A simulation of the Eddy accumulation method for measuring pollutant fluxes

Abstract

'Eddy accumulation' is a variation of standard eddy correlation techniques for determining eddy fluxes by sampling air in two separate systems depending on whether the vertical velocity is positive or negative. A numerical simulation of the eddy accumulation technique has been used to test the sensitivity of the method to errors arising from various sources, including sensor orientations, sampling limitations and chemical resolution. To detect a pollutant deposition velocity of 0. 1 cm s** minus **1, it appears necessary to maintain linear sampling characteristics over a dynamic range corresponding to two orders of magnitude of vertical wind speed (the limits are approximately 0. 05 sigma //w and 5 sigma //w in any given condition.