Arctic Research at the Rosenstiel School of Marine & Atmospheric Science, University of Miami.

1. Arctic Research at the Rosenstiel School of Marine & Atmospheric Science, University of Miami. Peter Minnett

2. 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

3. 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

4. DOC and Arctic Water Masses by SeasonDennis Hansell SBI Spring Cruise SBI Summer Cruise Yukon R. MacK. River Ice Melt Depth (m) Depth (m) 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.

5. ZooplanktonSharon 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 shelf-break 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.

6. Trace radionuclidesDavid 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.

7. Surface radiation, cloud forcing & heat budget of polynyasPeter 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 12 147-158. • 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

8. Modeling of Prince William SoundChris 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

9. 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.

10. 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: pminnett@rsmas.miami.edu

11. www.rsmas.miami.edu