Open AccessAn Evaluation of χT Estimation Techniques: Implications for Batchelor Fitting and ɛ
Author(s) -
Jonah V. Steinbuck,
Mark T. Stacey,
Stephen G. Monismith
Publication year - 2009
Publication title -
journal of atmospheric and oceanic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.774
H-Index - 124
eISSN - 1520-0426
pISSN - 0739-0572
DOI - 10.1175/2009jtecho611.1
Subject(s) - wavenumber , dissipation , thermistor , statistical physics , noise (video) , variance (accounting) , kinetic energy , focus (optics) , temperature gradient , turbulence , physics , computational physics , computer science , mechanics , thermodynamics , meteorology , optics , classical mechanics , accounting , quantum mechanics , artificial intelligence , business , image (mathematics)
Techniques for the accurate estimation of the dissipation rate of temperature variance χT from temperature microstructure measurements are synthesized and evaluated. The techniques focus on the treatment of contamination in the integration of the vertical temperature gradient spectrum. The essential improvements come from estimating χT from the wavenumber domain in which the signal exceeds the noise and from reconstructing unresolved wavenumber contributions using the best-fit Batchelor spectrum. The improvement in the estimates of χT results in better Batchelor fits and more robust estimates of the dissipation rate of turbulent kinetic energy ɛ. High correlations of independent measurements of χT and ɛ from two collocated FP07 thermistors demonstrate the value of the techniques and highlight the improvements at the low end of the resolvable ranges of χT and ɛ.