NOAA-20 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. This version 2022.0 near real-time product is sourced from NASA Earthdata and managed by OB_CLOUD.
Use Cases
- Estimating marine primary production rates using the daily 'par' variable.
- Analyzing phytoplankton bloom dynamics by correlating the 'ipar' variable with chlorophyll-a concentrations.
- Interpreting in-situ optical measurements by providing satellite-derived 'par' context.
- Initializing ecosystem models with the 'par' and 'ipar' geophysical variables.
- Filtering data quality by applying the 'l2_flags' bitmask to exclude low-confidence pixels.
Strengths
- Provides global spatial coverage of ocean surface PAR.
- Includes both daily ('par') and instantaneous ('ipar') radiation estimates for temporal analysis.
- Contains a 'l2_flags' bitmask for data quality assessment.
Limitations
- Specific row count, temporal range, and spatial resolution are unknown.
- Near real-time data may contain unvalidated artifacts requiring later reprocessing.
- Relies on satellite sensor performance and atmospheric correction algorithms which introduce uncertainty.
Provenance
- Source
- NASA Earthdata, from NOAA-20 VIIRS satellite sensor.
- Collection Method
- Satellite remote sensing, processed to Level-3 global mapped products.
- Time Range
- null
- Freshness
- Near real-time (NRT).
- Geography
- Global ocean coverage.