MISR¶

Terra Multi-angle Imaging SpectroRadiometer (MISR) Level 2 Aerosol (V23, 4.4 km) and Level 3 Component Global Aerosol

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At a glance¶

Note on period: FINAL L2 (MIL2ASAE V003) runs from 2000-03-01 to 2022-10-12, daily L3 (MIL3DAEN) to 2022-10-12, and monthly L3 (MIL3MAEN) from February 2000 to September 2022. FIRSTLOOK L2 (MIL2ASAF) runs from 2017-11-01 to the present; orbits from 2022-10-13 onward are produced with the new processing system (product version 30), and as checked on 2026-10-13 they extend to the 2026-10-11 orbits.

Overview¶

MISR on NASA's Terra satellite images each location with nine cameras at angles from nadir to 70.5° fore and aft in four bands (446, 558, 672 and 867 nm), and uses those multi-angle views to retrieve aerosol optical depth and particle size, absorption and non-sphericity over land and ocean. Its record since 2000 is widely used alongside MODIS for long-term aerosol change, wildfire smoke and dust, and climate model evaluation. Global coverage takes nine days, and since October 2022 the standard (FINAL) products have stopped, leaving only provisional (FIRSTLOOK) data for recent years.

What changes with the successor¶

MISR L2 Aerosol V22 (17.6 km) → MISR L2 Aerosol V23 (4.4 km)¶

Transition: 2018-02

V23 raised the aerosol retrieval resolution from 17.6 km to 4.4 km and moved from HDF4 to NetCDF-4; the whole mission was reprocessed as V23 (MIL2ASAE V003).

Sources: Data Quality Statement for the MISR Level 2 Aerosol Product (V023, 2018-02-07) · Garay et al. (2020), AMT — introducing the 4.4 km MISR aerosol product

Available variables¶

L2 field names follow the V23 L2 aerosol Data Product Specification; the main fields sit in the NetCDF group 4.4_KM_PRODUCTS (raw values in 4.4_KM_PRODUCTS/AUXILIARY, angles in GEOMETRY). Optical depth fields refer to 550 nm and the fill value is -9999.0. L3 variable names follow the CGAS Data Product Specification (F15_0032) and sit in the NetCDF group Aerosol_Parameter_Average.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

L2 aerosol (MIL2ASAE, MIL2ASAF, 4.4 km)¶

L3 Component Global Aerosol (MIL3DAEN daily / MIL3MAEN monthly, 0.5°)¶

The full variable list is in the official documentation.

How to get the data¶

• NASA Earthdata Search — MIL2ASAE V003 (FINAL L2, 2000-03 to 2022-10) — Earthdata Search / earthaccess / HTTPS, OPeNDAP (NetCDF-4)
• NASA Earthdata Search — MIL2ASAF V002 (FIRSTLOOK L2, 2017-11 to present) — Earthdata Search / earthaccess / HTTPS, direct S3 access
  • This provisional product is the only source for data after October 2022.
• NASA Earthdata Search — MIL3MAEN V004 (L3 monthly, 0.5°) — Earthdata Search / earthaccess
• ASDC MISR project page (product list, tools, notices) — Web
  • The MISR Toolkit, L2 Browse and Path/Block tools are set up only for orbits before 2022-10-14; updates for later orbits are still pending.

Example code¶

Run earthaccess.login() once with a NASA Earthdata account first. For data after October 2022, change short_name to MIL2ASAF and version to 002 (provisional).

# pip install earthaccess xarray netCDF4 numpy
import earthaccess
import xarray as xr

earthaccess.login()
results = earthaccess.search_data(
    short_name="MIL2ASAE", version="003",          # FINAL L2 aerosol V23, 4.4 km
    temporal=("2020-08-01", "2020-08-02"),
    bounding_box=(124, 33, 131, 39),               # around the Korean Peninsula (W, S, E, N)
)
files = earthaccess.download(results[:1], "./misr")

ds = xr.open_dataset(files[0], group="4.4_KM_PRODUCTS")
aod = ds["Aerosol_Optical_Depth"].where(ds["Aerosol_Optical_Depth"] > -9999)
print(float(aod.mean()), ds["Latitude"].shape)

Practical tips¶

• After October 2022 only FIRSTLOOK (provisional) data exist. FIRSTLOOK uses ancillary data from an earlier period, and later orbits come from the new processing system (product version 30). State this when splicing a time series across 2022.
• The quality statement says only Aerosol_Optical_Depth is Stage 3 validated, while particle properties (Ångström exponent, absorbing, non-spherical and size-resolved AOD) are Stage 2. Particle properties are more reliable when mid-visible AOD exceeds about 0.15.
• Known issues: high AOD from unscreened clouds, thin cirrus (optical depth below 0.3) appearing as non-spherical particles, thick plumes screened as cloud, anomalously high values over snow and ice, and no retrievals above AOD 3.0.
• Retrievals over Greenland and Antarctica are screened out of the user fields; the guidance is to look at the raw (_Raw) fields in the AUXILIARY group if needed.
• Terra has drifted since late 2020, with an earlier equator crossing time and lower altitude. Orbits after October 2022 no longer line up with the fixed 233 WRS-2 paths, so finding the same location by path number may not work.
• Because global coverage takes nine days, a location is not seen every day. When comparing monthly means with daily-global sensors such as MODIS, account for the difference in sampling.

Notices and change history¶

References for your paper¶

Dataset citation¶

L2 aerosol FINAL (MIL2ASAE V003) — DOI 10.5067/TERRA/MISR/MIL2ASAE_L2.003

@misc{misr_mil2asae_v003,
  author    = {Diner, David},
  title     = {{MISR} Level 2 Aerosol parameters {V003}},
  publisher = {NASA Langley Atmospheric Science Data Center Distributed Active Archive Center},
  doi       = {10.5067/TERRA/MISR/MIL2ASAE_L2.003},
  note      = {Accessed DD MMM YYYY}
}

L2 aerosol FIRSTLOOK (MIL2ASAF V002) — DOI 10.5067/Terra/MISR/MIL2ASAF_L2.002

@misc{misr_mil2asaf_v002,
  author    = {Diner, David},
  title     = {{MISR} Level 2 {FIRSTLOOK} Aerosol parameters {V002}},
  publisher = {NASA Langley Atmospheric Science Data Center Distributed Active Archive Center},
  doi       = {10.5067/Terra/MISR/MIL2ASAF_L2.002},
  note      = {Accessed DD MMM YYYY}
}

L3 monthly aerosol (MIL3MAEN V004) — DOI 10.5067/Terra/MISR/MIL3MAEN_L3.004

@misc{misr_mil3maen_v004,
  author    = {Diner, David},
  title     = {{MISR} Level 3 Component Global Aerosol product in netCDF format covering a month {V004}},
  publisher = {NASA Langley Atmospheric Science Data Center Distributed Active Archive Center},
  doi       = {10.5067/Terra/MISR/MIL3MAEN_L3.004},
  note      = {Accessed DD MMM YYYY}
}

Reference papers¶

V23 4.4 km aerosol product — DOI 10.5194/amt-13-593-2020

@article{garay2020misr,
  author  = {Garay, Michael J. and Witek, Marcin L. and Kahn, Ralph A. and Seidel, Felix C. and Limbacher, James A. and Bull, Michael A. and Diner, David J. and Hansen, Earl G. and Kalashnikova, Olga V. and Lee, Huikyo and Nastan, Abigail M. and Yu, Yan},
  title   = {Introducing the 4.4 km spatial resolution Multi-Angle Imaging SpectroRadiometer ({MISR}) aerosol product},
  journal = {Atmospheric Measurement Techniques},
  volume  = {13},
  number  = {2},
  pages   = {593--628},
  year    = {2020},
  doi     = {10.5194/amt-13-593-2020}
}

Dark-water AOD and uncertainty retrieval (V23) — DOI 10.5194/amt-11-429-2018

@article{witek2018misr,
  author  = {Witek, Marcin L. and Garay, Michael J. and Diner, David J. and Bull, Michael A. and Seidel, Felix C.},
  title   = {New approach to the retrieval of {AOD} and its uncertainty from {MISR} observations over dark water},
  journal = {Atmospheric Measurement Techniques},
  volume  = {11},
  number  = {1},
  pages   = {429--439},
  year    = {2018},
  doi     = {10.5194/amt-11-429-2018}
}

Acknowledgements¶

ASDC asks users to generate citations with the citation generator on each DOI landing page and to include "These data were obtained from the NASA Langley Research Center Atmospheric Science Data Center." The CMR citation metadata ask that the data be credited as produced by the MISR Science Team and processed and stored at the Langley DAAC.

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• ASDC MISR project page
• MISR L2 aerosol V23 Data Quality Statement
• MISR L2 aerosol V23 Data Product Specification
• MISR L3 Component Global Aerosol DPS
• MISR project (NASA JPL)
• NASA Science — Terra: The End of An Era