Test of Scintillometer Saturation Correction Methods Using Field Experimental Data

作者：Kleissl J^*; Hartogensis O K; Gomez J D

来源：Boundary-Layer Meteorology, 2010, 137(3): 493-507.

DOI：10.1007/s10546-010-9540-x

• Large aperture scintillometer
• Sensible heat flux
• Signal saturation
• Wave propagation

Saturation of large aperture scintillometer (LAS) signals can result in sensible heat flux measurements that are biased low. A field study with LASs of different aperture sizes and path lengths was performed to investigate the onset of, and corrections for, signal saturation. Saturation already occurs at C(n)(2) approximate to 0.074 D(5/3)lambda(1/3)L(-8/3), where C(n)(2) is the structure parameter of the refractive index, D is the aperture size, lambda is the wavelength, L is the transect length, which is smaller than theoretically derived saturation limits. At a transect length of 1 km, a height of 2.5 m, and aperture approximate to 0.15 m the correction factor exceeds 5% already at C(n)(2)=2 x 10(-12)m(-2/3), which will affect many practical applications of scintillometry. The Clifford correction method, which only depends on C(n)(2) and the transect geometry, provides good saturation corrections over the range of conditions observed in our study. The saturation correction proposed by Ochs and Hill results in correction factors that are too small in large saturation regimes. An inner length scale dependence of the saturation correction factor was not observed. Thus for practical applications the Clifford correction method should be applied.

• 出版日期2010-12