Cloud Parameters CLARA-A3 from EUMETSAT CM-SAF AVHRR
Topics
- Access
- Description
- Parameters
- Coverage, spatial and temporal resolution
- Data quality
- Contact person
- References
- Data citation
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.
- Data access via file system: /data/icdc/atmosphere/eumetsat_clara3_cloud
Description
CLARA-A3 stands for "CM SAF cLouds, Albedo RAdiation data record, AVHRR-based, Edition 3" and comprises a suite of radiation and cloud parameters derived within the EUMETSAT Climate Monitoring Satellite Application Facility (CM-SAF) from Advanced Very High Resolution Radiometer (AVHRR) data.
Here we offer (for internal use only) the cloud products. Note that we do not offer the Joint Cloud Property Histograms. Products are also available for surface albedo and radiation.
For detailed information about the data product we refer to the respective CM-SAF web page.
Last update of data set at ICDC: February 22, 2024
Parameters
| Name | Unit |
|---|---|
|
Total cloud fraction (all day) |
% |
|
Standard deviation of total cloud fraction (all day) |
% |
|
Total daytime cloud fraction |
% |
|
Total nighttime cloud fraction |
% |
|
Cloud fraction (low-level clouds) |
% |
|
Cloud fraction (middle-level clouds) |
% |
|
Cloud fraction (high-level clouds) |
% |
|
Mean cloud probability (all, day, night) |
% |
|
Cloud fraction mean uncertainty |
% |
|
Cloud top temperature (all clouds, only ice, only liquid, only day, only night) |
K |
|
Standard deviation of cloud top temperature (all clouds) |
K |
|
Cloud top height (all clouds, only ice, only liquid, only day, only night) |
m |
|
Standard deviation of cloud top height (all clouds) |
m |
|
Cloud top pressure (all clouds, only ice, only liquid, only day, only night) |
hPa |
|
Standard deviation of cloud top pressure (all clouds) |
hPa |
|
Fraction of liquid water clouds (all day) |
% |
|
Fraction of liquid water clouds standard deviation (all day) |
% |
|
Daytime fraction of liquid water clouds |
% |
|
Daytime fraction of liquid water clouds standard deviation |
% |
|
Nighttime fraction of liquid water clouds |
% |
|
Nighttime fraction of liquid water clouds standard deviation |
% |
|
Cloud liquid water path (CLWP) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
kg/m² |
|
Water cloud mean geometrical thickness (including standard deviation, mean retrieval error and retrieval error standard deviation) |
m |
|
Water cloud mean optical thickness (tau) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
- |
|
Mean cloud droplet effective radius (Reff) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
m |
|
Cloud droplet number concentration of liquid clouds (cdnc) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
1/m³ |
|
Cloud ice water path (CIWP) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
kg /m² |
|
Ice cloud mean optical thickness (tau_ice) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
- |
|
Mean ice particle effective radius (Reff_ice) (including standard deviation, mean retrieval error and retrieval error standard deviation) |
m |
Coverage, spatial and temporal resolution
Period and temporal resolution:
- 1979-01 to 2023-11
- Monthly
Coverage and spatial resolution:
- Global // pol-centric (only cloud top parameters and cloud fractions)
- Spatial resolution: 0.25 degrees x 0.25 degrees, equally spaced lat/lon grid (Climate Modeling Grid, CMG) // 25 km x 25 km EASE grid
- Geographic longitude:-179.875°E to 179.875°E
- Geographic latitude: -89.875°N to 89.875°N // 30.6°N to 90°N; -90°N to -30.6°N
- Dimension: 1440 columns x 720 rows // 360 columns x 360 rows
- Altitude: following terrain
Format:
- NetCDF
Data quality
Information about the data quality can be found on the respective CM-SAF web page and in the references.
Contact
Climate Monitoring Satellite Application Facility (CM-SAF)
Helpdesk at www.cmsaf.eu
email: contact.cmsaf (at) dwd.deStefan Kern
E-Mail: stefan.kern (at) uni-hamburg.de
References
- ATBD Algorithm Theoretical Basis Document (pdf, not barrier free)
- PUM Product Users Manual (pdf, not barrier free)
- Validation report (pdf, not barrier free)
- Karlsson, K.-G., et al., CLARA-A3: The third edition of the AVHRR-based CM SAF climate data record on clouds, radiation and surface albedo covering the period 1979 to 2023, Earth Syst. Sci. Data, 15, 4901–4926, https://doi.org/10.5194/essd-15-4901-2023.
- Karlsson, K.-G., et al., Global Cloudiness and Cloud Top Information from AVHRR in the 42-Year CLARA-A3 Climate Data Record Covering the Period 1979–2020. Remote Sens.,15, 3044, https://doi.org/10.3390/rs15123044
Data citation
Please cite the data as follows:
Karlsson, Karl-Göran; Riihelä, Aku; Trentmann, Jörg; Stengel, Martin; Solodovnik, Irina; Meirink, Jan Fokke; Devasthale, Abhay; Jääskeläinen, Emmihenna; Kallio-Myers, Viivi; Eliasson, Salomon; Benas, Nikos; Johansson, Erik; Stein, Diana; Finkensieper, Stephan; Håkansson, Nina; Akkermans, Tom; Clerbaux, Nicolas; Selbach, Nathalie; Schröder, Marc; Hollmann, Rainer (2023): CLARA-A3: CM SAF cLoud, Albedo and surface RAdiation dataset from AVHRR data - Edition 3, Satellite Application Facility on Climate Monitoring, DOI:10.5676/EUM_SAF_CM/CLARA_AVHRR/V003, https://doi.org/10.5676/EUM_SAF_CM/CLARA_AVHRR/V003 [last accessed February 23 2024].