Preferred Label : background concentration;
Detailed label : background concentration (level) in atmospheric chemistry;
IUPAC definition : The concentration of a given species in a pristine air mass in which anthropogenic
impurities of a relatively short lifetime are not present. The background concentrations
of relatively long-lived molecules, methane, carbon dioxide, halocarbons (CF sub 3
/sub Cl, CF sub 2 /sub Cl sub 2 /sub , etc.) and some other species continue to rise
due to anthropogenic input, so the composition of background air is undergoing continual
change. Background concentration of a given species is sometimes considered to be
the concentration of that impurity in a given air mass when the contribution from
anthropogenic sources under study is absent. Synonymous with baseline concentration.;
Origin ID : B00578;
See also
The concentration of a given species in a pristine air mass in which anthropogenic
impurities of a relatively short lifetime are not present. The background concentrations
of relatively long-lived molecules, methane, carbon dioxide, halocarbons (CF sub 3
/sub Cl, CF sub 2 /sub Cl sub 2 /sub , etc.) and some other species continue to rise
due to anthropogenic input, so the composition of background air is undergoing continual
change. Background concentration of a given species is sometimes considered to be
the concentration of that impurity in a given air mass when the contribution from
anthropogenic sources under study is absent. Synonymous with baseline concentration.
