measurements in an urban site
Summary: This paper focused on the air pollution episodes occurred in Beijing, China, during January of 2013. Highly time-resolved measurements of water soluble ions associated with PM2.5 were conducted at an urban site. The paper analyzed the potential roles of water-soluble ions in the formation of air pollution episodes, and found sulfate might be one of the key factors in episodes by analyzing ions compositions in different PM2.5 concentrations.
Atmos. Chem. Phys. Discuss., 15, 11111-11141, doi:10.5194/acpd-15-11111-2015, 2015
Multi-model evaluation of short-lived pollutant distributions over East Asia during summer 2008
Summary: This paper evaluate the ability of 6 global and one regional models in reproducing short-lived pollutants (defined here as ozone and its precursors, aerosols and black carbon) concentrations over Asia using satellite, ground-based and airborne observations. Key findings are that models reproduce homogeneously the trace gas observations although nitrous oxides are underestimated, whereas the aerosol distributions are heterogeneously reproduced implicating important uncertainties.
Atmos. Chem. Phys. Discuss., 15, 11049-11109, doi:10.5194/acpd-15-11049-2015, 2015
Monitoring compliance with sulphur content regulations of shipping fuel by in-situ measurements of ship emissions
Summary: On 1 January 2015, the International Maritime Organisation has tightened the regulations for sulfur content of shipping fuels in Sulfur Emission Control Areas. Here we present data from a station near Hamburg harbour in the North Sea SECA, which uses in-situ measurements of atmospheric trace gases to deduce the sulphur fuel content of passing ships. We compare data from 2014 before the regulation change and from January 2015 and show how this method can be used for compliance monitoring.
Atmos. Chem. Phys. Discuss., 15, 11031-11047, doi:10.5194/acpd-15-11031-2015, 2015
Characteristics and formation mechanism of continuous extreme hazes in China: a case study in autumn of 2014 in the North China Plain
Atmos. Chem. Phys. Discuss., 15, 10987-11029, doi:10.5194/acpd-15-10987-2015, 2015
On the scaling of the solar incident flux
Atmos. Chem. Phys. Discuss., 15, 10971-10986, doi:10.5194/acpd-15-10971-2015, 2015
What is the limit of stratospheric sulfur climate engineering?
Summary: The injection of sulfur dioxide is considered as an option for solar radiation management. We have calculated the effects of SO2 injections up to 100 Tg(S)/y. Our calculations show that the forcing efficieny of the injection decays exponentially. This result implies that SO2 injections in the order of 6 times Mt. Pinatubo eruptions per year are required to keep temperatures constant at that anticipated for 2020, whilst maintaining `business as usual' emission conditions.
Atmos. Chem. Phys. Discuss., 15, 10939-10969, doi:10.5194/acpd-15-10939-2015, 2015
Trace metal characterization of aerosol particles and cloud water during HCCT 2010
Atmos. Chem. Phys. Discuss., 15, 10899-10938, doi:10.5194/acpd-15-10899-2015, 2015
Biotic stress accelerates formation of climate-relevant aerosols in boreal forests
Summary: Global warming will induce large-scale insect outbreaks in boreal forests. Our results from field and laboratory experiments, satellite observations and global scale modelling suggest that more frequent insect outbreaks, in addition to temperature dependent increases in VOC emissions, could result in substantial increases in biogenic SOA formation and therefore affect both aerosol direct and indirect forcing of climate at regional scales. This should be considered in future climate predictions.
Atmos. Chem. Phys. Discuss., 15, 10853-10898, doi:10.5194/acpd-15-10853-2015, 2015
Sensitivity analysis of the potential impact of discrepancies in stratosphere–troposphere exchange on inferred sources and sinks of CO2
Summary: The upper troposphere and lower stratosphere (UTLS) is characterized by strong gradients in the distribution of long-lived tracers, which are sensitive to discrepancies in transport in models. We found that our model overestimates CO2 in the polar UTLS through comparison of modeled CO2 with aircraft observations. We then corrected the modeled CO2 and quantified the impact of the correction on the flux estimates using an atmospheric model together with atmospheric CO2 measured from a satellite.
Atmos. Chem. Phys. Discuss., 15, 10813-10851, doi:10.5194/acpd-15-10813-2015, 2015
Improvements in AOD retrieval from geostationary measurements over Asia with aerosol optical properties derived from the DRAGON-Asia campaign
Summary: Aerosol model optimized for East Asia is improved by applying inversion data from the DRAGON-Asia 2012 campaign, and is applied to an AOD retrieval algorithm using single visible measurement from GEO satellite. In sensitivity tests, a 4% overestimation in SSA can cause an underestimation over 20% in AOD. In accordance with the test, the overestimating tendency of AOD was improved by ~8% after the modification of the aerosol model.
Atmos. Chem. Phys. Discuss., 15, 10773-10812, doi:10.5194/acpd-15-10773-2015, 2015
Emissions of biogenic volatile organic compounds and subsequent formation of secondary organic aerosols in a Larix kaempferi forest
Summary: Simultaneous measurements of concentrations and above-canopy fluxes of isoprene and α-pinene in a forest, along with their oxidation products in aerosols, suggest that the inflow of anthropogenic precursors/aerosols enhanced the formation of both isoprene- and α-pinene-derived secondary organic aerosol (SOA) within the forest canopy even when the flux was low. We also emphasize the role of vegetation/soils near the forest floor as important sources of isoprene and α-pinene in the forest.
Atmos. Chem. Phys. Discuss., 15, 10739-10771, doi:10.5194/acpd-15-10739-2015, 2015
Parameterizations for convective transport in various cloud-topped boundary layers
Summary: By using Large-Eddy Simulation model data for 10 meteorological situations, we systematically studied the ability of current parameterizations, used in large-scale models, to capture convective transport by clouds. We found that the currently applied parameterization for the cloud area fraction does not suffice and a novel parameterization is proposed. Furthermore, the scaling of the upward velocity and the parameterization for the concentrations of atmospheric reactants are improved.
Atmos. Chem. Phys. Discuss., 15, 10709-10738, doi:10.5194/acpd-15-10709-2015, 2015
Particulate organic nitrates observed in an oil and natural gas production region during wintertime
Summary: Secondary organic aerosol affects both the environment and human health. We characterized the aerosol composition in Uintah Basin by measuring the concentration of nitrooxy group moiety which is produced through chemical interaction of volatile organic compounds and NOx emitted largely from local human activity. We found nitrooxy compounds to be a persistent, if not dominant, portion of fine aerosol mass. Similar results may be expected from emissions due to traffic in cities.
Atmos. Chem. Phys. Discuss., 15, 10677-10708, doi:10.5194/acpd-15-10677-2015, 2015
Variability of air ion concentrations in urban Paris
Atmos. Chem. Phys. Discuss., 15, 10629-10676, doi:10.5194/acpd-15-10629-2015, 2015
A PV-based determination of the transport barrier in the Asian summer monsoon anticyclone
Atmos. Chem. Phys. Discuss., 15, 10593-10628, doi:10.5194/acpd-15-10593-2015, 2015
Secondary organic aerosol formation from photochemical aging of light-duty gasoline vehicle exhausts in a smog chamber
Atmos. Chem. Phys. Discuss., 15, 10553-10592, doi:10.5194/acpd-15-10553-2015, 2015
Aerosol characterization over the southeastern United States using high resolution aerosol mass spectrometry: spatial and seasonal variation of aerosol composition, sources, and organic nitrates
Summary: Year-long comprehensive characterization of ambient aerosol was performed in both rural and urban sites in the southeastern US as part of Southeastern Center of Air Pollution and Epidemiology (SCAPE) study and Southeastern Oxidant and Aerosol Study (SOAS). Three independent methods were applied to estimate the concentration of particle-phase organic nitrates. The spatial distribution of organic aerosol is investigated by comparing simultaneous HR-ToF-AMS and ACSM measurements at different sites.
Atmos. Chem. Phys. Discuss., 15, 10479-10552, doi:10.5194/acpd-15-10479-2015, 2015
Current model capabilities for simulating black carbon and sulfate concentrations in the Arctic atmosphere: a multi-model evaluation using a comprehensive measurement data set
Summary: The concentrations of sulfate, black carbon and other aerosols in the Arctic are characterized by high values in late winter and spring (so-called Arctic Haze) and low values in summer. Models have long been struggling to capture this seasonality. In this study, we evaluate sulfate and BC concentrations from different updated models and emissions against a comprehensive pan-Arctic measurement data set. We find that the models improved, but still struggle to get the maximum concentrations.
Atmos. Chem. Phys. Discuss., 15, 10425-10477, doi:10.5194/acpd-15-10425-2015, 2015
Source attribution and process analysis for atmospheric mercury in East China simulated by CMAQ-Hg
Summary: This study estimated the contributions to mercury concentration and deposition in East China from seven categories of emission sources by CMAQ-Hg. Also, this study focuses on diagnostic and process analysis for atmospheric mercury pollution formation and identification of the dominant atmospheric processes for mercury.
Atmos. Chem. Phys. Discuss., 15, 10389-10424, doi:10.5194/acpd-15-10389-2015, 2015
Variability of aerosols forecast over the Mediterranean area during July 2013 (ADRIMED/CHARMEX)
Summary: The atmospheric composition was extensively studied in the Euro-Mediterranean region and during the summer 2013, in the framework of the ADRIMED project. During the campaign experiment, the WRF and CHIMERE models were used in forecast mode in order to help scientists to decide whether Intensive Observation Periods should be triggered or not. This study quantifies the origin of the forecast error by comparing several forecast leads to the corresponding measurements.
Atmos. Chem. Phys. Discuss., 15, 10341-10388, doi:10.5194/acpd-15-10341-2015, 2015
Effects of urban land expansion on the regional meteorology and air quality of Eastern China
Summary: In This paper, We examine the response of a range of meteorological and air quality indicators to the expansion of urban land using WRF/Chem. Our study indicates that 1) the responses of some meteorological factors and pollutant concentrations to the spatial extent of urbanization are linear near the surface, but nonlinear at higher altitudes; 2) urban heat island circulation and a deeper boundary layer with stronger turbulent intensities play significant roles in relocating the pollutants.
Atmos. Chem. Phys. Discuss., 15, 10299-10340, doi:10.5194/acpd-15-10299-2015, 2015
A mechanism for biologically-induced iodine emissions from sea-ice
Atmos. Chem. Phys. Discuss., 15, 10257-10297, doi:10.5194/acpd-15-10257-2015, 2015
Uncertainties in global aerosols and climate effects due to biofuel emissions
Summary: We examine sensitivities in aerosol concentration and climate effects from biofuel combustion emissions. We find a strong sensitivity in the overall sign and magnitude of the direct radiative effect and cloud-albedo indirect effect due to uncertainties regarding emissions size distribution, composition, mass, and optical mixing-state. This uncertainty limits our ability to evaluate black carbon mitigation strategies to counter warming effects from greenhouse-gases.
Atmos. Chem. Phys. Discuss., 15, 10199-10256, doi:10.5194/acpd-15-10199-2015, 2015
Detection of anthropogenic dust using CALIPSO lidar measurements
Atmos. Chem. Phys. Discuss., 15, 10163-10198, doi:10.5194/acpd-15-10163-2015, 2015
Receptor modelling of both particle composition and size distribution from a background site in London, UK
Summary: Particles in the air of London have been assessed both by weight and by number. They have also been subject to chemical analysis. The data from two years of sampling have been used to investigate the sources contributing to the measured concentrations both in terms of the weight of the particles and the number of particles.
Atmos. Chem. Phys. Discuss., 15, 10123-10162, doi:10.5194/acpd-15-10123-2015, 2015
A method for merging nadir-sounding climate records, with an application to the global-mean stratospheric temperature data sets from SSU and AMSU
Summary: This is the first paper of its kind describing a method for merging the long-term satellite records of global stratospheric temperature from SSU and AMSU to yield a continuous data set from 1979 to present (and beyond). Since global-mean stratospheric temperature is close to radiative equilibrium, our "extended" SSU data set is an important climate record for the detection and attribution of anthropogenic influence.
Atmos. Chem. Phys. Discuss., 15, 10085-10122, doi:10.5194/acpd-15-10085-2015, 2015
A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations
Summary: Employing the well-established "Match" technique, we quantify polar stratospheric ozone loss during multiple Arctic and Antarctic winters, based on observations from the spaceborne Aura Microwave Limb Sounder (MLS) instrument. The dense MLS spatial coverage enables many more matches than is possible for balloon-based observations. Applying the same technique to MLS observations of the long-lived N2O molecule gives an measure of the impact of transport errors on our ozone loss estimates.
Atmos. Chem. Phys. Discuss., 15, 10041-10083, doi:10.5194/acpd-15-10041-2015, 2015
The influences of mass loading and rapid dilution of secondary organic aerosol on particle volatility
Summary: Secondary organic aerosol from the dark ozonolysis of α‑pinene was formed at a range of mass loadings from 1-800μg m-3. The amount of mass loss during evaporation in a thermodenuder was found to be independent of mass loading. A kinetic model of evaporation was fit to the observations and good agreement was obtained when the particle was either composed of dimers that decompose into semi-volatile monomers or when it was composed of low-volatility compounds that evaporate directly.
Atmos. Chem. Phys. Discuss., 15, 9997-10039, doi:10.5194/acpd-15-9997-2015, 2015
Impact of different Asian source regions on the composition of the Asian monsoon anticyclone and on the extratropical lowermost stratosphere
Summary: The Asian summer monsoon circulation is an important global circulation system associated with strong upward transport of tropospheric source gases. We show that the contribution of different boundary source regions to the Asian monsoon anticyclone strongly depends on its intraseasonal variability and that emissions from Asia have a significant impact on the chemical compositions of the lowermost stratosphere of the northern hemisphere at the end of the monsoon season in Sep./Oct. 2012.
Atmos. Chem. Phys. Discuss., 15, 9941-9995, doi:10.5194/acpd-15-9941-2015, 2015
Particle sized-resolved source apportionment of primary and secondary organic tracer compounds at urban and rural locations in Spain
Summary: Molecular organic tracer compounds were analyzed in six particle sizes in an urban background site (Barcelona) and in a rural site in Spain. The results improve considerably our current understanding on the composition and particle-size distribution of organic air pollution in traffic intensive urban areas and rural sites where combustion of biomass plays an important role on the local and regional air quality, either by emissions from open fires or from domestic heating.
Atmos. Chem. Phys. Discuss., 15, 9897-9939, doi:10.5194/acpd-15-9897-2015, 2015
Development and optimization of a wildfire plume rise model based on remote sensing data inputs – Part 2
Summary: The transport of Biomass Burning emissions in Chemical Transport Model rely on parametrization of plumes injection height. Using fire observation selected to ensure match-up of fire-atmosphere-plume dynamics; a popular plume rise model was improved and optimized. The resulting model shows response to the effect of atmospheric stability consistent with previous findings and is able to predict higher injection height than any other tested parametrizations, giving a closer match with observation.
Atmos. Chem. Phys. Discuss., 15, 9815-9895, doi:10.5194/acpd-15-9815-2015, 2015
Meteor radar quasi two-day wave observations over 10 years at Collm (51.3° N, 13.0° E)
Atmos. Chem. Phys. Discuss., 15, 9631-9659, doi:10.5194/acpd-15-9631-2015, 2015
Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities
Summary: Technological shifts between fuel sources have had unexpected impacts on atmospheric composition and these significant changes can go undetected if source-specific monitoring infrastructure is not in place. We present chemically comprehensive, continuous measurements of organic compounds in a developed megacity (London), that show diesel-related hydrocarbons can dominate reactive carbon and ozone formation potential, highlighting a serious underestimation of this source in emission inventories.
Atmos. Chem. Phys. Discuss., 15, 9541-9571, doi:10.5194/acpd-15-9541-2015, 2015
Vertical profiling of aerosol hygroscopic properties in the planetary boundary layer during the PEGASOS campaigns
Summary: This study presents PEGASOS project data from field campaigns in the Po Valley, Italy and the Netherlands. Vertical profiles of aerosol hygroscopicity and chemical composition were investigated with airborne measurements on board a Zeppelin NT airship. A special focus was on the evolution of different mixing layers within the PBL as a function of daytime. A closure study showed that variations in aerosol hygroscopicity can well be explained by the variations in chemical composition.
Atmos. Chem. Phys. Discuss., 15, 9445-9505, doi:10.5194/acpd-15-9445-2015, 2015
Size-resolved source apportionment of particulate matter in urban Beijing during haze and non-haze episodes
Summary: Size-resolved chemical information of particulate matter remains unclear in China due to a paucity of measurement data. One-year observation of water-soluble ions, carbonaceous species and trace elements in size-resolved particles with cutoff points as 0.43, 0.65, 1.1, 2.1, 3.3, 4.7, 5.8 and 9.0μm were conducted in mega city Beijing. This unique dataset provided multidimensional insights into the sources among different size fractions, seasons or wind flows and between non-haze and haze days.
Atmos. Chem. Phys. Discuss., 15, 9405-9443, doi:10.5194/acpd-15-9405-2015, 2015
Radiative forcing and climate response to projected 21st century aerosol decreases
Summary: Decreases in aerosols over the 21st century as projected by the Representative Concentration Pathways (RCPs) lead to increases up to 1 ºC in global temperature and up to 0.1 mm/day in global precipitation. In East Asia and other regions, future aerosol decreases could be responsible for 30-40% of total climate warming by 2100, even under the high greenhouse gas emissions scenario (RCP8.5). Radiative forcing and climate response to decreasing aerosols is largely similar in each of the RCPs.
Atmos. Chem. Phys. Discuss., 15, 9293-9353, doi:10.5194/acpd-15-9293-2015, 2015
Springtime variability of lower tropospheric ozone over Eastern Asia: contributions of cyclonic activity and pollution as observed from space with IASI
Atmos. Chem. Phys. Discuss., 15, 9203-9252, doi:10.5194/acpd-15-9203-2015, 2015
The role of semi-volatile organic compounds in the mesoscale evolution of biomass burning aerosol: a modelling case study of the 2010 mega-fire event in Russia
Summary: (1) The mesoscale evolution of aerosol from open biomass burning (BB) has been successfully simulated using the volatility basis set (VBS) approach to organic aerosol (OA) modeling. (2) The simulations made for the region and period affected by the Russian 2010 wildfires are found to be inconsistent with available measurements, when OA ageing processes are essentially disregarded. (3) Using the VBS approach improves the agreement of "top-down" and "bottom-up" estimates of BB aerosol emissions.
Atmos. Chem. Phys. Discuss., 15, 9107-9172, doi:10.5194/acpd-15-9107-2015, 2015
PLAM – a meteorological pollution index for air quality and its applications in fog-haze forecasts in north China
Summary: On the basis of parameterized meteorological condition principle method, this paper discussed the mutual impact of emission and meteorological condition, and studied the structure and function of meteorological conditions PLAM index in quantitatively identifying, diagnosing and forecasting large scope of fog-haze weather. A new model of PLAM/h – the meteorological pollution Index for air quality has been developed and used in NRT air quality forecasts, by considering both meteorology and polluta
Atmos. Chem. Phys. Discuss., 15, 9077-9106, doi:10.5194/acpd-15-9077-2015, 2015
Contribution from biogenic organic compounds to particle growth during the 2010 BEACHON-ROCS campaign in a Colorado temperate needle leaf forest
Atmos. Chem. Phys. Discuss., 15, 9033-9075, doi:10.5194/acpd-15-9033-2015, 2015
Comparing the CarbonTracker and TM5-4DVar data assimilation systems for CO2 surface flux inversions
Summary: We compare two different data assimilation systems for estimating sources and sinks of CO_2 from a concentration measurements. The systems are Carbontracker and TM5-4DVar, which have both been used in a number of scientific studies. We analyze the differences between both models as well as the sensitivity of the estimated sources and sinks to the observation coverage. The results provide a lower limit for the uncertainty of surface carbon fluxes with the current measurement network.
Atmos. Chem. Phys. Discuss., 15, 8883-8932, doi:10.5194/acpd-15-8883-2015, 2015
A tropospheric chemistry reanalysis for the years 2005–2012 based on an assimilation of OMI, MLS, TES and MOPITT satellite data
Summary: This paper reports on an eight-year reanalysis of tropospheric chemistry based on an assimilation of multiple satellite-derived data sets. The reanalysis performed well on regional and global scales and for seasonal and interannual variations. The simultaneous assimilation of multiple species data, involving the optimisation of both concentration and emission fields, provides unique information on year-to-year variations of the atmospheric environment.
Atmos. Chem. Phys. Discuss., 15, 8687-8770, doi:10.5194/acpd-15-8687-2015, 2015
In-situ, satellite measurement and model evidence for a~dominant regional contribution to fine particulate matter levels in the Paris Megacity
Summary: A detailed characterization of air quality in Paris (France), a megacity of more than 10 million inhabitants, during two one month intensive campaigns and from additional one year observations, revealed that about 70% of the fine particulate matter (PM) at urban background is transported on average into the megacity from upwind regions. A major part of organic PM is of modern origin (woodburning, cooking activities, secondary formation from biogenic VOC).
Atmos. Chem. Phys. Discuss., 15, 8647-8686, doi:10.5194/acpd-15-8647-2015, 2015
Past changes in the vertical distribution of ozone – Part 3: Analysis and interpretation of trends
Summary: Trends in the vertical distribution of ozone are reported for new and recently revised datasets. The amount of ozone-depleting compounds in the stratosphere peaked in the second half of the 1990s. We examine the trends before and after that peak to see if any change in trend is discernible. The previously reported decreases are confirmed. Further the downward trend in upper stratospheric ozone has not continued. The possible significance of any increase is discussed in detail.
Atmos. Chem. Phys. Discuss., 15, 8565-8608, doi:10.5194/acpd-15-8565-2015, 2015
Deriving polarization properties of desert-reflected solar spectra with PARASOL data
Atmos. Chem. Phys. Discuss., 15, 8525-8564, doi:10.5194/acpd-15-8525-2015, 2015
Airborne measurements of new particle formation in the free troposphere above the Mediterranean Sea during the HYMEX campaign
Summary: In the present paper, we report airborne measurements of new particle formation (NPF) above the Mediterranean sea (HYMEX campaign). We show that NPF is occurring over large areas above the sea but the process is clearly promoted at high altitude, above 1000 m, i.e. frequently in the free troposphere. Also, NPF seems to be mainly influenced by local processes occurring above the sea. After they formed, particles slowly grow at high altitude while being poorly depleted by coagulation processes.
Atmos. Chem. Phys. Discuss., 15, 8151-8189, doi:10.5194/acpd-15-8151-2015, 2015
OMI tropospheric NO2 profiles from cloud slicing: constraints on surface emissions, convective transport and lightning NOx
Atmos. Chem. Phys. Discuss., 15, 8017-8072, doi:10.5194/acpd-15-8017-2015, 2015
Utilization of O4 slant column density to derive aerosol layer height from a spaceborne UV-visible hyperspectral sensor: sensitivity and case study
Summary: The sensitivities of oxygen-dimer (O4) slant column densities (SCDs) to changes in aerosol layer height are investigated using simulated radiances by a radiative transfer model, Linearized Discrete Ordinate Radiative Transfer (LIDORT), and Differential Optical Absorption Spectroscopy (DOAS) technique. A new algorithm is developed and tested to derive the aerosol effective height for cases over East Asia using radiance data from the Ozone Monitoring Instrument (OMI).
Atmos. Chem. Phys. Discuss., 15, 7933-7975, doi:10.5194/acpd-15-7933-2015, 2015
Two decades of water vapor measurements with the FISH fluorescence hygrometer: a review
Atmos. Chem. Phys. Discuss., 15, 7735-7782, doi:10.5194/acpd-15-7735-2015, 2015
A comprehensive inventory of ship traffic exhaust emissions in the European sea areas in 2011
Summary: This manuscript describes the emissions from shipping in European sea areas. The work is based on automatic position reports (AIS) sent by ships and reflects realistic activity patterns of ships. The work demonstrates that it is feasible to construct a full bottom-up emission inventories based on large-volume activity data sets.
Atmos. Chem. Phys. Discuss., 15, 7459-7491, doi:10.5194/acpd-15-7459-2015, 2015
The impact of speciated VOCs on regional ozone increment derived from measurements at the UK EMEP supersites between 1999 and 2012
Summary: In this study the regional component of ground level ozone is linked to the chemical loss of 27 measured VOCs at two UK monitoring sites, and integrated with gridded European VOC emissions. The relative VOC chemical loss indicates that emission controls of a large number of VOCs, and targeting VOCs with highest chemical loss, are both required to reduce regional ozone. The benefit resulting from the disaggregation of VOC source sectors to the identification of high VOC emitting sources is shown.
Atmos. Chem. Phys. Discuss., 15, 7267-7308, doi:10.5194/acpd-15-7267-2015, 2015
Five-year flask measurements of long-lived trace gases in India
Summary: We present 5-year flask measurements (2007–2011) of greenhouse gases (GHGs) at three atmospheric stations in India. The results suggest significant sources of CO2, CH4, N2O, CO, and H2 over South and NE India, while SF6 sources are weak. The seasonal cycles for each species reflect the seasonality of sources/sinks and influences of the Indian monsoon circulations. The data show potential to infer regional patterns of GHG fluxes and atmospheric transport over this under-documented region.
Atmos. Chem. Phys. Discuss., 15, 7171-7238, doi:10.5194/acpd-15-7171-2015, 2015
Analysis of CO2 mole fraction data: first evidence of large-scale changes in CO2 uptake at high northern latitudes
Summary: The two new results from our analysis are: 1) a significant revision to phase changes in atmospheric CO2 and 2) an indirect observation that is consistent with high northern latitude ecosystems actively taking up more CO2.
Atmos. Chem. Phys. Discuss., 15, 7089-7139, doi:10.5194/acpd-15-7089-2015, 2015
Seasonal trends in concentrations and fluxes of volatile organic compounds above central London
Summary: Concentrations and fluxes of selected volatile organic compounds were measured over a five month period in central London as part of the ClearfLo project using a proton transfer reaction-mass spectrometer. Emission sources within the city were inferred from spatio-temporal patterns and showed a non-negligible biogenic source during warmer months, which was modelled using the Guenther 95 algorithm. Comparisons were made with the local emissions inventories showing mostly underestimated emissions.
Atmos. Chem. Phys. Discuss., 15, 6601-6644, doi:10.5194/acpd-15-6601-2015, 2015
Water vapour profiles from Raman lidar automatically calibrated by microwave radiometer data during HOPE
Summary: We present a method to derive water vapour profiles from Raman lidar measurements calibrated by the integrated water vapour from a collocated microwave radiometer. These simultaneous observations provide an operational and continuous measurement of water vapour profiles. The stability of the calibration factor allows to calibrate the lidar even in the presence of clouds. Based on this approach water vapour profiles can be retrieved during all non-precipitating conditions.
Atmos. Chem. Phys. Discuss., 15, 6567-6599, doi:10.5194/acpd-15-6567-2015, 2015
Effect of atmospheric ageing on volatility and ROS of biodiesel exhaust nano-particles
Summary: The study concludes that more saturated and more oxygenated diesel fuels caused more volatile particles carrying more reactive oxygenated species whether before or after ageing. Flow-throw reactors are reliable tools for carrying out experiments on diesel exhaust ageing and finding out the potential of diesel fuels in generation of secondary organic aerosols.
Atmos. Chem. Phys. Discuss., 15, 6481-6508, doi:10.5194/acpd-15-6481-2015, 2015
Source apportionment of methane and nitrous oxide in California's San Joaquin Valley at CalNex 2010 via positive matrix factorization
Summary: We perform a positive matrix factorization (PMF) based source apportionment by combining GHG measurements with coincident VOC measurements in the San Joaquin valley of California. Using VOCs as source tracers, we identify dairies and livestock as major sources of CH4 and N2O in the region. Agriculture is a significant source of N2O enhancements too, while vehicle emissions are found to be a negligible source of N2O. The findings are relevant to the state’s GHG inventory verification process.
Atmos. Chem. Phys. Discuss., 15, 6077-6124, doi:10.5194/acpd-15-6077-2015, 2015
Partitioning and budget of inorganic and organic chlorine species observed by MIPAS-B and TELIS in the Arctic in March 2011
Atmos. Chem. Phys. Discuss., 15, 5391-5422, doi:10.5194/acpd-15-5391-2015, 2015
Global evaluation of ammonia bi-directional exchange
Atmos. Chem. Phys. Discuss., 15, 4823-4877, doi:10.5194/acpd-15-4823-2015, 2015
Ozone and NOx chemistry in the eastern US: evaluation of CMAQ/CB05 with satellite (OMI) data
Atmos. Chem. Phys. Discuss., 15, 4427-4461, doi:10.5194/acpd-15-4427-2015, 2015
Black carbon emissions from Russian diesel sources: case study of Murmansk
Summary: We estimated BC emissions from diesel sources in Murmansk Region and Murmansk City, the largest city in the Arctic. We developed a detailed inventory including on-road vehicles, off-road transport (mining, locomotives, construction and agriculture), fishing and diesel generators. We conducted several surveys to understand the vehicle fleet and driving patterns. BC emissions in Murmansk Region were 0.40 Gg in 2012. Total BC emissions from diesel sources in Russia estimated at 56.7 Gg in 2010.
Atmos. Chem. Phys. Discuss., 15, 3257-3284, doi:10.5194/acpd-15-3257-2015, 2015
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).
Atmos. Chem. Phys. Discuss., 15, 2355-2404, doi:10.5194/acpd-15-2355-2015, 2015
Ice nucleation terminology
Atmos. Chem. Phys. Discuss., 14, 22155-22162, doi:10.5194/acpd-14-22155-2014, 2014