Temperature (T) and Salinity (S) profiles

How to interpret Argo profiles


The T and S profiles show how water temperature (T) or salinity (S) change with depth. Understanding the profiles means thinking about the float trajectory, - the climate of the region the float has passed through, and the currents that have moved the float to where it is.
It is handy to look at the temperature and salinity profiles alongside each other. (Also the trajectory of the float)
Argo_graph_WMO=_1900693_.jpg
Salinity and Temperature profiles of Argo float WMO= 1900693.

This float has been in action since 7 Oct 2006.
Things to look for-
Salinity- note the change in salinity in more recent times for float WMO 1900693. This will be to do with where the float is travelling. There are different salinity levels in different parts of the ocean. Less dense water floats on top of more dense water. Given two layers of water with the same salinity, the warmer water will float on top of the colder water. BUT…. temperature has a greater effect on the density of water than salinity does. So a layer of water with higher salinity can actual float on top of water with lower salinity if the layer with higher salinity is quite a bit warmer than the lower salinity layer.

Temperature- note on the Temperature Profile for float WMO 1900693 how you get a darker pink (higher temp) regularly, lining up nicely with the seasons of the year.
Have a look at where this float was deployed and it’s trajectory
Traject_of_1900693.jpg
Trajectory of Float WMO= 1900693.

Now compare this data with an Argo Float situated further south…
WMO=_5901265graph.jpg
Salinity and Temperature profiles of Argo float WMO= 5901265.

WMO=_5901265_.jpg
Trajectory of Argo float WMO= 5901265.

…and one at the equator
WMO=_5901282_.jpg
Salinity and Temperature profiles of Argo float WMO= 5901282

WMO=_5901282_traject_.jpg
Trajectory of WMO 5901282

So what!

Argo data are easy to access and are truly global.


  • bring more of an awareness of how our oceans work.
  • keep a watch on major temperature and salinity anomalies and changes in ocean circulation.
  • aid the monitoring of environmental conditions that affect fish stocks and biological productivity.
  • give oceanographers and climate scientists a comprehensive ocean data set.

A key objective of Argo is to observe ocean signals related to climate change. Argo data hasn’t been around long enough to show global change but is keeping tabs on seasonal changes taking place.