The atmospheric boundary layer during swell – a field study and interpretation of the turbulent kinetic energy budget for high wave ages

• Analysis of the turbulent kinetic energy (TKE) budget for five slightly unstable cases with swell has been performed based on measurements of   mechanical production, buoyancy production, turbulent transport, and   dissipation at five levels over the sea, from 2.5 to 26 m. The time   rate of change and advection of TKE were found to be small, so the TKE   residual is interpreted as an estimate of the pressure transport term   (T-p). In two cases with high wave age, the T-p term is a gain at all   heights. For three cases with smaller wave age, T-p is a loss in the   TKE budget below 5-10 m and a gain for greater heights, where the   decrease is exponential, thus showing the combined effects of swell   waves and a range of waves traveling slower than the wind. The TKE   budget for a case with growing sea but similar wind speed and stability   as some of the swell cases has T-p close to zero at all heights. It is   shown that the observed characteristic wind profile with either a   low-level maximum in the 5-10-m range or a distinct "knee'' at that   height is an effect of the T-p term.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences (hsv//eng)

Keyword

Earth sciences

Geovetenskap

Publication and Content Type

ref (subject category)

art (subject category)