Evolution and dynamics of the vertical temperature profile in an oligotrophic lake

摘要: Abstract. In this study, the fine-scale responses of a stratified oligotrophic karstic lake (Kozjak Lake, Plitvice Lakes, Croatia; fetch is 2.3  km , and maximum depth 46  m ) to atmospheric forcing on surface are investigated. Lake temperatures measured at a resolution 2  min at 15 depths ranging from 0.2 to 43  which were observed during 6 July–5 November 2018 period, analyzed. The results show thermocline deepening from 10  beginning observation period 16  end where the latter corresponds approximately one-third depth. pycnocline followed the same pattern, except that deepening occurred throughout entire approximately 1  above thermocline. On average, was 3–4  cm d−1 , while (12.5  coincided with occurrence internal seiches. Furthermore, indicate three different types forcings surface; two these have diurnal periodicity – (1) continuous heat fluxes (2) occasional periodic stronger winds whereas (3) occasional nonperiodic steady along-basin directions. Continuous produced forced diurnal oscillations in temperature within first 5  the entire period. Noncontinuous periodic resulted occasional forced oscillations 7 to 20  . Occasional strong triggered both baroclinic internal seiches a principal 8.0  h barotropic with a principal 9  currents by under realistic-topography conditions generated baroclinic region (at depths 9 17  periods corresponding seiches ( ≈ ), which, best our knowledge, has not been reported previous lake studies.