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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

Collection Version 6.1 Processing and Reprocessing

Product Summary

Platforms
Terra,
Aqua
Instruments
MODIS
Spatial Extent
N: 90 S: -90 E: 180 W: -180
Spatial Resolution
5600 Meters x 5600 Meters
Geographic Region
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
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: 2025-11-07

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

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. 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 -28672 to 6000 0.001
AOD_055 Daily averaged AOD for 550nm band N/A int16 -28672 -28672 to 6000 0.001
CloudFraction Daily average cloud fraction N/A int16 -28672 -28672 to 10000 0.0001
ColumnWaterVapor _Aqua Daily average of column water vapor for Aqua in cm cm int16 -28672 -28672 to 30000 0.001
ColumnWaterVapor _Terra Daily average of column water vapor for Terra in cm cm int16 -28672 -28672 to 30000 0.001
Compact_AOD_055 AOD record compacted into 1-D array, for 550nm band N/A int16 N/A N/A to 6000 0.001
Line X coordinate of compacted AOD record N/A int16 N/A N/A to 3599 N/A
nAOD Number of AOD in compacted AOD record N/A int16 N/A N/A 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 N/A to 1440 N/A
Sample Y coordinate of compacted AOD record N/A int16 N/A N/A to 7199 N/A
Sigma_AOD_055 Standard deviation/Uncertainty of daily AOD for 550nm band N/A int16 -28672 -28672 to 30000 0.0001
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