However, the amount of deep-ocean data on intraseasonal
time scales has increased by at least an order
of magnitude with the deployment of Argo floats from
2000 onwards (Gould et al. 2004; Alverson and Baker
2006). Each float drifts at a parking depth (normally at
1000 m), and then every 10 days it descends to a base
level (normally at 2000 m) and then ascends to the surface,
measuring a profile of temperature and salinity as
it rises. At the surface, the data are sent via satellite,
then the float automatically descends back to its parking
depth. The 10-day repeat cycle and large number of
floats are now providing the oceanographic community
with unprecedented high spatial and temporal resolution
data of the upper 1000–2000m of the world oceans.