Please use this identifier to cite or link to this item: https://apo.ansto.gov.au/dspace/handle/10238/8283
Title: A radon-only technique for characterising baseline constituent concentrations at Cape Grim
Authors: Chambers, SD
Williams, A
Crawford, J
Griffiths, AD
Krummel, PB
Steele, LP
Schoot, VD
Keywords: Carbon dioxide
Radon 222
Aerosol monitoring
Bases
Concentration ratio
Air
Issue Date: 12-Nov-2014
Publisher: Bureau of Meteorology and CSIRO Oceans and Atmosphere Flagship
Citation: Chambers, S. D., Williams, A., Crawford, J., Griffiths, A. D., Krummel, P. B., Steele, L. P., & Schoot, V. D. (12-14 November, 2014). A Radon-only technique for characterising baseline constituent concentrations at Cape Grim. Paper presented at Atmospheric Composition and Chemistry Observations and Modelling Conference incorporating the Cape Grim Annual Science Meeting; 12-13 November 2014; Aspendale, Victoria.
Abstract: Nine years (2004-2013) of hourly Radon-222, carbon dioxide and ozone concentration observations at Cape Grim are used to assess the residual terrestrial influence on air masses with radon concentrations below the 100 mBq m-3 threshold traditionally used for ‘baseline’ delineation (Figure 1a). Subsequently, a two step radon-only approach for estimating ‘baseline’ constituent concentrations on monthly timescales is proposed. Based on a stringent 40mBq m-3 radon threshold followed by a simple 10th/90th percentile constitute outlier removal, the technique is completely independent of meteorological or aerosol observations. An initial evaluation of the techniqueusing hourly carbon dioxide and ozone records yielded monthly ‘baseline’ concentration estimates more consistent with expectations of minimally perturbed Southern Ocean air masses than existing baseline selection techniques (Figure 1c). This work builds upon prior studies that have identified radon as a valuable baseline criteria [e.g Gras and Whittlestone, 1992; Molly and Galbally, 2014]. CSIRO Oceans and Atmosphere Flagship Aspendale, Victoria, Australia.
Gov't Doc #: 7849
URI: http://apo.ansto.gov.au/dspace/handle/10238/8283
Appears in Collections:Conference Publications

Files in This Item:
File Description SizeFormat 
Chambers 2014.pdf288.49 kBAdobe PDFThumbnail
View/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.