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Entry information for CLARA_AVHRR_V002

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Title

CLARA-A2: CM SAF cLoud, Albedo and surface RAdiation dataset from AVHRR data - Edition 2

Citation

Karlsson, Karl-Göran; Anttila, Kati; Trentmann, Jörg; Stengel, Martin; Meirink, Jan Fokke; Devasthale, Abhay; Hanschmann, Timo; Kothe, Steffen; Jääskeläinen, Emmihenna; Sedlar, Joseph; Benas, Nikos; van Zadelhoff, Gerd-Jan; Schlundt, Cornelia; Stein, Diana; Finkensieper, Stephan; Håkansson, Nina; Hollmann, Rainer; Fuchs, Petra; Werscheck, Martin (2017): CLARA-A2: CM SAF cLoud, Albedo and surface RAdiation dataset from AVHRR data - Edition 2, Satellite Application Facility on Climate Monitoring, DOI:10.5676/EUM_SAF_CM/CLARA_AVHRR/V002, https://doi.org/10.5676/EUM_SAF_CM/CLARA_AVHRR/V002. [BibTeX entry]

Publisher

Satellite Application Facility on Climate Monitoring (CM SAF)

Publication year

2017

Author(s)

Karlsson, Karl-Göran; Anttila, Kati; Trentmann, Jörg; Stengel, Martin; Meirink, Jan Fokke; Devasthale, Abhay; Hanschmann, Timo; Kothe, Steffen; Jääskeläinen, Emmihenna; Sedlar, Joseph; Benas, Nikos; van Zadelhoff, Gerd-Jan; Schlundt, Cornelia; Stein, Diana; Finkensieper, Stephan; Håkansson, Nina; Hollmann, Rainer; Fuchs, Petra; Werscheck, Martin

Description

The CLARA-A2 record provides cloud properties, surface albedo and surface radiation parameters derived from the AVHRR sensor onboard polar orbiting NOAA and METOP satellites. This second edition is the improved and extended follow-up of the first version of the record (Karlsson et al., 2013; CLARA-A1 DOI: 10.5676/EUM_SAF_CM/CLARA_AVHRR/V001) which now covers a 34 year time period (1982-2015). Original visible radiances were inter-calibrated and homogenised, using MODIS data as a reference, before applying the various parameter retrievals. The inter-calibration was based on an original method introduced by Heidinger et al. (2010) which now has been updated (MODIS Collection 6) and extended (six years have been added). CLARA-A2 features a range of cloud products: cloud mask, cloud top temperature/pressure/height, cloud thermodynamic phase, and (for liquid and ice clouds separately) cloud optical thickness, particle effective radius and cloud water path. Cloud products are available as monthly and daily averages and also as daily resampled global products (Level 2b) for individual satellites. Cloud parameter results are also presented as multi-parameter distributions (i.e., joint frequency histograms of cloud optical thickness, cloud top pressure and cloud phase) for daytime conditions. Surface albedo is presented as monthly and pentad (5 day) averages and is derived using all available data during the studied period. Surface radiation products are provided as monthly averages for the downwelling shortwave (including also daily averages) and the down- and upwelling longwave components. The monthly and daily averages are available on a 0.25°x0.25° global grid. Surface albedo and cloud products are also provided in two equal area grids with a resolution of 25 km x 25 km covering the polar regions. Daily resampled cloud products (level 2b) are provided in a global grid with a resolution of 0.05°x0.05°. For the latter, also a probabilistic cloud mask is added as an experimental product. The advancements compared to CLARA-A1 can be summarized as follows: (1) Extended AVHRR measurement record (six years). (2) Upgraded inter-calibration (using MODIS Collection 6 as reference). (3) Significantly improved cloud screening (utilizing CALIPSO-CALIOP data during development). (4) Improved efficiency of cloud top height retrievals (i.e., reduced number of pixels with no retrieval solutions). (5) Improved cloud phase discrimination and ice cloud property retrieval. (6) Improved atmospheric correction using dynamic aerosol optical depths for the full surface albedo data record. (7) Extended product portfolio (i.e., adding daily resampled Level 2b cloud products including experimental cloud probabilities). A summary of the CLARA-A2 characteristics and a comprehensive evaluation of the results are provided by Karlsson et al., (2016). Along with the data, a comprehensive documentation including user guide, algorithm descriptions, reprocessing layout and extensive validation studies, is provided.

Format

NetCDF-4

Version

2.0

Temporal coverage

1982-01-01 - 2015-12-31

Geographic coverage

Latitude: -90.0° S to 90.0° N
Longitude: -180.0° W to 180.0° E

Size

12.4 TiB

Documentation

Related publications

Auxiliary data

Related Data Records

Data record details and ordering

This data record is superseded by a new version (see related data records). If you need access to products from this data record, please contact our User Help Desk (contact.cmsaf@dwd.de).

Products from Polar Orbiting Satellites (LEO)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Monthly mean (Southern Polar Region),
  • Monthly mean (Northern Polar Region),
  • Daily mean (Global),
  • Daily mean (Southern Polar Region),
  • Daily mean (Northern Polar Region)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Monthly mean (Southern Polar Region),
  • Monthly mean (Northern Polar Region),
  • Daily mean (Global),
  • Daily mean (Southern Polar Region),
  • Daily mean (Northern Polar Region)

Cloud water path (CWP)

  • Monthly histogram (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Monthly mean (Northern Polar Region),
  • Monthly mean (Southern Polar Region),
  • Daily mean (Global),
  • Daily mean (Southern Polar Region),
  • Daily mean (Northern Polar Region)

Ice water path (IWP)

  • Monthly mean (Global),
  • Monthly mean (Southern Polar Region),
  • Monthly mean (Northern Polar Region),
  • Daily mean (Southern Polar Region),
  • Daily mean (Northern Polar Region),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Northern Polar Region),
  • Monthly mean (Southern Polar Region),
  • Monthly mean (Global),
  • Daily mean (Global),
  • Daily mean (Northern Polar Region),
  • Daily mean (Southern Polar Region)

Surface albedo (SAL)

  • Pentad mean (Southern Polar Region),
  • Pentad mean (Northern Polar Region),
  • Pentad mean (Global),
  • Monthly mean (Global),
  • Monthly mean (Southern Polar Region),
  • Monthly mean (Northern Polar Region)

Surface downward longwave radiation (SDL)

  • Monthly mean (Global)

Surface incoming shortwave radiation (SIS)

  • Monthly mean (Global),
  • Daily mean (Global)

Surface outgoing longwave radiation (SOL)

  • Monthly mean (Global)

Products from METOP A

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly histogram (Global),
  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from METOP B

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly histogram (Global),
  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 7 (NOAA-7)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 9 (NOAA-9)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 11 (NOAA-11)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 12 (NOAA-12)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 14 (NOAA-14)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 15 (NOAA-15)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly histogram (Global),
  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 16 (NOAA-16)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly histogram (Global),
  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 17 (NOAA-17)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly histogram (Global),
  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 18 (NOAA-18)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Products from NOAA POES 19 (NOAA-19)

Cloud mask (CMA)

  • Instantaneous (Global)

Cloud phase (CPH)

  • Monthly mean (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud top parameters CTT, CTP and CTH (CTO)

  • Monthly mean (Global),
  • Monthly histogram (Global),
  • Instantaneous (Global),
  • Daily mean (Global)

Cloud water path (CWP)

  • Monthly histogram (Global),
  • Instantaneous (Global)

Fractional cloud cover (CFC)

  • Monthly mean (Global),
  • Daily mean (Global)

Ice water path (IWP)

  • Monthly mean (Global),
  • Daily mean (Global)

Joint cloud property histograms (JCH)

  • Monthly histogram (Global)

Liquid water path (LWP)

  • Monthly mean (Global),
  • Daily mean (Global)