NOAA-21 VIIRS satellite data provides global mapped estimates of Photosynthetically Available Radiation (PAR) at the ocean surface. The dataset quantifies daily and instantaneous usable light energy in the 400–700 nm range, expressed in moles of photons per square meter. It is produced by the OB_CLOUD organization using near real-time processing.
Use Cases
- Estimate marine primary production rates using the daily 'par' variable as a key input to productivity models.
- Analyze phytoplankton bloom timing and intensity by correlating the 'ipar' (instantaneous PAR) field with other biogeochemical measurements.
- Interpret satellite ocean color data by using the 'l2_flags' bitmask to filter for valid pixels in optical measurements.
- Initialize and validate marine ecosystem models by assimilating the global mapped 'par' data for light availability constraints.
Strengths
- Provides global spatial coverage for ocean surface PAR.
- Includes both daily ('par') and instantaneous ('ipar') radiation variables for temporal analysis.
- Near real-time (NRT) processing supports timely monitoring applications.
Limitations
- Specific temporal coverage, row count, and spatial resolution details are not provided.
- Relies on satellite retrievals which can be affected by cloud cover and atmospheric conditions.
- The 'l2_flags' bitmask requires interpretation of per-variable attributes for correct use.
Provenance
- Source
- NOAA-21 VIIRS satellite sensor, processed via NASA Earthdata platform.
- Collection Method
- Satellite-based remote sensing estimates of downwelling solar radiation in the 400–700 nm wavelength range.
- Time Range
- null
- Freshness
- Near real-time (NRT).
- Geography
- Global ocean surface.