Near-canopy horizontal concentration heterogeneity of semivolatile oxygenated organic compounds and implications for 2-methyltetrols primary emissions

Abstract

This study calls attention to the primary emissions of semivolatile oxygenated organic compounds (SV-OVOCs) and demonstrates how mapping out the near-canopy concentration can effectively isolate atmospheric SV-OVOC production from direct emissions.

Tight Coupling of Surface and In-Plant Biochemistry and Convection Governs Key Fine Particulate Components over the Amazon Rainforest

“…We chose the molar emission ratio of 2-methyltetrols to isoprene as 0.5% approaching the lower bound of the reported range of the estimated range of 0.2−3% over the rainforest. 10 The plant biochemical source of 2-methyltetrols is expected to be spatially heterogeneous and vary with plant species and environmental stressors, 10 but additional measurements are needed to quantify this heterogeneity. Here, we assumed methyltetrols to have the same spatial heterogeneity as isoprene emissions (Supporting Information, Figure S3).…”

“…5−9 Recent measurements of 2-methyltetrols over the Amazon proposed that direct emissions of 2methyltetrols from the rainforest due to biological processes and environmental stressors were the most plausible explanation for their observations. 10 However, previous studies have largely focused on atmospheric chemical processes as a source of SOAs, 2,3 largely neglecting the potential role of inplant biochemical products in their formation.…”

“…Isoprene is mainly thought to be oxidized in the atmosphere , but has also been reported to be oxidized within leaves . Isoprene oxidation products significantly contribute to the formation of secondary organic aerosols (SOAs), particularly through multiphase chemical processes in aqueous aerosol particles and clouds. − Recent measurements of 2-methyltetrols over the Amazon proposed that direct emissions of 2-methyltetrols from the rainforest due to biological processes and environmental stressors were the most plausible explanation for their observations . However, previous studies have largely focused on atmospheric chemical processes as a source of SOAs, , largely neglecting the potential role of in-plant biochemical products in their formation.…”

Optimization and Representativeness of Atmospheric Chemical Sampling by Hovering Unmanned Aerial Vehicles Over Tropical Forests

“…Hovering UAVs of 25 kg and lighter are especially promising for filling data gaps in near‐surface concentrations for species that are horizontally heterogeneous above the landscape on scales of 10–1,000 m (Chang et al., 2018; McKinney et al., 2019). Atmospheric measurements can be achieved by mounting compact sensors or samplers onto UAVs of 1–25 kg (Aurell et al., 2017; Black et al., 2018; Guimarães et al., 2019, 2020; B. Liu et al., 2020; McKinney et al., 2019; Neumann et al., 2019; Ye et al., 2020). For example, Aurell et al.…”

“…Atmospheric measurements can be achieved by mounting compact sensors or samplers onto UAVs of 1-25 kg (Aurell et al, 2017;Black et al, 2018;Guimarães et al, 2019Guimarães et al, , 2020B. Liu et al, 2020;McKinney et al, 2019;Neumann et al, 2019;Ye et al, 2020). For example, Aurell et al (2017) installed an emission sampler system on a hovering UAV to characterize the gas and particle emissions from open fires and thereby followed the transport of the combustion plume.…”