An improved inlet for precisely measuring the atmospheric Ar/N2 ratio
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0244, USA
Abstract. The atmospheric Ar/N2 ratio is expected to be useful as a tracer of air-sea heat exchange, but this application has been hindered in part due to sampling artifacts. Here we show that the variability in δ(Ar/N2) due to thermal fractionation at the inlet can be on the order of 40-80 per meg, and we introduce the use of an aspirated solar shield that successfully minimizes such fractionation. The data collected using this new inlet have a mean diurnal cycle of 1.0 per meg or less, suggesting that any residual thermal fractionation effect is reduced to this level.
Blaine, T. W., Keeling, R. F., and Paplawsky, W. J.: An improved inlet for precisely measuring the atmospheric Ar/N2 ratio, Atmos. Chem. Phys., 6, 1181-1184, doi:10.5194/acp-6-1181-2006, 2006.