Ozone production during the field campaign RISFEX 2003 in the sea of Japan: analysis of sensitivity and behaviour based on an improved indicator Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Materials Science, Xian 710062, China
Received: 02 April 2010 – Published in Atmos. Chem. Phys. Discuss.: 21 April 2010 Abstract. The ratio Φ=kHC+OH[HC]/kNOx+OH[NOx] is used as an indicator for
the sensitivity of ozone production (P(O3)) to HC and NOx in the
field campaign RISFEX 2003 (RIShiri Fall EXperiment 2003) at Rishiri Island
(45.07° N, 141.12° E, and 35 m a.s.l.) in the sea of Japan during September 2003.
Four different sensitivity regimes are obtained based on the indicator. The
sensitivity is found to show a distinctive pattern in each regime. In Regime I
(Φ<1), P(O3) almost linearly increases with increasing HC and
almost linearly decreases with increasing NOx. In Regime II (1<Φ<9 ± 5), there is a less-than-linear increase in P(O3) with HC and
a less-than-linear decrease with NOx. P(O3) less-than-linearly
increases with both HC and NOx in Regime III (9 ± 5<Φ<45 ± 7),
and near linearly increases with NOx and is nearly constant with
increasing HC in Regime IV (Φ>45 ± 7). During the campaign, 91 percent
of P(O3) data appear in Regime III and IV, indicating that NOx is a
limiting factor of ozone production. Hence, it may be an efficient strategy
to control NOx emission for ozone abatement at the site.
Revised: 16 August 2010 – Accepted: 13 September 2010 – Published: 11 October 2010
Comparisons between the observed P(O3) and the ones modelled have represented
general agreement. However, the model tends to underestimate P(O3) in
Regime II, implying that an important source of peroxy radicals is possibly
missed. In Regime IV, the modelled P(O3) is systematically larger than
the measured one under a low j(O1D) condition, which may be caused by the
over-estimated yields of peroxy radicals from the reactions of monoterpenes
with ozone. A budget analysis indicates that sensitivity of P(O3) is
declining with HC and enhancing with NO when the condition shifts from
Regime II to Regime IV, which is also observed through the analysis of
P(O3) sensitivity using Φ. Sensitivity studies for P(O3) are
conducted to determine the effect of NOx and monoterpenes on ozone
production and the conclusions are very consistent with those derived from
the indicator. This study demonstrates that the ratio Φ could be a useful
index to ascertain the sensitivity of P(O3) to HC and NOx in the
clean marine boundary layer.
Citation: Wang, Z. Q., Chen, Y. S., Qi, B., and Yang, B.: Ozone production during the field campaign RISFEX 2003 in the sea of Japan: analysis of sensitivity and behaviour based on an improved indicator, Atmos. Chem. Phys., 10, 9579-9591, doi:10.5194/acp-10-9579-2010, 2010.