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Cloud type, amount and cloud top temperature


The study of clouds, their location and characteristics, plays a key role in the understanding of climate change. Low, thick clouds primarily reflect solar radiation and cool the surface of the Earth. High, thin clouds primarily transmit incoming solar radiation, but at the same time they trap some of the outgoing infrared radiation emitted by the Earth and radiate it back downward, thereby warming the surface. Parameters include temperature and moisture profiles, fractional cloud cover, cloud top height, cloud top pressure, surface temperature and surface emissivity.
Detailed MeasurementDescription*InstrumentsTimeline
Cloud coverFraction of sky filled by clouds, in several layers. Requested in the troposphere (assumed height: 12 km), and as projection of the total column - Physical unit: [ % ] - Accuracy unit: [ % ].33 instruments
Cloud imageryIntended for observation of features like cloud occurrence, pattern, frontal bands, cyclones, volcanic ash plumes.39 instruments
Cloud maskBinary product (cloud or cloud-free) derived from Cloud imagery - Accuracy expressed as Hit Rate [ HR ] and False Alarm Rate [ FAR ].2 instruments
Cloud top heightHeight of the upper surface of the cloud - Physical unit: [ km ] - Accuracy unit: [ km ].37 instruments
Cloud top temperatureTemperature of the upper surface of the cloud - Physical unit: [ K ] - Accuracy unit: [ K ].18 instruments
Cloud typeResult of cloud type classification - Accuracy expressed as number of classes. Actually [ classes-1 ] is used, so that smaller figure corresponds to better performance, as usual.42 instruments
Freezing level heightHeight of the atmospheric layer in cloud where liquid-solid states transform into each other - Physical unit: [ km ] - Accuracy unit: [ km ].0 instruments
Melting layer depth in cloudsDepth of the atmospheric layer in cloud where liquid-solid states transform into each other - Physical unit: [ km ] - Accuracy unit: [ km ].0 instruments
* Description adapted from WMO.
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