NDLI: OH production from the photolysis of isoprene-derived peroxy radicals: cross-sections, quantum yields and atmospheric implications

Content Provider	Royal Society of Chemistry (RSC)
Author	Hansen, Robert F. Seakins, Paul W. Graham, Lee Whalley, Lisa K. Heard, Dwayne E. Lewis, Tom R. Blitz, Mark A.
Copyright Year	2017
Abstract	In environments with high concentrations of biogenic volatile organic compounds and low concentrations of nitrogen oxides (NOx = NO + NO2), significant discrepancies have been found between measured and modeled concentrations of hydroxyl radical (OH). The photolysis of peroxy radicals from isoprene (HO-Iso-O2) in the near ultraviolet represents a potential source of OH in these environments, yet has not been considered in atmospheric models. This paper presents measurements of the absorption cross-sections for OH formation (σRO2,OH) from the photolysis of HO-Iso-O2 at wavelengths from 310–362.5 nm, via direct observation by laser-induced fluorescence of the additional OH produced following laser photolysis of HO-Iso-O2. Values of σRO2,OH for HO-Iso-O2 ranged from (6.0 ± 1.6) × 10−20 cm2 molecule−1 at 310 nm to (0.50 ± 0.15) × 10−20 cm2 molecule−1 at 362.5 nm. OH photodissociation yields from HO-Iso-O2 photolysis, ϕOH,RO2, were determined via comparison of the measured values of σRO2,OH to the total absorption cross-sections for HO-Iso-O2 (σRO2), which were obtained using a newly-constructed spectrometer. ϕOH,RO2 was determined to be 0.13 ± 0.04 at wavelengths from 310–362.5 nm. To determine the impact of HO-Iso-O2 photolysis on atmospheric OH concentrations, a modeling case-study for a high-isoprene, low-NOx environment (namely, the 2008 Oxidant and Particle Photochemical Processes above a South-East Asian Tropical Rainforest (OP-3) field campaign, conducted in Borneo) was undertaken using the detailed Master Chemical Mechanism. The model calculated that the inclusion of HO-Iso-O2 photolysis in the model had increased the OH concentration by only 1% on average from 10:00–16:00 local time. Thus, HO-Iso-O2 photolysis alone is insufficient to resolve the discrepancy seen between measured OH concentrations and those predicted by atmospheric chemistry models in such environments.
Starting Page	2332
Ending Page	2345
Page Count	14
File Format	HTM / HTML PDF
ISSN	14639076
Volume Number	19
Issue Number	3
Journal	Physical Chemistry Chemical Physics
DOI	10.1039/c6cp06718b
Language	English
Publisher	Royal Society of Chemistry
Access Restriction	Open
Subject Keyword	Nitrogen oxide Borneo Biogenic substance Asian people Volatile organic compound Photodissociation Nitrogen Ultraviolet Spectrometer Laser-induced fluorescence Atmospheric chemistry Laser Hydroxyl radical Isoprene
Content Type	Text
Resource Type	Article
Subject	Physics and Astronomy Physical and Theoretical Chemistry

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Biogenic Hydrocarbon Chemistry within and Above a Mixed Deciduous Forest

Chemical ionisation mass spectrometer for measurements of OH and Peroxy radical concentrations in moderately polluted atmospheres

Atmospheric chemistry and physics near-ir photodissociation of peroxy acetyl nitrate (2004).

Second-Order Kinetic Rate Coefficients for the Aqueous-Phase Hydroxyl Radical (OH) Oxidation of Isoprene-Derived Secondary Organic Aerosol Compounds at 298 K

Peroxy radical chemistry and OH radical production during the NO 3-initiated oxidation of isoprene

Photodissociation of 3-Bromo-1,1,1-trifluoro-2-propanol at 193 nm: Laser-Induced Fluorescence Detection of OH(ν′′ = 0, J′′)

Johannes gutenberg university mainz isoprene oxidation and its impacts on the atmospheric composition (2010).

Volatile organic compound conversion by ozone, hydroxyl radicals, and nitrate radicals in residential indoor air: Magnitudes and impacts of oxidant sources.

Studies of the Atmospheric Chemsitry of Energy-Related Volatile Organic Compounds and of their Atmospheric Reaction Products

OH production from the photolysis of isoprene-derived peroxy radicals: cross-sections, quantum yields and atmospheric implications

Similar Documents

Biogenic Hydrocarbon Chemistry within and Above a Mixed Deciduous Forest

Chemical ionisation mass spectrometer for measurements of OH and Peroxy radical concentrations in moderately polluted atmospheres

Atmospheric chemistry and physics near-ir photodissociation of peroxy acetyl nitrate (2004).

Second-Order Kinetic Rate Coefficients for the Aqueous-Phase Hydroxyl Radical (OH) Oxidation of Isoprene-Derived Secondary Organic Aerosol Compounds at 298 K

Peroxy radical chemistry and OH radical production during the NO 3-initiated oxidation of isoprene

Photodissociation of 3-Bromo-1,1,1-trifluoro-2-propanol at 193 nm: Laser-Induced Fluorescence Detection of OH(ν′′ = 0, J′′)

Johannes gutenberg university mainz isoprene oxidation and its impacts on the atmospheric composition (2010).

Volatile organic compound conversion by ozone, hydroxyl radicals, and nitrate radicals in residential indoor air: Magnitudes and impacts of oxidant sources.

Studies of the Atmospheric Chemsitry of Energy-Related Volatile Organic Compounds and of their Atmospheric Reaction Products

OH production from the photolysis of isoprene-derived peroxy radicals: cross-sections, quantum yields and atmospheric implications