M008901 Why salinity and temperature are measured

M008901 Why salinity and temperature are measured

Description

This is a colour video clip in which Dr Phil Sutton, a physical oceanographer from New Zealand’s National Institute of Water and Atmospheric Research, details the reasons for collecting data on the temperature and salinity of the oceans. It includes sequences showing Dr Sutton at work.

Acknowledgements: Copyright Education Services Australia Ltd.

Educational value
The degree of salinity (salt content) of sea water varies across the globe. High salinity occurs in places where rainfall is low and warm temperatures cause high evaporation rates. Places with high rainfall, or those close to land masses where fresh water from rivers or melting ice is added to the ocean, have relatively low salinity.
Salinity and water temperature influence global ocean currents. As water becomes more saline its density increases, so that highly saline water sinks below less saline water. Cooling also produces an increase in density, and the sinking of cool, highly saline water at high latitudes helps drive ocean circulation.
Ocean currents, temperatures and salinity across the globe are monitored by a network of floating sensors as part of the international Argo project. There are more than 3,000 floats at present, and each one spends most of a 10-day cycle submerged up to 2,000 metres below the surface. At the end of the 10 days, it rises to the surface, gathering data, and transmits it via satellite to a recording station.
In addition to helping scientists to understand the driving mechanisms of ocean currents, temperature measurements allow them to monitor the progress of global warming, also called 'climate change'. The oceans exchange heat with the atmosphere and act as a reservoir of heat energy for the planet. Measurement of the heat content of the oceans is vital in determining how much thermal energy is accumulating in them.
Year level
5; 6; 7; 8; 9
Topics
Climate change
Density
Global warming
Ocean currents
Salinity
Learning area
Science
Strand
Science
Rights
© Education Services Australia Ltd 2011 (except where otherwise indicated). You may copy, communicate and adapt this metadata for non-commercial educational purposes provided you retain all acknowledgements associated with the material.