Search results for "urban atmosphere"
showing 2 items of 2 documents
Tobacco plants detect a decrease of environmental genotoxicity in Toulouse (France).
2003
Tobacco plants, heterozygous for two independent loci involved in the chlorophyll parenchyma differentiation, allow the genotoxic effects of the atmosphere of the industrial estate South of Toulouse to be estimated. Somatic spots of green cellular colonies on yellow-green background, were counted to calculate the cellular rates of reversion. Two experiments were carried out in 1981, and in 1997. A general decrease of genotoxic effects was observed. These observations were interpreted as being due to a general decrease of the air pollution evaluated by the development of the concentrations of three toxic gases before and after the implementation of cleanup devices. The results obtained demon…
Origin of atmospheric aerosols at the Pierre Auger Observatory using studies of air mass trajectories in South America
2014
The Pierre Auger Observatory is making significant contributions towards understanding the nature and origin of ultra-high energy cosmic rays. One of its main challenges is the monitoring of the atmosphere, both in terms of its state variables and its optical properties. The aim of this work is to analyze aerosol optical depth $\tau_{\rm a}(z)$ values measured from 2004 to 2012 at the observatory, which is located in a remote and relatively unstudied area of the Pampa Amarilla, Argentina. The aerosol optical depth is in average quite low - annual mean $\tau_{\rm a}(3.5~{\rm km})\sim 0.04$ - and shows a seasonal trend with a winter minimum - $\tau_{\rm a}(3.5~{\rm km})\sim 0.03$ -, and a sum…