Trajectory and Time-Series Vertical Section

Use a time-series vertical section to compare oceanographic parameters by pressure and profile cycle along one float’s trajectory.

Accessing Time-Series Vertical Sections

1. Select a Float: Start by selecting an Argo float from the search results or the map view.
2. Turn on Trajectory: In the upper-right map command bar, turn on Trajectory to load every cycle from the selected float’s trajectory. Trajectory is disabled until a profile is selected.
3. Show vertical section: Open Analyze and select View section. On narrower layouts, open Tools, then use the same Analyze item.
4. Choose a parameter: Use θ, S, or BGC above the section, independently of the Profile chart. Hover over, click, or tap BGC (or the selected variable name), then choose a variable.

During loading, the button immediately highlights and shows Loading… with a spinner; the map and selected profile remain visible. Once ready, it shows On with a checkmark. Click again or select another profile to cancel loading. If loading fails, it returns to Off with an error message; click again to retry.

The Date Range continues to show the filter used for the original search. Trajectory then loads all published cycles for the selected WMO ID, so Profile Details can show a cycle outside that range.

Turning Trajectory off restores the profile that was selected when it started, even if you moved to another cycle. Using the Trajectory button to turn it off also returns keyboard control to the map. A new search clears that saved selection. Toggling Trajectory closes the previous θ–S display, cancels an active θ–S or Clustering job, and closes the section when Trajectory ends.

With Trajectory on, ← / → select the previous or next profile, and none of the arrow keys pans the map. Mouse controls and map zoom shortcuts remain available. Text inputs, menus and the 3D view keep keyboard priority.

Signed-in users can also open θ–S from Analyze while Trajectory is on. θ–S and the section can be displayed together; θ–S uses every cycle in the selected WMO trajectory. When both charts are visible, selecting a profile updates the selected marker, the section’s dashed line, and the highlighted profile curve in θ–S together.

You can also generate a 3D view from loaded trajectory profiles within a rectangle. Toggling Trajectory cancels an unfinished 3D selection, but preserves generation already in progress and the latest successful result.

Interpret the Section

• The vertical section is linked with the vertical profiles in Profile Details, and the position of the selected profile is shown with a dashed line.
• Every parameter uses the same 0–2000 dbar coordinate at 5 dbar intervals. The 500 and 1000 dbar views crop this coordinate, so colors and MLD/SOM data-layer points remain aligned. Values are not extrapolated above the shallowest finite observation.
• Missing areas mean unavailable, masked, or insufficiently supported values, not zero. Interpolation is limited to pressure within a profile; missing cycles remain gaps.
• A parameter with a published section displays its chart. If individual profiles contain usable values but adjacent cycles do not provide enough support to draw a section, the parameter remains selectable and the section area explains the limitation. A parameter with no usable profile data is disabled.
• Signed-in users can show MLD or SOM with Data layer. Points mark valid results, and lines connect consecutive cycles only. Gaps indicate missing cycles or unavailable results; the lines are visual guides, not interpolation through time.

Related Reading

For help interpreting patterns, gaps, and changes across repeated profiles, read Time-Series Vertical Sections in Oceanography Explained in OceanGraph Articles.