| Vertical profiles using the SCAMP
( 1 mm resolution) show the tight linkage between changes in fluorescence
and steps in temperature and density. Often values of the rate of
turbulent kinetic energy dissipation (e) are
high at these discontinuities indicating shear which is likely from intrusions.
The plate of Picocystis occurs where the water column is not turbulent
but the layer is turbulent at its edges, again suggesting advection of
layers. The shape of the peak has changed since the profile
taken two days previously. Rather than having a high fluorescence
in the middle, it is divided into two sub peaks. Evidence that they
are in discrete layers is the nearly isothermal 'step' in temperature between
the two layers.
Current meter data indicate that flow within the metalimnion changes
direction on scales of 20 cm to a meter. Consequently, while the fluorescence
data would indicate one large abundance peak, detailed examination of the
combined data indicates that it is likely comprised of two layers that
will be advected relative to each other. The implications of
these different pathways remain to be discovered. |
