Lab 5.1 – How does salinity and temperature change with water depth over time?

Estimated time to complete: 30 minutes

Materials needed: none

Understanding properties that control the formation and movement of different water masses can give us insight into how heat energy is moved around the globe. Temperature and salinity are important oceanographic parameters that play a vital role in driving ocean circulation and affecting primary production. The ocean is layered like a cake (without frosting) according to differences in temperature and salinity. In this activity, you will explore how the layering of the ocean at one location changes over the course of a year.

Below you are able to see a dataset of temperature and salinity with pressure (depth) at the Coastal Pioneer Array over the course of a year. You can interact with the data by:

  • Viewing the data (temperature, salinity) for one or more months by clicking on that month under the “Toggle Month” menu at right of graphs
  • Hovering your mouse over a profile to view the value of data variables at different water depths


Interpretation Questions:

  1. Describe how the depth range of the thermocline, halocline, and surface mixed layer changes throughout the year.
  2. During which season (summer or winter) is the mixed layer depth deeper?
  3. Suggest an explanation for the seasonal difference in the depth of the surface mixed layer.