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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.

Float trajectory and time-series vertical section

Accessing Time-Series Vertical Sections

Select a profile, turn on Trajectory, then open Analysis → View section (under Tools on narrower layouts). The section’s parameter selection is independent of the Profile chart.

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.

Trajectory mode and Analysis menu

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

Comparing Profiles

With Trajectory on, ← / → moves in cycle-number order, skipping missing cycles. You can also click or drag across the section to select a profile directly.

Signed-in users can also open θ–S from Analysis while Trajectory is on. θ–S uses every cycle in the selected WMO trajectory and can stay open alongside the section, highlighting the selected cycle.

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.

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