Search results
Results From The WOW.Com Content Network
Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. Ground-level or tropospheric ozone is created by chemical reactions between NOx gases (oxides of nitrogen produced by combustion) and volatile organic compounds (VOCs). The combination of these chemicals in the presence of sunlight form ozone.
Tropospheric ozone depletion events are phenomena that reduce the concentration of ozone in the earth's troposphere. Ozone (O3) is a trace gas which has been of concern because of its unique dual role in different layers of the lower atmosphere. [1] Apart from absorbing UV-B radiation and converting solar energy into heat in the stratosphere ...
Ozone's effect on signalling in animals may therefor become more significant than its direct affect as an antibiotic at higher concentrations. [8] Developments of techniques capable of more accurately monitoring ozone levels inside cells will enable investigation of endogenous ozone in cells, perhaps clarifying how cells use endogenous ozone. [9]
Ground-level ozone, or tropospheric ozone, is the most concerning type of ozone pollution in urban areas and is increasing in general. [60] Ozone pollution in urban areas affects denser populations, and is worsened by high populations of vehicles, which emit pollutants NO 2 and VOCs, the main contributors to problematic ozone levels. [61]
Ozone in the troposphere is primarily produced through the photolysis of nitrogen dioxide by photons with wavelengths (λ) less than 420 nanometers, [1] which are able to reach the lowest levels of the atmosphere, through the following mechanism: [2]: pg. 22
Once the concentration of NO x exceeds a certain level, atmospheric reactions result in net ozone formation. Since tropospheric ozone can absorb infrared radiation, this indirect effect of NO x is intensifying global warming. There are also other indirect effects of NO x that can either increase or decrease the greenhouse effect.
The Dobson unit (DU) is a unit of measurement of the amount of a trace gas in a vertical column through the Earth's atmosphere.It originated by, and continues to be primarily used in respect to, the study of atmospheric ozone, whose total column amount, usually termed "total ozone", and sometimes "column abundance", is dominated by the high concentrations of ozone in the stratospheric ozone layer.
In the troposphere observations show that the total abundance of ozone-depleting compounds continues to decline slowly from the peak that occurred in 1992-1994. Observations in the stratosphere indicate that the total chlorine abundance is at or near a peak, while bromine abundances are probably still increasing.