Tropospheric chemical composition measurements in Brazil during the dry season

Crutzen, Paul J.; Delany, A. C.; Greenberg, J.; Haagenson, Philip L.; Heidt, L. E.; Lueb, R.; Pollock, W. H.; Seiler, W.; Wartburg, A. F.; Zimmerman, P. R.

doi:10.1007/bf00051075

Cited by 377 publications

(181 citation statements)

References 60 publications

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“…The enhancements found within the TOMS elevated integrated amounts over Brazil were consistent with the in situ aircraft profiles measured in a NCAR field campaign measured in 1980 (Crutzen et al, 1985). Subsequent measurements from the TRACE-A field campaign (Fishman et al, 1996a; using ozonesonde, in situ, aircraft remotely sensed, and satellite measurements confirmed that enhancements in the TOMS total ozone signal were a result of widespread biomass burning over Brazil and southern Africa (Fishman et al, 1990), which, because of the low-level transport from the east and the upper-level transport from the west, highest TOR amounts were found over the south Atlantic Ocean.…”

Section: B Previous Ozone Enhancements Observed By Satellitessupporting

confidence: 84%

Analysis of a Regional Scale Chemical-Transport Model to Investigate the Potential Capability of Satellites for Identifying a Widespread Air Pollution Event

Welsh¹,

Fishman²

2017

Preprint

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We use a regional scale photochemical transport model to investigate the surface concentrations and column integrated amounts of ozone (O3) and nitrogen dioxide (NO2) during a pollution event that occurred in the St. Louis metropolitan region in 2012. These trace gases will be two of the primary constituents that will be measured by TEMPO, an instrument on a geostationary platform, which will result in a dataset that has hourly temporal resolution during the daytime and ~4 km spatial resolution. Although air quality managers are most concerned with surface concentrations, satellite measurements provide a quantity that reflects a column amount, which may or may not be directly relatable to what is measured at the surface. The model results provide good agreement with observed surface O3 concentrations, which is the only trace gas dataset that can be used for verification. The model shows that a plume of O3 extends downwind from St. Louis and contains an integrated amount of ozone of ~ 16 DU (1 DU = 2.69 x 10 16 mol. cm -2 ), a quantity that is two to three times lower than what was observed by satellite measurements during two massive pollution episodes in the 1980s. Based on the smaller isolatable emissions coming from St. Louis, this quantity is not unreasonable, but may also reflect the reduction of photochemical ozone production due to the implementation of emission controls that have gone into effect in the past few decades.

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Section: B Previous Ozone Enhancements Observed By Satellitessupporting

confidence: 84%

Analysis of a Regional Scale Chemical-Transport Model to Investigate the Potential Capability of Satellites for Identifying a Widespread Air Pollution Event

Welsh¹,

Fishman²

2017

Preprint

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“…The similarity of secondary biogenic particles from live forests with those emitted during forest fires is not surprising, because emissions from burning forests will be mixed with contributions from live trees. Biogenic VOCs associated with forests (such as monoterpenes and isoprene) are also observed in forest fires (37)(38)(39), and the similarity of these precursors results in similarities in the resulting SOA. There is also chemical similarity in the primary particles associated with forest and fire emissions because both include cellulose breakdown products (40).…”

Section: Resultsmentioning

confidence: 99%

Identifying organic aerosol sources by comparing functional group composition in chamber and atmospheric particles

Russell

Bahadur

Ziemann

2011

Proc. Natl. Acad. Sci. U.S.A.

217

273

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Measurements of submicron particles by Fourier transform infrared spectroscopy in 14 campaigns in North America, Asia, South America, and Europe were used to identify characteristic organic functional group compositions of fuel combustion, terrestrial vegetation, and ocean bubble bursting sources, each of which often accounts for more than a third of organic mass (OM), and some of which is secondary organic aerosol (SOA) from gas-phase precursors. The majority of the OM consists of alkane, carboxylic acid, hydroxyl, and carbonyl groups. The organic functional groups formed from combustion and vegetation emissions are similar to the secondary products identified in chamber studies. The near absence of carbonyl groups in the observed SOA associated with combustion is consistent with alkane rather than aromatic precursors, and the absence of organonitrate groups can be explained by their hydrolysis in humid ambient conditions. The remote forest observations have ratios of carboxylic acid, organic hydroxyl, and nonacid carbonyl groups similar to those observed for isoprene and monoterpene chamber studies, but in biogenic aerosols transported downwind of urban areas the formation of esters replaces the acid and hydroxyl groups and leaves only nonacid carbonyl groups. The carbonyl groups in SOA associated with vegetation emissions provides striking evidence for the mechanism of esterification as the pathway for possible oligomerization reactions in the atmosphere. Forest fires include biogenic emissions that produce SOA with organic components similar to isoprene and monoterpene chamber studies, also resulting in nonacid carbonyl groups in SOA.atmospheric aerosol | organic particles | smog chamber aerosol | alkane oxidation products | photochemical reactions R ecent literature reviews have highlighted significant advances in identifying compounds formed as "secondary" organic aerosol (SOA) in a wide range of laboratory-simulated atmospheric conditions, and field studies have identified several individual products from chamber studies (1-3). Paulot et al. have used global modeling to show that extrapolating these laboratory results for modeled global oxidant distributions helps explain biogenic SOA (4). However, the observations needed to confirm the proposed sources of organic aerosols (OAs) in global modelsnamely, quantitative field measurements of the proposed products to compare with the model predictions-remain elusive (5). Without such confirmation, it is difficult to identify which of the mechanisms proposed to explain controlled laboratory studies of simple volatile organic compound (VOC)-oxidant systems would satisfactorily capture those aspects of the chemistry that determine SOA formation in the more complex atmosphere.There has been significant progress in quantifying organic mass (OM, the particle-phase components of OA) from the fragments produced by online mass spectrometry of particles, with recent promulgation of techniques to quantify the resulting mixtures by two to four fragment-based positive matri...

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“…However, in large parts of the tropics, the natural seasonality of the ozone concentration is strongly affected by anthropogenic biomass burning activities during the dry season (e.g. Crutzen et al, 1985;Kirchhoff et al, 1988;Kirchhoff et al, 1990;Logan and Kirchhoff, 1986). O 3 mixing ratios of 50-100 ppb are frequently reached in haze layers at altitudes between 1 and 4 km (Andreae et al, 1988;Cros et al, 1988).…”

Section: Introductionmentioning

confidence: 99%

Seasonal variation of ozone deposition to a tropical rain forest in southwest Amazonia

et al. 2007

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Abstract. Within the project EUropean Studies on Trace gases and Atmospheric CHemistry as a contribution toLarge-scale Biosphere-atmosphere experiment in Amazonia (LBA-EUSTACH), we performed tower-based eddy covariance measurements of O 3 flux above an Amazonian primary rain forest at the end of the wet and dry season. Ozone deposition revealed distinct seasonal differences in the magnitude and diel variation. In the wet season, the rain forest was an effective O 3 sink with a mean daytime (midday) maximum deposition velocity of 2.3 cm s −1 , and a corresponding O 3 flux of −11 nmol m −2 s −1 . At the end of the dry season, the ozone mixing ratio was about four times higher (up to maximum values of 80 ppb) than in the wet season, as a consequence of strong regional biomass burning activity. However, the typical maximum daytime deposition flux was very similar to the wet season. This results from a strong limitation of daytime O 3 deposition due to reduced plant stomatal aperture as a response to large values of the specific humidity deficit. As a result, the average midday deposition velocity in the dry burning season was only 0.5 cm s −1 . The large diel ozone variation caused large canopy storage effects that masked the true diel variation of ozone deposition mechanisms in the measured eddy covariance flux, and for which corrections had to be made. In general, stomatal aperture was sufficient to explain the largest part of daytime ozone deposition. However, during nighttime, chemical reaction with nitrogen monoxide (NO) was found to contribute substantially to the O 3 sink in the rain forest canopy. Further contributions Correspondence to: U. Rummel (udo.rummel@dwd.de) were from non-stomatal plant uptake and other processes that could not be clearly identified.Measurements, made simultaneously on a 22 years old cattle pasture enabled the spatially and temporally direct comparison of O 3 dry deposition values from this site with typical vegetation cover of deforested land in southwest Amazonia to the results from the primary rain forest. The mean ozone deposition to the pasture was found to be systematically lower than that to the forest by 30% in the wet and 18% in the dry season.

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Tropospheric chemical composition measurements in Brazil during the dry season

Cited by 377 publications

References 60 publications

Analysis of a Regional Scale Chemical-Transport Model to Investigate the Potential Capability of Satellites for Identifying a Widespread Air Pollution Event

Analysis of a Regional Scale Chemical-Transport Model to Investigate the Potential Capability of Satellites for Identifying a Widespread Air Pollution Event

Identifying organic aerosol sources by comparing functional group composition in chamber and atmospheric particles

Seasonal variation of ozone deposition to a tropical rain forest in southwest Amazonia

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