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The cloud height, more commonly known as cloud thickness or depth, is the distance between the cloud base and the cloud top. [1] It is traditionally expressed either in metres or as a pressure difference in hectopascal (hPa, equivalent to millibar ).
Overlapping clouds (in meteorology, probably duplicatus clouds) are thought to imply eternal happiness [170] and clouds of different colors are said to indicate "multiplied blessings". [170] Informal cloud watching or cloud gazing is a popular activity involving watching the clouds and looking for shapes in them, a form of pareidolia. [171] [172]
Clouds of the genus nimbostratus tend to bring constant precipitation and low visibility. This cloud type normally forms above 2 kilometres (6,600 ft) [10] from altostratus cloud but tends to thicken into the lower levels during the occurrence of precipitation. The top of a nimbostratus deck is usually in the middle level of the troposphere.
The height of the cloud base can be measured using a ceilometer. This device reflects a beam of light off the cloud base and then calculates its distance using either triangulation or travel time. Alternatively, the cloud base can be estimated from surface measurements of air temperature and humidity by calculating the lifted condensation level.
Cloud top height is often much more variable than cloud base elevation. Clouds greatly affect the transfer of radiation in the atmosphere. In the solar spectral domain, cloud albedo is directly related to the nature, size and shape of cloud particles, which themselves are affected by the height of the cloud top.
the cloud height, measured above sea level, ranging from 0 to 20 km; the cloud IR emissivity, with values between 0 and 1, with a global average around 0.7; the effective cloud amount, the cloud amount weighted by the cloud IR emissivity, with a global average of 0.5; the cloud (visible) optical depth varies within a range of 4 and 10.
Noctilucent clouds are composed of tiny crystals of water ice up to 100 nm in diameter [4] and exist at a height of about 76 to 85 km (249,000 to 279,000 ft), [5] higher than any other clouds in Earth's atmosphere. [6]
A stratocumulus cloud, occasionally called a cumulostratus, belongs to a genus-type of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumulus, and the whole being at a lower height, usually below 2,000 metres (6,600 ft).