نتایج جستجو برای: surface ozone
تعداد نتایج: 653219 فیلتر نتایج به سال:
Ozone is an important pollutant and greenhouse gas, and tropospheric ozone variations are generally associated with both natural and anthropogenic processes. As one of the most pristine and inaccessible regions in the world, the Tibetan Plateau 15 has been considered as an ideal region for studying processes of the background atmosphere. Due to the vast area of the Tibetan Plateau, sites in the...
[1] We present a novel capability in satellite remote sensing with implications for air pollution control strategy. We show that the ratio of formaldehyde columns to tropospheric nitrogen dioxide columns is an indicator of the relative sensitivity of surface ozone to emissions of nitrogen oxides (NOx NO + NO2) and volatile organic compounds (VOCs). The diagnosis from these space-based observati...
Surface ozone measurements at the southernmost tropical semi-urban site Nagercoil (8 o 11’ N, 77 o 29’ E, 25m), India has been studied for the first time for the period from 2007 to 2010. A Gas Sensitive Semiconductor (GSS) sensor based ozone monitor is used for measurement. The measurement showed that the ozone concentration is a function of time and it varies from morning minimum to afternoon...
We develop a statistical model to predict June-July-August (JJA) daily maximum 8-h average (MDA8) ozone concentrations in the eastern United States based on large-scale climate patterns during the previous spring. We find that anomalously high JJA ozone in the East is correlated with these springtime patterns: warm tropical Atlantic and cold northeast Pacific sea surface temperatures (SSTs), as...
The room temperature kinetics of gas-phase ozone loss via heterogeneous interactions with thin alumina films has been studied in real-time using 254 nm absorption spectroscopy to monitor ozone concentrations. The films were prepared from dispersions of fine alumina powder in methanol and their surface areas were determined by an in situ procedure using adsorption of krypton at 77 K. The alumina...
We use a global chemical transport model (GEOS-Chem) driven by the GISS GCM to investigate the effect on China’s ozone air quality from 2000-2050 global changes in climate and anthropogenic emissions of ozone precursors. The climate and emission effect in combination will increase afternoon mean surface ozone over China by an annual average of 8.7 ppbv, of which 65% is attributed to the project...
The reliance on global mean radiative forcing as an index of climate change is questionable for highly inhomogeneous forcing agents such as tropospheric ozone or aerosols. Using a general circulation model, we have carried out a pair of equilibrium climate simulations with previously calculated present-day and preindustrial ozone distributions. We show that the radiative forcing of 0.49 W m-2 d...
We quantify the sources contributing to background surface ozone concentrations in the US Intermountain West by using the GEOS-Chem chemical transport model with 1/2× 2/3 horizontal resolution to interpret the Clean Air Status and Trends Network (CASTNet) ozone monitoring data for 2006–2008. We isolate contributions from lightning, wildfires, the stratosphere, and California pollution. Lightnin...
We present the chemistry-climate model UM CAM in which a relatively detailed tropospheric chemical module has been incorporated into the UK Met Office’s Unified Model version 4.5. We obtain good agreements between the modelled ozone/nitrogen species and a range of observations including surface ozone measurements, ozone sonde data, and some aircraft campaigns. Four 2100 calculations assess mode...
Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx ≡ NO + NO2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from...
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