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CDM in Africa - Finance and Support
As early as 2006, Parties to the Kyoto Protocol recognized the importance of a balanced regional distribution of CDM projects and welcomed the establishment of the Nairobi Framework, which brings together UN and regional organizations to support equitable access to the mechanism. In light of the benefits that the CDM can bring to lesser developed regions, the Nairobi Framework partners and others began funding technical support and capacity-building programmes for the CDM, particularly in Africa. The following pages provide a short description of the most important financing and support opport ...
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Benefits of the Clean Development Mechanism 2012
This study assesses the claims made by project participants in the project design documents submitted for registration. The relative reliability of these claims, as verified by a follow-up survey, suggests that the CDM is making a contribution to sustainable development in host countries in addition to the mitigation of greenhouse gas (GHG) emissions. Almost all CDM projects claim multiple sustainable development benefits, but the mix of benefits claimed varies considerably by project type.
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The World’s Worst Pollution Problems : Assessing Health Risks at Hazardous Waste Sites
The World’s Worst Pollution Problems: Assessing Health Risks at Hazardous Waste Sites report reveals that close to 125 million people are at risk from toxic pollution across 49 low to middle-income countries. Also, the report, for the first time estimates the total global burden of disease attributed to toxic pollution from industrial sites in these countries. It establishes the global burden of disease from toxic pollution as on par with better-known public health problems such as malaria and tuberculosis.
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Green growth -- lessons from growth theory
This paper reviews dynamic general equilibrium models in order to collect insights on the interaction between economic growth and environmental issues. The authors discuss the Ramsey model and extend it for natural resource inputs and pollution, as well as for endogenous technical change. Green growth becomes within reach if there is good substitution, a clean backstop technology, a small share of natural resources in gross domestic product, and/or green directed technical change.
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Zones in relation to EU air quality thresholds, 2010 : In EEA Datasets
EEA, 2012Member States provide an annual assessment of air quality in comparison to EU air quality thresholds.
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Air & Climate: conversations about molecules and planets, with humans in between
European Commission, 2012This is a collection of conversations with some of the ‘fathers’ of air pollution and climate change science. Through careful observation and a mix of intuition and critical thought, they have uncovered some of the workings of our planet: its atmosphere and climate. They were generally driven by curiosity and gradually by a concern that mankind might indeed have a devastating impact on Earth and the life it hosts. Their findings were so important that they could not stay in the ivory tower of scientific research. They personally reached out to decision makers and the public at large because in ...
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Climate change and agriculture: can market governance mechanisms reduce emissions from the food system fairly and effectively?
Agriculture accounts for 30 per cent of global greenhouse gas emissions. How agriculture is practised, therefore, has significant potential for mitigating climate change, providing food security and improving the livelihoods of food producers worldwide. There is growing interest in the use of market governance mechanisms for tackling climate change by giving the financial incentives to make the required changes. The key messages emerging from this study are that economic measures have a vital part to play, but to be effective, emissions from food production and consumption must be addressed to ...
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Progress report on the work of the Consultative Group of Experts on National Communications from Parties not included in Annex I to the Convention: report on the hands-on training workshop for the Africa region on national greenhouse gas inventories (Note by the Secretariat)
UNFCCC, 2012The Consultative Group of Experts on National Communications from Parties not included in Annex I to the Convention (CGE), in collaboration with the Technical Support Unit for the Intergovernmental Panel on Climate Change Task Force on National Greenhouse Gas Inventories, organized a hands-on training workshop for the Africa region on national greenhouse gas inventories, held in Swakopmund, Namibia, from 23 to 27 April 2012. This report outlines the proceedings of the workshop; it summarizes the feedback and recommendations from the participants of the workshop, the updated CGE training ...
Climate and clean air coalition to reduce short-lived climae pollutants (CCAC)
The Coalition's initial focus is on methane, black carbon, and HFCs. At the same time, Partners recognize that action on Short lived climate pollutants must complement and supplement, not replace, global action to reduce carbon dioxide, in particular efforts under the UNFCCC.
The Coalition's objectives are to address short lived climate pollutants by: Raising awareness of short lived climate pollutant impacts and mitigation strategies; Enhancing and developing new national and regional actions, including by identifying and overcoming barriers, enhancing capacity, and mobilizing ...
Health effects of black carbon
WHO, 2012This report presents the results of a systematic review of evidence of the health effects of black carbon (BC). The Task Force on Health agreed that a reduction in exposure to PM2.5 containing BC and other combustion-related PM material for which BC is an indirect indicator should lead to a reduction in the health effects associated with PM. The Task Force recommended that PM2.5 should continue to be used as the primary metric in quantifying human exposure to PM and the health effects of such exposure, and for predicting the benefits of exposure reduction measures. The use of BC as an addition ...
European Union emission inventory report 1990–2010 under the UNECE Convention on Long-range Transboundary Air Pollution
EEA, 2012This document is the annual European Union emission inventory report under the United Nations Economic Commission for Europe (UNECE) Convention on Long-range Transboundary Air Pollution (LRTAP). The report and its accompanying data are provided as an official submission to the secretariat for the Executive Body of the LRTAP Convention by the European Commission on behalf of the European Union. The report is compiled by the European Environment Agency (EEA).
Down to earth: territorial approach to climate change - Green, Low-Emission and Climate-Resilient Development Strategies at the Sub-national Level, 2012 update
UNDP, 2012This guidebook provides background information on Early Childhood Development (ECD) and Disaster Risk Reduction (DRR), and sets out processes for assessing the capacity and needs at community levels to further identify future steps to improve ECD in DRR. Furthermore, it addresses the vulnerability faced by children and the efforts to mitigate underlying causes of these vulnerabilities. Beyond national and international, policy and political issues, DRR occurs within communities and at the programme level. DRR processes and activities have the potential to address the special needs of young chi ...
Energy Resources Development Series, 41. Low Carbon Green Growth Roadmap for Asia and the Pacific
UNCTAD, 2012he report explores the opportunities that a low carbon green growth path offers to the region. It articulates five tracks on which to drive the economic system change necessary to pursue low carbon green growth as a new economic development path.
In particular, the “visible structure” of the economy, comprising such physical infrastructure as transport, buildings and energy systems, together with the “invisible structure”, which encompasses market prices, governance, regulations and lifestyles, have to be re-oriented towards resource efficiency. The Roadmap provides policymakers ...
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The Little Green Data Book 2012
World Bank, 2012The Little Green Data Book is a pocket-sized ready reference on key environmental data for over 200 economies. Key indicators are organized under the headings of agriculture, forestry, biodiversity, energy, emission and pollution, and water and sanitation.
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Sustainable low-carbon city development in China
Cities contribute an estimated 70 percent of the world's energy-related greenhouse gases (GHG). Their locations, often in low-elevation coastal zones, and large populations make them particularly vulnerable to the impacts of climate change. But cities often take steps, even ahead of national governments, to reduce GHG emissions. So it is with China's cities, which are well placed to chart a low-carbon growth path to help reach China's national targets for reducing the energy and carbon intensity of its economy. China's cities will need to act on multiple fronts, in some cases scaling up elemen ...
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Agricultural GHGs in East and West Africa baseline emissions and mitigation potential
Emissions of greenhouse gases (GHGs) from agriculture are substantial. This paper looks into how can agricultural greenhouse gas emissions be reduced or sequestration enhanced while maintaining and even increasing food supply. The paper relies on a research undertaken in nine chosen African countries.
The authors reveal that croplands and grazing lands cover more than half of the East African countries’ lands and about 40% of the West African countries’ lands. In the nine African countries, the largest amount of GHG emissions is from the livestock sector, followed by emissions f ...
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Estrategia Nacional para Fortalecer los Recursos Humanos y las Habilidades para Avanzar hacia un Desarrollo Verde, con Bajas Emisiones y Resiliencia Climática
UN CC:Learn, 2012
Seasonal variability in the optical properties of Baltic aerosols
A five-year dataset of spectral aerosol optical thickness was used to analyse the seasonal variability of aerosol optical properties (the aerosol optical thickness (AOT) at wavelength λ=500 nm, AOT(500) and the Ångström exponent for the 440-870 nm spectral range, α(440, 870)) over the Baltic Sea and dependence of these optical properties on meteorological factors (wind direction, wind speed and relative humidity). The data from the Gotland station of the global radiometric network AERONET (Aerosol Robotic Network, http://aeronet.gsfc.nasa.gov) were taken to be representative of the Baltic Sea ...
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Evaluation of the accuracy of analysis tools for atmospheric new particle formation
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Korhonen H.; Sihto S.-L.; Kerminen V.-M.; et al. - Copernicus GmbH, 2011Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3 nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3) showed significant sensitivity to the details of the analysis, i.e. form of equations used and assumptions made about the initial size of nucleating clusters, with the fraction o ...
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Analysis of number size distributions of tropical free tropospheric aerosol particles observed at Pico Espejo (4765 m a.s.l.), Venezuela
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Schmeissner T.; Krejci R.; Ström J.; et al. - Copernicus GmbH, 2011The first long-term measurements of aerosol number and size distributions in South-American tropical free troposphere (FT) were performed from March 2007 until March 2009. The measurements took place at the high altitude Atmospheric Research Station Alexander von Humboldt. The station is located on top of the Sierra Nevada mountain ridge at 4765 m a.s.l. nearby the city of Mérida, Venezuela. Aerosol size distribution and number concentration data was obtained with a custom-built Differential Mobility Particle Sizer (DMPS) system and a Condensational Particle Counter (CPC). The analysis of the ...
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Microphysical and radiative effects of aerosols on warm clouds during the Amazon biomass burning season as observed by MODIS: impacts of water vapor and land cover
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Ten Hoeve J.E.; Remer L.A.; Jacobson M.Z. - Copernicus GmbH, 2011Aerosol, cloud, water vapor, and temperature profile data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are utilized to examine the impact of aerosols on clouds during the Amazonian biomass burning season in Rondônia, Brazil. It is found that increasing background column water vapor (CWV) throughout this transition season between the Amazon dry and wet seasons likely exerts a strong effect on cloud properties. As a result, proper analysis of aerosol-cloud relationships requires that data be stratified by CWV to account better for the influence of background meteorological vari ...
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Projections of air pollutant emissions and its impacts on regional air quality in China in 2020
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Xing J.; Wang S.X.; Chatani S.; et al. - Copernicus GmbH, 2011Anthropogenic emissions of air pollutants in China influence not only local and regional environments but also the global atmospheric environment; therefore, it is important to understand how China's air pollutant emissions will change and how they will affect regional air quality in the future. Emission scenarios in 2020 were projected using forecasts of energy consumption and emission control strategies based on emissions in 2005, and on recent development plans for key industries in China. We developed four emission scenarios: REF[0] (current control legislations and implementation status), ...
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A two-dimensional volatility basis set: 1. organic-aerosol mixing thermodynamics
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Donahue N.M.; Epstein S.A.; Pandis S.N.; et al. - Copernicus GmbH, 2011We develop the thermodynamic underpinnings of a two-dimensional volatility basis set (2D-VBS) employing saturation mass concentration (Co) and the oxygen content (O:C) to describe volatility, mixing thermodynamics, and chemical evolution of organic aerosol. The work addresses a simple question: "Can we reasonably constrain organic-aerosol composition in the atmosphere based on only two measurable organic properties, volatility and the extent of oxygenation?" This is an extension of our earlier one-dimensional approach employing volatility only (C* = γ Co, where γ is an activity coefficient). U ...
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On the potential contribution of open lead particle emissions to the central Arctic aerosol concentration
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Held A.; Brooks I.M.; Leck C.; et al. - Copernicus GmbH, 2011We present direct eddy covariance measurements of aerosol number fluxes, dominated by sub-50 nm particles, at the edge of an ice floe drifting in the central Arctic Ocean. The measurements were made during the ice-breaker borne ASCOS (Arctic Summer Cloud Ocean Study) expedition in August 2008 between 2°–10° W longitude and 87°–87.5° N latitude. The median aerosol transfer velocities over different surface types (open water leads, ice ridges, snow and ice surfaces) ranged from 0.27 to 0.68 mm s−1 during deposition-dominated episodes. Emission periods were observed more frequently over the open ...
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Global distribution of sea salt aerosols: new constraints from in situ and remote sensing observations
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Jaeglé L.; Quinn P.K.; Bates T.S.; et al. - Copernicus GmbH, 2011We combine in situ measurements of sea salt aerosols (SS) from open ocean cruises and ground-based stations together with aerosol optical depth (AOD) observations from MODIS and AERONET, and the GEOS-Chem global chemical transport model to provide new constraints on SS emissions over the world's oceans. We find that the GEOS-Chem model using the Gong (2003) source function overestimates cruise observations of coarse mode SS mass concentrations by factors of 2–3 at high wind speeds over the cold waters of the Southern, North Pacific and North Atlantic Oceans. Furthermore, the model systematical ...
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The effect of meteorological and chemical factors on the agreement between observations and predictions of fine aerosol composition in southwestern Ontario during BAQS-Met
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Markovic M.Z.; Hayden K.L.; Murphy J.G.; et al. - Copernicus GmbH, 2011The Border Air Quality and Meteorology Study (BAQS-Met) was an intensive, collaborative field campaign during the summer of 2007 that investigated the effects of transboundary pollution, local pollution, and local meteorology on air quality in southwestern Ontario. This analysis focuses on the measurements of the inorganic constituents of particulate matter with diameter of less than 1 μm (PM1), with a specific emphasis on nitrate. We evaluate the ability of AURAMS, Environment Canada's chemical transport model, to represent regional air pollution in SW Ontario by comparing modelled aerosol in ...
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Latitudinal distributions of organic nitrogen and organic carbon in marine aerosols over the western North Pacific
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Miyazaki Y.; Kawamura K.; Jung J.; et al. - Copernicus GmbH, 2011Marine aerosol samples were collected over the western North Pacific along the latitudinal transect from 44° N to 10° N in late summer 2008 for measurements of organic nitrogen (ON) and organic carbon (OC) as well as isotopic ratios of total nitrogen (TN) and total carbon (TC). Increased concentrations of methanesulfonic acid (MSA) and diethylammonium (DEA+) at 40–44° N and subtropical regions (10–20° N) together with averaged satellite chlorophyll-a data and 5-day back trajectories suggest a significant influence of marine biological activities on aerosols in these regions. ON exhibited incre ...
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Atmospheric degradation of 3-methylfuran: kinetic and products study
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Tapia A.; Villanueva F.; Salgado M.S.; et al. - Copernicus GmbH, 2011A study of the kinetics and products obtained from the reactions of 3-methylfuran with the main atmospheric oxidants has been performed. The rate coefficients for the gas-phase reaction of 3-methylfuran with OH and NO3 radicals have been determined at room temperature and atmospheric pressure (air and N2 as bath gases), using a relative method with different experimental techniques. The rate coefficients obtained for these reactions were (in units cm3 molecule−1 s−1) kOH = (1.13 ± 0.22) × 10−10 and kNO3 = (1.26 ± 0.18) × 10−11. Products from the reaction of 3-methylfuran with OH, NO3 and Cl at ...
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Saharan and Asian dust: similarities and differences determined by CALIPSO, AERONET, and a coupled climate-aerosol microphysical model
This study compares the properties of atmospheric dust from the Saharan deserts and the Asian deserts using data from CALIPSO and AERONET during 2006 and 2007 along with simulations using a coupled climate-microphysical sectional model. Saharan deserts are largely south of 30° N, while Asian ones are primarily north of 30° N, hence they experience different meteorological regimes. Saharan dust lifting occurs all year long, primarily due to subtropical weather systems. However, Asian dust is lifted mostly in spring when mid-latitude frontal systems lead to high winds. Rainfall is more abundant ...
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Analysis on the impact of aerosol optical depth on surface solar radiation in the Shanghai megacity, China
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Xu J.; Li C.; Shi H.; et al. - Copernicus GmbH, 2011This study investigated the decadal variation of the direct surface solar radiation (DiSR) and the diffuse surface solar radiation (DfSR) during 1961–2008 in the Shanghai megacity as well as their relationships to Aerosol Optical Depth (AOD) under clear-sky conditions. Three successive periods with unique features of long term variation of DiSR were identified for both clear-sky and all-sky conditions: a "dimming" period from the late 1960s to the mid 1980s, a "stabilization"/"slight brightening" period from the mid 1980s to the mid 1990s, and a "renewed dimming" period thereafter. During the ...
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Impact of model grid spacing on regional- and urban- scale air quality predictions of organic aerosol
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Stroud C.A.; Makar P.A.; Moran M.D.; et al. - Copernicus GmbH, 2011Regional-scale chemical transport model predictions of urban organic aerosol to date tend to be biased low relative to observations, a limitation with important implications for applying such models to human exposure health studies. We used a nested version of Environment Canada's AURAMS model (42- to- 15- to- 2.5-km nested grid spacing) to predict organic aerosol concentrations for a temporal and spatial domain corresponding to the Border Air Quality and Meteorology Study (BAQS-Met), an air-quality field study that took place in the southern Great Lakes region in the summer of 2007. The use o ...
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New particle formation events in semi-clean South African savannah
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 7. Vakkari V.; Laakso H.; Kulmala M.; et al. - Copernicus GmbH, 2011This study is based on 18 months (20 July 2006–5 February 2008) of continuous measurements of aerosol particle size distributions, air ion size distributions, trace gas concentrations and basic meteorology in a semi-clean savannah environment in Republic of South Africa. New particle formation and growth was observed on 69% of the days and bursts of non-growing ions/sub-10 nm particles on additional 14% of the days. This new particle formation frequency is the highest reported from boundary layer so far. Also the new particle formation and growth rates were among the highest reported in the li ...
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Gases com efeito de estufa, redução das emissões
Esporo, N° 151. CTA, 2011De acordo com um estudo realizado, seria possível diminuir o total das emissões relacionadas com o gado, em cerca de 12%, mediante simples melhoramentos na produção.
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Greenhouse gases, curbing emissions
Spore: the magazine for agricultural and rural development in ACP countries, N° 151. CTA, 2011Some 12% of total livestock-related emissions could be cut with simple improvements in production, says a study.
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Gaz à effet de serre, résorber les émissions
Spore: le magazine du développement agricole et rural des pays ACP, N°151. CTA, 2011D’après une étude, quelque 12 % des émissions totales imputables au bétail pourraient être supprimés grâce à de simples améliorations de la production, incluant l’adoption de pâtures plus nutritives et l’ajout de faibles quantités de résidus de récoltes ou de céréales.
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The 2009–2010 Arctic polar stratospheric cloud season: a CALIPSO perspective
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Pitts M.C.; Poole L.R.; Dörnbrack A.; et al. - Copernicus GmbH, 2011Spaceborne lidar measurements from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) are used to provide a vortex-wide perspective of the 2009–2010 Arctic PSC (polar stratospheric cloud) season to complement more focused measurements from the European Union RECONCILE (reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions) field campaign. The 2009–2010 Arctic winter was unusually cold at stratospheric levels from mid-December 2009 until the end of January 2010, and was one of only ...
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Insights into the secondary fraction of the organic aerosol in a Mediterranean urban area: Marseille
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. El Haddad I.; Marchand N.; Temime-Roussel B.; et al. - Copernicus GmbH, 2011A comprehensive aerosol characterization was conducted at Marseille during summer, including organic (OC) and elemental carbon (EC), major ionic species, radiocarbon (14C), water-soluble OC and HULIS (HUmic LIke Substances), elemental composition and primary and secondary organic markers. This paper is the second paper of a two-part series that uses this dataset to investigate the sources of Organic Aerosol (OA). While the first paper investigates the primary sources (El Haddad et al., 2010), this second paper focuses on the secondary fraction of the organic aerosol.
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Primary sources of PM2.5 organic aerosol in an industrial Mediterranean city, Marseille
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. El Haddad I.; Marchand N.; Wortham H.; et al. - Copernicus GmbH, 2011Marseille, the most important port of the Mediterranean Sea, represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. This paper presents a Chemical Mass Balance (CMB) approach based on organic markers and metals to apportion the primary sources of organic aerosol in Marseille, with a special focus on industrial emissions. Overall, the CMB model accounts for the major primary anthropogenic sources including motor vehicles, biomass burning and the a ...
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Three-year ground based measurements of aerosol optical depth over the Eastern Mediterranean: the urban environment of Athens
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Gerasopoulos E.; Amiridis V.; Kazadzis S.; et al. - Copernicus GmbH, 2011Three years (2006–2008) of ground-based observations of the Aerosol Optical Depth (AOD) in the urban environment of Athens, in the Eastern Mediterranean, are analysed in this work. Measurements were acquired with a Multi-Filter Rotating Shadowband Radiometer at five wavelengths. The daily average AOD at 500 nm is 0.23, and the mean Ångström coefficient calculated between 415 and 867 nm is 1.41. The annual variability of AOD has a spring maximum dominated by coarse dust particles from the Sahara (AOD 0.34–0.42), while the diurnal pattern is typical for urban sites, with AOD steadily increasing ...
Boundary layer dynamics over London, UK, as observed using Doppler lidar during REPARTEE-II
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Barlow J.F.; Dunbar T.M.; Nemitz E.G.; et al. - Copernicus GmbH, 2011Urban boundary layers (UBLs) can be highly complex due to the heterogeneous roughness and heating of the surface, particularly at night. Due to a general lack of observations, it is not clear whether canonical models of boundary layer mixing are appropriate in modelling air quality in urban areas. This paper reports Doppler lidar observations of turbulence profiles in the centre of London, UK, as part of the second REPARTEE campaign in autumn 2007. Lidar-measured standard deviation of vertical velocity averaged over 30 min intervals generally compared well with in situ sonic anemometer measure ...
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Charge induced stability of water droplets in subsaturated environment
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Nielsen J.K.; Maus C.; Rzesanke D.; et al. - Copernicus GmbH, 2011Atmospheric liquid and solid water particles are stabilized if they are coated with either negative or positive electric charge. The surface charge causes an increase of the partial pressure of water vapour close to the surface of each particle, effectively allowing the particles to remain in their condensed phase even if the environmental relative humidity drops below unity. The theory, briefly presented in this paper, predicts a zero parameter relation between surface charge density and water vapour pressure. This relation was tested in a series of Electrodynamic Balance experiments. The mea ...
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Corrigendum to "Controls of carbon dioxide concentrations and fluxes above central London" published in Atmos. Chem. Phys., 11, 1913–1928, 2011
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Helfter C.; Famulari D.; Phillips G.J.; et al. - Copernicus GmbH, 2011
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Dependence of aerosol-precipitation interactions on humidity in a multiple-cloud system
This study examines the dependence of aerosol-precipitation interactions on environmental humidity in a mesoscale cloud ensemble (MCE) which is composed of convective and stratiform clouds. The author found that increases in aerosol concentration enhance evaporative cooling, which raises not only the intensity of vorticity and entrainment but also that of downdrafts and low-level convergence. The increase in vorticity tends to suppress precipitation. The increase in low-level convergence tends to enhance precipitation by generating more secondary clouds in a muptiple-cloud system simulated her ...
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New cloud chamber experiments on the heterogeneous ice nucleation ability of oxalic acid in the immersion mode
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 5. Wagner R.; Möhler O.; Saathoff H.; et al. - Copernicus GmbH, 2011The heterogeneous ice nucleation ability of oxalic acid in the immersion mode has been investigated by controlled expansion cooling runs with airborne, ternary solution droplets composed of, (i), sodium chloride, oxalic acid, and water (NaCl/OA/H2O) and, (ii), sulphuric acid, oxalic acid, and water (H2SO4/OA/H2O). Polydisperse aerosol populations with median diameters ranging from 0.5–0.7 μm and varying solute concentrations were prepared. The expansion experiments were conducted in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at initial temperatures of 244 and 2 ...
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Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Brock C.A.; Cozic J.; Bahreini R.; et al. - Copernicus GmbH, 2011We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea ...
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HFC-152a and HFC-134a emission estimates and characterization of CFCs, CFC replacements, and other halogenated solvents measured during the 2008 ARCTAS campaign (CARB phase) over the South Coast Air Basin of California
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Barletta B.; Nissenson P.; Meinardi S.; et al. - Copernicus GmbH, 2011This work presents results from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study. Whole air samples were obtained on board research flights that flew over California during June 2008 and analyzed for selected volatile organic compounds, including several halogenated species. Samples collected over the South Coast Air Basin of California (SoCAB), which includes much of Los Angeles (LA) County, were compared with samples from inflow air masses over the Pacific Ocean. The levels of many halocarbon species were enhanced significantly over t ...
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Impact of deep convection and dehydration on bromine loading in the upper troposphere and lower stratosphere
Atmospheric Chemistry and Physics (ACP), Vol. 11. N° 3. Aschmann J.; Sinnhuber B.-M.; Chipperfield M.P.; et al. - Copernicus GmbH, 2011Stratospheric bromine loading due to very short-lived substances is investigated with a three-dimensional chemical transport model over a period of 21 years using meteorological input data from the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis from 1989 to the end of 2009. Within this framework we analyze the impact of dehydration and deep convection on the amount of stratospheric bromine using an idealized and a detailed full chemistry approach. We model the two most important brominated short-lived substances, bromoform (CHBr3) and dibromomethane (CH2Br2), assumin ...
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