Quick Start: Your First 10 Minutes
This page is a guided path for your first session with OceanGraph. It walks you from searching the map to exploring water masses and BGC-derived metrics, and links out to the detailed feature pages along the way.
Open OceanGraph and follow along.
What you can do without signing in
Search, WMO ID lookup, Trajectory View, and time-series View section work without an account. Signing in unlocks a longer search range and the analysis displays:
- Anonymous: search up to a 30-day range.
- Signed in: search up to a 90-day range, plus θ-S, Clustering, MLD, SOM, mode water map overlays, profile downloads, saved searches (up to 3), bookmarks (up to 5), and screenshots.
You can complete steps 1–3 below without signing in. Steps 4–5 require a signed-in account.
Step 1: Search the map
- Set a Date Range (anonymous: up to 30 days; signed in: up to 90 days).
- Set the Geographic Bounds by interacting with the map.
- Optionally check Only profiles with BGC to keep only profiles that include a biogeochemical parameter (dissolved oxygen, chlorophyll, nitrate, backscattering, pH, irradiance at 490 nm, or PAR).
- Run the search. Matching profiles appear as markers on the map.
If you already know a float, enter its WMO ID in the Profile Details panel and press Enter to load all of its profiles.
Too many results? Narrow the date range or geographic bounds. θ-S and Clustering accept at most 500 profiles, so a tighter search keeps those features available.
See Search and Bookmark for details.
Step 2: Select a marker
Click a marker to open its profile details (WMO ID, cycle number, date, latitude, longitude). Selecting a profile is the starting point for following a single float and for highlighting it in the analyses below.
Step 3: Follow one float (Trajectory and Section)
- Turn on the Trajectory View switch to load profiles along the selected float’s trajectory.
- Click View section to see the time-series vertical section.
The dashed line on the section marks the currently selected profile. Gray or blank areas are places where data did not pass quality control (QC). BGC section charts appear only when the selected float carries that parameter.
See Trajectory and Time-Series Vertical Section.
Step 4: Explore water masses (θ-S) — signed in
With a search active, click View θ-S in the top-right corner of the map to generate a θ-S diagram from the current results. Selecting a float on the map highlights its temperature-salinity line on the diagram. Click Close θ-S to hide it.
To group profiles by their vertical structure instead, click Clustering in the top-right corner and wait for the job to finish; markers are then colored by cluster. Both θ-S and Clustering accept a maximum of 500 profiles.
See θ-S Diagram and Clustering.
Step 5: Derived map overlays — signed in
Derived map overlays require a signed-in account and are shown via the map controls. Only one overlay can be active at a time.
- MLD — Open MLD / SOM and choose MLD. Mixed Layer Depth is computed from potential temperature, absolute salinity, and potential density. It does not require BGC data, so it works on core Argo profiles. Profiles with no valid MLD are shown in gray.
- SOM — Open MLD / SOM and choose SOM. Subsurface Oxygen Maximum requires dissolved oxygen, so it needs BGC profiles. Use Only profiles with BGC in your search first. Profiles without oxygen or a valid result are shown as no-data markers.
- Mode Water — Open Mode Water and choose a type such as NPSTMW or NASTMW. Profiles with the selected mode water are colored by detected layer thickness; profiles without that selected mode water are shown as no-data markers.
When Trajectory View and the matching section chart are open, MLD or SOM can also be overlaid on the section. Mode water coloring applies to map markers.
See Mixed Layer Depth (MLD), Subsurface Oxygen Maximum (SOM), and Mode Water Map Overlay.
If something doesn’t work
| Symptom | Likely cause and next step |
|---|---|
| No search results | The date range or area is too restrictive, or the BGC filter is on. Widen the range/area, or uncheck Only profiles with BGC. |
| θ-S or Clustering won’t run | Your search has more than 500 profiles. Narrow the date range or bounds. |
| A feature is missing from the screen | θ-S, Clustering, MLD, SOM, mode water overlays, and downloads require signing in. Sign in and try again. |
| BGC selected but a chart is missing | Not every BGC parameter has an in-app chart (e.g., irradiance at 490 nm is searchable and downloadable but not charted), and the float may not carry that parameter. |
| Vertical section is gray or blank | Those depths/times did not pass QC. See Limitations. |
| MLD, SOM, or mode water markers are gray / no-data | The profile lacks a valid derived result. For SOM, use BGC profiles with dissolved oxygen. For mode water, the selected type may not have been detected under the current criteria. |
| Vertical Profiles won’t open on mobile | Vertical Profiles is desktop-only. Open it on a desktop browser via Menu > Analysis Lab > Vertical Profiles. |
For more on why data can be sparse or missing, see Limitations.
Where to go next
- Compare your own Argo-format JSON files in Vertical Profiles (signed-in, desktop only).
- Browse precomputed views in Visual Lab.
- Read the Articles for background on Argo floats, T-S diagrams, BGC parameters, and more.