MCD19A2CMG v061

MODIS/Terra+Aqua AOD and Water Vapor from MAIAC, Daily L3 Global 0.05 Deg CMG


PI: Alexei Lyapustin

The MAIAC data products have been released with the caveat that the reprocessing for the full mission is expected to continue through spring 2023.

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.

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Characteristics

Improvements/Changes from Previous Versions

No previous versions.

Product Maturity

Validation at stage1 has been achieved for the MODIS AOD product. Further details regarding MODIS land product validation for MCD19 data products are available from the MODIS Land Team Validation site.

Collection and Granule

Collection

Characteristic Description
CollectionCombined MODIS
DOI10.5067/MODIS/MCD19A2CMG.061
File Size~50 MB
Temporal ResolutionDaily
Temporal Extent2000-02-24 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers12
Columns/Rows7200 x 3600
Pixel Size5600 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
AOD_055 Daily averaged AOD for 550nm band N/A 16-bit signed integer -28672 N/A 0 to 6000 0.001
AOD_047 Daily averaged AOD for 470nm band N/A 16-bit signed integer -28672 N/A 0 to 6000 0.001
Sigma_AOD_055 Standard deviation/Uncertainty of daily AOD for 550nm band N/A 16-bit signed integer -28672 N/A 0 to 30000 0.0001
ColumnWaterVapor _Terra Daily average of column water vapor for Terra in cm cm 16-bit signed integer -28672 N/A 0 to 30000 0.001
ColumnWaterVapor _Aqua Daily average of column water vapor for Aqua in cm cm 16-bit signed integer -28672 N/A 0 to 30000 0.001
CloudFraction Daily average cloud fraction N/A 16-bit signed integer -28672 N/A 0 to 10000 0.0001
Compact_AOD_055 AOD record compacted into 1-D array, for 550nm band N/A 16-bit signed integer N/A N/A 0 to 6000 0.001
OverpassTime Satellite overpass time incorresponding AOD record,minutes since 00:00 of the given day N/A 16-bit signed integer N/A N/A 0 to 1440 N/A
Line X coordinate of compacted AOD record N/A 16-bit signed integer N/A N/A 0 to 3599 N/A
Sample Y coordinate of compacted AOD record N/A 16-bit signed integer N/A N/A 0 to 7199 N/A
Offset_AOD_055 Offset in compacted AOD record N/A 32-bit signed integer N/A N/A N/A N/A
nAOD Number of AOD in compacted AOD record N/A 16-bit signed integer N/A N/A 0 to 100 N/A

The CMG AOD file stores the daily average AOD (at 0.47 and 0.55µm) as well as AOD from all overpass orbits for a given day. Since the individual orbit data are sparse due to clouds (snow), the orbital data are stored in a compact way, similar to the MOD09 product. The compact format is described in more detail in Section 10 in the User Guide.

Product Quality

Product quality information is described in Section 5.8 in the User Guide.

Known Issues

Known issues are described in Section 6 of the User Guide.


About the image

Combined MODIS Aerosol Optical Depth 047 data from the MCD19A2CMG product across the globe, September 26, 2009.

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Documentation

User Guide
Algorithm Theoretical Basis Document (ATBD)

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MCD19A2CMG.061