Objectives
- Improve understanding and quantification of vertical exchange processes
in the water column, in the surface and benthic boundary layers and across
the pycnocline.
- Explore mechanisms of physical-biological coupling in which vertical exchanges
and turbulence significantly affect the environmental conditions experienced by biota.
- Apply innovative technologies to the measurement of physical microstructure features and
phenomena, in particular turbulence properties in the water column.
- Provide a new, comprehensive and synoptic data set for validation of vertical fluxes of
energy and matter calculated by physical and biological models.
- Develop 1-D physical models for the computation of statistical moments of
microstructure phenomena and integrated biological-physical models of the water column,
including fluxes from the surface and the sediment.
- Test and validate the models against measurements of mean and fluctuating properties
in the water column.
- Provide modules for vertical exchanges which can be implemented in state-of-the-art
3-D water quality and ecological models.
Summary
The project is founded on the integration of experimental, theoretical and
modelling studies of vertical exchanges in shelf seas, including the joint
analysis and interpretation of measurements and model calculations.
Innovative measurements of turbulence properties in continental shelf seas
(dissipation rate throughout the water column and intensity over a wide
frequency range) are the heart of the proposal.
These, together with biological measurements concentrating on fluxes near
the sea bed, will be made at two contrasting sites in the North Sea - one
shallow, high energy, the other deeper, low energy.
Since turbulence directly affects the environment perceived by particles,
including living biota, detritus and suspended sediment, studies will
be made of aggregation, flocculation and sedimentation, and of trophhic
interactions. New hypotheses about turbulence effects on zooplankton
grazing rates, diet selectivity, vertical distribution and patchiness
will be tested against process oriented field and laboratory measurements.
Water column numerical models describing turbulent physics and integrated
biology/physics will incorporate the understanding gained from the process
studies and be rigorously tested against these fundamental measurements, to
establish the robustness of parameterisation and the domain of validity of
the models.
The improved understanding will be applied to the exchange of nutrients
across the thermocline and to nutrient recycling in the benthic boundary
layer. This fundamental research will contribute towards the long term goal
of developing robust water column plankton models applicable in the full range
of turbulence environments encountered in shelf seas.
