DISSIPATION AND MIXING IN A COASTAL JET - A BALTIC SEA CASE-STUDY

Vertical profiles of dissipation rate are used to study mixing propert ies within a shallow water region influenced by a coastal jet. In the upper 10-m layer dissipation rates of the order of epsilon proportiona l to 10(-6) W kg(-1) have been measured. Most dissipation results from local production of turbulent kinetic energy, caused by Reynolds-stre ss in the coastal jet. Some high-energetic turbulent events are not lo cally balanced and are most probably advected to the measurement site by the coastal jet. Estimates of the associated eddy diffusivities for locally balanced situations are in the order of K-p proportional to 1 0(-4) m(2)s(-1). This comparably high value is due to the high level o f turbulence throughout the water column and high mixing intensity (ga mma(mix) approximate to 0.22). This feature is clearly related to the coastal jet in its stratified environment.