Transcript 1.7 MB - arcus

Arctic Research at the Rosenstiel
School of Marine & Atmospheric
Science, University of Miami.
Peter Minnett
Arctic Research at the Rosenstiel
School of Marine & Atmospheric
Science, University of Miami.
RSMAS is divided into six divisions:






Applied Marine Physics
Marine & Atmospheric Chemistry
Marine Affairs & Policy
Marine Biology & Fisheries
Marine Geology & Geophysics
Meteorology & Physical Oceanography
Arctic Research at the Rosenstiel
School of Marine & Atmospheric
Science, University of Miami.
RSMAS is divided into six divisions:






Applied Marine Physics
Marine & Atmospheric Chemistry
Marine Affairs & Policy
Marine Biology & Fisheries
Marine Geology & Geophysics
Meteorology & Physical Oceanography
DOC and Arctic Water Masses by Season
Dennis Hansell
SBI Spring Cruise
Ice Melt
Yukon R.
Depth (m)
Depth (m)
MacK. River
SBI Summer Cruise
Pacific Water
Atlantic Water
The relationship between DOC concentrations and salinity (or water masses) in the Chukchi/Beafort shelf region during two cruises in
2002. During spring, the relationship is fairly conservative, with MacKenzie R. water adding the highest loads of DOC. In Summer, the
influence of the Yukon R. and Arctic sea ice melt is seen. The deeper waters (Pacific and Atlantic) are relatively unchanged between the
seasons.
Zooplankton
Sharon Smith
The response of the Chukchi/Beaufort shelf
ecosystem to warmer climate could follow two quite
different pathways:
•reduced ice cover and could create stronger
thermal stratification, less mixing, limited
nutrient supply, lower primary production,
smaller-sized phytoplankton and smaller, more
eurythermal coastal-like zooplankton.
•less ice, increased wind could result in shelfbreak upwelling and mixing, enhanced nutrient
supply, larger-sized phytoplankton and larger,
deep-water zooplankton advected onto the shelf.
Will global change, particularly warming, result in
more large zooplankton supporting fish, birds and
mammals over the Chukchi and Beaufort shelves
and slopes or small-sized zooplankton which will
favor sedentary benthic organisms?
Traditional methods of plankton collection are used
to measure the distribution and abundance of adult
and juvenile copepods and euphausiids over the
shelves. New molecular techniques are being
developed to identify juveniles of the dominant
zooplankton taxa to determine which species utilize
the shelf habitat for reproduction. Juvenile and
adult distributions, combined with measurements of
the physical circulation in the region, will allow us
to determine likely changes in the regional food
web if major climate change occurs.
Trace radionuclides
David Kadko
SHEBA
Heat exchange between the leads and underlying mixed layer
was evaluated through the use of a naturally occurring,
radioactive tracer, 7Be. An illustration showing how 7Be was
used as a dye tracer for heat introduced into leads through
summer insolation. The partitioning of the 7Be inventory
between open water and sub-ice water offered a direct measure
of the partitioning of the heat flux absorbed through the leads,
and identified that heat introduced in the previous 80 days (the
mean life of 7Be). [Kadko D. (2000) Modeling the Evolution of
the Arctic Mixed Layer during the Fall 1997 SHEBA Project
using measurements of 7Be. J.G.R., 105, 3369-3378.]
SBI
To investigate the rate of exchange between the Arctic shelves and
the Arctic Ocean interior the measurement of the water activity of
two naturally occurring radium isotopes 228Ra (T1/2= 5.77y) and
224Ra (T1/2= 3.6d) are being used. Because these isotopes are
derived solely through input from shelf sediments, they are
unambiguous markers of water that has been in contact with
shelves. Their relative distribution in shelf and basin water is used
to assess the degree of shelf-basin interaction.
During the recent ICEX03 expedition evidence of rapid offshore
transport was found using the short-lived isotope 224Ra which was
measured at the ice camp.
Surface radiation, cloud forcing &
heat budget of polynyas
Peter Minnett
Polynya
A systematic study of the effects of clouds on the surface heat budget of
the Arctic, especially in and around polynyas. See:
•Minnett, P. J. (1999). "The influence of solar zenith angle and cloud type
on cloud radiative forcing at the surface in the Arctic." J. Climate 12 147158.
•Hanafin, J. A. and P. J. Minnett (2001). "Cloud forcing of surface
radiation in the North Water Polynya." Atmosphere-Ocean 39 239-255.
•Poster in Arctic Forum.
Fast Ice
Modeling of Prince William Sound
Chris Mooers
Numerical simulations
of the synoptic 3D
circulation of Prince
William Sound, Alaska,
are conducted in
collaboration with
observational
colleagues. In addition
to conducting process,
sensitivity, and
validation studies with
the mesoscale-resolving
circulation model, a
real-time, automated
Web-based nowcast/
forecast system has
been established which
is available to support
oil spill investigations
and marine ecosystem
studies. A mesoscale
atmospheric model
from the University of
Alaska is now being
used to force these
systems.
OPEL: Ocean Prediction Experimental Laboratory, RSMAS
Concerns
•Access to the Arctic –
Aging US icebreakers (Polar Class).

Impact of two ships each year for Antarctic Support.

•Better use of ice camps.
•Better coordination with Canadian and other international groups.
Concerns
•Access to the Arctic –
Aging US icebreakers (Polar Class).

Impact of two ships each year for Antarctic Support

•Better use of ice camps.
•Better coordination with Canadian and other international groups
For more details, please contact
Peter Minnett at:
[email protected]
www.rsmas.miami.edu