ESS200A
Prof. Jin-Yi Yu
Residence Time
long
residence
time
short
residence
time
q Individual air molecules stay in the atmosphere for a finite period of
time before they are
removed by whatever output processes are active.
q The average length of time that individual molecules remain in
the atmosphere is called the residence time.
q The residence time is found by dividing the mass of the
substance in the atmosphere (in kilograms) by the rate at which the substance
enters and exits the atmosphere (in kilograms per year).