An improved inlet for precisely measuring the atmospheric Ar/N2 ratio T. W. Blaine, R. F. Keeling, and W. J. Paplawsky 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.
Citation: 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.