Issue 10, 2018

On the application of spectral corrections to particle flux measurements

Abstract

To study the environmental fate of nanoparticles, reliable measurements of particle fluxes in the atmosphere are of importance. The eddy-covariance (EC) technique can be used to calculate surface fluxes. In this study, the EC technique has been applied to calculate particle fluxes in Helsinki (Finland) and Cabauw (the Netherlands). For reliable estimations of the surface fluxes, particle flux measurements need to be corrected for attenuation at the highest frequencies. This attenuation is caused by the relatively long response time of scalar sensors and measurement set-up. The attenuation can be estimated using a theoretical or an empirical approach. Horst [Horst, Boundary-Layer Meteorology, 1997, 82(2)] developed a simple formula to estimate the attenuation, based on the empirical approach. The empirical approach relies on the assumption of spectral similarity between two scalars. In this paper the effect of the spectral similarity assumption is investigated. It is shown that in order to apply the Horst formula reliably, a decent estimate of the sensor response time is required. Furthermore, it is shown that in order to apply the empirical method, a fast sensor response is required. It is concluded that theory does not predict the position of the peak in the cospectrum well, which means that for measurement set-ups not yet operational, this requirement is not easily evaluated. The assumption of spectral similarity seems reasonable for particle fluxes and heat fluxes, when compared to similarity between fluxes of other scalars. An altered assumption of spectral similarity has been applied, where similarity is assumed only at frequencies higher than the peak frequency in the cospectrum. This assumption leads to a better estimate for the attenuation, when applied to the Helsinki data. It does not lead to an improvement for the Cabauw data set, due to the large response time of the measurement set-up.

Graphical abstract: On the application of spectral corrections to particle flux measurements

  • This article is part of the themed collection: ICEENN

Article information

Article type
Paper
Submitted
11 mai 2018
Accepted
17 juil. 2018
First published
29 août 2018

Environ. Sci.: Nano, 2018,5, 2315-2324

On the application of spectral corrections to particle flux measurements

A. Oosterwijk, B. Henzing and L. Järvi, Environ. Sci.: Nano, 2018, 5, 2315 DOI: 10.1039/C8EN00501J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements