Note on the application of planar-fit rotation for non-omnidirectional sonic anemometers

Abstract

For non-omnidirectional sonic anemometers like the Kaijo-Denki DAT 600 TR61A probe, it is shown that separate planar-fit rotations must be used for the undisturbed (open part of the sonic anemometer) and the disturbed sector. This increases the friction velocity while no effect on the scalar fluxes was found. In the disturbed sector, irregular values of − <span style="text-decoration: overline"><i>u′</i><i>w′</i></span> < 0 were detected for low wind velocities. Up to a certain extent these results can be transferred to the CSAT3 sonic anemometer (Campbell Scientific Ltd). This study was done for data sets from the Naqu-BJ site on the Tibetan Plateau

The Role of Roughness and Stability on the Momentum Flux in the Marine Atmospheric Surface Layer: A Study on the Southwestern Atlantic Ocean

“…The flow distortion is evaluated by a combination of three tests: the angle-of-attack test , the distorted-sector test (Li et al, 2013), and the acceptable tilt-angle test. The first test flags segments in which the vertical angle-of-attack of the flow is greater than 5 ∘ compared with the horizontal plane.…”

Uncertainty Analysis of the Eddy-Covariance Turbulent Fluxes Measured over a Heterogeneous Urban Area: A Coordinate Tilt Impact

“…에디 공분산 측정 자료를 이용하여 정확한 난류 플 럭스를 산정하기 위해서는 엄격한 품질 관리 과정이 필요하다 (Foken and Wichura, 1996;Vickers and Mahrt, 1997;Ruppert et al, 2006). 특히, 경사 지형이나 비 균질 지면피복 지역에서 측정된 에디 공분산 자료는 난류 플럭스 산정 과정에서 평균 유선면을 이용한 좌 표계 편향(coordinate tilt) 효과를 적절히 보정하는 것 이 중요하다(e.g., Sun, 2007;Yuan et al, 2007Yuan et al, , 2011; Lee et al, 2013;Li et al, 2013;Kim et al, 2014;Lee, 2015b;Ross and Grant, 2015). 유선 좌표계 (natural wind coordinate)는 지형이나 지면 피복의 비 균질성에 기인하는 국지 순환의 영향을 제거하기에 유용한 방법으로 제안되었다 (Tanner and Thurtell, 1969).…”

“…또한, 대상지역에서 두 회전 좌표변환에 의해 산정된 난류 플럭스의 차이는 상대적으로 균질한 자연 지표 에서 보고되고 있는 결과에 비해 상대적으로 큰 값을 나타내는 특징이 있다(e.g., Yuan et al, 2007;Li et al, 2013;Shimizu, 2015). (Fig.…”

Adapting Tilt Corrections and the Governing Flow Equations for Steep, Fully Three-Dimensional, Mountainous Terrain

“…In addition, velocity data for flow behind sonic anemometers are often not used in practice because the mounting arms can disturb the flow field (Foken 2008). Li et al (2013) suggest separating these sectors when performing SPF tilt corrections. However, these data have been retained in the present study so as not to impose any sector definitions a priori.…”

“…However, these data have been retained in the present study so as not to impose any sector definitions a priori. Therefore, it should be assumed that data from these sectors are potentially of lower quality (see also Li et al 2013).…”