Overview: On the transport and transformation of pollutants in the outflow of major population centres – observational data from the EMeRGe European intensive operational period in summer 2017

Abstract. EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) is an international project focusing on atmospheric chemistry, dynamics and transport of local and regional pollution originating in megacities and other major population centres (MPCs). Airborne measurements, taking advantage of the long range capabilities of the HALO research platform (High Altitude and Long range research aircraft, www.halo-spp.de), are a central part of the research project. In order to provide an adequate set of measurements at different spatial scales, two field experiments were positioned in time and space to contrast situations when the photochemical transformation of plumes emerging from MPCs is large. These experiments were conducted in summer 2017 over Europe and in the inter-monsoon period over Asia in spring 2018. The intensive observational periods (IOP) involved HALO airborne measurements of ozone and its precursors, volatile organic compounds, aerosol particles and related species as well as coordinated ground-based ancillary observations at different sites. Perfluorocarbon (PFC) tracer releases and model forecasts supported the flight planning and the identification of pollution plumes. This paper describes the experimental deployment of the IOP in Europe, which comprised 7 HALO research flights with aircraft base in Oberpfaffenhofen (Germany) for a total of 53 flight hours. The MPC targets London (Great Britain), Benelux/Ruhr area (Belgium, The Netherlands, Luxembourg and Germany), Paris (France), Rome and Po Valley (Italy), Madrid and Barcelona (Spain) were investigated. An in-flight comparison of HALO with the collaborating UK-airborne platform FAAM took place to assure accuracy and comparability of the instrumentation on-board. Generally, significant enhancement of trace gases and aerosol particles are attributed to emissions originating in MPCs at distances of hundreds of kilometres from the sources. The proximity of different MPCs over Europe favours the mixing of plumes of different origin and level of processing and hampers the unambiguous attribution of the MPC sources. Similarly, urban plumes mix efficiently with natural sources as desert dust and with biomass burning emissions from vegetation and forest fires. This confirms the importance of wildland fire emissions in Europe and indicates an important but discontinuous contribution to the European emission budget that might be of relevance in the design of efficient mitigation strategies. The synergistic use and consistent interpretation of observational data sets of different spatial and temporal resolution (e.g. from ground-based networks, airborne campaigns, and satellite measurements) supported by modelling within EMeRGe, provides a unique insight to test the current understanding of MPC pollution outflows. The present work provides an overview of the most salient results and scientific questions in the European context, these being addressed in more detail within additional dedicated EMeRGe studies. The deployment and results obtained in Asia will be the subject of separate publications.

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MADE-IN: a new aerosol microphysics submodel for global simulation of potential atmospheric ice nuclei

Geoscientific Model Development Discussions ◽

10.5194/gmdd-3-2221-2010 ◽

2010 ◽

Vol 3 (4) ◽

pp. 2221-2290 ◽

Cited By ~ 1

Author(s):

V. Aquila ◽

J. Hendricks ◽

A. Lauer ◽

N. Riemer ◽

H. Vogel ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Aerosol Particles ◽

Ice Crystals ◽

Dust Particles ◽

Airborne Measurements ◽

Cloud Processing ◽

Ice Nuclei ◽

Hygroscopic Properties ◽

Mixing States ◽

Made In

Abstract. Black carbon (BC) and mineral dust are among the dominant atmospheric ice nuclei, i.e. aerosol particles that can initiate heterogeneous nucleation of ice crystals. When released, most BC and dust particles are externally mixed with other aerosol compounds. Through coagulation with particles containing soluble material and condensation of gases, externally mixed particles may obtain a coating and be transferred into an internal mixture. The mixing state of BC and dust aerosol particles influences their radiative and hygroscopic properties, as well as their ability of building ice crystals. We introduce the new aerosol microphysics submodel MADE-IN, implemented within the ECHAM/MESSy Atmospheric Chemistry global model (EMAC). MADE-IN is able to track separately mass and number concentrations of BC and dust particles in their different mixing states, as well as particles free of BC and dust. MADE-IN describes these three classes of particles through a superposition of seven log-normally distributed modes, and predicts the evolution of their size distribution and chemical composition. Six out of the seven modes are mutually interacting, allowing for the transfer of mass and number among them. Separate modes for the different mixing states of BC and dust particles in EMAC/MADE-IN allow for explicit simulations of the relevant aging processes, i.e. condensation, coagulation and cloud processing. EMAC/MADE-IN has been evaluated with surface and airborne measurements and performs well both in the planetary boundary layer and in the upper troposphere and lowermost stratosphere. Such a model represents a highly appropriate tool for the study of the concentration and composition of potential atmospheric ice nuclei.

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Global aerosol modeling with MADE3 (v3.0) in EMAC (based on v2.53): model description and evaluation

Geoscientific Model Development ◽

10.5194/gmd-12-541-2019 ◽

2019 ◽

Vol 12 (1) ◽

pp. 541-579 ◽

Cited By ~ 5

Author(s):

J. Christopher Kaiser ◽

Johannes Hendricks ◽

Mattia Righi ◽

Patrick Jöckel ◽

Holger Tost ◽

...

Keyword(s):

Atmospheric Chemistry ◽

General Circulation ◽

Particle Deposition ◽

Aerosol Particles ◽

Circulation Model ◽

Model Description ◽

Size Spectrum ◽

Near Surface ◽

Station Network ◽

Airborne Measurements

Abstract. Recently, the aerosol microphysics submodel MADE3 (Modal Aerosol Dynamics model for Europe, adapted for global applications, third generation) was introduced as a successor to MADE and MADE-in. It includes nine aerosol species and nine lognormal modes to represent aerosol particles of three different mixing states throughout the aerosol size spectrum. Here, we describe the implementation of the most recent version of MADE3 into the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model, including a detailed evaluation of a 10-year aerosol simulation with MADE3 as part of EMAC. We compare simulation output to station network measurements of near-surface aerosol component mass concentrations, to airborne measurements of aerosol mass mixing ratio and number concentration vertical profiles, to ground-based and airborne measurements of particle size distributions, and to station network and satellite measurements of aerosol optical depth. Furthermore, we describe and apply a new evaluation method, which allows a comparison of model output to size-resolved electron microscopy measurements of particle composition. Although there are indications that fine-mode particle deposition may be underestimated by the model, we obtained satisfactory agreement with the observations. Remaining deviations are of similar size to those identified in other global aerosol model studies. Thus, MADE3 can be considered ready for application within EMAC. Due to its detailed representation of aerosol mixing state, it is especially useful for simulating wet and dry removal of aerosol particles, aerosol-induced formation of cloud droplets and ice crystals as well as aerosol–radiation interactions. Besides studies on these fundamental processes, we also plan to use MADE3 for a reassessment of the climate effects of anthropogenic aerosol perturbations.

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Global aerosol modeling with MADE3 (v3.0) in EMAC (based on v2.53): model description and evaluation

10.5194/gmd-2018-185 ◽

2018 ◽

Author(s):

J. Christopher Kaiser ◽

Johannes Hendricks ◽

Mattia Righi ◽

Patrick Jöckel ◽

Holger Tost ◽

...

Keyword(s):

Atmospheric Chemistry ◽

General Circulation ◽

Particle Deposition ◽

Aerosol Particles ◽

Circulation Model ◽

Model Description ◽

Size Spectrum ◽

Near Surface ◽

Station Network ◽

Airborne Measurements

Abstract. Recently, the aerosol microphysics submodel MADE3 was introduced as a successor to MADE and MADE-in. It includes nine aerosol species and nine lognormal modes to represent aerosol particles of three different mixing states throughout the aeroso size spectrum. Here we describe the implementation of the most recent version of MADE3 into the atmospheric chemistry general circulation model EMAC, including a detailed evaluation of a ten-year aerosol simulation with MADE3 as part of EMAC. We compare simulation output to station network measurements of near-surface aerosol component mass concentrations, to airborne measurements of aerosol mass mixing ratio and number concentration vertical profiles, to ground-based and airborne measurements of particle size distributions, and to station network and satellite measurements of aerosol optical depth. Furthermore, we describe and apply a new evaluation method, which allows a comparison of model output to size-resolved electron microscopy measurements of particle composition. Although there are indications that fine mode particle deposition may be underestimated by the model, we obtained satisfactory agreement with the observations. Remaining deviations are of similar size as those identified in other global aerosol model studies. Thus, MADE3 can be considered ready for application within EMAC. Due to its detailed representation of aerosol mixing state, it is especially useful for simulating wet and dry removal of aerosol particles, aerosol-induced formation of cloud droplets and ice crystals as well as aerosol-radiation interactions. Besides studies on these fundamental processes, we also plan to use MADE3 for a reassessment of the climate effects of anthropogenic aerosol perturbations.

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Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-3173-2011 ◽

2011 ◽

Vol 11 (7) ◽

pp. 3173-3194 ◽

Cited By ~ 17

Author(s):

M. Huang ◽

G. R. Carmichael ◽

S. N. Spak ◽

B. Adhikary ◽

S. Kulkarni ◽

...

Keyword(s):

Long Range ◽

Atmospheric Chemistry ◽

Surface Ozone ◽

Long Range Transport ◽

Sulfur Oxides ◽

Near Surface ◽

Fire Emissions ◽

Multi Scale ◽

Range Transport ◽

Local Emissions

Abstract. Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O3 levels. California biogenic and fire emissions contribute 3–4 ppb to near-surface O3 over SC, with larger contributions to other regions in CA. During a long-range transport event from Asia starting from 22 June, high SOx levels (up to ~0.7 ppb of SO2 and ~1.3 ppb of SO4) is observed above ~6 km, but they did not affect CA surface air quality. The elevated SOx observed at 1–4 km is estimated to enhance surface SOx over SC by ~0.25 ppb (upper limit) on ~24 June. The near-surface SOx levels over SC during the flight week are attributed mostly to local emissions. Two anthropogenic SOx emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared withobservations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SOx by about a factor of two. Adjoint sensitivity analysis indicated that SO2 levels at 00:00 UTC (17:00 local time) at six SC surface sites were influenced by previous day maritime emissions over the ocean, the terrestrial emissions over nearby urban areas, and by transported SO2 from the north through both terrestrial and maritime areas. Overall maritime emissions contribute 10–70% of SO2 and 20–60% fine SO4 on-shore and over the most terrestrial areas, with contributions decreasing with in-land distance from the coast. Maritime emissions also modify the photochemical environment, shifting O3 production over coastal SC to more VOC-limited conditions. These suggest an important role for shipping emission controls in reducing fine particle and O3 concentrations in SC.

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Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

Atmospheric Chemistry and Physics ◽

10.5194/acp-5-2989-2005 ◽

2005 ◽

Vol 5 (11) ◽

pp. 2989-3002 ◽

Cited By ~ 69

Author(s):

P. Guyon ◽

G. P. Frank ◽

M. Welling ◽

D. Chand ◽

P. Artaxo ◽

...

Keyword(s):

Large Scale ◽

Particle Number ◽

Aerosol Particles ◽

Secondary Growth ◽

Combustion Efficiency ◽

Vertical Transport ◽

Airborne Measurements ◽

Sampling Campaign ◽

Wide Range ◽

Emission Ratios

Abstract. As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign, we studied the emission of carbon monoxide (CO), carbon dioxide (CO2), and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN) relative to CO (ERCN/CO) fell in the range 14-32 cm-3 ppb-1 in most of the investigated smoke plumes. Particle number emission ratios have to our knowledge not been previously measured in tropical deforestation fires, but our results are in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependent on the fire conditions (combustion efficiency). Variability in ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2), which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, reflecting the fact that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF) for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC) fraction of emissions that are not sampled by the aircraft, which increased the EF by a factor of 1.5-2.1. Vertical transport of smoke from the boundary layer (BL) to the cloud detrainment layer (CDL) and the free troposphere (FT) was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non-precipitating clouds. The detrained aerosol particles released in the CDL and FT were larger than in the unprocessed smoke, mostly due to coagulation and secondary growth, and therefore more efficient at scattering radiation and nucleating cloud droplets. This process may have significant atmospheric implications on a regional and larger scale.

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Source attributions of pollution to the Western Arctic during the NASA ARCTAS field campaign

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4707-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4707-4721 ◽

Cited By ~ 49

Author(s):

H. Bian ◽

P. R. Colarco ◽

M. Chin ◽

G. Chen ◽

J. M. Rodriguez ◽

...

Keyword(s):

Biomass Burning ◽

Field Experiments ◽

Transport Model ◽

Background Level ◽

Anthropogenic Emissions ◽

Airborne Measurements ◽

Ch4 Production ◽

Regional Sources ◽

Western Arctic ◽

Co Concentrations

Abstract. We use the NASA GEOS-5 transport model with tagged tracers to investigate the contributions of different regional sources of CO and black carbon (BC) to their concentrations in the Western Arctic (i.e., 50–90° N and 190–320° E) in spring and summer 2008. The model is evaluated by comparing the results with airborne measurements of CO and BC from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaigns to demonstrate the strengths and limitations of our simulations. We also examine the reliability of tagged CO tracers in characterizing air mass origins using the measured fossil fuel tracer of dichloromethane and the biomass burning tracer of acetonitrile. Our tagged CO simulations suggest that most of the enhanced CO concentrations (above background level from CH4 production) observed during April originate from Asian anthropogenic emissions. Boreal biomass burning emissions and Asian anthropogenic emissions are of similar importance in July domain wise, although the biomass burning CO fraction is much larger in the area of the ARCTAS field experiments. The fraction of CO from Asian anthropogenic emissions is larger in spring than in summer. European sources make up no more than 10% of CO levels in the campaign domain during either period. Comparisons of CO concentrations along the flight tracks with regional averages from GEOS-5 show that the along-track measurements are representative of the concentrations within the large domain of the Western Arctic in April but not in July.

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Detecting signatures of competition from observational data: a combined approach using DNA barcoding, diversity partitioning and checkerboards at small spatial scales

Freshwater Biology ◽

10.1111/fwb.12732 ◽

2016 ◽

Vol 61 (5) ◽

pp. 646-657 ◽

Cited By ~ 1

Author(s):

Trevor T. Bringloe ◽

Sarah J. Adamowicz ◽

Vivian F. I. Harvey ◽

John K. Jackson ◽

Karl Cottenie

Keyword(s):

Dna Barcoding ◽

Observational Data ◽

Spatial Scales ◽

Combined Approach ◽

Diversity Partitioning

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Spectral optical properties of long-range transport Asian dust and pollution aerosols over Northeast Asia in 2007 and 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-5391-2010 ◽

2010 ◽

Vol 10 (12) ◽

pp. 5391-5408 ◽

Cited By ~ 39

Author(s):

J. Jung ◽

Y. J. Kim ◽

K. Y. Lee ◽

M. G. -Cayetano ◽

T. Batmunkh ◽

...

Keyword(s):

Optical Properties ◽

Long Range ◽

Atmospheric Chemistry ◽

Light Attenuation ◽

Measurement Data ◽

Absorption Efficiency ◽

Asian Dust ◽

Urban Site ◽

Long Range Transport ◽

Range Transport

Abstract. As a part of the IGAC (International Global Atmospheric Chemistry) Mega-cities program, aerosol physical and optical properties were continuously measured from March 2007 to March 2008 at an urban site (37.57° N, 126.94° E) in Seoul, Korea. Spectral optical properties of long-range transported Asian dust and pollution aerosols have been investigated based on the year long measurement data. Optically measured black carbon/thermally measured elemental carbon (BC/EC) ratio showed clear monthly variation with high values in summer and low values in winter mainly due to the enhancement of light attenuation by the internal mixing of EC. Novel approach has been suggested to retrieve the spectral light absorption coefficient (babs) from Aethalometer raw data by using BC/EC ratio. Mass absorption efficiency, σabs (=babs/EC) at 550 nm was determined to be 9.0±1.3, 8.9±1.5, 9.5±2.0, and 10.3±1.7 m2 g−1 in spring, summer, fall, and winter, respectively with an annual mean of 9.4±1.8 m2 g−1. Threshold values to classify severe haze events were suggested in this study. Increasing trend of aerosol single scattering albedo (SSA) with wavelength was observed during Asian dust events while little spectral dependence of SSA was observed during long-range transport pollution (LTP) events. Satellite aerosol optical thickness (AOT) and Hysplit air mass backward trajectory analyses as well as chemical analysis were performed to characterize the dependence of spectral optical properties on aerosol type. Results from this study can provide useful information for studies on regional air quality and aerosol's effects on climate change.

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Development of a small unmanned aircraft system to derive CO2 emissions of anthropogenic point sources

10.5194/egusphere-egu21-8465 ◽

2021 ◽

Author(s):

Maximilian Reuter ◽

Heinrich Bovensmann ◽

Michael Buchwitz ◽

Jakob Borchard ◽

Sven Krautwurst ◽

...

Keyword(s):

Point Sources ◽

Unmanned Aircraft ◽

Mitigation Strategies ◽

Observation System ◽

Unmanned Aircraft System ◽

Ancillary Data ◽

Flight Pattern ◽

Airborne Measurements ◽

Wind Measurements ◽

Aircraft System

A reduction of the anthropogenic emissions of CO2 (carbon dioxide) is necessary to stop or slow down man-made climate change. To verify mitigation strategies, a global monitoring system such as the envisaged European Copernicus anthropogenic CO2 monitoring mission (CO2M) is required. Those satellite data are going to be complemented and validated with airborne measurements. UAV (unmanned aerial vehicle) based measurements can provide a cost-effective way to contribute to these activities. Here we present the development of a sUAS (small unmanned aircraft system) to quantify the CO2 emissions of a nearby point source from its downwind mass flux without the need for any ancillary data. Specifically, CO2 is measured by an in situ NDIR (non-dispersive infrared) detector and the wind speed and direction is measured with a 2D ultrasonic acoustic resonance anemometer. In order to minimize the effect of rotor downwash, we calibrate the anemometer by analyzing wind measurements taken while following a suitable flight pattern and assuming stationary wind conditions. We quantify the quality of the CO2 and wind measurements with an in-flight validation at the ICOS (Integrated Carbon Observation System) atmospheric station Steinkimmen (STE) near Bremen, Germany. By means of two flights downwind of the ExxonMobil natural gas processing facility in Gro&#223;enkneten about 40km east of Bremen, Germany, we demonstrate how the measurements of elevated CO2 concentrations can be used to infer mass fluxes of atmospheric CO2 related to the emissions of the facility.

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Denitrification, dehydration and ozone loss during the Arctic winter 2015/2016

10.5194/acp-2017-503 ◽

2017 ◽

Cited By ~ 3

Author(s):

Farahnaz Khosrawi ◽

Oliver Kirner ◽

Björn-Martin Sinnhuber ◽

Sören Johansson ◽

Michael Höpfner ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Stratospheric Ozone ◽

Satellite Observations ◽

The Arctic ◽

Cold Pool ◽

Polar Stratospheric Clouds ◽

Airborne Measurements ◽

Ozone Loss ◽

Polar Stratosphere ◽

Stratospheric Clouds

Abstract. The Arctic winter 2015/2016 was one of the coldest stratospheric winters in recent years. A stable vortex formed by early December and the early winter was exceptionally cold. Cold pool temperatures dropped below the Nitric Acid Trihydrate (NAT) existence temperature of about 195 K, thus allowing Polar Stratospheric Clouds (PSCs) to form. The low temperatures in the polar stratosphere persisted until early March allowing chlorine activation and catalytic ozone destruction. Satellite observations indicate that sedimentation of PSC particles led to denitrification as well as dehydration of stratospheric layers. Model simulations of the Arctic winter 2015/2016 nudged toward European Center for Medium-Range Weather Forecasts (ECMWF) analyses data were performed with the atmospheric chemistry–climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) for the Polar Stratosphere in a Changing Climate (POLSTRACC) campaign. POLSTRACC is a High Altitude and LOng Range Research Aircraft (HALO) mission aimed at the investigation of the structure, composition and evolution of the Arctic Upper Troposphere and Lower Stratosphere (UTLS). The chemical and physical processes involved in Arctic stratospheric ozone depletion, transport and mixing processes in the UTLS at high latitudes, polar stratospheric clouds as well as cirrus clouds are investigated. In this study an overview of the chemistry and dynamics of the Arctic winter 2015/2016 as simulated with EMAC is given. Further, chemical-dynamical processes such as denitrification, dehydration and ozone loss during the Arctic winter 2015/2016 are investigated. Comparisons to satellite observations by the Aura Microwave Limb Sounder (Aura/MLS) as well as to airborne measurements with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) performed on board of HALO during the POLSTRACC campaign show that the EMAC simulations are in fairly good agreement with observations. We derive a maximum polar stratospheric O3 loss of ~ 2 ppmv or 100 DU in terms of column in mid March. The stratosphere was denitrified by about 8 ppbv HNO3 and dehydrated by about 1 ppmv H2O in mid to end of February. While ozone loss was quite strong, but not as strong as in 2010/2011, denitrification and dehydration were so far the strongest observed in the Arctic stratosphere in the at least past 10 years.

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