Cloud Parameters from MODIS

MODIS Aqua Cloud Fraction 2002-Jul-04. Copyright: UHH/CEN/AJB

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Access

RESTRICTED: This link to the data set is only available for a restricted user group . The data set is only accessible in CEN/MPI net or accessible from external nets with a customer account. Please contact ICDC if you would like to access this data from outside the network.

View MODIS AQUA data at LAS: cloud fractions | radiative | top parameters | water paths
View MODIS TERRA data at LAS: cloud fractions | radiative | top parameters | water paths
Access MODIS data via OPeNDAP: AQUA | TERRA
AQUA Data access via file system: /data/icdc/atmosphere/modis_aqua_cloud
TERRA Data access via file system: /data/icdc/atmosphere/modis_terra_cloud

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Description

MODIS stands for MODerate resolution Imaging Spectroradiometer. This sensor, equipped with 36 spectral channels from the visible into the infrared frequency range operates from aboard the EOS-TERRA and EOS-AQUA satellites since 2000 and 2002, respectively. Thanks to its high spectral resolution and the large number of different channels a large number of different atmospheric parameters can be retrieved. Here we refer to the cloud properties parameter data sets.

The MODIS cloud parameter products are based on calibrated, geo-located reflectances and radiances measured at a variety of the MODIS channels. Different approaches are used to derive the parameters. Cloud top parameters for mid- and high level clouds, e.g., are derived using a CO2 slicing technique combined with numerical and radiative transfer model input as described in Menzel et al. 2015. The variety of the approaches used is too large to allow a proper representation of these here within a few lines. Therefore we refer to the MODIS-Atmosphere Group webpage and to the references , in particular to the ATBD for MOD06/MYD06 level-2 products and to the User Guide.

We offer at ICDC a large number of parameters for the MODIS cloud data set, which are listed in the following text files:

This is part of the level-3 MOD08/MYD08 data set derived from MOD06/MYD06 level-2 products of the MODIS Collection 6.1.

Additionally, we offer monthly mean cloud droplet number concentrations (CDNC) for years 2003 through 2015 computed from MODIS AQUA (see Bennartz and Rausch in References ).

Last update of data set at ICDC: July 11, 2024.

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Parameters

Parameters of MODIS data sets. The full description of the file content is given in the parameter lists under Description.
Type of data	Comment	Specific Wavelengths	Histograms
Solar angles	Azimuth & zenith
Sensor angles	Azimuth & zenith
Surface Property Fractions	Ocean, Coast, Desert, Land
Total Cloud Fraction	All, Day & Night		X
Cirrus Cloud Fraction	IR & SWIR
Cloud Fraction, cloudy & partly cloudy pixels	different phases
Cloud Fraction, single layer clouds	liquid & ice
Cloud Fraction, multilayer clouds	different phases
Cloud Fraction, cloudy & partly cloudy pixels	liquid & ice	1.6 µm, 3.7 µm, 1.6 & 2.1 µm
Cloud Top Temperature	All, Day & Night		X
Cloud Top Pressure	All, Day & Night		X
Cloud Top Geopotential Height	All, Day & Night		X
Cloud Water Path, cloudy & partly cloudy pixels	different phases
Cloud Water Path, single layer clouds	liquid & ice
Cloud Water Path, cloudy & partly cloudy pixels	liquid & ice	1.6 µm, 3.7 µm, 1.6 & 2.1 µm
Cirrus Cloud Reflectance
Cloud Effective Emissivity	All, Day & Night		X
Cloud Optical Thickness, cloudy & partly cloudy pixels	different phases		X
Cloud Optical Thickness, single layer clouds	liquid & ice
Cloud Optical Thickness, cloudy & partly cloudy pixels	liquid & ice	1.6 µm, 3.7 µm, 1.6 & 2.1 µm	X
Cloud Particle Effective Radius, cloudy & partly cloudy pixels	different phases		X
Cloud Particle Effective Radius, single layer clouds	liquid & ice
Cloud Particle Effective Radius, cloudy & partly cloudy pixels	liquid & ice	1.6 µm, 3.7 µm, 1.6 & 2.1 µm	X
Cloud Droplet Number Concentration	monthly

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Coverage, spatial and temporal resolution

Period and temporal resolution:

MODIS EOS-TERRA: 2000-02-24 to 2024-06-30, daily
MODIS EOS-AQUA: 2002-07-04 to 2024-06-30, daily
MODIS EOS-AQUA CDNC: 2003-01 to 2015-12, monthly

Coverage and spatial resolution:

Global
Spatial resolution: 1° x 1°, cartesian grid
Geographic longitude: 180°W to 180°E
Geographic latitude: 90°S to 90°N
Dimension: 360 columns x 180 rows
Altitude: following terrain

Format:

NetCDF

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Data quality

The offered gridded Level-3 cloud property data contain as a measure of uncertainty the standard deviation of all level-2 grid cells used for the computation of the level-3 product.

For some of the products the confidence flags of the level-2 products are used to come with with uncertainty estimates (as described in the level-3 data ATBD). In contrast to the MODIS Aerosol Properties product, no histograms about data quality are provided.

This data set is from Collection 6.1 of the MODIS collection 6 product family. Hence a substantial number of inconsistencies and potential retrieval problems, which have been identified in the past product versions (4, 5), has been taken care of in this newest MODIS product release. In addition several new variables are included, e.g. 1) cloud top height, 2) cirrus / high cloud fraction, 3) joint histograms of all cloud top parameters with the cloud top pressure, 4) retrievals of cloud water path, particle effective radius, optical thickness, and fractions also for partly cloudy pixels, and finally, 5) separate retrievals of these parameters for MODIS bands at 1.6 µm, at 3.7 µm, and 1.6 and 2.1 µm combined.

The effect of radiometric calibration drift of MODIS EOS-TERRA band 29 (8.6 µm) as well as other effects of the sensor, such as cross-talk between adjacent frequency bands, on the data products have been mitigated in this newest collection 6.1 product.

The data has some gaps in time. The following days are missing:

TERRA: August 7-18 2000; June 16 - July 2 2001; March 20-27 & April 15 2002; December 21-22 2008
AQUA: July 30 - August 6 2002

We refer to the documents listed in the references.

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Contact

Steve Platnick
MODIS - Atmosphere Level-3 Product Group
NASA / GSFC
email: steve.platnick (at) nasa.gov

Gala Wind
MODIS - Cloud Optical Properties
NASA / GSFC
email: gala.wind (at) nasa.gov

Richard Frey
MODIS - Cloud Top Properties
Space Science Engineering Center (SSEC) / WISC
email: richard.frey (at) ssec.wisc.edu

Stefan Kern
University of Hamburg
email: stefan.kern (at) uni-hamburg.de

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References

MODIS - Atmosphere Group Webpage, https://atmosphere-imager.gsfc.nasa.gov/
Platnick, S., et al., MODIS Cloud optical properties: User guide for the Collection 6/6.1 level-2 MOD06/MYD06 product and associated level-3 data sets. v1.1, July 2018 (pdf, not barrier-free)
MODIS ATBD for Level-3 Global Gridded Atmosphere Products (Collection 006, v4.3) (pdf, not barrier-free)
Hubanks, P, (2017): Collection 6.1 Change Document MODIS Atmosphere Level-3 Global Products, Adnet Systems, Lanham, MD, Version 1.0, August 23 2017, 20 pp, see also modis-atmos.gsfc.nasa.gov/documentation/collection-61 (pdf, not barrier-free)
Moeller, C., and R. Frey, Terra MODIS Collection 6.1 calibration and cloud product changes, v1.0, June 27, 2017. (pdf, not barrier-free)
Moeller, C., and R. Frey, Collection 6.1 Terra MODIS IR Bands (MOD021KM) calibration change supplement. v1.0, June 27 2017. (pdf, not barrier-free)
Platnick, S., et al., Collection 6.1 change summary for the MODIS cloud optical property (06_OD) algorithm, July 17 2017. (pdf, not barrier-free)
King, M. D., et al., (2003), Cloud and aerosol properties, precipitable, water, and profiles of temperature and water vapor, Trans. Geosci. Rem. Sens., 41(2), 442-458. (pdf, not barrier-free)
Baum, B. A., et al. (2012), MODIS cloud-top property refinement for Collection 6, J. Appl. Meteorol. Climatol., 51(6), 1145-1163. (pdf, not barrier-free)
King, M. D., et al. (2013), Spatial and temporal distribution of clouds observed by MODIS onboard the Terra and Aqua Satellites, IEEE Trans. Geosci. Rem. Sens., 51(7), 3826-3852. (pdf, not barrier-free)
Lyapustin, A., et al., (2014), Scientific impact of MODIS C5 calibration degradation and C6+ improvements, Atmos. Meas. Tech., 7, 4353-4365. (pdf, not barrier-free)
Cho, H.-M., et al. (2015), Frequency and causes of failed MODIS cloud property retrievals for liquid phase clouds over global oceans, J. Geophys. Res. - Atmos., 120, 4132-4154. (pdf, not barrier-free)
Wang, T., et al., (2016), Validation of MODIS cloud mask and multilayer flag using CloudSat-CALIPSO caloud profiles and a cross-reference of their cloud classifications, J. Geophys. Res. - Atmos., 121, 11620-11635. (pdf, not barrier-free)
Yi, B., et al. (2017), A comparison of Aqua MODIS ice and liquid water cloud physical and optical properties between collection 6 and collection 5.1: Pixel-to-pixel comparisons, J. Geophys. Res. - Atmos., 122, 4528-4549. (pdf, not barrier-free)
Bennartz, R., and J. Rausch (2017), Global and regional estimates of warm cloud droplet number concentration based on 13 years of AQUA-MODIS observations, Atmos. Chem. Phys., 17, 9815-9836. (pdf, not barrier-free)
Menzel et al, Cloud top properties and cloud phase algorithm theoretical basis document, ATBD, NASA, 2015

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Data citation

Please cite the data as follows:

Platnick, S., et al., 2017. MODIS Atmosphere L3 Daily Product. NASA MODIS Adaptive Processing System, Goddard Space Flight Center, USA: http://dx.doi.org/10.5067/MODIS/MOD08_D3.061 [last accessed: July 3, 2024]
(if MODIS EOS-AQUA data are used accordingly: dx.doi.org/10.5067/MODIS/MYD08_D3.061)

and the following acknowledgments:

Original MODIS collection 6.1 cloud parameter data provided in hdf format by https://ladsweb.modaps.eosdis.nasa.gov/ were downloaded in netCDF file format from the Integrated Climate Data Centre (ICDC). Thanks to ICDC, CEN, University of Hamburg for data support.

For the CDNC data set please refer the the paper by Bennartz and Rausch.

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