| Volumes and Issues Contents of Issue 1 |
www.atmos-meas-tech-discuss.net/5/447/2012/
doi:10.5194/amtd-5-447-2012
© Author(s) 2012. This work is distributed
under the Creative Commons Attribution 3.0 License.
Using sonic anemometer temperature to measure sensible heat flux in strong winds
1National Center for Atmospheric Research, Boulder, Colorado, USA
2Department of Geography, University of Colorado, Boulder, USA
3School of Natural Resources and the Environment, University of Arizona, Tucson, USA
Abstract. The sensible heat flux (H) is a significant component of the surface energy balance (SEB). Sonic anemometers simultaneously measure the turbulent fluctuations of vertical wind (w') and sonic temperature (Ts'), and are commonly used to measure H. Our study examines 30-min heat fluxes measured with a Campbell Scientific model CSAT3 sonic anemometer above a subalpine forest. We compare H calculated with Ts to H calculated with a co-located thermocouple and find that for horizontal wind speed (U) less than 8 m s−1 the agreement is ≈±30 W m−2. However, for U >≈ 8 m s−1, the CSAT3 H becomes larger than H calculated with the thermocouple, reaching a maximum difference of ≈250 W m−2 at U ≈ 18 m s−1. H calculated with the thermocouple results in a SEB that is relatively independent of U at high wind speeds. In contrast, the SEB calculated with H from the CSAT3 varies considerably with U, particularly at night. Cospectral analysis of w'Ts' suggest that spurious correlation is a problem during high winds which leads to a positive (additive) increase in H calculated with the CSAT3. At night, when H is typically negative, this CSAT3 error results in a measured H that falsely approaches zero or even becomes positive. Within a broader context, the usefulness of side-by-side instrument comparisons are discussed.
Discussion Paper (PDF, 1834 KB) Interactive Discussion (Final Response, 17 Comments) Manuscript under review for AMT
Citation: Burns, S. P., Horst, T. W., Blanken, P. D., and Monson, R. K.: Using sonic anemometer temperature to measure sensible heat flux in strong winds, Atmos. Meas. Tech. Discuss., 5, 447-469, doi:10.5194/amtd-5-447-2012, 2012. Bibtex EndNote Reference Manager XML
