1. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 1 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok The Role of Ice Shelf - Ocean Interaction in the ECCO2 Data Synthesis Michael Schodlok, Dimitris Menemenlis

2. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 2 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Outline Model Set up Results Outlook

3. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 3 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Sea Ice Thickness & Sea Ice Velocities (Cube 78) Section: Kapp Norvegia (KN) - Joinville Island (JI) Model data vs AWI ULS data Motivation Weddell Sea JI KN

4. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 4 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Ice Shelf Ocean Interaction:

5. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 5 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok BEDMAP: ● Ice Shelf Thickness ● Water Column Thickness => Ice Shelf Draft + Water Column Thickness = Bathymetry beneath Ice Shelves Bathymetry as in CS510: ● Bathymetry South to Ice Shelf Edge How good are the data sets? ● Ice Shelf reliable ● Bathymetry questionable in parts Combination of 2 Datasets:

6. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 6 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Face 6 as in CS510

7. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 7 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Face 6 with sub-ice shelf cavities Filchner Ronne IS Ross IS Amery IS

8. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 8 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Ice Shelf Thickness Filchner Ronne IS Ross IS Amery IS Larsen IS Brunt IS Riiser IS

9. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 9 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Test Case for Regional Domain from CS 510 Weddell Sea no Ice Shelves at West AP Regional Domain: Weddell Sea 220 x 220 x 50 Boundary conditions from Cube 78 Monthly Ocean Values - T, S, u, v Daily Sea Ice Values - H, A, Sn, Sl, u, v Ice shelf pkg ( Losch 2008 ) RUNS: - control - ISOMIP ( Grosfeld et al., 1997 ) - BRIOS/Hellmer ( Hellmer and Olbers, 1989 ) - Down slope flow ( J-M Campin, 1991. ) BRIOS – Bremerhaven Regional Ice Ocean Simulations

10. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 10 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Ice Shelf Ocean Interaction ISOMIP: heat flux proportional to temperature difference ice shelf base and sea water neglecting heat flux through ice all heat used for basal melting and freezing virtual salt flux computed with constant reference salinity BRIOS/Hellmer:system of 3 equations heat flux, salt flux, and linear equation of freezing point temperature (Tf) heat flux through ice shelf considered constant surface temperature –20C virtual salt flux across ice shelf ocean interface equal to salt flux due to melting and freezing solved for temperature and salinity at ice shelf base  Smaller melt rates: freshwater flux decreases salinity -> raises Tf -> less freezing at interface Constant turbulent exchange coefficients equal to a velocity of ~0.25 m/s

11. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 11 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Weddell 220x220 January 1998 TemperatureSalinity 0 2000 -2.5 2.0 -2.534 35 34 640 m WDW South Georgia Filchner Ronne Iceshelf Continental Shelf Hydrography 2000 m cavity?

12. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 12 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Hydrography

13. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 13 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Sea Ice Thickness

14. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 14 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Quickscat Backscatter Sep Red-ish – multi year ice Blue-ish – first year ice

15. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 15 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Weddell Sea Mean Ice Shelf Melt Rates (1992-1999) Substantially smaller than e.g. BRIOS (Beckmann et al., 1999, Schodlok et al., 2002, Timmermann et al., 2002) LIS in good agreement with estimates ( E Rignot, 2008) Standard deviation

16. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 16 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Filchner Ronne Ice Shelf Melt Time Series Trend: ISOMIP: 0.017 m/yr Hellmer:0.012 m/yr

17. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 17 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Filchner Ronne Horizontal Melt Distribution BI HI KI BI – Berkner Island KI – Korff Ice Rise HI – Henry Ice Rise BI HI KI

18. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 18 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Filchner Ronne Horizontal Melt Distribution BI HI KI BI – Berkner Island KI – Korff Ice Rise HI – Henry Ice Rise BI HI KI Distribution of Basal Melt/Freeze (Joughin & Padman, GRL, 2003) BI HI KI

19. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 19 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Larsen Ice Shelf Melt Rate Time Series

20. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 20 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Larsen Horizontal Melt Distribution

21. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 21 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Brunt Ice Shelf Melt Rate Time Series

22. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 22 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Brunt Horizontal Melt Distribution

23. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 23 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Model – Data comparison sea ice velocities from SSM/I data on 1° grid (R. Kwok)

24. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 24 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok

25. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 25 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Summary working Ice Shelf – Ocean Interaction Package smaller melt rates than previous estimates trend in the Filchner Ronne melt rates major differences in T and S at Shelf Break

26. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 26 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Outlook IceSat/Glas data set for ice shelf thickness compatible version downslope and iceshelf package parameter optimization for Weddell Sea domain global ECCO2 run with ice shelf package implemented

27. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 27 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Wish List to represent mixing at slope front/shelf break and velocity dependent cavity processes tide package in MITgcm

28. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 28 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Model Set up: Ocean model MITgcm z-coordinates (shaved cells) 6 `Faces` à 510x510 ~ 18 km 50 vertical layers ECCO2 data syntheses are obtained by least squares fit to available satellite and in-situ data An objective function expresses the extent of optimization: J = u T Q -1 u + n T R -1 n Estimating the Circulation and Climate of the Ocean, Phase II: High Resolution Global-Ocean and Sea-Ice Data Synthesis http://ecco2.jpl.nasa.gov

29. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 29 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Early Model Results: Velocities at 15 m http://ecco2.jpl.nasa.gov

30. Click to edit the title text format Click to edit the outline text format –Second Outline Level Third Outline Level –Fourth Outline Level »Fifth Outline Level »Sixth Outline Level »Seventh Outline Level »Eighth Outline Level »Ninth Outline Level 30 23. September 2008 ECCO2 Meeting – Boston, 2008 Michael Schodlok Latest Optimized Solution (Cube 78)