Preliminary results from the FARCE 2015 campaign: multidisciplinary study of the forest–gas–aerosol–cloud system on the tropical island of La Réunion

Duflot, Valentin; Tulet, Pierre; Flores, Olivier; Barthe, Christelle; Colomb, A.; Deguillaume, Laurent; Vaïtilingom, Mickaël; Perring, A. E.; Huffman, J. A.; Hernandez, Mark; Sellegri, Karine; Robinson, Elmer; O’Connor, David J.; Gomez, Odessa M.; Burnet, Frédéric; Bourrianne, Thierry; Strasberg, Dominique; Rocco, Manon; Bertram, Allan K.; Chazette, Patrick; Totems, Julien; Fournel, Jacques; Staménoff, Pierre; Metzger, Jean‐Marc; Chabasset, Mathilde; Rousseau, Clothilde; Bourrianne, Eric; Sancelme, Martine; Delort, Anne-Marie; Wegener, Rachel; Chou, C.; Elizondo, Pablo

doi:10.5194/acp-19-10591-2019

Cited by 24 publications

(55 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ER can be computed from the EF by taking the molecular weights (MWs) of both species into B. Verreyken et al: African biomass burning plumes over the south-west Indian Ocean Table 1. In situ routine observations at RUN and their respective limits of detection (LoDs) and statistical uncertainties (σ ) (Zhou et al, 2018;Duflot et al, 2019 xylenes a (C 8 H 10 ) 10 Y 7 137 sum of monoterpenes a (C 10 H 16 ) 10 Y 8…”

Section: Enhancement Ratiosmentioning

confidence: 99%

“…Photochemical degradation and dry and wet deposition are the major sink processes. Global OVOC budgets are still prone to large uncertainties due to an incomplete understanding of direct emissions, photochemical production and loss processes, oceanatmosphere exchange (Millet et al, 2010;Fischer et al, 2012;Read et al, 2012;Wang et al, 2019), and a paucity of (O)VOC data, especially in remote marine areas where the oxidative capacity of the atmosphere is mainly controlled by OVOCs in comparison to all other NMVOCs (Lewis et al, 2005;Carpenter and Nightingale, 2015;Travis et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…A summary of routine measurements from the observatory used in this study is shown in Table 1. A detailed description of these and other operational routine instruments at the observatory can be found in Duflot et al (2019), Baray et al (2013) and Zhou et al (2018).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean

et al. 2020

Self Cite

View full text Add to dashboard Cite

Abstract. We present an investigation of biomass burning (BB) plumes originating from Africa and Madagascar based on measurements of a suite of volatile organic compounds (VOCs), carbon monoxide (CO), ozone (O3) and nitrogen dioxide (NO2) obtained during the dry season of 2018 and 2019 at the high-altitude Maïdo observatory (21.1∘ S, 55.4∘ E, 2160 ma.s.l.), located on the remote island of La Réunion in the south-west Indian Ocean (SWIO). Biomass burning plume episodes were identified from increased acetonitrile (CH3CN) mixing ratios. Enhancement ratios (EnRs) – relative to CO – were calculated from in situ measurements for CH3CN, acetone (CH3COCH3), formic acid (HCOOH), acetic acid (CH3COOH), benzene (C6H6), methanol (CH3OH) and O3. We compared the EnRs to emission ratios (ERs) – relative to CO – reported in the literature in order to estimate loss or production of these compounds during transport. For CH3CN and CH3COOH, the calculated EnRs are similar to the ERs. For C6H6 and CH3OH, the EnR is lower than the ER, indicating a net sink of these compounds which was found to be in line with the expected atmospheric lifetime. For CH3COCH3 and HCOOH, the calculated EnRs are larger than the ERs. The discrepancy reaches an order of magnitude for HCOOH (18–34 pptv ppbv−1 compared to 1.8–4.5 pptv ppbv−1). This points to significant secondary production of HCOOH during transport. The Copernicus Atmospheric Monitoring Service (CAMS) global model simulations reproduce the temporal variation of CO mixing ratios well at the observatory but underestimate O3 and NO2 mixing ratios in the plumes by on average 16 ppbv and 60 pptv respectively. This discrepancy between modelled and measured O3 mixing ratios was attributed to (i) large uncertainties in VOC and NOx (NO+NO2) emissions due to BB in CAMS and (ii) misrepresentation of NOx recycling in the model during transport. Finally, transport of pyrogenically emitted CO is calculated with FLEXPART in order to (i) determine the mean plume age during the intrusions at the observatory and (ii) estimate the impact of BB on the pristine marine boundary layer (MBL). By multiplying the excess CO in the MBL with inferred EnRs at the observatory, we calculated the expected impact of BB on CH3CN, CH3COCH3, CH3OH and C6H6 concentrations in the MBL. These excesses constitute increases of ∼20 %–150 % compared to background measurements in the SWIO MBL reported in the literature.

show abstract

Section: Enhancement Ratiosmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In situ routine observations at RUN and their respective limits of detection (LoD) and statistical uncertainties (σ). (Zhou et al, 2018;Duflot et al, 2019 xylenes α (C8H10) 10 Y 7 sum of monoterpenes α (C10H16) 10 Y 8…”

Section: A2 Austral Winter Variation Of In Situ Measurements At Runmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the South-West Indian Ocean

Verreyken¹,

Amelynck²,

Brioude³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. We present an investigation of biomass burning (BB) plumes originating from Africa and Madagascar based on measurements of carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2) and a suite of volatile organic compounds (VOCs) obtained during the dry season of 2018 and 2019 at the high altitude Maïdo observatory (21.1° S, 55.4° E, 2250 m above sea level), located on the remote island of La Réunion in the South-West Indian Ocean (SWIO). Biomass burning plume episodes were identified from increased acetonitrile (CH3CN) mixing ratios. Enhancement ratios (EnRs) – relative to CO – were calculated from in situ measurements for CH3CN, acetone (CH3COCH3), formic acid (HCOOH), acetic acid (CH3COOH), benzene (C6H6), methanol (CH3OH) and O3. We compared the EnRs to emission ratios (ERs) – relative to CO – reported in literature in order to estimate loss/production of these compounds during transport. For CH3CN and CH3COOH, the calculated EnRs are similar to the ERs. For C6H6 and CH3OH, the EnR is lower than the ER, indicating a significant net sinks of these compounds. For CH3COCH3 and HCOOH, the calculated EnRs are larger than the ERs. The discrepancy reaches an order of magnitude for HCOOH (18–34 pptv ppbv−1 compared to 1.8–4.5 pptv ppbv−1). This points to significant secondary production of HCOOH during transport. The Copernicus Atmospheric Monitoring Service (CAMS) global model simulations reproduces well the temporal variation of CO mixing ratios at the observatory but underestimates O3 and NO2 mixing ratios in the plumes on average by 16 ppbv and 60 pptv respectively. This discrepancy between modelled and measured O3 mixing ratios was attributed to (i) large uncertainties in VOC and NOx (NO + NO2) emissions due to BB in CAMS and (ii) misrepresentation of NOx recycling in the model during transport. Finally, transport of pyrogenically emitted CO is calculated with FLEXPART in order to (i) determine the mean plume age during the intrusions at the observatory and (ii) estimate the impact of BB on the pristine marine boundary layer (MBL). By multiplying the excess CO in the MBL with inferred EnRs at the observatory, we calculated the expected impact of BB on CH3CN, CH3COCH3, CH3OH and C6H6 concentrations in the MBL. These excesses constitute increases of ~ 20 %–150 % compared to background measurements in the SWIO MBL reported in literature.

show abstract

A first evaluation of multiple automatic pollen monitors run in parallel

et al. 2021

View full text Add to dashboard Cite

A range of commercially-available automatic pollen monitors were run in parallel and evaluated for the first time during the 2019 spring season; this includes the Droplet Measurement Technologies WIBS-NEO, Helmut-Hund BAA-500, the Plair Rapid-E, two Swisens Poleno, and two Yamatronics KH-3000 devices. The instruments were run from 19 April to 31 May 2019 and located in Payerne, Switzerland, representative of a semi-rural site on the Swiss plateau. The devices were validated against Hirst-type traps in terms of total pollen counts for daily and sub-daily averages. While the manual measurements cannot be considered a "gold standard" in terms of absolute values, they provide an established reference against which the automatic instruments can be evaluated. Overall, there was considerable spread between instruments compared to the manual observations. The devices showed better performance when daily averages were considered, with three of the seven showing non-significantly different values from the manual measurements. However, when six-hourly averages were considered, only one of the instruments was not significantly different from the Hirst trap average. The largest differences between instruments were evident at low pollen concentrations (< 20 pollen grains/m 3 ), no matter the temporal resolution considered. This is in part, however, to be expected since it is at such low concentrations that the Hirst measurements are most uncertain. It is also important to note that in 2019 many of the instruments tested had only recently been developed. Differences may also have arisen due to their varying abilities to identify specific pollen taxa or because the classification algorithms applied were developed for different pollen taxa and not total pollen, the variable considered in this study Keywords pollen • automatic monitoring • validation • real-time • Hirst 1. Introduction Airborne pollen form just a small fraction of the atmospheric bioaerosol loading ([36]; [18]; [39]), but despite their low number concentrations these particles are of significant importance because of their impact on human health ([38]; [47]; [14]), agriculture and sylviculture ([6]; [20]), as well as on climate through their role in the hydrological cycle ([35]; [10]). Pollen monitoring networks exist in most countries, providing information to a range of end-users from allergy sufferers and their doctors through to researchers. The current standard that is used across these networks is based on manual technology developed in the early 1950s ([17]; [13]; [2]) that is both time-consuming and laborious. Furthermore, this measurement technique suffers from several shortcomings, including the fact that data are delivered at low temporal resolution (usually daily averages) with a delay of between 3-9 days from the time of observation. New technologies developed over the past few years have made it possible to automatically measure pollen at high temporal resolutions and in real-time ([41],[33], [40]). The provision of such observations is dramatically ...

show abstract

Preliminary results from the FARCE 2015 campaign: multidisciplinary study of the forest–gas–aerosol–cloud system on the tropical island of La Réunion

Cited by 24 publications

References 110 publications

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean

Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the South-West Indian Ocean

A first evaluation of multiple automatic pollen monitors run in parallel

Contact Info

Product

Resources

About