Spatial and temporal variations in NO(2) distributions over Beijing, China measured by imaging differential optical absorption spectroscopy.
During the CAREBEIJING campaign in 2006, imaging differential optical absorption spectroscopy (I-DOAS) measurements were made from 08:00 to 16:00 on September 9 and 10 over Beijing, China. Detailed images of the near-surface NO(2) differential slant column density (DSCD) distribution over Beijing were obtained. Images with less than a 30-min temporal resolution showed both horizontal and vertical variations in NO(2) distributions. For DSCD to mixing ratio conversion, path length along the lines of I-DOAS lines of sight was estimated using the light-extinction coefficient and Angstrom exponent data obtained by a transmissometer and a sunphotometer, respectively. Mixing ratios measured by an in-situ NO(2) analyzer were compared with those estimated by the I-DOAS instrument. The obtained temporal and spatial variations in NO(2) distributions measured by I-DOAS for the two days are interpreted with consideration of the locations of the major NO(x) sources and local wind conditions. I-DOAS measurements have been applied in this study for estimating NO(2) distribution over an urban area with multiple and distributed emission sources. Results are obtained for estimated temporal and spatial NO(2) distributions over the urban atmosphere; demonstrating the capability of the I-DOAS technique. We discuss in this paper the use of I-DOAS measurements to estimate the NO(2) distribution over an urban area with multiple distributed emission sources.
Lee
Hanlim
H
Advanced Environmental Monitoring Research Center (ADEMRC), Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-Dong, Bukgu, Gwangju, Republic of Korea.
Kim
Young J
YJ
Jung
Jinsang
J
Lee
Chulkyu
C
Heue
Klaus-Peter
KP
Platt
Ulrich
U
Hu
Min
M
Zhu
Tong
T
D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D009585:Nitrogen Dioxide / Q000032:analysis*; D055095:Optics and Photonics; D013057:Spectrum Analysis / Q000379:methods*
D000393:Air Pollutants; D009585:Nitrogen Dioxide