Sea surface height anomalies from satellite altimeter data are used to esti
mate heat storage. Since variability in sea surface height is mostly due to
expansion and contraction of the water column it can be correlated with va
riations in the heat and salt content. Therefore, estimation of heat storag
e from altimeter data, when compared to in situ estimates, requires correct
ions for the haline effect. Three sites with a nearly continuous time serie
s of temperature and salinity profiles simultaneous with TOPEX/POSEIDON dat
a are studied: HOT, CalCOFI and Hydrostation "S". Haline corrections based
on in situ and climatological salinity measurements are contrasted. For the
studied regions, the haline corrections based on climatology provide equiv
alent or worse results than not applying a correction at all. The use of in
situ salinity estimates decreased the differences between the heat storage
estimates (up to 17 x 10(7) J m(-2)) and significantly improved their corr
elation (up to 0.18).