1 / 30

Arctic Change and Barrow Cabled Observatory Winter Lead Convection

This presentation discusses the study of environmental changes in the Arctic and the role of the Barrow Cabled Observatory in monitoring winter lead convection. It explores the impact of these changes on ecosystems and society.

reedn
Download Presentation

Arctic Change and Barrow Cabled Observatory Winter Lead Convection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Study of Environmental Arctic Change (SEARCH) and the Barrow Cabled Observatory Winter Lead Convection Presentation at Science and Education Opportunities for an Arctic Cabled Seafloor Observatory February 7-8, 2005 Jamie Morison Polar Science Center, University of Washington morison@apl.washington.edu

  2. SEARCH Motivation The Arctic has been characterized in recent decades by a complex of significant, interrelated, pan-Arctic changes (Unaami).

  3. Decreased sea level atmospheric pressure, • Increased air temperature over most of the Arctic, • More cyclonic ocean circulation and rising coastal sea level, • Warmer Atlantic waters, • Reduced sea ice cover, • Warming of permafrost • The physical changes of Unaami impact ecosystems and society. Complex of change appears related to a spin up of the Northern Hemisphere atmospheric Polar Vortex. Complex of Arctic change is a possible component of climate change. Motivates a program of long-term observations, analysis, and modeling Examples

  4. SEARCH Implementation Implementation Strategy at SEARCH Web site:http://psc.apl.washington.edu/search/index.html • Eight SEARCH Activities Areas include: • - DTO: Distributed Terrestrial Observatories • - DMO: Distributed Marine Observatories • - LAO: Large-scale Atmospheric Observatories • DQU: Detecting and Quantifying Unaami and Other Modes of Variability • LGC: Linkages and Global Coupling • - ASR: Arctic System Reanalysis • - SEI: Social and Economic Interaction • - SOR: Social Response Current Activities at http://psc.apl.washington.edu/search/Activities/activities.html

  5. Distributed Terrestrial Observatories

  6. Large-scale Atmospheric Observatories DTO Sites

  7. DMO: Distributed Marine Observatories Make large-scale atmospheric, oceanographic, sea ice and ecosystem observations in the marine environment. SEARCH Implementation Strategy available at http://psc.apl.washington.edu/search/index.html

  8. Distributed Marine Observatories

  9. DMO Philosophy Scales are pan-Arctic and decadal. Therefore the DMO emphasis is on: - Basin-wide coverage - Long, relatively low res time-series And because startup is urgent: - Use of proven, existing technologies

  10. So, what role can a high-tech, high-bandwidth cabled observatory at Barrow have in DMO? Two DMO elements near Barrow: • Ocean pathway moorings • Cross shelf exchange moorings

  11. Role for high-bandwidth, localized measurements particularly in • Cross shelf exchange mooring function of DMO, and • The Linkages and Global Coupling (LGC) activity area

  12. Processes in the shelf and slope region are important to ventilation of the deep ocean, e.g. • Generation of eddies that move into the basin • Cross shelf exchange driven by buoyancy flux in the Seasonal Ice Zone (SIZ) and winter shore leads and polynyas These processes tend to be intermittent and spatially variable.

  13. AIDJEX Lead Experiment, 1974

  14. Indication of cross-shelf exchange Example of bottom boundary layer generated by Barrow shore lead (ALEX, 1974)

  15. Consider buoyancy flux and cross shelf exchange.

  16. Consider buoyancy flux and cross shelf exchange. These processes create density structure parallel to shore and cross shore pressure gradients, which drive alongshore currents.

  17. So where does cross-shelf exchange occur? In the surface and bottom boundary layers where flow moves down pressure gradient.

  18. How would we use the BCO to measure shelf processes?

  19. Supercoolometer: Seamore ROV Optical Backscatter SBE 39 T Probe Water In Heater SBE-19+ Temperature & Conductivity

  20. JAMSTEC UROV 7k Remotely Operated Vehicle Battery Operated Fiber Optic Link KAIKO Hanger UROV

  21. TIC

  22. Van Mijen Fjord Instruments SonTek Instrument Cluster 0.6 m Ice T-string SBE 04 conductivity meter 1 m SBE 03 thermometer ROV- CTD SBE 07 micro-conductivity meter SonTek ADVOcean (5 MHz) Miles McPhee Turbulent Inst Cluster

  23. Autonomous Flux Buoy Tim Stanton Flux Buoy

  24. The Autonomous Microconductivity-Temperature Vehicle (AMTV)

  25. AMTV

  26. Under Lead Back Toward Ice Under Ice Cooler & T’ small Warmer Cooler Fresher S constant & S’ small S constant? AMTV Results SHEBA Summer Lead Study, Day 219.9 From Hayes Dissertation, 2003

  27. AMTV Turbulence on 219.9 S’ and T’ Vigorous Under Lead S’ and T’ Reduced Under Ice Turbulence Enhanced Under Ice? Lower Frequency Turbulence Significant Under Lead From Hayes Dissertation, 2003

  28. 98 W m-2 144 W m-2 1.7x10-5 kg m-2 s-1 2.4x10-5 kg m-2 s-1 1.9x10-5 Substantial Turbulent Heat and Salt Flux in the Lead, Reduced Fluxes Under Ice AMTV Turbulent Fluxes on 219.9, 1998 at SHEBA Summer Lead Turbulent Stress, u*=(t/r)1/2, Increased Under Ice From Hayes Dissertation, 2003

  29. Conclusions: • The BCSO can play an important part in SEARCH. • Focus as an intensive observing point for shelf-basin processes critical for the large scale behaviour of the marine environment

  30. The End

More Related