We will estimate the heat storage from hydrographic observations, including statistical errors. We are currently estimating the heat storage from satellite observations (sea height anomaly and sea surface temperature) in regions where the correlation between SHA and heat storage is high.

The overall error will be based on:

1. Difference between in situ-based and satellite-based estimates.
2. Global coverage with heat storage estimates from in situ observations.
3. Global coverage with heat storage estimates from satellite observations.

Comparison between in situ-based and satellite-based estimates.

Time series (1992-2004) of heat storage in the upper 400 m from in situ observations (red) and from satellite altimetry (black) in a 5° by 1.5° box centered at 27.5°W, 5.25°N. The correlation coefficient between the two time series is 0.9 and their rms difference is 0.04 10¹⁰ J/m².