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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

Improvements/Changes from Previous Versions

  • The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.
  • A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).
  • The MCD19 Version 6.1 products have added 250 m resolution bands.
  • The previous BRDF product (MCD19A3) was reported once every eight days and the new MCD19A3D is a daily product.
  • MCD19A3D introduces gap-filled NDVI and gap-filled 250 m NBAR.
  • Snow Fraction, Snow Fit, and Snow Grain size layers were moved from MCD19A1 to the MCD19A3D.
  • There are four additional Climate Modeling Grid (CMG) products: MCD19A1CMGL, MCD19A1GO, MCD19A2CMG, and MCD19A3CMG.

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
1000 Meters x 1000 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
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
C2324689816-LPCLOUD
Data State
ACTIVE
Processing Level
2G
Published
Updated
Science Keywords
Aerosol Optical Depth/Thickness

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., & Wang, Y. (2022). MODIS/Terra+Aqua Land Aerosol Optical Depth Daily L2G Global 1km SIN Grid V061 [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/MODIS/MCD19A2.061 Date Accessed: 2025-10-21

File Naming Convention

MCD19A2.A2023081.h22v02.061.2023082164002.hdf

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

GENERAL DOCUMENTATION

Publications Citing This Dataset

Filters
Title Year Author
Gap-filling MODIS daily aerosol optical depth products by developing a spatiotemporal fitting algorithm Zhang, T.
Spatiotemporal pattern and long-term trend of global surface urban heat islands characterized by dynamic urban-extent method and MODIS data Si, M.
Long-term changes in aerosol loading over the ‘BIHAR’ State of India using nineteen years (2001–2019) of high-resolution satellite data (1 × 1 km2) Nair, M.
The environmental story during the COVID-19 lockdown—How human activities affect PM2.5 concentration in China? Tan, Z. Y.
Evaluation of trophic state for inland waters through combining Forel-Ule Index and inherent optical properties Liu, Y.
Aerosol retrieval algorithm for Sentinel-2 images over complex urban areas Yang, Y.
High spatiotemporal resolution PM2.5 concentration estimation with machine learning algorithm—A case study for wildfire in California Cui, Q.
Characteristics of the severe March 2021 Gobi Desert dust storm and its impact on air pollution in China Filonchyk, M.
Temporal and spatial distribution mapping of particulate matter in southwest of Iran using remote sensing, GIS, and statistical techniques Soleimany, A.
Vegetation activity enhanced in India during the COVID-19 lockdowns—Evidence from satellite data Ranjan, A. K.
SHOWING 10 OF 85

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 Science Data Set (SDS) 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
AngstromExp_470- 780 Angstrom Exponent 470-780nm over the ocean N/A int16 -28672 -28672 to 30000 0.0001
AOD_QA AOD QA N/A uint16 0 0 to 65535 N/A
AOD_Uncertainty AOD uncertainty based on blue-band surface brightness (reflectance) N/A int16 -28672 -28672 to 30000 0.0001
Column_WV Column Water Vapor (cm) over land cm int16 -28672 -28672 to 8000 0.001
cosSZA Cosine of Solar zenith angle (5 km) N/A int16 -28672 -28672 to 10000 0.0001
cosVZA Cosine View zenith angle (5 km) N/A int16 -28672 -28672 to 10000 0.0001
FineModeFraction Fine mode fraction for ocean N/A float32 -99999 -99999 to 1000 N/A
Glint_Angle Glint Angle (5 km) N/A int16 -28672 -28672 to 18000 0.01
Injection_Height Smoke injection height (m above ground) Meters float32 -99999 -99999 to 10000 N/A
Optical_Depth_047 Blue band (0.47 μm) aerosol optical depth over land N/A int16 -28672 -28672 to 6000 0.001
Optical_Depth_055 Green band (0.55 μm) aerosol optical depth over land N/A int16 -28672 -28672 to 6000 0.001
RelAZ Relative azimuth angle (5 km) N/A int16 -28672 -28672 to 18000 0.01
Scattering_Angle Scattering Angle (5 km) N/A int16 -28672 -28672 to 18000 0.01
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