V2021007_D1_NRT_WW00_chlorapdif_800_0.png

 

Data are available through the following servers:

Service Resource Locator
HTTPS

S-NPP NRT Anomaly Difference in Data Portal

S-NPP NRT Anomaly Ratio (proportional difference) in Data Portal

NOAA-20 NRT Anomaly Difference in Data Portal

NOAA-20 NRT Anomaly Ratio (proportional difference) in Data Portal

ERDDAP  
THREDDS

S-NPP:
https://www.star.nesdis.noaa.gov/thredds/socd/coastwatch/catalog_viirs_npp_global_chloranom_daily.html

NOAA-20:
https://www.star.nesdis.noaa.gov/thredds/socd/coastwatch/catalog_viirs_n20_global_chloranom_daily.html

V2021007_D1_NRT_WW00_chlorapdif_800_0.png

Near-real-time (NRT) global daily chlorophyll-a (Chl-a) anomaly products that can be used to detect and identify algae blooms from satellite ocean color measurements such as those from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) and NOAA-20. Specifically, the production of the two Chl-a anomaly products, one for the Chl-a anomaly in difference and another for the Chl-a anomaly ratio (actually, the proptional difference or relative difference; product is labelled "pdif" in the files) compared to the 61-day Chl-a median value from the previous time period (as a Chl-a reference), has been implemented in the daily global NRT satellite data processing. These two Chl-a anomaly products represent the global ocean and coastal/inland water Chl-a abnormal condition for a given location and can provide more complete characteristics for the daily phytoplankton (or algae) biomass status by comparing to the normal condition. 

KeyDescription
Platform/Sensor

S-NPP/VIIRS
NOAA-20/VIIRS

Measurement/Products

chlorophyll-a anomaly difference
chlorophyll-a aonomaly ratio (proportional difference)

DOI
Short Name

NOAA VIIRS Chlorophyll Anomaly

Sample Filename
Dataset Type

NetCDF-4

Processing Level

Level-4

Spatial Coverage

Global

Temporal Coverage

Daily; computed by difference or ratio of a 61 day mean

Latency

48 hours

Resolution

2km (2.3163 km or 0.02°)

Projection

Geographic/WGS84
(EPSG:4326)

Swath Width

N/A

Sample Frequency

N/A

Temporal Repeat

daily

Orbital Period

N/A

Orbit

N/A

Data Provider

NOAA

Formats

NetCDF-4

Keywords

NOAA, JPSS, VIIRS, Chlorophyll, Anomaly, CoastWatch, NOAA National Environmental Satellite, Data, and Information Service, Center for Satellite Applications and Research, STAR, global, daily, 4km

Documentation: 

Wang M., L. Jiang, K. Mikelsons, X. Liu, Satellite-derived global chlorophyll-a anomaly products, International Journal of Applied Earth Observation and Geoinformation, Volume 97, 2021, 102288,  https://doi.org/10.1016/j.jag.2020.102288.