Anthropogenic ozone radiative forcing is traditionally separately attributed to tropospheric and stratospheric changes assuming that these have distinct causes1. Using the interactive composition–climate model GISS-E2-R we find that this assumption is not justified. Our simulations show that changes in emissions of tropospheric ozone precursors have substantial effects on ozone in both regions,...

A meso-scale model was used to understand and describe the dynamical processes driving high ozone concentrations observed during both dry and monsoon season in monthly climatologies profiles over Lagos (Nigeria, 6.6 N, 3.3 E), obtained with the MOZAIC airborne measurements (ozone and carbon monoxide). This study focuses on ozone enhancements observed in the upper-part of the lower troposphere, ...

Biogenic sources contribute a large portion of emissions of volatile organic compounds (VOCs), a precursor to tropospheric ozone (O3). These emissions are difficult to control and are affected by land-use and climate. A sensitivity analysis was performed using an emissions scenario with a 100% increase in biogenic emissions and another scenario with an additional 100% increase in motor vehicle ...

The techniques currently available to measure the ambient atmospheric concentrations of O 3 , O 3 -precursors (including the odd-hydrogen free radicals), the oxidation products of these compounds, and gas-phase aerosol precursors are outlined below. This critical review focuses on the recent developments, and, in particular those developments that have been reported in the published literature ...

Fossil diesel fuel and rape seed oil methylester are compared with regard to exhaust gas emissions and effects of these emissions on human health and the environment. Tests were carried out using an agricultural tractor and a test engine. The aspects treated are: use of blends, particle sizes, mutagenic potency of the particulate matter, and ozone precursors. Whereas slight disadvantages of bio...

The analysis of ozone precursors has been a feature of the EPA air quality surveillance regulations since 1992 with the establishment of Photochemical Assessment Monitoring Stations (PAMS) as part of State Implementation Plans (SIP) for ozone non-attainment areas classified as serious, severe or extreme. At that time, guidance documentation allowed for the measurements of VOC precursors either ...

Derived from measurements it has been concluded that in the last hundred years the ground-based ozone concentration has risen by about a factor of two. Models also show a doubling of the tropospheric ozone content due to human activities. It is very likely that mean ozone concentration will further increase. In contrast, episodes with excess ozone levels ("summer smog") have become rare in Cent...

Data from four continuous ozone and weather monitoring sites operated by the National Park Service in Sierra Nevada, California, are used to develop an ozone forecasting model and to estimate the contribution of wildland fires on ambient ozone levels. The analyses of weather and ozone data pointed to the transport of ozone precursors from the Central Valley as an important source of pollution i...

Measurement of the levels of ozone and carbon monoxide (a tracer of anthropogenic pollution) at three surface sites on the Atlantic coast of Canada allow the estimation of the amount of ozone photochemically produced from anthropogenic precursors over North America and transported to the lower troposphere over the temperate North Atlantic Ocean. This amount is greater than that injected from 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...