Skip to main content

Description

The MCD18A2 Version 6.2 is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Photosynthetically Active Radiation (PAR) gridded Level 3 product produced daily at 1 kilometer pixel resolution with estimates of PAR every 3 hours. PAR is incident solar radiation in the visible spectrum (400-700 nanometers) and is an important variable in land-surface models that address a variety of scientific and application issues. The MCD18 products are based on a prototyping algorithm that uses multi-temporal signatures of MODIS data to derive surface reflectance and then calculate incident PAR using the look-up table (LUT) approach. The LUTs consider different types of loadings of aerosols and clouds at a variety of illumination/viewing geometry. Global PAR products are generated from MODIS and geostationary satellite data. Additional details regarding the methodology used to create the data are available in the Algorithm Theoretical Basis Document (ATBD).

Provided in the MOD18A2 product are layers for instantaneous PAR array for each individual MODIS overpass and 3-hour PAR array along with a View Zenith Angle layer.

Known Issues

Version Description

The following changes and improvements were implemented for inputs to MODIS Version 6.2 PAR data products: (1) MODIS shortwave infrared bands are included in the retrieval algorithm, which significantly reduces estimation uncertainties in cloud- and snow-covered pixels, (2) Inclusion of a new multispectral algorithm has been implemented to replace the blue band retrieval algorithm, and (3) An improved climatology of surface spectral and broadband albedo was produced and used in the retrieval algorithm.

Product Summary

Platforms
Terra ,
Aqua
Instruments
MODIS
Projects
TERRA ,
Aqua
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
1000 Meters x 1000 Meters
Spatial Reference System(s)
MODIS Sinusoidal Tiling System
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2000-02-24 to Present
Temporal Resolution
3 Hour
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC) ,
MODIS Adaptive Processing System, Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/MODAPS)
Concept ID
C2486282714-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
2916405
Processing Level
3
Published
Updated
Science Keywords
Reflectance ,
Albedo ,
Anisotropy

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Wang, D. (2024). MODIS/Terra+Aqua Photosynthetically Active Radiation Daily/3-Hour L3 Global 1km SIN Grid V062 [Dataset]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MCD18A2.062 Date Accessed: 2026-08-08

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

PRODUCT QUALITY ASSESSMENT

SCIENCE DATA PRODUCT VALIDATION

GENERAL DOCUMENTATION

Publications Citing This Dataset

Filters
Title Year Author Topic
Comparison of Sentinel-2 and MODIS for estimating GPP along an ecosystem gradient in eastern Germany Sayeed, Mostafa, Ahmadpour, Somayeh, Trachte, Katja Reflectance, Albedo, Anisotropy, Land Surface Temperature, Emissivity
Estimates of high spatiotemporal resolution solar shortwave radiation from Himawari-8 radiation products in mountainous areas Liu, FengYang, Zhang, YanLi, Cui, DuDu, Li, Xuan, Zhang, Chen Reflectance, Albedo, Anisotropy
Regional fire dynamics and its contributions to carbon flux variability in South Asia Das, Chiranjit, Chatterjee, Abhishek, Kunchala, Ravi Kumar, Liu, Junjie Surface Pressure, Heat Flux, Longwave Radiation, Shortwave Radiation, Surface Temperature, Humidity, Evapotranspiration, Surface Winds, Rain, Precipitation Rate, Snow, Soil Moisture/Water Content, Soil Temperature, Land Surface Temperature, Snow Water Equivalent, Runoff, Land Use/Land Cover Classification, Reflectance, Albedo, Anisotropy, Snow Cover, Snow Cover
Achieving LDN target of India: challenges and pathways. Kumar, Gopal, Madhu, M., Mandal, D., Roy, T., Mandal, U., Parihar, K., Sikka, A. K. Reflectance, Albedo, Anisotropy
Forest fragmentation impacts the seasonality of Amazonian evergreen canopies Nunes, Matheus Henrique, Camargo, Jose Luis Campana, Vincent, Gregoire, Calders, Kim, Oliveira, Rafael S., Huete, Alfredo, Mendes de Moura, Yhasmin, Nelson, Bruce, Smith, Marielle N., Stark, Scott C., Maeda, Eduardo Eiji Reflectance, Albedo, Anisotropy, Shortwave Radiation
Estimation of land surface incident shortwave radiation from Geostationary Advanced Himawari Imager and Advanced Baseline Imager observations using an optimization method Zhang, Yi, Liang, Shunlin, He, Tao, Wang, Dongdong, Yu, Yunyue, Ma, Han Reflectance, Albedo, Anisotropy, Shortwave Radiation
Accounting for Carbon Sink and its Dominant Influencing Factors in Chinese Ecological Space Lin, Gang, Jiang, Dong, Li, Xiang, Fu, Jingying Vegetation Index, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Reflectance, Albedo, Anisotropy, Photosynthesis, Primary Production, Vegetation Productivity, Land Use/Land Cover Classification
El Nino Southern Oscillation and enhanced arid land vegetation productivity in NW South America Vining, Benjamin R., Hillman, Aubrey, Contreras, Daniel A. Photosynthesis, Primary Production, Vegetation Productivity, Reflectance, Albedo, Anisotropy
Retrieving high-resolution surface photosynthetically active radiation from the MODIS and GOES-16 ABI data Zhang, Hailong, Dong, Xiquan, Xi, Baike, Xin, Xiaozhou, Liu, Qinhuo, He, Hongming, Xie, Xiuping, Li, Li, Yu, Shanshan Reflectance, Albedo, Anisotropy
A New index assessing the viability of par application projects used to validate PAR models Ferrera-Cobos, Francisco, Vindel, Jose M., Valenzuela, Rita X. Reflectance, Albedo, Anisotropy, Shortwave Radiation
Combination of Models to Generate the First PAR Maps for Spain Ferrera-Cobos, Francisco, Vindel, Jose M., Wane, Ousmane, Navarro, Ana A., Zarzalejo, Luis F., Valenzuela, Rita X. Reflectance, Albedo, Anisotropy, Shortwave Radiation
Correcting PAR data from photovoltaic quantum sensors on remote weather stations on the Great Barrier Reef Nunez, Manuel, Cantin, Neal, Steinberg, Craig, van Dongen-Vogels, Virginie, Bainbridge, Scott Reflectance, Albedo, Anisotropy
Analysis of Spatial and Temporal Variability of the PAR/GHI Ratio and Ferrera-Cobos, Francisco, Vindel, Jose M., Valenzuela, Rita X., Gonzalez, Jose A. Reflectance, Albedo, Anisotropy, Shortwave Radiation
A new set of MODIS land products (MCD18)Downward shortwave radiation and photosynthetically active radiation Wang, Dongdong, Liang, Shunlin, Zhang, Yi, Gao, Xueyuan, Brown, Meredith G. L., Jia, Aolin Reflectance, Albedo, Anisotropy, Shortwave Radiation
Exploration of machine learning techniques in emulating a coupled soil canopy atmosphere radiative transfer model for multi-parameter estimation from satellite observations Shi, Hanyu, Xiao, Zhiqiang, Tian, Xiaodan Reflectance, Albedo, Anisotropy, Shortwave Radiation, Leaf Area Index (LAI), Fraction Of Absorbed Photosynthetically Active Radiation (fapar)
You're viewing 15 of 15