Seminar on the Southern Ocean State Estimate

SIO219 Winter quarter, 2014

ThursdayÕs, 11-noon,  Nierenberg Hall 401

 

Lynne Talley with major assistance from Matt Mazloff

 

Goal: For participants to learn more about SOSE, its architecture, input data, uncertainties, and applications.  In a 1-unit seminar, we cannot approach the depth of understanding of state estimates that a proper 4-unit course would provide, but this seminar should provide useful information and framework for your own more intensive exploration of state estimation and its uses.

 

Format:  student/staff presentation each week, based on an in-depth paper and/or explore major website, and, if applicable, student/staff personal work/experience with SOSE or other state estimates or data assimilations

 

Credit and grading option:  1 unit, S/U only. Enrolled students are required to participate each week and to lead one week.

 

Syllabus

Jan. 9  Introduction to SOSE and state estimation – Matt Mazloff

Reading (skim): Mazloff, M., P. Heimbach, and C. Wunsch, An eddy-permitting Southern Ocean state estimate, J. Phys. Oc., 40, 880-899, 2010. [pdf]

Jan. 16 Continuation of introduction to state estimation.    Jessica Millar [pdf of talk 10 MB]

Reading: Wunsch, C. and P. Heimbach, Dynamically and kinematically consistent global ocean circulation and ice state estimates. Ocean Circulation and Climate, 2nd Edition, Siedler, G., Griffies, S., Gould, J., Church, J. Eds., Elsevier, 553-579, 2013. [pdf]

Jan. 23  Workings of SOSE: the adjoint.  Uriel Zajaczkovski [pdf of talk]

Reading: C. Wunsch and P. Heimbach, 2007: "Practical Global Oceanic State Estimation." Physica D. (pdf)

Jan. 30  Workings of MITgcm and SOSE: KPP parameterization.  Veronica Tamsitt

Reading: MITgcm http://mitgcm.org/ website documentation, section on KPP: click on section 6.4.2.1 Introduction http://mitgcm.org/public/r2_manual/latest/online_documents/node241.html

 

and

Large, William G., Gokhan Danabasoglu, Scott C. Doney, James C. McWilliams, 1997: Sensitivity to Surface Forcing and Boundary Layer Mixing in a Global Ocean Model: Annual-Mean Climatology. J. Phys. Oceanogr., 27, 2418–2447.

doi: http://dx.doi.org/10.1175/1520-0485(1997)027<2418:STSFAB>2.0.CO;2

 

Feb 6  Agulhas and tracer releases in SOSE. Jinbo Wang. 

Reading:  Klocker, A., Ferrari, R., LaCasce, J.H., Merrifield, S. T., 2014. Reconciling float-based and tracer-based estimates of eddy diffusivities.  Preprint.

http://web.mit.edu/raffaele/www/Publications_files/KlocherFerrariLaCasceMerrifield12.pdf

 

Feb. 13   Effective diffusivity.  Ivana Cerovecki.

Reading: Marshall, J., E. Shuckburgh, H. Jones, and C. Hill, 2006: Estimates and implications of surface eddy diffusivity in the Southern Ocean derived from tracer transport. J. Phys. Oceanogr., 36, 1806–1821.  doi: http://dx.doi.org/10.1175/JPO2949.1

 

Feb. 20 Kalman filtering comparison with state estimation.  Aneesh Subramanian.

Reading: KALNAY, E., LI, H., MIYOSHI, T., YANG, S.-C. and BALLABRERA-POY, J. (2007), 4-D-Var or ensemble Kalman filter?. Tellus A, 59: 758–773. doi: 10.1111/j.1600-0870.2007.00261.x

 

Feb. 27 (no seminar – Ocean Sciences Meeting)

March 6 SOSE and sea ice. Angelica Gilroy

Reading:  Fenty, I.G. and P. Heimbach, 2013: Coupled Sea Ice-Ocean State Estimation in the Labrador Sea and Baffin Bay. J. Phys. Oceanogr., 43(6), 884-904, doi:10.1175/JPO-D-12-065.1.http://journals.ametsoc.org/doi/abs/10.1175/JPO-D-12-065.1

 

March 13 (Un)Validation of near real time ECCO in the western North Atlantic with a useful application. Sam Billheimer.

Reading: Billheimer, S. and L. D. Talley, 2013. Near-cessation of Eighteen Degree Water renewal in the western North Atlantic in the warm winter of 2011-2012. J. Geophys. Res. Oceans, 118, doi:10.1002/2013JC009024.

 

Principal website links:

SOSE http://sose.ucsd.edu

MITgcm http://mitgcm.org/

 

Background papers and resources:

Large, McWilliams and Doney, Oceanic vertical mixing: a review and a model with a nonlocal boundary layer parameterization.  Rev. Geophys., 32, 363-403. 1994.

 

Mazloff, M., P. Heimbach, and C. Wunsch, An eddy-permitting Southern Ocean state

estimate, J. Phys. Oc., 40, 880-899, 2010. [pdf]

 

C. Wunsch and P. Heimbach, 2007: "Practical Global Oceanic State Estimation." Physica D. (pdf)

 

Wunsch, C. and P. Heimbach, Dynamically and kinematically consistent global ocean

circulation and ice state estimates. Ocean Circulation and Climate, 2nd Edition, Siedler, G.,

Griffies, S., Gould, J., Church, J. Eds., Elsevier, 553-579, 2013. [pdf]

 

Wunsch, C., Discrete Inverse and State Estimation Problems. With Geophysical Fluid Applications, Cambridge Un. Press, Cambridge 371pp., 2006.

 

Wunsch, C. Inverse Methods, Inverse Problems, State Estimation, and Data Assimilation: 5 Lectures at Harvard January 2013 (pdf)

 

Examples of topics that you might choose from, to be decided at and after first meeting on Jan. 8.

 

Expansion on each major section of Wunsch and Heimbach.

 

Data assimilation and state estimation:

            Other approaches to data assimilation: Kalman filters, GreenÕs functions

            Other data assimilation and state estimation products useful for the Southern Ocean

            The MITgcm

            Validation of SOSE output: comparison with data sets; issues with independence

            Uncertainty estimates

            How ocean state estimates adjust air-sea fluxes

 

Parameterizations in the MITgcm

            KPP mixing

            Sea ice model

            Representation of the bottom boundary layer and stresses in the MITgcm, SOSE and other models

 

Techniques and results from  analyzing SOSE output

            Tracer releases and particle tracking

            Heat budgets in SOSE

            Momentum budgets in SOSE

            Buoyancy budgets in SOSE or other state estimates