These set of visualizations show changes in temperature and salinity with depth for the first ice-tethered profiler deployed, ITP 1. Pressure is closely correlated with depth and thus the terms are interchangeable in this context. Pressure is measured in decibars (dbar), temperature in degrees Celsius (°C), and salinity in practical salinity units (psu).
The visualization to the right demonstrates each profile through the seasons of the machine's journey. Winter is pictured as dark blue, followed by spring in green, summer in pink and fall in light blue. The tabs can be used to change the focus of the plot, either viewing all temperature profiles, all salinity profiles, or profiles by season. Notice how pressure changes on the y-axis. It may seem weird that the numbers become smaller further away from the origin. The top of the graph corresponds to the surface of the ocean, where there is no hydrostatic pressure.
Questions for thought:
What changes or patterns do you observe throughout the water column? Between seasons? What range of temperature do you observe? Salinity? How could you interpret the steep drop-off present on every salinity graph, beginning around 400 dbar?
Changes with Depth over Time
The second and third plots are heatmaps, which indicate temperature or salinity through the use of color over a period of time. We can see that the y-axis from the first set of graphs is the same and shows pressure or depth. c A day’s worth of temperature and salinity data is averaged for each interval of depth, so each day is a snapshot in time. Therefore, the heatmaps represent consecutive snapshots over the duration of an ITP machine’s active lifetime.
Questions for thought:
What changes or patterns do you observe over time? Can you match patterns to those observed in the earlier graph? If so, how do you interpret them? What can you infer from the consistency of patterns over time for temperature? For salinity?
Recreate these visualizations for a different ITP machine. Navigate to Data Notebooks under the Resources tab, and open ITP Profile Visualization. and ITP Heatmap Visualization.