Nitrate in surface water (DP1.20033.001) algorithm updates

In June 2026, the data processing algorithm for Nitrate in surface water (DP1.20033.001) was updated. For provisional data not included in a previous release (data collected after June 30, 2025) these changes will be reflected immediately. For data included in a previous release, these changes will take effect beginning with RELEASE-2027. The categoricalCodes file is temporarily unavailable for provisional data but will be available in time for RELEASE-2027.

The major updates were:

• When available, logged data are now included, potentially filling gaps where data failed to stream in real time or were corrupted. This resulted in a noticeable increase in data availability at some sites. An informational logDataQF was added to indicate when logged data was available.
• The data quality flagging algorithm was also updated. Individual measurements within a 15-minute burst which receive a quality flag are omitted from burst stats, and the insufficientDataQF is used to indicate whether there are an insufficient number of unflagged measurements available to accurately calculate the stats and expanded uncertainty. The nitrateConfigQF was also added to indicate when the sensor was incorrectly configured. These two new flags, along with the SciRvwQF are used to determine the finalQF. The α and β quality metrics are no longer used for this data product.  

For full details, see the updated Algorithm Theorical Basis Document (ATBD) on the data product landing page or accompanying the download.

All code used to generate the data product is open-source and available in the NEONScience/NEON-IS-data-processing Github repository.

For more information on this update, please use the NEON Contact Us Form, and reference DP1.20033.001.