NASA's Terra MODIS Level-3 Photosynthetically Available Radiation (PAR) dataset provides satellite-based estimates of downwelling solar radiation in the 400–700 nm range at the ocean surface. The data quantifies daily or instantaneous usable light energy in moles of photons per square meter. It is produced by OB_CLOUD and supports marine primary production estimation and ecosystem modeling.
Use Cases
- Estimate marine primary production based on daily photosynthetically available radiation.
- Interpret phytoplankton bloom dynamics based on instantaneous PAR measurements.
- Provide context for optical and biogeochemical measurements based on light availability data.
- Support ecosystem models of light–biology interactions based on PAR energy estimates.
Strengths
- Provides estimates for a specific geophysical variable: daily photosynthetically available radiation (PAR).
- Includes additional variables for Level-2/3 processing flags and instantaneous PAR.
- Quantifies usable light energy in a standardized unit (mol photons m⁻²).
Limitations
- Column-level documentation is absent; field semantics must be inferred after download.
- Row count is unknown, which may limit suitability assessment.
- Data may reflect geographic/temporal bias inherent to satellite sensor coverage.
Provenance
- Source
- NASA Earthdata via OB_CLOUD
- Collection Method
- Satellite-based remote sensing from the Terra MODIS instrument.
- Geography
- Global ocean surface