Biogenic volatile organic compounds (BVOCs) reactivity related to new particle formation (NPF) over the Landes forest
KAMMER, J.
Interactions Sol Plante Atmosphère [UMR ISPA]
Environnements et Paléoenvironnements OCéaniques [EPOC]
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Interactions Sol Plante Atmosphère [UMR ISPA]
Environnements et Paléoenvironnements OCéaniques [EPOC]
KAMMER, J.
Interactions Sol Plante Atmosphère [UMR ISPA]
Environnements et Paléoenvironnements OCéaniques [EPOC]
< Reduce
Interactions Sol Plante Atmosphère [UMR ISPA]
Environnements et Paléoenvironnements OCéaniques [EPOC]
Language
en
Article de revue
This item was published in
Atmospheric Research. 2020-06, vol. 237, p. 1-11
Elsevier
English Abstract
Atmospheric particles play a major role in both air quality and climate change. Formation of secondary particles in the atmosphere has been observed over many different environments and is believed to provide up to half ...Read more >
Atmospheric particles play a major role in both air quality and climate change. Formation of secondary particles in the atmosphere has been observed over many different environments and is believed to provide up to half of the atmospheric cloud condensation nuclei (CCN) at a global scale. However, high uncertainties are still remaining in the description of mechanisms involved in new particle formation (NPF). Especially, more evidences of the implication of biogenic volatile organic compounds (BVOCs) in NPF from field studies are still needed. To investigate this question, two field campaigns have been set up during July 2014 and July 2015, in the French Landes forest (south west of France). Summer 2015 was characterized by a strong hydric stress, whereas summer 2014 was rainy. In 2015, frequent nocturnal NPF was observed, reaching a frequency of occurrence of similar to 55% of the nights, while only one event was observed in 2014. In July 2015, monoterpene mixing ratios (dominated by alpha- and beta-pinene) were higher, mostly due to high ambient temperatures and drought. A focus was made on the 2015 field campaign, where NPF was mostly observed. The mean diurnal variation of the ratio between alpha- and beta-pinene mixing ratios highlighted in-canopy reactivity of monoterpenes with ozone in the early night. This hypothesis was reinforced by the increasing gas phase levels of pinonaldehyde and nopinone, the main first-generation products arising from alpha- and beta-pinene ozonolysis, at night, before NPF started. It strongly suggests that monoterpene oxidation further generated very-low volatility gases involved in NPF. This finding is also supported by the high concentrations of the SOA traditional biogenic tracers, e.g. pinic and pinonic acids, quantified in the particulate phase. The role of BVOCs in NPF is thus highlighted, as well as the importance of nighttime NPF.Read less <
Keywords
Landes - France
Changement climatique
Atmosphere
Landes - France
English Keywords
Monoterpenes
BVOCs
Oxidation products
Nighttime NPF
Landes forest
Foret
Monoterpenes
Origin
Hal imported