Heavy Methanes as Atmospheric Tracers

Abstract

Methane-21 (¹³CD₄) is potentially a useful nonradioactive tracer for testing atmospheric transport and diffusion models on a continental scale. In an experiment to demonstrate this long-range utility, the release of 84 grams of methane-21 was detected at distances of 1500 to about 2500 kilometers at concentrations of about 1 part in 2 x 10¹⁶ parts (by volume) in the air by a technique in which methane was separated and the methane-21 content was measured with a mass spectrometer.