How altimetry can complement in situ observations in the estimation of the upper ocean heat storage
Gustavo Jorge Goni(1) and Claudia Schmid(1)
4301 Rickenbacker Causeway,
The main objective of this study is to improve the estimates of the
upper ocean heat storage, which is key to achieve a better
understanding of the heat balance in the world oceans.
These estimates are necessary to improve climate forecast
capabilities of coupled general circulation models.
The data we use cover the years 1992 through 2005. Temperature
profiles, approximately 500,000, are obtained from XBTs and profiling
floats. The altimeter data consist of the gridded AVISO sea
height anomaly fields. The correlation between the sea height anomaly
and the depth of the mixed layer and of selected isotherms is
investigated in the upper 800m. The sea height anomaly fields are
used to monitor the upper ocean heat storage within a two layer
reduced gravity approximation where these correlations are good.
We present here global maps of altimeter-derived upper ocean heat
storage and the errors associated with these estimates obtained from
the XBT and profiling float observations. The final goal of this work
will be to fill with altimetry estimates the spatial gaps created
where profiling float coverage is not adequate. Moreover, this
work will also provide information on where more in-situ observations
are needed because altimetry cannot be used as a proxy to estimate
the mixed layer depth or the upper ocean heat storage.