Data from profiling floats, expendable bathythermographs (XBTs), thermistor chains and CTDs collected from 1997 one are used to derive the upper ocean properties heat storage rate. The primary source for the float profiles are the Argo Global Data Centers, USGODAE and IFREMER.
Additional float profiles as well as the data from the other instruments are available through the Global Telecommunication System (GTS) used by the meteorological and oceanographic community. Oceanographic (and other) data sets are retrieved from GTS by MEDS (Marine Environmental Data Services, Canada) and are available from GTSPP.
Annual maps the data coverage as percent of months with hydrographic observations are derived after an objective analysis has been performed (see Methods).
The maps reveal that the data coverage is improving significantly in the South Atlantic, particularly around 30-35˚ starting in 2003. This is due to observations from Argo floats and the roughly quarterly collection of XBT profiles from Voluntary Observing Ships along the AX18 line.