###TITEL_ICDC###

MODIS Cloud Parameters

Access

UNRESTRICTED

This data set is only available for a restricted user group, please contact us if you want to access these data.

RESTRICTED only accessable in CEN/MPI net or via CliSAP login  What does that mean?

View data via LAS:

AQUA: cloud fractions | radiative | top parameters | water paths

TERRA: cloud fractions | radiative | top parameters | water paths

Access data via OPeNDAP: AQUA | TERRA

Data access via file system:
/data/icdc/atmosphere/modis_aqua_cloud
/data/icdc/atmosphere/modis_terra_cloud

 

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 section - here in particular to the ATBD for MOD06/MYD06 level-2 products and to the User Guide.

We list the cloud parameters which we offer via ICDC in the following parameter lists for:

This is part of the level-3 MOD08/MYD08 data set derived from MOD06/MYD06 level-2 products of the MODIS Collection 6.1, download August 2018.

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: March 15, 2019

To top

Parameters

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
The full description of the file content is given in the parameter lists under Description| | |
|||
Cloud Droplet Number Concentration | monthly ||

To top

Coverage, spatial and temporal resolution

Period and temporal resolution: 

  • 2000-02-24 to 2019-02-28 (MODIS EOS-TERRA)
  • 2002-07-04 to 2019-02-28 (MODIS EOS-AQUA)
  • Daily
  • 2003-01 to 2015-12 (MODIS EOS-AQUA CDNC)
  • 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

Missing days:

  • 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

To top

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.

We refer to the documents listed in the References.

To top

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
ICDC / CEN / University of Hamburg
email: stefan.kern (at) uni-hamburg.de

To top

References

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 access date: 5/3/2019

(if MODIS EOS-AQUA data are used accordingly: dx.doi.org/10.5067/MODIS/MYD08_D3.061)

and acknowledge the source of your data download as:

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), CliSAP/KlimaCampus, University of Hamburg, Hamburg, Germany, http://icdc.cen.uni-hamburg.de

For the CDNC data set please refer the the paper by Bennartz and Rausch (see above).

To top

###BACKLINK###     ###TOPLINK###    
Print