Clouds
Global Cloud Cover
Figure: Climatological mean total cloud fraction averaged over 26-year period (1984–2009) from Climate Monitoring Satellite Application Facility (CM SAF) Cloud, Albedo (CLARA-A2). The CM SAF project is a part of the ground segment of the European organization for the exploitation of meteorological satellites (EUMETSAT). Source: Karlsson, K.-G.; Devasthale, A. Inter-Comparison and Evaluation of the Four Longest Satellite-Derived Cloud Climate Data Records: CLARA-A2, ESA Cloud CCI V3, ISCCP-HGM, and PATMOS-x. Remote Sens. 2018, 10, 1567. |
ECV Products and Requirements
These products and requirements reflect the Implementation Plan 2022 (GCOS-244).
The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Clouds.
| Products | Cloud cover | Cloud Optical Depth | Cloud Liquid Water Path | Cloud Ice Water Path | ||||
| (*) | Unit | Values | Values | Unit | Values | Values | ||
| Horizontal Resolution | G | km | 25 | 25 | km | 25 | 25 | |
| B | 100 | 100 | 100 | 100 | ||||
| T | 500 | 500 | 500 | 500 | ||||
| Vertical Resolution | G | - | - | |||||
| B | - | - | ||||||
| T | - | - | ||||||
| Temporal Resolution | G | h | 1 | 1 | h | 1 | 1 | |
| B | 24 | 24 | 24 | 24 | ||||
| T | 720 | 720 | 720 | 720 | ||||
| Timeliness | G | h | 1 | 1 | h | 1 | 1 | |
| B | 3 | 3 | 3 | 3 | ||||
| T | 12 | 12 | 12 | 12 | ||||
| Required Measurement Uncertainty (2-sigma) | G | % | 3 | 20 | Kg m-2 | 0.05 | 0.05 | |
| B | 6 | 40 | 0.1 | 0.1 | ||||
| T | 12 | 80 | 0.2 | 0.2 | ||||
| Stability | G | %/ decade | 0.3 | 2 | Kg m-2/ decade | 0.005 | 0.005 | |
| B | 0.6 | 4 | 0.01 | 0.01 | ||||
| T | 1.2 | 8 | 0.02 | 0.02 |
| Products | Cloud Drop Effective Radius | Cloud Top Temperature | Cloud Top Height | ||||||
| (*) | Unit | Values | Unit | Values | Unit | Values | |||
| Horizontal Resolution | G | km | 25 | km | 25 | km | 25 | ||
| B | 100 | 100 | 100 | ||||||
| T | 500 | 500 | 500 | ||||||
| Vertical Resolution | G | - | - | - | |||||
| B | - | - | - | ||||||
| T | - | - | - | ||||||
| Temporal Resolution | G | h | 1 | h | 1 | h | 1 | ||
| B | 24 | 24 | 24 | ||||||
| T | 720 | 720 | 720 | ||||||
| Timeliness | G | h | 1 | h | 1 | h | 1 | ||
| B | 3 | 3 | 3 | ||||||
| T | 12 | 12 | 12 | ||||||
| Required Measurement Uncertainty (2-sigma) | G | µm | 1/2 | K | 2 | km | 0.3 | ||
| B | 2/4 | 4 | 0.6 | ||||||
| T | 4/8 | 8 | 1.2 | ||||||
| Stability | G | µm/ decade | 0.1/0.2 | K/decade | 0.2 | km/ decade | 0.03 | ||
| B | 0.2/0.4 | 0.4 | 0.06 | ||||||
| T | 0.4/0.8 | 0.8 | 0.12 | ||||||
(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful
Data sources
This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelli
wmo [dot] int (GCOS Secretariat).
Reanalysis:
- REANALYSES.ORG (Inventory for Reanalysis)
Satellite:
- Satellite ECV Inventory by the CEOS/CGMS Working Group on Climate (WGClimate)
