Modeling the influence of biogenic volatile organic compound emissions on ozone concentration during summer season in the Kinki region of Japan Hai Bao a , Kundan Lal Shrestha b, * , Akira Kondo b , Akikazu Kaga b , Yoshio Inoue b a Chemistry and Environment Science College, Inner Mongolia Normal University, Hohhot 010022, China b Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan article info Article history: Received 26 May 2009 Received in revised form 13 October 2009 Accepted 14 October 2009 Keywords: Biogenic volatile organic compound Ozone MM5 CMAQ Growth chamber abstract Tropospheric ozone adversely affects human health and vegetation, and biogenic volatile organic compound (BVOC) emission has potential to influence ozone concentration in summer season. In this research, the standard emissions of isoprene and monoterpene from the vegetation of the Kinki region of Japan, estimated from growth chamber experiments, were converted into hourly emissions for July 2002 using the temperature and light intensity data obtained from results of MM5 meteorological model. To investigate the effect of BVOC emissions on ozone production, two ozone simulations for one-month period of July 2002 were carried out. In one simulation, hourly BVOC emissions were included (BIO), while in the other one, BVOC emissions were not considered (NOBIO). The quantitative analyses of the ozone results clearly indicate that the use of spatio-temporally varying BVOC emission improves the prediction of ozone concentration. The hourly differences of monthly-averaged ozone concentrations between BIO and NOBIO had the maximum value of 6 ppb at 1400 JST. The explicit difference appeared in urban area, though the place where the maximum difference occurred changed with time. Overall, BVOC emissions from the forest vegetation strongly affected the ozone generation in the urban area. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Photochemical oxidants cause a lot of damage to humans and vegetation. The increase in precursor emissions (oxides of nitrogen and volatile organic compounds) of ozone can significantly increase the ozone pollution (Emberson et al., 2001). It is well known that biogenic volatile organic compound (BVOC) emission increases with the rise in temperature and that BVOC plays an important role in the generation of ozone (Chameides et al., 1988). Though the impact of biogenic emission on ozone pollution is mainly observed in rural and suburban sites (Tsigaridis and Kanakidou, 2002), it can also be significant in urban region (Chameides et al., 1988; Solmon et al., 2004). Vogel et al. (1995) used a non-hydrostatic mesoscale model coupled with a transport and diffusion model and the gas phase mechanism RADM2 to study the influence of BVOC emission on the ozone concentration during episodes of high air temperatures in the state of Baden-W€ urttemberg, Germany. They found that simulations without using biogenic VOC emissions show a maximum difference in the ozone concentration of 18 ppb, while the maximum ozone values are of the order of 100 ppb. They concluded that biogenic VOC emissions play an important role when high temperatures are present in Baden-W€ urttemberg. Solmon et al. (2004) used Meso- NHeC mesoscale atmospheric chemistry model to study summer- time biogenic emission impacts on regional ozone formation in Paris and northern France. They found that, when biogenic emission was included in the simulation, the simulated surface ozone concen- tration reached 18e30% in Paris. They also found improvement in simulated ozone concentrations at some observation stations in the urban and rural areas after including biogenic emissions. In Japan, the standard for the photochemical oxidant was formulated in 1970, and due to its effectiveness, the concentration of photochemical oxidant decreased until 1990. However, recently the concentration of photochemical oxidant has been gradually increasing in Japan. One of its causes is the increase of the back- ground ozone concentration due to transboundary transport (Aki- moto, 2003). Furthermore, temperature increase due to global warming, urban heat island and the increase of ultraviolet rays (Wakamatsu et al., 1996) are also considered as some of its major causes. Izuta (2002) has pointed out that, though the western countries have used AOT40 (Accumulated dose over a threshold of 40 ppb) as a critical level of ozone for the preservation of crops from ozone, Japan has yet to come up with such criteria of its own. BVOC * Corresponding author. Tel./fax: þ81 (0) 6 68797670. E-mail address: kundan@ea.see.eng.osaka-u.ac.jp (K.L. Shrestha). Contents lists available at ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv ARTICLE IN PRESS 1352-2310/$ e see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2009.10.021 Atmospheric Environment xxx (2009) 1e11 Please cite this article in press as: Bao, H., et al., Modeling the influence of biogenic volatile organic compound emissions on ozone..., Atmo- spheric Environment (2009), doi:10.1016/j.atmosenv.2009.10.021