O3-NO-NO2 photostationary state and near-surface ozone generation from ZOTTO Tower data (central Siberia)
K.B. Moiseenko1, A.V. Vasileva1, A.I. Skorokhod1, Yu.A. Shtabkin1, I.B. Belikov1, A.Yu. Repin2
1A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Moscow, Russia
2E.K. Fedorov Institute of Applied Geophysics of the Russian Academy of Sciences, Moscow, Russia
Keywords: atmospheric boundary layer, ozone generation, peroxy radical, volatile organic compound, ZOTTO Tower
Abstract
The rates of ozone production ( P ) and sink ( L ) and total peroxide (OX) content are assessed with the use of the photostationary state approach from measurements of ozone (O3) and nitrogen oxides (NO, NO2) at Zotino Tall Tower Observatory (ZOTTO), central Siberia, in 2007-2014. Mean diurnal cycles of the above quantities for May - September cloud-free days peak at 6 ppb/hour ( P ), 1.4 ppb/hour ( L ), and 115 ppb ([OX]) between 11:00 and 15:00 local time. The linear dependence of P on [NOx] is derived in the range of measured NOx mixing ratios from 0.2-0.8 ppb, suggesting for NOx-limiting conditions of ozone production, with the slope rate P (O3)/[NOx] estimated at 13 (ppb/h)/ppb. The estimated high OX levels along with the condition P >> L manifest for high rates of the in-situ oxidation of biogenic volatile organic compounds and ozone generation. The surface air layer in boreal forest around the site can be considered an ozone source for the atmospheric boundary layer over remote central Siberia at NOx levels characteristic for both weakly polluted and clean (background) air masses.
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