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

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(9), P. 5877 - 5924

Published: May 5, 2022

Abstract. Megacities and other major population centres (MPCs) worldwide are sources of air pollution, both locally as well downwind. The overall assessment prediction the impact MPC pollution on tropospheric chemistry challenging. present work provides an overview highlights a new contribution to understanding this issue based data analysis EMeRGe (Effect transport transformation pollutants Regional Global scales) international project. focuses atmospheric chemistry, dynamics, local regional originating in MPCs. Airborne measurements, taking advantage long range capabilities High Altitude LOng Range Research Aircraft (HALO, https://www.halo-spp.de, last access: 22 March 2022), central part synergistic use consistent interpretation observational sets different spatial temporal resolution (e.g. from ground-based networks, airborne campaigns, satellite measurements) supported by modelling within provide unique insight test current outflows. In order obtain adequate set measurements at scales, two field experiments were positioned time space contrast situations when photochemical plumes emerging MPCs is large. These conducted summer 2017 over Europe inter-monsoon period Asia spring 2018. intensive periods (IOPs) involved HALO ozone its precursors, volatile organic compounds, aerosol particles, related species coordinated ancillary observations sites. Perfluorocarbon (PFC) tracer releases model forecasts flight planning, identification plumes, chemical transformations during transport. This paper describes experimental deployment scientific questions IOP Europe. targets – London (United Kingdom; UK), Benelux/Ruhr area (Belgium, Netherlands, Luxembourg Germany), Paris (France), Rome Po Valley (Italy), Madrid Barcelona (Spain) investigated seven research flights with aircraft base Germany for total 53 hours. An in-flight comparison collaborating UK-airborne platform Facility Atmospheric Measurements (FAAM) took place assure accuracy comparability instrumentation board. Overall, unites near- far-field emissions hence deals complex masses distant sources. several European outflows was successfully identified measured. Chemical processing inferred primary secondary ratios between having lifetimes. Photochemical formation or acids evident plumes. Urban mix efficiently natural mineral dust biomass burning vegetation forest fires. confirms importance wildland fire indicates important but discontinuous emission budget that might be relevance design efficient mitigation strategies. most salient results context, these being addressed more detail additional dedicated studies. obtained will subject separate publications.

Language: Английский

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Rapid increase in atmospheric glyoxal and methylglyoxal concentrations in Lhasa, Tibetan Plateau: Potential sources and implications

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 824, P. 153782 - 153782

Published: Feb. 18, 2022

Language: Английский

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Glyoxal tropospheric column retrievals from TROPOMI – multi-satellite intercomparison and ground-based validation

Atmospheric measurement techniques, Journal Year: 2021, Volume and Issue: 14(12), P. 7775 - 7807

Published: Dec. 10, 2021

Abstract. We present the first global glyoxal (CHOCHO) tropospheric column product derived from TROPOspheric Monitoring Instrument (TROPOMI) on board Sentinel-5 Precursor satellite. Atmospheric results oxidation of other non-methane volatile organic compounds (NMVOCs) and direct emissions caused by combustion processes. Therefore, this is a useful indicator VOC emissions. It generated with an improved version BIRA-IASB scientific retrieval algorithm relying differential optical absorption spectroscopy (DOAS) approach. Among algorithmic updates, DOAS fit now includes corrections to mitigate impact spectral misfits scene brightness inhomogeneity strong NO2 absorption. The comes along full error characterization, which allows for providing random systematic estimates every observation. Systematic errors are typically in range 1 ×1014–3 ×1014 molec. cm−2 (∼30 %–70 % emission regimes) originate mostly priori data uncertainties interferences absorbing species. latter may be at origin, least partly, enhanced signal over equatorial oceans, further investigation needed them. Random large (>6×1014 cm−2) but can reduced averaging observations space and/or time. Benefiting high signal-to-noise ratio number small-size observations, TROPOMI provides fields unprecedented level detail. Using same baseline, sets also Ozone (OMI) Aura Global Experiment-2 (GOME-2) Metop-A Metop-B. Those four intercompared large-scale regions worldwide show consistency. satellite columns compared retrieved ground-based Multi-AXis (MAX-DOAS) instruments nine stations Asia Europe. In general, MAX-DOAS provide consistent both terms absolute values variability. Correlation coefficients between 0.61 0.87. correlation only poorer one mid-latitude station, where appear biased low during wintertime. mean generally agree well low/moderate differences less than 1×1014 cm−2. A larger bias identified two sites very large. Despite bias, consistency seasonal variability high.

Language: Английский

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Modification of a conventional photolytic converter for improving aircraft measurements of NO<sub>2</sub> via chemiluminescence

Atmospheric measurement techniques, Journal Year: 2021, Volume and Issue: 14(10), P. 6759 - 6776

Published: Oct. 20, 2021

Abstract. Nitrogen oxides (NOx≡NO+NO2) are centrally involved in the photochemical processes taking place Earth's atmosphere. Measurements of NO2, particularly remote areas where concentrations order parts per trillion by volume (pptv), still a challenge and subject to extensive research. In this study, we present NO2 measurements via photolysis–chemiluminescence during research aircraft campaign CAFE Africa (Chemistry Atmosphere – Field Experiment Africa) 2018 around Cabo Verde results laboratory experiments characterize photolytic converter used. We find reservoir species MPN (methyl peroxy nitrate) produce only relevant thermal interference under operating conditions Africa. identify memory effect within conventional (type 1) associated with high NO rapidly changing water vapor concentrations, accompanying changes altitude measurements, which is due porous structure material. As result, artifacts, amplified low conversion efficiencies, varying instrumental background adversely affect measurements. test an alternative 2) made from quartz glass, improves reliability field studies.

Language: Английский

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Satellite Evidence for Glyoxal Depletion in Elevated Fire Plumes

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(4)

Published: Feb. 24, 2023

Abstract Space‐borne observations are used to characterize the fate of formaldehyde and glyoxal in wildfire plumes. Their distribution measured by Tropospheric Monitoring Instrument reveals striking differences between two compounds near intense fires. In typical situations, glyoxal‐to‐formaldehyde ratio is highest fire (∼0.1) decreases downwind source area due larger contribution pyrogenic emissions abundance longer lifetime formaldehyde. However, a pronounced depletion detected above high‐level clouds, not seen for formaldehyde, likely processing pyrocumulonimbus clouds generated This suggests retention upon droplet freezing and/or its outgassing hydrated form upper troposphere. The absence sizable loss during convection indicates that hydration liquid droplets subsequent as methanediol represent at most minor sink

Language: Английский

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Implementation of HONO into the chemistry–climate model CHASER (V4.0): roles in tropospheric chemistry

Geoscientific model development, Journal Year: 2023, Volume and Issue: 16(3), P. 927 - 960

Published: Feb. 6, 2023

Abstract. Nitrous acid (HONO) is an important atmospheric gas given its contribution to the cycles of NOx and HOx, but role in global photochemistry not fully understood. This study implemented three pathways HONO formation chemistry–climate model CHASER (MIROC-ESM) explore physical phenomena: gas-phase kinetic reactions (GRs), direct emission (EM), heterogeneous on cloud aerosol particles (HRs). We evaluated simulations by aircraft-based measurements from EMeRGe-Asia-2018 (Effect Megacities Transport Transformation Pollutants Regional Global Scales), ATom-1 (atmospheric tomography), observations ship R/V Mirai, EANET (Acid Deposition Monitoring Network eastern Asia)/EMEP (European Evaluation Programme) ground-based stationary observations, OMI (Ozone Instrument). showed that inclusion chemistry modelling process reduced bias against for PM2.5, NO3-/HNO3, NO2, OH, HO2, O3, CO, especially lower troposphere North Pacific (NP) region. found retrieved abundance tropospheric was 1.4 TgN. Of source pathways, HRs EM contributed 63 % 26 net production, respectively. also observed surfaces larger amounts (51 %) than those (12 %). The exhibited significant negative biases daytime Asian off-the-coast region, compared with airborne EMeRGe-Asia-2018, indicating existence unknown sources. Strengthening uptake NO2 near surface middle troposphere, uptake, were all potential yet-unknown most promising this combination enhanced surface-catalysed HNO3 photolysis (maxST+JANO3-B case), which could remedy O3 during EMeRGe. simulated impact NOx–O3 sensitive yield conversion (vs. HNO3). Inclusion (NO + NO2) levels 20.4 %, thereby weakening oxidizing capacity (OH, O3) occurring NOx-deficit environments (remote regions upper altitudes), turn increased CH4 lifetime (13 CO (8 calculated reduction effect ozone level overestimates column spaceborne a large portion Hemisphere. particles, have been neglected previous studies, main drivers these impacts. particularly salient substantial reductions OH (40 %–67 (30 %–45 NP region summer, (50 %–95 In contrast, China (Beijing) winter mean 600 %–1700 10 %–33 respectively, regards their minima winter. Furthermore, sensitivity revealed heterogenous coincided real atmosphere. Nevertheless, effects combined case (enhancing uptakes implementing HNO3), captured measured level, still capacity. Overall, our findings suggest does consider mechanisms (especially photochemical formations) may erroneously predict remote areas polluted regions.

Language: Английский

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Application of Space-Based Glyoxal Observation for Estimating Global Nonmethane Volatile Organic Compounds Emissions from Urban Sources and Biomass Burning

Environmental Science & Technology Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 13, 2025

Nonmethane volatile organic compound (NMVOC) pollution severely impacts urban atmospheric quality. We propose a top-down method for estimating NMVOC emissions based on glyoxal─an important oxidation product of NMVOCs observed from space. applied the wind rotation aggregation and exponential modified Gaussian methods to estimate glyoxal effective lifetime production rate in plumes downwind. These were 60 cities worldwide, was screened out 22 cities, ranging 0.8 ± 0.3 13.7 3.3 mol/s. The results indicate significant correlation with total emission bottom-up inventory (r = 0.85, p < 0.01). Additionally, we utilized daily satellite identify biomass burning sources Australian fire events. Our research offers novel perspective monitoring transient provides new data source reduction policymaking.

Language: Английский

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Vertical distribution and temporal evolution of formaldehyde and glyoxal derived from MAX-DOAS observations: The indicative role of VOC sources

Journal of Environmental Sciences, Journal Year: 2022, Volume and Issue: 122, P. 92 - 104

Published: Feb. 1, 2022

Language: Английский

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Formaldehyde and hydroperoxide distribution around the Arabian Peninsula – evaluation of EMAC model results with ship-based measurements

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(1), P. 119 - 142

Published: Jan. 4, 2023

Abstract. Formaldehyde (HCHO), hydrogen peroxide (H2O2) and organic hydroperoxides (ROOH) play a key role in atmospheric oxidation processes. They act as sources sinks for HOx radicals (OH + HO2), with OH the primary oxidant that governs self-cleaning capacity. Measurements of these species allow evaluation chemistry-transport models which need to account multifarious source distributions, transport, complex photochemical reaction pathways deposition processes species. HCHO is an intermediate during volatile compounds (VOCs) indicator activity combustion-related emissions. In this study, we use situ observations HCHO, H2O2 ROOH marine boundary layer (MBL) evaluate results general circulation model EMAC (ECHAM5/MESSy2 Atmospheric Chemistry; European Center HAMburg, Modular Earth Submodel System). The dataset was obtained Air Quality Climate Change Arabian Basin (AQABA) ship campaign around Peninsula summer 2017. This region characterized by high levels air pollution, humidity solar irradiation, especially areas Suez Canal Gulf. High pollution up 12 ppbv 2.3 relatively low (≤0.5 ppbv) were detected over We find failed predict absolute mixing ratios high-pollution events Gulf, while it reproduced on average within factor 2. Dry velocities determined at night 0.77±0.29 cm s−1 1.03±0.52 Sea, matched EMAC. budget revealed elevated radical concentrations EMAC, resulted overestimation more than 5 AQABA dataset. underestimated Gulf related EMAC's coarse spatial resolution missing anthropogenic emissions model.

Language: Английский

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Atmospheric formaldehyde at El Teide and Pic du Midi remote high-altitude sites

Atmospheric Environment, Journal Year: 2020, Volume and Issue: 234, P. 117618 - 117618

Published: May 26, 2020

Language: Английский

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