This project is funded for the time period 2002 to 2007
with field sampling in spring 2002 and summer 2004 on icebreakers and
experimental studies in 2003 and 2005 in Barrow, Alaska.
Our major research objectives are:
- Physical/chemical components:
(1) Characterize temporal and spatial variability of ice microstructure
and physical/chemical properties of the sea ice layers.
(2) determine fluid (and nutrient) exchange in the lowermost ice layers
for a number of different cases and scenarios; extend this work well into
the ice decay regime,
(3) obtain data sets on ice morphology and relate it to the distribution
of under-ice meltwater layers reducing IPP, assess the prerequisites for
their sustained presence,
(4) determine areal flux of ice (FY/MY) and associated biomass for SBI
study area from remote sensing and field data.
- Biological components:
(1) characterize the temporal and spatial variability of ice algal biomass
(algal pigments, species composition, size spectra, ∂13C and ∂15N)
over the entire range of relevant ice thicknesses,
(2) determine the activity of ice algae (with optical and tracer techniques)
in the lowermost ice layers as a function of nutrient (nitrogen compounds)
and light availability (P vs I curves),
(3) determine the same biological properties as in (1) and (2) for the
under-ice water layers (scale of cm to meters),
(4) identify nutrient and/or light limitation of ice algae through determination
of 13C incorporation along different metabolic pathways..
Techniques and analyses involve determination of ice
thicknesses, salinity, temperature, porosity and permeability. The biological
signature is measured as ice algal biomass (including stable isotope data)
Presentations and Publications:
to be added