N: 90 S: -90 E: 180 W: -180
Description
The MCD19A2 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) gridded Level 2 product produced daily at 1 kilometer (km) pixel resolution. The MCD19A2 product provides the atmospheric properties and view geometry used to calculate the MAIAC Land Surface Bidirectional Reflectance Factor (BRF) or surface reflectance, MCD19A1 product.
The MCD19A2 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, fine mode fraction over water, column water vapor over land and clouds (in cm), smoke injection height (m above ground), AOD QA, AOD model at 1km, cosine of solar zenith angle, cosine of view zenith angle, relative azimuth angle, scattering angle, and glint angle at 5km. 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.
Each SDS layer within each MCD19A2 Hierarchical Data Format 4 (HDF4) file contains a third dimension that represents the number of orbit overpasses. This factor could affect the total number of bands for each SDS layer.
Known Issues
- Known issues are described in Section 6 of the User Guide.
- For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.
- Users should be aware that they may see a dip in AOD values for the first 5 months of 2022. A fix is planned to be implemented in Collection 7.
Version Description
Product Summary
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.
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File Naming Convention
The file name begins with the Product Short Name (MCD19A2) followed by the Julian Date of Acquisition (AYYYYDDD), the Tile Identifier which is horizontal tile and vertical tile (h22v02), the Version of the data collection (061), the Julian Date of Production (YYYYDDDHHMMSS), and the Data Format (hdf).
Documents
USER'S GUIDE
ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
PRODUCT QUALITY ASSESSMENT
SCIENCE DATA PRODUCT VALIDATION
Publications Citing This Dataset
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 Sort descending | Description | Units | Data Type | Fill Value | Valid Range | Scale Factor |
|---|---|---|---|---|---|---|
| AngstromExp_470- 780 | Angstrom Exponent 470-780nm over the ocean | N/A | int16 | -28672 | -5000 to 30000 | 0.0001 |
| AOD_QA | AOD QA | N/A | uint16 | 0 | 1 to 65535 | N/A |
| AOD_Uncertainty | AOD uncertainty based on blue-band surface brightness (reflectance) | N/A | int16 | -28672 | -100 to 30000 | 0.0001 |
| Column_WV | Column Water Vapor (cm) over land | cm | int16 | -28672 | 0 to 8000 | 0.001 |
| cosSZA | Cosine of Solar zenith angle (5 km) | N/A | int16 | -28672 | 0 to 10000 | 0.0001 |
| cosVZA | Cosine View zenith angle (5 km) | N/A | int16 | -28672 | 0 to 10000 | 0.0001 |
| FineModeFraction | Fine mode fraction for ocean | N/A | float32 | -99999 | 0 to 1000 | N/A |
| Glint_Angle | Glint Angle (5 km) | N/A | int16 | -28672 | -18000 to 18000 | 0.01 |
| Injection_Height | Smoke injection height (m above ground) | Meters | float32 | -99999 | 0 to 10000 | N/A |
| Optical_Depth_047 | Blue band (0.47 μm) aerosol optical depth over land | N/A | int16 | -28672 | -100 to 6000 | 0.001 |
| Optical_Depth_055 | Green band (0.55 μm) aerosol optical depth over land | N/A | int16 | -28672 | -100 to 6000 | 0.001 |
| RelAZ | Relative azimuth angle (5 km) | N/A | int16 | -28672 | -18000 to 18000 | 0.01 |
| Scattering_Angle | Scattering Angle (5 km) | N/A | int16 | -28672 | -18000 to 18000 | 0.01 |