Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces

0485223 - ÚVGZ 2019 RIV CZ eng C - Conference Paper (international conference)
Fischer, Milan - Katul, G. - Pozníková, Gabriela - Noormets, A. - Domec, J.-C. - Trnka, Miroslav - King, J.
Potential of flux-variance and surface renewal methods for sensible heat flux measurements at agricultural and forest surfaces.
Quo vaditis agriculture, forestry and society under global change? Conference proceeding. Brno: Global change research institute, 2017 - (Urban, O.; Šprtová, M.; Klem, K.), s. 53-57. ISBN 978-80-87902-22-6.
[Quo vaditis agriculture, forestry and society under Global Change? Velké Karlovice (CZ), 02.10.2017-04.10.2017]
R&D Projects: GA MŠMT(CZ) LO1415
Institutional support: RVO:86652079
Keywords : Temperature fluctuation * flux variance * agriculture and forest surface
OECD category: Meteorology and atmospheric sciences

Two alternative micrometeorological methods, flux-variance (FV) and surface renewal (SR), based on
measurements of high-frequency temperature fluctuation and Obukhov length stability parameter, were
tested against eddy covariance (EC) sensible heat flux (H) measurements. The study was conducted at
three sites representing agricultural, forestry, and agroforestry systems. In terms of measurement setup,
these sites represented surface, roughness, and canopy top layer, respectively. As expected, the best match
of all the methods was in the surface layer, whilst it was poorer in the roughness and canopy sublayers.
Systematic deviation from EC across all three investigated surfaces was within 16% and 8% for FV and SR,
respectively. While FV resulted in higher correlation with EC measurements (0.93–0.98 vs. 0.89–0.97),
SR provided less systematic biases (1.02–1.08 vs. 0.94–1.16). In general, both FV and SR provided slightly
higher H as compared to EC. We suggest that parallel deployment of FV and SR is useful, as both methods
require the same instrumentation yet they are based on sufficiently different theories. Therefore, the agreement
between FV and SR increases confidence in the results obtained and vice versa.
Permanent Link: http://hdl.handle.net/11104/0280293