Unique isoprene oxidation products demonstrate chlorine atom chemistry occurs in the Houston,Texas urban area |
| |
| Authors: | Daniel D. Riemer Eric C. Apel John J. Orlando Geoffrey S. Tyndall William H. Brune Eric J. Williams William A. Lonneman James D. Neece |
| |
| Affiliation: | (1) University of Miami, RSMAS/MAC, 4600 Rickenbacker Cswy., Miami, FL 33149, USA;(2) National Center for Atmospheric Research, Box 3000, Boulder, CO 80303, USA;(3) Department of Meteorology, Pennsylvania State University, University Park, PA 16802, USA;(4) NOAA Earth System Research Laboratory, Boulder, CO 80305, USA;(5) U. S. Environmental Protection Agency, SEE Program, Research Triangle Park, NC 27711, USA;(6) Texas Commission on Environmental Quality, Austin, TX 78758, USA |
| |
| Abstract: | As part of the 2000 Texas Air Quality Study (TexAQS), we studied the isoprene oxidation process under ambient conditions to discern the presence of chlorine atom (Cl) chemistry in the Houston, Texas urban area. By measuring chloromethylbutenone (CMBO) and an isomer of chloromethylbutenal (CMBA), we clearly observed sixteen episodes of active Cl chemistry during the 24-day experiment. Estimated median Cl concentration during each of these episodes was between the detection limit of ~102 atoms cm−3 and 50 - 30 + 70 ×104 50_{ - 30}^{ + 70} times {10^4} atoms cm−3. Cl concentration during all the episodes averaged 7.6 - 2.0 + 4.7 ×104 7.6_{ - 2.0}^{ + 4.7} times {10^4} atoms cm−3 and thus amounted to less than 3% of the OH concentration during the same periods. During the episodes, the fraction of oxidation chemistry initiated by Cl ranged from 3–43% and was strongly dependent on the quantity and type of hydrocarbons present in the atmosphere. Because of its intermittent presence and low concentration, Cl is not a broadly influential oxidant in the Houston, Texas urban area. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
