The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) NASA standard Level-2 (L2) dark target (DT) aerosol product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The VIIRS incarnation of the DT aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua mission’s MODIS instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible).
This orbit-level product (Short-name: AERDT_L2_VIIRS_SNPP) has an at-nadir resolution of 6 km x 6 km, and progressively increases away from nadir given the sensor’s scanning geometry and Earth’s curvature. Viewed differently, this product’s resolution accommodates 8 x 8 native VIIRS moderate-resolution (M-band) pixels that nominally have ~750 m horizontal pixel size. Hence, the L2 DT AOT data product incorporates 64 (750 m) pixels over a 6-minute acquisition. In contrast to collection-001 of this product, this collection-011 uses bowtie-restored pixels that are used for both cloud masking and for performing some retrievals using the restored pixels as well.
The L2 netCDF product contains the following 37 Science Data Set (SDS) layers:
Consult the NASA MODIS and VIIRS Dark Target Aerosol Product User Guide for additional information regarding these SDS parameters.
|File Size (MB):
||7 - 12 MB
||Global (daytime only)
||NPP VIIRS Atmosphere data 1.1.0 (UWisc) (ArchiveSet 5111)
||R.C. Levy, S. Mattoo, V. Sawyer, L.A. Munchak
||Dark Target aerosol team, Climate and Radiation Laboratory, NASA Goddard Space Flight Center
|File Naming Convention:
- Syntax: ESDT.AYYYYDDD.HHMM.CCC.YYYYDDDHHMMSS.Format
- ESDT = Earth Science Data Type or Shortname
- A = Stands for Acquisition
- YYYYDDD = Data acquisition year and Day-of-year
- HHMM = Acquisition Hour and Minute
- CCC = Version ID of the data collection
- YYYYDDDHHMMSS = Processing year, Day-of-year, UTC time (hour, minutes, seconds)
- Format = File format suffix, which in the above case represents netCDF4
||We kindly request that you cite the use of this data set in a publication using the following references:
Sawyer, V., R.C. Levy, S. Mattoo, G. Cureton, Y. Shi, and L.A. Remer (2020), Continuing the MODIS Dark Target Aerosol Time Series with VIIRS. Remote Sens. 2020, 12, 308; https://doi.org/10.3390/rs12020308
Levy, R.C., L. A. Munchak, S. Mattoo, F. Patadia, L. A. Remer, and R. E. Holz (2015), Towards a long-term global aerosol optical depth record: applying a consistent aerosol retrieval algorithm to MODIS and VIIRS-observed reflectance, Atmos. Meas. Tech., 8, 4083–4110.
||SNPP VIIRS, L2 Swath, 6-Minute, Dark Target Aerosol Optical Thickness