@article{fdi:010084742,
  title = {{M}ean flow structure of katabatic winds and turbulent mixing properties},
  author = {{C}harrondiere, {C}. and {B}run, {C}hristophe and {H}opfinger, {E}. {J}. and {C}ohard, {J}. {M}. and {S}icart, {J}ean-{E}mmanuel},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he recent field measurements of katabatic winds on steep alpine slopes provide a unique database for theoretical analysis of the mean flow development and the determination of mixing properties. {T}he theory is based on the depth-integrated momentum and heat equations, and demonstrates an increase in mean velocity {U} with downstream distance x according to x(n) (n <= 1/2). {A}n equation for the mean wind velocity is established, expressing its dependency on the buoyancy flux, related to the heat flux to the ground, entrainment and bottom friction. {N}o ambient stratification, and ambient wind and constant ground surface temperature, lead to {U} similar to x(1/2), while constant heat flux to the ground leads to {U} similar to x(1/3) and requires that the reduced gravity decreases as x(-1/3). {S}table ambient stratification {N} causes, in addition to small-amplitude mean flow oscillations, a decrease in reduced gravity with x, in which case the assumption of constant surface heat flux along x is only an approximation. {T}he turbulent fluxes are a function of gradient {R}ichardson number {R}i with the ratio of turbulent diffusivity to viscosity {K}-h/{K}-m changing from nearly 1.4 to approximately 0.5 at {R}i approximate to 0.5. {A} new mixing efficiency is introduced that includes turbulence kinetic energy production or consumption by along-slope turbulent buoyancy flux. {I}t increases with {R}i up to 0.25 at {R}i approximate to 0.5 and then remains nearly constant. {T}he measurements allowed us to determine the bottom drag coefficients and interfacial entrainment, with the ground surface heat flux being determined from the mean buoyancy flux.},
  keywords = {gravity currents ; stratified turbulence ; turbulent mixing ; {FRANCE} ; {GRENOBLE} ; {ALPES} ; {BELLEDONNE}},
  booktitle = {},
  journal = {{J}ournal of {F}luid {M}echanics},
  volume = {941},
  numero = {},
  pages = {{A}11 [24 ]},
  ISSN = {0022-1120},
  year = {2022},
  DOI = {10.1017/jfm.2022.281},
  URL = {https://www.documentation.ird.fr/hor/fdi:010084742},
}