MCD18C2: Daily and 3-Hour Photosynthetically Active Radiation at 0.05°

This dataset provides daily and 3-hourly estimates of Photosynthetically Active Radiation (PAR) globally from 2000 onward, derived from combined MODIS Terra and Aqua satellite observations. It is a gridded Level 3 product with a spatial resolution of 0.05 degrees (approximately 5.6 km at the equator). The data is generated using a prototyping algorithm that calculates PAR from surface reflectance via look-up tables accounting for aerosols, clouds, and viewing geometry.

Use Cases

• Modeling terrestrial carbon uptake and primary productivity based on daily PAR estimates.
• Assessing light availability for vegetation growth in land-surface models using the 3-hour PAR arrays.
• Studying diurnal patterns of solar radiation for ecosystem studies using the high-temporal-resolution data.
• Validating and calibrating other satellite-derived PAR or solar radiation products.

Strengths

• Provides high-temporal-resolution data with estimates every 3 hours.
• Offers global coverage at a consistent 0.05-degree spatial resolution.
• Integrates data from two MODIS sensors (Terra and Aqua) for improved temporal sampling.
• Algorithm uses look-up tables that consider varying aerosol/cloud loadings and viewing geometries.

Limitations

• Dataset is explicitly decommissioned (as of June 1, 2024), with users directed to a newer version.
• Specific column names and data volume (rows/size) are not provided in the source metadata.
• Known issues exist, requiring users to consult external quality assessment websites.

Provenance

Source

NASA LPCLOUD, derived from MODIS Terra and Aqua satellite sensors.

Collection Method

Generated using a prototyping algorithm that derives surface reflectance from multi-temporal MODIS signatures, then calculates PAR via look-up tables.

Time Range

The temporal coverage is not explicitly stated, but MODIS data collection began in 2000, suggesting a likely range from 2000 onward.

Freshness

Last updated metadata dates conflict: one source shows 2026-04-10, another shows 2024-06-01.

Geography

Global