September 29, 2023
Please be aware NOAA CoastWatch has noted a positional shift in S-NPP/NOAA-20 VIIRS ocean color global mapped datasets. We are investigating the cause within the processing chain and correction/re-processing that will be taken to resolve the issue. The shift in data appears to be a systematic 2 pixel (9.3 km) westward shift in data pixels. Although the shifted data predominantly occurs beginning June 29, 2022 (Day of Year 180) there are some interspersed reprocessed datasets pre-dating that date.
NOAA CoastWatch will reprocess the affected datasets and update this notice as more information is known (note, during a Government shutdown, updates will not be published but may occur. Please contact email@example.com for information).
Datasets affected by this include:
Global 4km Anomaly Ratio and Difference Products (NRT + Science Quality):
Example Filenames: V2021293_D1_NRT_WW00_chlorapdif.nc, V2021221_D1_NRT_WW00_chloradiff.nc
Global 4km Chlorophyll OCI S-NPP+NOAA-20 (NRT)
Example Filename: V2023145_D1_NPP-N20_WW00_chloci.nc
Global 4km Ocean Color IOP (NRT)
Example Filename: V2022365_D1_WW00_adg443.nc
Global 4km Ocean Color S-NPP VIIRS (Science Quality)
Daily, Weekly, and Monthly (Chlorophyll-a, kd490, kdPAR, nLw[410,443,486,551,671,638ag], PAR, SPM)
Example Filenames: V2023049_D1_WW00_chlora.nc, V2022213_2022243_F31_WW00_chlora.nc