Diurnal variations in H2O2, O3, PAN, HNO3 and aldehyde concentrations and NO/NO2 ratios at Rishiri Island, Japan: potential influence from iodine chemistry.
The presence of iodine chemistry, hypothesized due to the overprediction of HO(2) levels by a photochemical box model at Rishiri Island in June 2000, was quantitatively tested against the observed NO/NO(2) ratios and the net production rates of ozone. The observed NO/NO(2) ratios were reproduced reasonably well by considering the conversion of NO to NO(2) by IO, whose amount was calculated so as to reproduce the observed HO(2) levels. However, the net production rates of ozone were calculated to be negative when such high mixing ratios of IO were considered, which was inconsistent with the observed buildup of ozone during daytime. These results suggest that iodine chemistry may not be the sole mechanism for the reduced mixing ratios of HO(2), or that "hot spots" for iodine chemistry were present. Diurnal variations in the mixing ratios of HCHO, CH(3)CHO, peroxy acetyl nitrate (PAN) and HNO(3) observed during the study are presented along with the simulated ones. The box model simulations suggest that the effect of iodine chemistry on these concentrations is small and that important sources of CH(3)CHO and sinks of PAN are probably missing from our current understanding of the tropospheric chemistry mechanism.
Kanaya
Yugo
Y
Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan. yugo@jamstec.go.jp
Tanimoto
Hiroshi
H
Matsumoto
Jun
J
Furutani
Hiroshi
H
Hashimoto
Shigeru
S
Komazaki
Yuichi
Y
Tanaka
Shigeru
S
Yokouchi
Yoko
Y
Kato
Shungo
S
Kajii
Yoshizumi
Y
Akimoto
Hajime
H
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000447:Aldehydes / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring; D005843:Geography; D006861:Hydrogen Peroxide / Q000032:analysis / Q000737:chemistry; D007455:Iodine / Q000737:chemistry*; D007564:Japan; D008956:Models, Chemical; D017942:Nitric Acid / Q000032:analysis / Q000737:chemistry; D009589:Nitrogen Oxides / Q000032:analysis / Q000737:chemistry; D016877:Oxidants / Q000032:analysis / Q000737:chemistry; D010083:Oxidants, Photochemical / Q000032:analysis / Q000737:chemistry; D010126:Ozone / Q000032:analysis / Q000737:chemistry; D010463:Peracetic Acid / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D010545:Peroxides / Q000032:analysis / Q000737:chemistry; D013997:Time Factors
D000393:Air Pollutants; D000447:Aldehydes; D009589:Nitrogen Oxides; D016877:Oxidants; D010083:Oxidants, Photochemical; D010545:Peroxides; C049375:perhydroxyl radical; D017942:Nitric Acid; D010126:Ozone; D007455:Iodine; D006861:Hydrogen Peroxide; D010463:Peracetic Acid; C004185:peroxyacetyl nitrate