World Ocean Heat Content, 1955-2000

1. World Ocean Heat Content, 1955-2000 Sydney Levitus Ocean Climate Laboratory National Oceanographic Data Center- NOAA First Argo Science Workshop November 14, 2003 Tokyo, Japan

2. OCL co-P.I.s on this work John Antonov Tim Boyer Cathy Stephens OCL staff supporting WOD01 development Olga Baranova Daphne Johnson Margarita Conkright Ricardo Locarnini Carla Forgy Todd O’ Brien Hernan Garcia Igor Smolyar Bob Gelfeld

3. Outline • Data added since prior work • Review of prior work • New results and future work

4. Building Ocean Profile-Plankton Databases for Climate System Research

5. OSD cast data acquired through the GODAR Project for 1900-1991 compared to NODC archive holdings as of 1991

6. OSD data added to WOD98 and included in WOD01

7. Japan Ocean Station Data in WOD01

8. World Ocean- Climatological annual cycle of ocean heat content 1022J (0-500 m layer) S. Hem. range = 20 N. Hem. range = 13 World Ocean range = 10

9. World Ocean heat content 2003

10. Expected accuracy increase of world ocean heat content estimates due to Argo deployment (0-3000 m, 5-yeat estimates)

11. Based on analyses of data in WOD01 Fourier smoothing of yearly fields to eliminate phenomenon with periods < 10 years EOF accounts for 23.1 % of variance 1st EOF of yearly content (0-1000) for 1956-2000 Indo-Pacific

12. 1st EOF of yearly content (0-1000) for 1956-2000 Atlantic Based on analyses of data in WOD01 Fourier smoothing of yearly fields to eliminate phenomenon with periods < 10 years EOF accounts for 33.4 % of variance: Correlation matrix

13. Location of all profiles (OSD+MBT+XBT+CTD+MRB+UOR+PFL+APB+DRB) in WOD01 for year 2000 (93, 424 profiles) NODC/OCL 10/30/03

14. Linear trend of yearly (1956-2000) ocean heat content (1018 J) 0-1500 m

15. World Ocean heat content (1020J), 0-100 m

16. World Ocean- Linear trend (1956-2000) of zonally integrated ocean heat content (1020 J) (100 m thick layers) Latitude

17. Changes in Earth’s Heat Balance Components (1022 J) during 1955-2000

18. What will Argo measure in the immediate future? The parameters of state temperature, salinity, and pressure as a function of depth. Thus Argo will provide a “Minimum Ocean Observing System” (MOOS). MOOS/GOOS

19. Rossby (1959) (2) “The assumption that our planet as a whole stands in firm radiation balance with outer space cannot be accepted without reservations, even if periods of several decades are taken into account.” “Anomalies in heat probably can be stored and temporarily isolated in the sea and after periods of the order of a few decades to a few centuries again influence the heat and water vapour exchange with the atmosphere.”

20. Rossby (1959) (1) “The role of the sea as a secular heat reservoir assumes quite a different character at the moment that one takes up the question of secular changes of the total heat balance, taking into account the circulation of the deeper layers. An elementary calculation gives the result that even as much as 1 % of the total incoming heat radiation could be stored in a layer of 1000 m thickness in the interior of the sea, without producing a temperature increase greater than 0.015°C per year.”

21. Future work • Describe spatial and temporal characteristics of ocean warming; • 2) Perform diagnostic studies, e.g., earth’s heat balance; • 3) Add “new” historical ocean profile data to reduce uncertainty, • e.g., there are probably data for: • 1 million Ocean Station Data casts and • 0.5 million bathythermographs • still in manuscript form or simply not yet available.

22. Temperature difference (°C) at 1750 m depth of the N. Atlantic (1970-74)-(1955-59) (1988-92)-(1970-74)

23. Heat storage (W m-2) for the North Atlantic for (1988-92) – (1970-74) 0-300 m depth 0-3000 m depth

24. Earth’s climatological heat balance (Kiehl and Trenberth, 2000)

25. World Ocean heat content 2003 for different layers