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Measurements of mixing parameters in atmospheric stably stratified parallel shear flow

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Abstract

The mixing coefficient Г = B/ε, defined as the ratio of the magnitude of buoyancy flux B to the rate of turbulent kinetic energy (TKE) dissipation ε, plays a key role in modeling atmospheric and oceanic flows. Г is sometimes estimated using yet another fundamental quantity, the flux Richardson number (or mixing efficiency) Rif = B/P, where P is the rate of production of TKE. In practice, Г and Rif are commonly assumed as constants, but studies show that they depend on multiple parameters determined by the type of flow, for example, the gradient Richardson number Rig for stratified shear flows. During the MATERHORN field program, direct measurements of velocity and temperature profiles as well as B, ε, and P were made over an extended period using a densely instrumented flux tower. A ~ 90 min period of stratified parallel shear flow was identified in the data record, including recurrent intervals of nominally stationary flow. Measurements during this period supported the study of mixing parameters as reported in this paper. Even for this case of nature resembling an ideal flow, Г was found to be dependent on multiple parameters. Nevertheless, for periods robustly identified as shear flow in equilibrium with embedded turbulence, the measurements were in agreement with those of past stratified shear flow experiments in the laboratory. This result points to the challenges of parameterizing turbulent mixing in environmental flow models.

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References

  1. Ivey GN, Winters KB, Koseff JR (2008) Density stratification, turbulence, but how much mixing? Annu Rev Fluid Mech 40:169–184. https://doi.org/10.1146/annurev.fluid.39.050905.110314

    Article  Google Scholar 

  2. Ellison TH (1957) Turbulent transfer of heat and momentum from an infinite rough plane. J Fluid Mech 2:456–466. https://doi.org/10.1017/S0022112057000269

    Article  Google Scholar 

  3. Osborn TR (1980) Estimates of the local rate of vertical diffusion from dissipation measurements. J Phys Oceanogr 10:83–89. https://doi.org/10.1175/1520-0485(1980)010%3c0083:EOTLRO%3e2.0.CO;2

    Article  Google Scholar 

  4. Hopfinger EJ, Linden PF (1982) Formation of thermoclines in zero-mean-shear turbulence subjected to a stabilizing buoyancy force. J Fluid Mech 114:157–173. https://doi.org/10.1017/S0022112082000081

    Article  Google Scholar 

  5. Maffioli A, Brethouwer G, Lindborg E (2016) Mixing efficiency in stratified turbulence. J Fluid Mech. https://doi.org/10.1017/jfm.2016.206

    Article  Google Scholar 

  6. Turner JS (1979) Buoyancy effects in fluids. Cambridge University Press, Cambridge, pp 116–123

    Google Scholar 

  7. Ivey GN, Imberger J (1991) On the nature of turbulence in a stratified fluid. Part I: the energetics of mixing. J Phys Oceanogr 21:650–658. https://doi.org/10.1175/1520-0485(1991)021%3c0650:OTNOTI%3e2.0.CO;2

    Article  Google Scholar 

  8. Mater BD, Venayagamoorthy SK (2014) The quest for an unambiguous parameterization of mixing efficiency in stably stratified geophysical flows. Geophys Res Lett 41:4646–4653. https://doi.org/10.1002/2014GL060571

    Article  Google Scholar 

  9. Linden PF (1980) Mixing across a density interface produced by grid turbulence. J Fluid Mech 100:691–703. https://doi.org/10.1017/S002211208000136X

    Article  Google Scholar 

  10. Strang EJ, Fernando HJS (2001) Entrainment and mixing in stratified shear flows. J Fluid Mech 428:349–386. https://doi.org/10.1017/S0022112000002706

    Article  Google Scholar 

  11. Pardyjak ER, Monti P, Fernando HJS (2002) Flux Richardson number measurements in stable atmospheric shear flows. J Fluid Mech 459:307–316. https://doi.org/10.1017/S0022112002008406

    Article  Google Scholar 

  12. Monti P, Fernando HJS, Princevac M et al (2002) Observations of flow and turbulence in the nocturnal boundary layer over a slope. J Atmos Sci 59:2513–2534. https://doi.org/10.1175/1520-0469(2002)059%3c2513:OOFATI%3e2.0.CO;2

    Article  Google Scholar 

  13. Lozovatsky ID, Fernando HJS (2012) Mixing efficiency in natural flows. Philos Trans R Soc. https://doi.org/10.1098/rsta.2012.0213

    Article  Google Scholar 

  14. Mellor GL, Yamada T (1982) Development of a turbulence closure model for geophysical fluid problems. Rev Geophys Sp Phys 20:851–875. https://doi.org/10.1029/RG020i004p00851

    Article  Google Scholar 

  15. Wyngaard JC, Coté OR (1971) The budgets of turbulent kinetic energy and temperature variance in the atmospheric surface layer. J Atmos Sci 28:190–201. https://doi.org/10.1175/1520-0469(1971)028%3c0190:TBOTKE%3e2.0.CO;2

    Article  Google Scholar 

  16. Kit E, Cherkassky A, Sant T, Fernando HJS (2010) In situ calibration of hot-film probes using a collocated sonic anemometer: implementation of a neural network. J Atmos Ocean Technol 27:23–41. https://doi.org/10.1175/2009JTECHA1320.1

    Article  Google Scholar 

  17. Gibson CH (1980) Fossil temperature, salinity and vorticity turbulence in the ocean. Mar Turbul Elsevier Oceanogr Ser 28:221–257. https://doi.org/10.1016/S0422-9894(08)71223-6

    Article  Google Scholar 

  18. Fernando HJS (1991) Turbulent mixing in stratified fluids. Annu Rev Fluid Mech 23:455–493. https://doi.org/10.1146/annurev.fl.23.010191.002323

    Article  Google Scholar 

  19. Fernando HJS (2003) Turbulent patches in a stratified shear flow. Phys Fluids 15:3164–3169. https://doi.org/10.1063/1.1949203

    Article  Google Scholar 

  20. Fernando HJS, Pardyjak ER, Di Sabatino S et al (2015) The MATERHORN: unraveling the intricacies of mountain weather. Bull Am Meteorol Soc 96:1945–1968. https://doi.org/10.1175/BAMS-D-13-00131.1

    Article  Google Scholar 

  21. Kit E, Hocut CM, Liberzon D, Fernando HJS (2017) Fine-scale turbulent bursts in stable atmospheric boundary layer in complex terrain. J Fluid Mech 833:745–772. https://doi.org/10.1017/jfm.2017.717

    Article  Google Scholar 

  22. Skelly BT, Miller DR, Meyer TH (2002) Triple-hot-film amemometer performance in CASES-99 and a comparison with sonic anemometer measurements. Bound-Layer Meteorol 105:275–304. https://doi.org/10.1023/A:1019906521898

    Article  Google Scholar 

  23. Gulitski G, Kholmyansky M, Kinzelbach W et al (2007) Velocity and temperature derivatives in high-Reynolds-number turbulent flows in the atmospheric surface layer. Part 1. Facilities, methods and some general results. J Fluid Mech 589:57–81. https://doi.org/10.1017/S0022112007007495

    Article  Google Scholar 

  24. Hinze JO (1959) Turbulence: an introduction to its mechanism and theory. McGraw-Hill, New York

    Google Scholar 

  25. Kaimal JC, Finnigan JJ (1994) Atmospheric boundary layer flows: their structure and measurement, 1st edn. Oxford University Press, New York

    Google Scholar 

  26. Elsner JW, Elsner W (1996) On the measurement of turbulence energy dissipation. Meas Sci Technol 7:1334–1348. https://doi.org/10.1088/0957-0233/7/10/005

    Article  Google Scholar 

  27. Azad R, Kassab S (1989) New method of obtaining dissipation. Exp Fluids 7:81–87. https://doi.org/10.1007/BF00207299

    Article  Google Scholar 

  28. Grachev AA, Andreas EL, Fairall CW et al (2015) Similarity theory based on the Dougherty–Ozmidov length scale. Q J R Meteorol Soc 141:1845–1856. https://doi.org/10.1002/qj.2488

    Article  Google Scholar 

  29. Long RL (1982) A new theory of the energy spectrum. Bound-Layer Meteorol 24:137–160

    Article  Google Scholar 

  30. Williams RM, Paulson CA (1977) Microscale temperature and velocity spectra in the atmospheric boundary layer. J Fluid Mech 83:547–567. https://doi.org/10.1017/S0022112077001335

    Article  Google Scholar 

  31. Gibson CH, Stegen GR, Robert D, Williams B (1970) Statistics of the fine structure of turbulent velocity and temperature fields measured at high Reynolds number. J Fluid Mech 41:153–167. https://doi.org/10.1017/S0022112070000551

    Article  Google Scholar 

  32. Sheih CM, Tennekes H, Lumley JL (1971) Airborne hot-wire measurements of the small-scale structure of atmospheric turbulence. Phys Fluids 14:201–215. https://doi.org/10.1063/1.1693416

    Article  Google Scholar 

  33. Ishihara T, Morishita K, Yokokawa M et al (2016) Energy spectrum in high-resolution direct numerical simulations of turbulence. Phys Rev Fluids. https://doi.org/10.1103/PhysRevFluids.1.082403

    Article  Google Scholar 

  34. Gargett AE, Osborn TR, Nasmyth PW (1984) Local isotropy and the decay of turbulence in a stratified fluid. J Fluid Mech 144:231–280. https://doi.org/10.1017/S0022112084001592

    Article  Google Scholar 

  35. Venayagamoorthy S, Koseff J (2016) On the flux Richardson number in stably stratified turbulence. J Fluid Mech 798:R1. https://doi.org/10.1017/jfm.2016.340

    Article  Google Scholar 

  36. Riley JJ, Lindborg E (2008) Stratified turbulence: a possible interpretation of some geophysical turbulence measurements. J Atmos Sci 65:2416–2424. https://doi.org/10.1175/2007JAS2455.1

    Article  Google Scholar 

  37. De Silva IPD, Fernando HJS (1998) Experiments on collapsing turbulent regions in stratified fluids. J Fluid Mech 358:29–60. https://doi.org/10.1017/S0022112097008094

    Article  Google Scholar 

  38. Maderich VS, Van Heijst GJF, Brandt A (2001) Laboratory experiments on intrusive flows and internal waves in a pycnocline. J Fluid Mech 432:285–311

    Article  Google Scholar 

  39. Kit E, Strang EJ, Fernando HJS (1997) Measurement of turbulence near shear-free density interfaces. J Fluid Mech 334:293–314. https://doi.org/10.1017/S0022112096004442

    Article  Google Scholar 

  40. Strang EJ, Fernando HJS (2001) Vertical mixing and transports through a stratified shear layer. J Phys Oceanogr 31:2026–2048. https://doi.org/10.1175/1520-0485(2001)031%3c2026:VMATTA%3e2.0.CO;2

    Article  Google Scholar 

  41. Mellor GL, Yamada T (1974) A hierarchy of turbulence closure models for planetary boundary layers. J Atmos Sci 31:1791–1806. https://doi.org/10.1175/1520-0469(1974)031%3c1791:AHOTCM%3e2.0.CO;2

    Article  Google Scholar 

  42. Fernando HJS, Pardyjak ER (2013) Field studies delve into the intracacies of mountain weather. Eos 94:313–315. https://doi.org/10.1002/2013EO360001

    Article  Google Scholar 

Download references

Acknowledgements

The MATERHORN program supported the technology development necessary to obtain the experimental data presented here and was funded under a Multidisciplinary University Research Initiative of the Office of Naval Research (Award # N00014-11-1-0709). PC was supported by the U.S. Department of Defense through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program. EK was supported by Israel Science Foundation (Grant 408/15). During the data analysis, HJSF was funded by U.S. National Science Foundation grants (AGS-1528451 and AGS-1565535). Dan Liberzon and Chris Hocut provided crucial support during various phases of the experiment. We acknowledge two anonymous reviewers for making comments that led to improvement of manuscript.

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Correspondence to Patrick Conry.

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Conry, P., Kit, E. & Fernando, H.J.S. Measurements of mixing parameters in atmospheric stably stratified parallel shear flow. Environ Fluid Mech 20, 1177–1197 (2020). https://doi.org/10.1007/s10652-018-9639-z

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