NASA's Aqua MODIS Level-3 Photosynthetically Available Radiation (PAR) dataset provides satellite-based estimates of downwelling solar radiation in the 400–700 nm range available for photosynthesis at the ocean surface. The data quantifies daily usable light energy in moles of photons per square meter and is used to estimate marine primary production and phytoplankton bloom dynamics. This version 2022.0 product is distributed via the NASA Earthdata platform.
Use Cases
- Estimating global marine primary production based on daily photosynthetically available radiation.
- Interpreting phytoplankton bloom dynamics based on satellite-derived light energy measurements.
- Providing context for in-situ optical and biogeochemical measurements based on surface PAR data.
- Supporting ecosystem and biogeochemical models based on daily light energy inputs.
Strengths
- Data is derived from the MODIS instrument on NASA's Aqua satellite, a trusted source for Earth observation.
- Focuses on the specific 400–700 nm wavelength range critical for photosynthesis.
- Provides a geophysical variable (par) expressed in the standard scientific unit of mol photons m⁻² d⁻¹.
Limitations
- Column-level documentation is absent; field semantics must be inferred after download.
- Row count and file size are unknown, which may limit suitability assessment.
- Data may reflect geographic or temporal bias inherent to satellite remote sensing from a single platform.
Provenance
- Source
- NASA Earthdata (OB_CLOUD organization)
- Collection Method
- Satellite remote sensing from the MODIS instrument aboard the Aqua spacecraft.
- Geography
- Global ocean coverage