System boundary
A threshold depends on the reference period and local seasonality, so duration, intensity and baseline must be read together. Relate that field focus to “Inspect the pattern” before moving to “How to read it.”
Data lab 02
Marine Heatwave Tracker
See how an anomaly becomes a marine heatwave when it stays above a location-specific 90th percentile threshold.
Last updated 2026-09-28 · Reviewed against listed sources
Inspect the pattern
The compact series on Marine Heatwave Tracker demonstrates an interface and interpretation workflow. It is neither a live feed nor a scientific estimate, and its values should not be detached from the stated teaching scenario.
How to read it
When reading Marine Heatwave Tracker, begin with its unit, baseline, time window and spatial coverage. Separate the displayed pattern from explanations that would require observations or models beyond this lab.
Limitations
Measurements used in Marine Heatwave Tracker are uneven in space and time. A comparison product may adopt another baseline, quality-control rule or interpolation method, so apparent differences must be traced to both ocean conditions and data construction.
Sources checked
- NOAA Marine Heatwave Watch · Hobday et al. definition · Copernicus Marine
- IPCC Sixth Assessment Report: ocean and coastal systems
- UNESCO IOC: ocean observing resources
Marine Heatwave Tracker data labs page summarizes public scientific and institutional material. Values relevant to Marine Heatwave Tracker may change with dataset, location, season and method, so comparisons should retain those conditions.
Ocean field notebook / data labs
Field plan: Marine Heatwave Tracker
See how an anomaly becomes a marine heatwave when it stays above a location-specific 90th percentile threshold.
Measurements to log
Pair a time series with an explicit baseline with a second measurement of the same process. Record depth, location, date, units and sampling effort so a change in conditions is not mistaken for a change in the ocean.
Change signal
Compare “How to read it” with “Limitations.” Decide whether the pattern represents exposure, response or recovery, and state the observation period needed to tell them apart.
Research dispatch
A marine heatwave is defined relative to a seasonally varying local climatology, commonly through a percentile threshold sustained for a minimum duration. Changing the baseline period can change which days qualify even when the observed temperatures do not. A complete analysis keeps event duration, peak intensity, cumulative intensity and spatial extent separate, then asks whether gaps or interpolation join events that should remain distinct. Ecological interpretation also needs exposure at the organism’s actual depth rather than surface temperature alone.
Open the pre-dive checklist
- Which variable can be observed directly?
- Which mechanism needs a second instrument or comparison site?
- What result from the page sources and linked institutional records would change the planned conclusion?