WMO OSCAR | Details for Variable: Cloud cover

Variable: Cloud cover

Definition

Full name	Cloud cover
Definition	3D field of fraction of sky filled by clouds.
Measuring Units	%	Uncertainty Units	%
Horizontal Res Units	km	Vertical Res Units
Stability Units	% (Stability /decade)

Comment:	The total cloud cover cannot be simply derived from the 3D cloud cover because of unknown overlapping of cloud layers over any given area.
Last modified:	2024-11-06
Applied in OSCAR/Space Gap Analysis:	Yes

Classification

Domain: Atmosphere
- Sub-domain: Clouds and precipitations
  - Variable: Cloud cover
    - Measured in Layers:
      - TrC
      - UTLS
      - FT
      - PBL

Cross-cutting themes:

Earth System Application Categories and its related Application Areas:
- 2. Atmospheric Applications
- 2. Atmospheric Applications
- 2. Atmospheric Applications
- 2. Atmospheric Applications
- 2. Atmospheric Applications
Unknown:
- Climate-AOPC (deprecated)
- GEWEX (deprecated)

Requirements defined for Cloud cover (8)

This tables shows all related requirements. For more operations/filtering, please consult the full list of Requirements
Note: In reading the values, goal is marked blue, breakthrough green, threshold orange
Application-dependent Technical Priority (ATP) Magenta and Relative priority of the attributes Red

Id	Variable	Layer	App Area	ATP	Uncertainty	Stability / decade	Hor Res	Obs Cyc	Timeliness	Coverage	Conf Level	Val Date	Source	General Comment
81	Cloud cover	TC	Climate-AOPC (deprecated)		10 % 15 % 20 %		99 km 100 km 500 km	3 h 4 h 6 h	3 h 6 h 12 h	Global	firm	2007-07-19	AOPC	Accuracies should apply to low and high clouds separately. See Hansen et L. (1995) in T.R. Karl (Ed.) 1995 Long term climate monitoring by the Global Climate Observing System. Kluwer. Also, Climatic Change 31, Nos. 2-4.
206	Cloud cover	TC	GEWEX (deprecated)		5 % 10 % 20 %		50 km 100 km 250 km	3 h 6 h 12 h	30 d 45 d 60 d	Global	reasonable	1998-10-29	WCRP
259	Cloud cover	TC	2.1 Global Numerical Weather Prediction and Real-time Monitoring		5 % 10 % 20 %		5 km 15 km 50 km	60 min 3 h 12 h	6 min 30 min 6 h	Global	reasonable	2009-02-10	John Eyre
343	Cloud cover	TrC	2.2 High-Resolution Numerical Weather Prediction		5 % 8 % 20 %		0.5 km 2 km 10 km	15 min 30 min 3 h	15 min 30 min 2 h	Global	tentative	2010-02-01	T Montmerle
430	Cloud cover	PBL	2.3 Nowcasting / Very Short-Range Forecasting		5 % 10 % 20 %		1 km 5 km 20 km	30 sec 3 min 60 min	60 sec 3 min 30 min	Global	firm	2003-10-20	ET ODRRGOS
703	Cloud cover	TrC	2.3 Nowcasting / Very Short-Range Forecasting		5 % 10 % 20 %		1 km 5 km 20 km	5 min 15 min 60 min	5 min 15 min 60 min	Global	reasonable	2013-04-15	P. Ambrosetti
727	Cloud cover	PBL	2.8 Aeronautical Meteorology		5 % 7 % 25 %			10 min 30 min 60 min	5 min 10 min 30 min	Point	firm	2014-03-31	J van der Meulen	At the aerodrome Source: ICAO Annex 3, Att A: "Cloud amount" ± 1 okta
791	Cloud cover		2.5 Atmospheric Climate Monitoring	0.5	3 % 6 % 12 % 0.5	0.3 % 0.6 % 1.2 % 0.5	25 km 100 km 500 km 0.5	60 min 24 h 30 d 0.5	60 min 3 h 12 h 0.5	Global	firm	2023-04-28	GCOS-245: The 2022 ECVs Requirements (GCOS-245)	Requirements for uncertainty are specified at 2-sigma.