1. Prospects for Ocean (Re)analyses James A. Carton University of Maryland Benjamin S. Giese Texas A&M University Outline: Current analyses Global heat storage: 0/700m temperature Upper ocean properties: mixed layers, water masses Future of SODA

2. Twelve Ocean (re)analyses AnalysisTime SpanAnalysis procedure CERFACS Davey (2005) 1962-2001Sequential ECMWF 1962-2001sequential GECCO Köhl et al. (2006) 1950-19994DVar GFDL 1,2 Sun et al. (2007) 1955-1999 1980-2005 Sequential, Coupled Sequential GODAS Behringer (2005) 1979-2005Sequential INGV Davey (2005) 1962-2001Sequential ISHII Ishii et al. (2006) 1945-2005Objective analysis LEVITUS Levitus et al. (2005) 1955-2003Objective analysis SODA Carton and Giese (2007) 1958-2005Sequential UK-OI1962-2001Objective Analysis UK-FOAM Bell. (2000), Bell et al. (2004) 1962-1998Sequential No model

3. Levitus (2005)

5. Heat Content by decade Vertical/Time Structure  1960-19691970-19791980-19891990-1999

7. Correlation with Pacific Decadal Oscillation Colors – heat content Contours - SST

8. Analysis-CTD Observation Differences 1970-19791980-1989 1990-1999

9. Response to volcanic aerosols El Chichon 1983-1986 minus 1979-1982 (after-before) Average response of five simulations of GFDL CM2.1 

12. Water mass properties Time-mean thickness of the 25.5-24.5 surfaces North Pacific subtropical mode water Eastern North Pacific subtropical mode water

13. Root-mean-square mode water variability (colors) and mixed layer variability

14. Response of the North Pacific to Heavy precipitation (’95-’97) Hawaii Ocean Time series Lukas (2001) How the analyses respond: Salinity on the sigma=24.5 surface Heavy rainfall Time  Depth  Salinity Precip

15. Future of SODA Continuing to address problems with hydrologic cycle, sea ice, etc. Shift to Letkf Centennial (following Compo) Accompanying bio-geochemistry

16. Displaced pole horizontal grid 900x720x40 = 25M grid points State Variables: u, v, T, S, … Time step: 20min (26K ts/yr) http://climate.lanl.gov/Models/POP/

17. Current Model Mixing –KPP, bi-harmonic Winds –ERA40 daily stress –QuikSCAT Topography –Sandwell and Smith (etopo30) with McClean modifications for some passages Freshwater flux –GPCP precipitation when avail., bulk formula evaporation, seasonal river discharge. Relaxation to clim. salinity under ice. Heat flux –Bulk formula Sea ice –Observed monthly cover 1979- Tracers  CFCs, …

18. In situ SST Observations

19. Temperature profile distribution

20. Conclusions We have begun comparing the ocean analyses led by GODAE BTs have clear warm bias in the 1970s. Several efforts are underway to address this problem Sequential ocean reanalyses show qualitative agreement when vertically averaged except in the Southern Ocean Vertical structure of the stratification in the upper ocean and its variability remains uncertain. These issues need to be improved before coupled assimilation will be useful.