Laboratory measurements and modeling of trace atmospheric species

Trace species play a major role in many physical and chemical processes in the atmosphere. Improving our understanding of the impact of each species requires a combination of laboratory exper- imentation, field measurements, and modeling. The results presented here focus on spectroscopic and kinetic laboratory measurements and photochemical box modeling. Laboratory experiments were conducted using IntraCavity Laser Absorption Spectroscopy (ICLAS), a high-resolution, high sensitivity spectroscopic method that had been used primarily for static cell measurements in the Steinfeld Laboratory at MIT. Several modifications and improvements have been made to expand its versatility. Firstly, a discharge flow tube was coupled with the ICLA Spectrometer, and the formation kinetics of nitrosyl hydride, HNO, were measured as a means to test the system. Secondly, a novel edge-tuner was introduced as a means to expand the spectral range of the ICLA Spectrometer. An experiment for the detection of the hydroperoxyl radical employing the edge-tuner in the ICLA Spectrometer is discussed and proposed. The results from the laboratory measurements are followed by the presentation of a near-explicit kinetic box model designed to improve our understanding of the oxidative capacity of the urban troposphere in the Mexico City Metropolitan Area (MCMA). The box model was constructed using the Master Chemical Mechanism and was constrained using a large dataset of field measurements collected during the 2003 MCMA field campaign.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Sheehy, Philip M. (Philip Michael)

Advisor dc:contributor.advisor

• Jeffrey I. Steinfeld and Mario J. Molina.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/32491
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/32491

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32491