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Description

The MCD19A2CMG Version 6.1 data product is a Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua combined Multi-Angle Implementation of Atmospheric Correction (MAIAC) Land Aerosol Optical Depth (AOD) and Water Vapor Level 3 product produced daily in a 0.05 degree (5,600 meters at the equator) Climate Modeling Grid (CMG). The MCD19A2CMG product provides the atmospheric properties and view geometry used to calculate the MAIAC Surface Reflectance data products (MCD19A1CMGL and MCD19A1CMGO).

The MCD19A2CMG AOD data product contains the following Science Dataset (SDS) layers: blue band AOD at 0.47 µm, green band AOD at 0.55 µm, AOD uncertainty, column water vapor for Terra, column water vapor for Aqua, average cloud fraction, available AOD, satellite overpass times, line and sample number, offset, and number of AOD records. A low-resolution browse image is also included showing AOD of the blue band at 0.47 µm created using a composite of all available orbits.

Known Issues

Version Description

The AOD and Water Vapor data products in a Climate Modeling Grid (CMG) were introduced in MODIS Version 6.1.

Product Summary

Platforms
Terra ,
Aqua
Instruments
MODIS
Spatial Extent

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

Spatial Resolution
5600 Meters x 5600 Meters
Spatial Reference System(s)
MODIS Climate Modeling Grid (CMG)
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2000-02-24 to Present
Temporal Resolution
1 Day
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
C2565807733-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
9457
Processing Level
3
Published
Updated
Science Keywords
Reflectance

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

Lyapustin, A. (2023). MODIS/Terra+Aqua AOD and Water Vapor from MAIAC, Daily L3 Global 0.05Deg CMG V061 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MCD19A2CMG.061 Date Accessed: 2026-03-04

File Naming Convention

MCD19A2CMG.A2025218.061.2025219193209.hdf

The file name begins with the Product Short Name (MCD19A2CMG) followed by the Julian Date of Acquisition formatted as AYYYYDDD (A2025218), the Version of the data collection (061), the Julian Date and Time of Production designated as YYYYDDDHHMMSS (2025219193209), and the Data Format (hdf).

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
AOD_047 Daily averaged AOD for 470nm band N/A int16 -28672 0 to 6000 0.001
AOD_055 Daily averaged AOD for 550nm band N/A int16 -28672 0 to 6000 0.001
CloudFraction Daily average cloud fraction N/A int16 -28672 0 to 10000 0.0001
ColumnWaterVapor _Aqua Daily average of column water vapor for Aqua in cm cm int16 -28672 0 to 30000 0.001
ColumnWaterVapor _Terra Daily average of column water vapor for Terra in cm cm int16 -28672 0 to 30000 0.001
Compact_AOD_055 AOD record compacted into 1-D array, for 550nm band N/A int16 N/A 0 to 6000 0.001
Line X coordinate of compacted AOD record N/A int16 N/A 0 to 3599 N/A
nAOD Number of AOD in compacted AOD record N/A int16 N/A 0 to 100 N/A
Offset_AOD_055 Offset in compacted AOD record N/A int32 N/A N/A N/A
OverpassTime Satellite overpass time incorresponding AOD record,minutes since 00:00 of the given day N/A int16 N/A 0 to 1440 N/A
Sample Y coordinate of compacted AOD record N/A int16 N/A 0 to 7199 N/A
Sigma_AOD_055 Standard deviation/Uncertainty of daily AOD for 550nm band N/A int16 -28672 0 to 30000 0.0001
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