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www.ocean-sci-discuss.net/6/2975/2009/
doi:10.5194/osd-6-2975-2009
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under the Creative Commons Attribution 3.0 License.
The timescale and extent of thermal expansion of the oceans due to climate change
Department of Applied Mathematics, Research School of Physics and Engineering, The Australian National University, Canberra, Australia
Faculty of Science, University of Split, Split, Croatia
Abstract. With recently improved instrumental accuracy, the change in the heat content of the oceans and the corresponding contribution to the change of the sea level can be determined from in situ measurements of temperature variation with depth. Nevertheless, it would be favourable if the same changes could be evaluated from just the sea surface temperatures because the record could then be extended into the past and projected into the future. We show here that the average change in the heat content of the oceans and the corresponding contribution to a change in the sea level can be evaluated from the past sea surface temperatures. The calculation is based on the time-dependent diffusion equation with constant upwelling velocity and has no adjustable parameters. In the steady-state limit it recovers the well-known profile of the potential temperature variation as a function of depth.
The results are in good agreement with the estimates obtained from the in situ data, even though most of the warming occurs in the upper 1000 m. The method allows us to obtain relevant timescales and average temperature profiles. The evaluation of the thermosteric sea level change is extended back to the beginning of accurate sea surface temperature records in 1880. The changes in sea surface temperature from 1880 until the present time led to a thermosteric sea level rise of 3 cm and to a commitment for a future rise of 5 cm.
Discussion Paper (PDF, 1615 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (OS)
Citation: Marčelja, S.: The timescale and extent of thermal expansion of the oceans due to climate change, Ocean Sci. Discuss., 6, 2975-2992, doi:10.5194/osd-6-2975-2009, 2009. Bibtex EndNote Reference Manager XML
