[1] Conflicting interpretations of the spring ozone maximum observed at Bermuda (32 N, 65 W) have fueled the debate on stratospheric influence versus tropospheric production as sources of tropospheric ozone. We use a global three-dimensional (3-D) model of tropospheric ozone-NOx-hydrocarbon chemistry driven by assimilated meteorological observations to reconcile these past interpretations. The ...

Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract A record low total ozone column of 177 DU was observed at Reading, UK, on 19 Jan-uary 2006. Low ozone values were also recorded at other stations in the British Isles and North West Europe on, and around, this date. Hemispheric maps of total ozone from the...

In many areas, natural sources contribute a substantial fraction of volatile organic compound (VOC) emissions, which are precursors to tropospheric ozone (O3). To investigate the significance of biogenic VOC emissions on ozone formation, meteorological and air quality modelling were used to generate hourly ozone estimates for a case-study high ozone episode in the Mid-Atlantic region of the Uni...

UNLABELLED Using computational fluid dynamics simulations of an occupant in a ventilated room, we find that breathing zone ozone levels can be substantially lower and ozone reaction products associated with human surfaces (ORPHS) levels considerably higher than room levels. For air exchange rates <3/h, the ratio of the breathing zone to the ozone concentration 1 m from the body (bulk air), r(oz...

The effect of gaseous ozone and hot water, alone or in combination, on the sensory and microbial quality of cantaloupe melon was investigated. Escherichia coli O157:H7 transmission from the rind to edible melon flesh during cutting practices was also investigated. Four different treatments consisting of hot water (75 degrees C, 1min), gaseous ozone (10,000ppm, 30min), gaseous ozone supplied by ...

Low-income households may be disproportionately affected by ozone pollution and ozone policy. We quantify how three factors affect the relative benefits of ozone policies with household income: (1) unequal ozone reductions; (2) policy delay; and (3) economic valuation methods. We model ozone concentrations under baseline and policy conditions across the full continental United States to estimat...

results although the antibacterial effect of 16 ppm aqueous ozone using a manual technique had an insufficient effect, its ultrasonic application technique resulted in complete disinfection in the root canals. conclusions the bactericidal activity of high concentration of aqueous ozone combined with ultrasonic application technique showed efficacy similar to that of 5.25% naocl in root canals. ...

About 90% of the ozone in the Earth’s atmosphere resides in the stratosphere, forming the ‘‘ozone layer’’ which shields life on Earth from harmful ultraviolet radiation. In the mid-1970s, it was recognized that anthropogenic chlorofluorocarbons (CFCs) could deplete the ozone layer. Observations of the ozone layer indicated that depletion was occurring due to the buildup of CFCs and Halons in th...

It has long been recognised that pollutant gases cause significant impacts on crops and studies conducted revealed that ground-level ozone is responsible for most of the crop-yield losses from air pollutants whereby losses from other pollutants are minimal, relative to ozone (Fuhrer et al., 1997; Pleijel et al., 1998; Ishii et al, 2004). Ozone is a secondary pollutant resulting from photochemic...

Following the establishment of point measurements of ground-level ozone concentrations have been attempts by many researchers to develop ozone surfaces. This paper offers a critique of ozone-mapping endeavors, while also empirically exploring the operational scale of ground-level ozone. The following issues are discussed: aspects of spatial scale; the spatial complexity of ground-level ozone co...