Logo image
Simultaneous Measurements of Atmospheric HONO and NO2 via Absorption Spectroscopy using Tunable Mid-Infrared Continuous-wave Quantum Cascade Lasers
Other   Open access   Peer reviewed

Simultaneous Measurements of Atmospheric HONO and NO2 via Absorption Spectroscopy using Tunable Mid-Infrared Continuous-wave Quantum Cascade Lasers

Ben H. Lee, Ezra Wood, Mark Zahniser, J. Barry Mcmanus, David D. Nelson, Scott C. Herndon, Gregory Santoni, Steven C. Wofsy and J. William Munger
Applied physics. B, Lasers and optics, v 102(2), pp 417-423
01 Feb 2011
url
https://dash.harvard.edu/bitstream/1/10085277/1/LEE_etal_APB_2011_final_submission.pdfView
SubmittedCC BY V4.0 Open

Abstract

Nitrous acid (HONO) is important as a significant source of hydroxyl radical (OH) in the troposphere and as a potent indoor air pollutant. It is thought to be generated in both environments via heterogeneous reactions involving nitrogen dioxide \((NO_2)\). In order to enable fast-response HONO detection suitable for eddy-covariance flux measurements and to provide a direct method that avoids interferences associated with derivatization, we have developed a 2-channel tunable infrared laser differential absorption spectrometer (TILDAS) capable of simultaneous high-frequency measurements of HONO and NO2. Beams from two mid-infrared continuous-wave mode quantum cascade lasers (cw-QCLs) traverse separate 210 m paths through a multi-pass astigmatic sampling cell at reduced pressure for the direct detection of HONO \((1660 cm^{−1})\) and \((NO_2)\) \((1604 cm^{−1})\). The resulting one-second detection limits (S/N=3) are 300 and 30 ppt (pmol/mol) for HONO and \((NO_2)\), respectively. Our HONO quantification is based on revised line-strengths and peak positions for cis-HONO in the 6-micron spectral region that were derived from laboratory measurements. An essential component of ambient HONO measurements is the inlet system and we demonstrate that heated surfaces and reduced pressure minimize sampling artifacts. Earth and Planetary Sciences Engineering and Applied Sciences

Metrics

21 Record Views
66 citations in Scopus

Details

UN Sustainable Development Goals (SDGs)

This publication has contributed to the advancement of the following goals:

#11 Sustainable Cities and Communities
#13 Climate Action
#3 Good Health and Well-Being

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Collaboration types
Industry collaboration
Domestic collaboration
Web of Science research areas
Optics
Physics, Applied
Logo image