Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within...

This study presents annual simulations of tropospheric ozone and related species made for the first time using the WRF-Chem model over South Asia for the year 2008. The model-simulated ozone, CO, and NOx are evaluated against ground-based, balloon-borne and satellite-borne (TES, OMI and MOPITT) observations. The comparison of model results with surface ozone observations from seven sites and CO...

A gold coated copper rotating electrode was used to eliminate surface oxidation effect. This study examined the effect of electrode rotation on the ozone generation process and showed that an ozonizer with an electrode rotating system might be a possible way to increase ozone-synthesis efficiency. Two new phenomena appeared during experiments with the rotating electrode. First was that ozone co...

Previous research has shown that ozone reactions on surface-sorbed D-limonene can promote gas phase secondary organic aerosol (SOA) formation indoors. In this work, we conducted 13 steady state chamber experiments to measure the SOA formation entirely initiated by ozone reactions with squalene sorbed to glass, at chamber ozone of 57e500 ppb for two relative humidity (RH) conditions of 21% and 5...

Regulatory air quality models, such as the Community Multiscale Air Quality model (CMAQ), are used by federal and state agencies to guide policy decisions that determine how to best achieve adherence with National Ambient Air Quality Standards for surface ozone. We use observations of ozone and its important precursor NO2 to test the representation of the photochemistry and emission of ozone pr...

WRF-Chem simulations were performed for the March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) to investigate the direct effects of aerosols on surface radiation and air quality. Domain-wide, WRF-Chem showed a decrease of 20W/m in surface shortwave (SW) radiation due to the aerosol direct effect (ADE), co...

A model, based on ozone-concentration tendency equation, is developed to study synoptic ozone-column variations. The application is referred to a middle-latitude site and to an atmospheric layer extending from the surface up to about 35-km altitude. Photochemical effects at the considered location for synoptic time scales are considered negligible. The data input consists of umkehr ozone profil...

The present work investigated the evolution of catalytic activity of activated carbon in 1,3,6-naphthalenetrisulphonic acid (NTS) ozonation in aqueous phase. Activated carbons pre-treated with ozone showed a reduction in NTS oxidation rate and efficacy of TOC removal that increased with ozone exposure time. The ozone treatment increased the number of surface oxygenated (electron-withdrawing) gr...