residence time
Quick Summary
In atmospheric science, residence time refers to the average duration a substance, such as a gas molecule, persists in the atmosphere. It is calculated from the time a substance leaves its source until it encounters a sink, which is a process that removes it from the atmosphere either chemically or physically.1
For example, methane (CH4) has a residence time of about 10 years, significantly shorter than carbon dioxide (CO2), which can remain in the atmosphere for hundreds of years. This concept is crucial for understanding how atmospheric composition changes over time, especially in relation to human activities that introduce or remove gases.21
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evolution of the atmosphereProcesses…expressed in terms of the residence time, the average time spent by a molecule in the atmosphere after it leaves a source and before it encounters a sink.
Read More…expressed in terms of the residence time, the average time spent by a molecule in the atmosphere after it leaves a source and before it encounters a sink.
Read More- evolution of the atmospherePhotochemical production
…at Earth’s surface) and that residence times for O2 were so short that significant atmospheric concentrations could not accumulate. The best estimate is that pressures of O2 at sea level and ground level were less than 5 × 10−8 PAL.
Read More…at Earth’s surface) and that residence times for O2 were so short that significant atmospheric concentrations could not accumulate. The best estimate is that pressures of O2 at sea level and ground level were less than 5 × 10−8 PAL.
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