The turbulent kinetic energy budget in the marine atmospheric surface layer -: art. no. 3142

[1] The terms in the turbulent kinetic energy (TKE) budget have been analyzed according to stability, wave age, and wind speed, using long-term measurements over the sea. The measurements were performed at the island Ostergarnsholm in the middle of the Baltic Sea. The results show that there is an imbalance between normalized production and normalized dissipation, also in neutral conditions, and that this imbalance depends not only on stability, which has been previously suggested, but also on wave age and wind speed. For small wave ages and high wind speeds, production is larger than dissipation at neutral conditions. For saturated waves and moderate wind speeds, the sea surface resembles a land surface, while for swell and low wind speeds, dissipation strongly exceeds production. The normalized pressure transport becomes significant during swell conditions, and is not balanced by the normalized turbulent transport. "Inactive'' turbulence, where energy is being brought down to the surface from higher levels, is probably the reason for these high values of the pressure transport. The traditional "inertial dissipation method,'' where the sum of the transport terms is assumed small and neglected, therefore needs to be corrected for an imbalance between production and dissipation.