What should a field note say about water temperature checked online?

Identify the data you checked

An online temperature value needs enough detail for another reader to locate the same record. Write the exact station identifier and name, product, observation timestamp, date range requested, units, interval, and time zone. Also record when you retrieved the data, since an online product may be updated after the observation time. The CO-OPS API supports station and date parameters, water-temperature observations, units, time-zone choices, and interval settings. [1]

Keep retrieval time distinct from observation time. The first says when you accessed the data; the second says when the station reading was recorded. If either is missing, say that rather than filling the gap with an assumption.

Include missing-data handling

A useful note states whether the requested record returned a value or a gap. Do not interpolate a missing temperature unless a separate method justifies it; simply mark the missing timestamp and report any summary as based on available observations. If the product’s units or time basis are unclear, resolve them before comparing it with a field observation.

For a hypothetical example, imagine a note for a named station’s water-temperature product with a timestamp of 13:06 UTC, retrieved at 13:20 UTC on the same date, in metric units. If the adjacent interval is missing, record that gap explicitly and do not claim a continuous sequence. These example labels are illustrative only; they do not describe a real station retrieval.

Check the available local information when you need a temperature comparison for a field note. Record the displayed area and the time you checked it in a separate reference field, distinct from any temperature measured on site. Local water temperature reference.

Keep field conditions separate

If the temperature was checked online during a field visit, note the field observation time and location separately from the station record. A sensor reading represents water at the station’s measurement setting, not necessarily at the shoreline where the observer stands. A careful note preserves that spatial limit instead of calling the station value a direct local measurement.

When relevant, add the tide product and its datum in a separate field. Tide is the regular rise and fall of sea level, while temperature is a different measured quantity. [2]

Write a reproducible example note

A compact hypothetical note might read: “Station [exact ID and name]; product: water temperature; observation time: 13:06 UTC; retrieval date/time: the retrieval date, 13:20 UTC; date requested: the retrieval date; metric units; six-minute interval; one adjacent timestamp missing, no interpolation.” Replace each bracketed field with the actual retrieval details before sharing. This structure identifies the record without inventing a value or station result.

The CO-OPS API provides the request settings needed to document a retrieval, including station, product, dates, time zone, units, and interval. [1]