Take responsibility like crew, officer or Captain on yacht or any kind of boat is not just to know few knots and how to come in and out of marina it is many, many more, it is science, so take any chance to learn more, to be better. Predrag Captain Nedeljkovic Today we will wright about clouds, up to them if you know you will ( can ) up coming recognize weather . Formation of cloud Clouds form in the Earths atmosphere when water evaporates into vapor from oceans, lakes, ponds, and even streams and rivers; and by evaporation or transpiration over moist areas of Earths land surface.[1] The vapor rises up into colder areas of the atmosphere due to convective, orographic, or frontal lifting. This subjects the rising air to a process called adiabatic cooling. The water vapor attaches itself to condensation nuclei which can be anything from dust to microscopic particles of salt and debris. Once the vapor has been cooled to saturation, the cloud becomes visible. All weather-producing clouds form in the troposphere, the lowest major layer of the atmosphere. However very small amounts of water vapor can be found higher up in the stratosphere and mesosphere and may condense into very thin clouds if the air temperatures are sufficiently cold. The nephology branch of meteorology is focused on the study of cloud physics. Cloud classification: Order of listed types Terrestrial mesospheric, stratospheric, and tropospheric classes are listed on this page in descending order of altitude range. Within the troposphere, étages of non-vertical clouds are also listed in descending order of altitude. The genus types within each étage are arranged in descending order of average cloud base height. Their constituent species, varieties, supplementary features and mother clouds are arranged in approximate order of frequency of occurrence. Vertical or multi-étage cloud groups and their constituent genera and species are listed in ascending order of average altitude of cloud tops. Their varieties, supplementary features, and mother clouds are arranged in order of approximate frequency of occurrence. A count of basic tropospheric variants is shown as a number in parentheses after each variety, after nimbostratus that has no sub-types, and after certain species that are not always dividable into varieties. Other planets in our solar system that have clouds are listed in order of their distance from the sun, and the clouds on each planet are in approximate descending order of altitude. Polar mesospheric classification Clouds that form above the mesosphere have a generally cirriform structure, but are not given Latin names based on that characteristic. Polar mesospheric clouds are the highest in the atmosphere and are given the Latin name noctilucent which refers to their illumination during deep twilight. They are sub-classified alpha-numerically according to specific details of their cirriform physical structure. Tropospheric classification Tropospheric clouds are divided into physical forms defined by structure, and étages defined by altitude range. They are cross-classified to produce ten basic genus-types. They have Latin names as authorized by the World Meteorological Organization (WMO) that indicate physical structure, altitude or étage, and process of formation High cirriform, stratocumulus form, and stratiform High clouds form in the highest and coldest region of the troposphere from about 16,500 to 40,000 ft (5 to 12 km) in temperate latitudes.[5][6] At this altitude water almost always freezes so high clouds are generally composed of ice crystals or super cooled water droplets. Genus cirrus Abbreviation: Ci Cirrus tends to be wispy, and are mostly transparent or translucent. Isolated cirrus clouds do not bring rain, however, large amounts of cirrus clouds can indicate an approaching storm system eventually followed by fair weather. There are several variations of clouds of the cirrus genus based on species and varieties Species Cirrus fibratus High clouds having the traditional mares tail appearance. These clouds are long, fibrous, and curved, with no tufts or curls at the ends. Cirrus uncinus Filaments with up-turned hooks or curls. Cirrus spissatus Dense and opaque or mostly opaque patches. Cirrus castellanus A series of dense lumps, or towers, connected by a thinner base. Cirrus floccus Elements which take on a rounded appearance on the top, with the lower part appearing ragged. Opacity-based varieties None; always translucent except species spissatus which is inherently upaque. Fibratus pattern-based varieties Cirrus fibratus intortus Irregularly curved or tangled filaments. Cirrus fibratus vertebratus Elements arranged in the manner of a vertebrae or fish skeleton. Pattern-based variety radiatus Large horizontal bands that appear to converge at the horizon; normally associated with fibratus and uncinus species. Cirrus fibratus radiatus Cirrus uncinus radiatus Pattern-based variety duplicatus Sheets at different layers of the upper troposphere, which may be connected at one or more points; normally associated with fibratus and uncinus species. Cirrus fibratus duplicatus Cirrus uncinus duplicatus Varieties are not commonly associated with Ci species spissatus, castellanus, or floccus. Precipitation-based supplementary features Not associated with cirrus. Accessory cloud Mamma Bubble-like downward protuberances; mostly seen with species castellanus. Genitus mother clouds Cirrus cirrocumulogenitus Cirrus altocumulogenitus Cirrus cumulonimbogenitus Mutatus mother cloud Cirrus cirrostratomutatus Genus cirrocumulus Abbreviation: Cc Clouds of the genus cirrocumulus form when moist air at high tropospheric altitude reaches saturation, creating ice crystals or supercooled water droplets. Limited convective instability at the cloud level gives the cloud a rolled or rippled appearance. Despite the lack of a strato- prefix, cirrocumulus is physically more closely related to stratocumulus than the more freely convective cumulus genus. Species Cirrocumulus stratiformis Sheets or relatively flat patches of cirrocumulus. Cirrocumulus lenticularis Lenticular, or lens-shaped high cloud. Cirrocumulus castellanus Cirrocumulus with towers, or turrets. Cirrocumulus floccus Tufts with ragged bases. Opacity-based varieties None (always translucent) Pattern-based variety undulatus Cirrocumulus with an undulating base; normally associated with stratiformis and lenticularis species. Cirrocumulus stratiformis undulatus Cirrocumulus lenticularis undulatus. Genus cirrostratus Abbreviation: Cs Clouds of the genus cirrostratus consist of mostly continuous, wide sheets of cloud that covers a large area of the sky. It is formed when convectively stable moist air cools to saturation at high altitude, forming ice crystals.[12] Frontal cirrostratus is a precursor to rain or snow if it thickens into mid-level altostratus and eventually nimbostratus as the weather front moves closer to the observer. Middle stratocumuliform and stratiform Middle cloud forms from 6,500 to about 23,000 ft (2 to 7 km) in temperate latitudes, and may be composed of water droplets or ice crystals depending on the temperature profile at that altitude range. Genus altocumulus Abbreviation: Ac Clouds of the genus altocumulus are not always associated with a weather front but can still bring precipitation, usually in the form of virga which does not reach the ground. This genus is generally an indicator of limited convective instability, and is therefore structurally more closely related to stratocumulus than to the more freely convectice cumulus genus. Genus altostratus Abbreviation: As Altostratus translucidus near top of photo merging into altostratus opacus near bottom Altocumulus stratiformis perlucidus undulatus clouds merging into altostratus opacus, with higher layer of cirrus fibratus Clouds of the genus altostratus form when a large convectively stable airmass is lifted to condensation in the middle étage of the troposphere, usually along a frontal system. Altostratus can bring light rain or snow. If the precipitation becomes continuous, it may thicken into nimbostratus which can bring precipitation of moderate to heavy intensity. Low stratocumuliform, stratiform, and cumuliform. Low cloud forms from near surface to ca. 6,500 feet (2.0 km) and are generally composed of water droplets. Genus stratocumulus Abbreviation: Sc Clouds of the genus stratocumulus are lumpy, often forming in slightly unstable air, and they can produce very light rain or drizzle. Vertical or multi-étage stratiform, cumuliform, and cumulonimbiform (low to middle cloud base) Clouds with upward-growing vertical development usually form below 6,500 feet (2.0 km),[6] but can be based as high as 8,000 feet (2.4 km) in temperate climates, and often much higher in arid regions. Downward-growing cloud forms mostly above 6,500 feet (2.0 km) and achieves vertical extent as the base subsides into the low altitude range during precipitation. Genus nimbostratus: Moderate or deep vertical Abbreviation: Ns Clouds of the genus nimbostratus tend to bring constant precipitation and low visibility. This cloud type normally forms above 6,500 feet (2.0 km)[6] 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. Genus cumulus: Towering vertical Abbreviation: Tcu (towering cumulus) Cumulus congestus These large cumulus clouds have flat dark grey bases and very tall tower-like formations with tops mostly in the high level of the troposphere. The International Civil Aviation Organization (ICAO) designates this species as towering cumulus (Tcu). Genus cumulonimbus: Towering vertical Abbreviation: Cb Clouds of the genus cumulonimbus have very dark gray to nearly black flat bases and very high tops that can penetrate the tropopause. They develop from cumulus when the airmass is convectively highly unstable. They generally produce thunderstorms, rain or showers, and sometimes hail, strong outflow winds, and/or tornadoes at ground level. WMO general Altocumulus – altus and cumulus – high heap; now applied to middle stratocumuliform. Altostratus – altus and stratus – high sheet; now applied to middle stratiform. Cirrocumulus – cirrus and cumulus – thin, wispy heap; applied to high stratocumuliform. Cirrostratus – cirrus and stratus – thin, wispy sheet; applied to high stratiform. Cirrus – thin and wispy; applied to high cirriform. Cumulonimbus – cumulus and nimbus (Latin for raincloud) – precipitation-bearing heap; applied to vertical cumulonimbiform. Cumulus – Latin for heap; applied to low or vertical cumuliform. Nimbostratus – nimbus and stratus – precipitation-bearing sheet; applied to deep stratiform with vertical extent. Stratocumulus – stratus and cumulus – heap partly spread into a sheet; applied to low stratocumuliform. Stratus – Latin for sheet; applied to low mostly shallow stratiform. WMO species Castellanus – castle-like stratocumuliform (Sc, Ac, Cc cas) and dense cirriform (Ci cas) with a series of turret shapes – indicates air mass instability. Congestus – cumuliform (Cu con/Tcu) with great vertical development and heaped into cauliflower shapes – indicates considerable airmass instability and strong upcurrents. Fibratus – cirriform (Ci fib) or high stratiform (Cs fib) in the form of filaments, can be straight or slightly curved. Floccus – tufted middle and high stratocumuliform (Ac, Cc flo) and high cirriform (Ci flo) – indicates some mid and/or high level instability. Fractus – low stratiform (St fra) or cumuliform (Cu fra) with an irregular shredded appearance – forms in precipitation and/or gusty winds. Humilis – small, low, flattened cumuliform (Cu hum) – indicates relatively slight airmass instability. Lenticularis – stratocumuliform (Sc, Ac, Cc len) having a lens-like appearance – formed by standing waves of wind passing over mountains or hills. Mediocris – medium size cumuliform (Cu med) with bulges at the top – indicates moderate instability and upcurrents. Nebulosus – indistinct low and high stratiform (St, Cs neb) without features – indicates light wind if any and stable air mass. Spissatus – thick cirriform (Ci spi) with a grey appearance – indicates some upward movement of air in the upper troposphere. Stratiformis – horizontal cloud sheet of flattened stratocumuliform (Sc, Ac, Cc str) – indicates very slight airmass instability. Uncinus – cirriform (Ci unc) with a hook shape at the top – indicates a nearby backside of a weather system. WMO and informal terms related to free-convective cloud types and storms Accessory cloud (WMO supplementary feature) – cloud that is attached to and develops on body of main cloud. Anvil (WMO supplementary feature incus) – the top flatter part of a cumulonimbus cloud. Anvil dome (WMO supplementary feature incus) – the overshooting top on a Cb that is often present on a supercell. Anvil rollover – (slang) circular protrusion attached to underside of anvil. Arcus cloud (WMO supplementary feature) – arch or a bow shape, attached to cumulus, thick with ragged edges. Backsheared anvil – (slang) anvil that spreads upwind, indicative of extreme weather. Clear slot or dry slot (informal term) – an evaporation of clouds as a rear flank downdraft descends and dries out cloud and occludes around a mesocyclone. Cloud tags (WMO species fractus) – ragged detached portions of cloud. Collar cloud (WMO supplementary feature velum) – ring shape surrounding upper part of wall cloud. Condensation funnel (WMO supplementary feature tuba) – the cloud of a funnel cloud aloft or a tornado. Altocumulus castellanus (WMO genus and species) – castle crenellation-shaped altocumulus clouds. Cumulus (WMO genus) – heaped clouds. Cumulus castellanus – (informal variation of WMO genus and species cumulus congestus) cumulus with tops shaped like castle crenellations. Cumulus congestus (WMO genus and species) – considerable vertical development and heaped into cauliflower shapes. Cumulus fractus (WMO genus and species) – ragged detached portions of cumulus cloud. Cumulus humilis (WMO genus and species) – small, low, flattened cumulus, early development. Cumulus mediocris (WMO genus and species) – medium-sized cumulus with bulges at the top. Cumulus pileus (WMO genus and supplementary feature) – capped, hood-shaped cumulus cloud. Cumulus praecipitatio (WMO genus and supplementary feature) – cumulus whose precipitation reaches the ground. Cumulus radiatus (WMO genus and variety) – cumulus arranged in parallel lines that appear to converge near the horizon. Cumulus tuba (WMO genus and supplementary feature) – column hanging from the bottom of cumulus. Cumulonimbus (WMO genus) – heaped towering rain-bearing clouds that stretch to the upper levels of the troposphere. Cumulonimbus calvus (WMO genus and species) – cumulonimbus with round tops like cumulus congestus. Cumulonimbus capillatus (WMO genus and species) – Cb with cirriform top. Cumulonimbus incus (WMO genus and supplementary feature) – Cb with anvil top. Cumulonimbus mamma (WMO genus and supplementary feature) – Cb with pouch-like protrusions that hang from under anvil or cloud base. Cumulonimbus pannus (WMO genus and supplementary feature) – shredded sections attached to main Cb cloud. Cumulonimbus pileus (WMO genus and supplementary feature) – capped, hood-shaped cumulonimbus cloud. Cumulonimbus praecipitatio (WMO genus and supplementary feature) – Cb whose precipitation reaches the ground. Cumulonimbus tuba (WMO genus and supplementary feature) – column hanging from the bottom of cumulonimbus. Debris cloud (informal term) – rotating cloud of debris found at base of tornado. Funnel cloud (WMO supplementay feature tuba) – rotating funnel of cloud hanging from under Cb, not making contact with ground. Hail fog (informal term) – a shallow surface layer of fog that sometimes forms in vicinity of deep hail accumulation, can be very dense. Hot tower (informal term) - a tropical cumulonimbus cloud that penetrates the tropopause. Inflow band (informal term) – a laminar band marking inflow to a Cb, can occur at lower or mid levels of the cloud. Inverted cumulus (informal variation of WMO supplementary feature mamma) – cumulus which has transferred momentum from an exceptionally intense Cb tower and is convectively growing on the underside of an anvil. Knuckles (informal variation of WMO supplementary feature mamma) – lumpy protrusion that hangs from edge or underside of anvil. Pyrocumulus and Pyrocumulonimbus– intense ground-heat cloud proposed for WMO classification (see above). Rope – (slang) narrow, sometimes twisted funnel type cloud seen after a tornado dissipates. Rope cloud (informal term) – A narrow, long, elongated lines of cumulus cloud formation that develop at the leading edge of an advancing cold front or weather fronts that is often visible in satellite imagery. Scud cloud (informal term for WMO species fractus) – ragged detached portions of cloud that usually form in precipitation. Shelf cloud (informal term for WMO supplementary feature arcus) – wedge-shaped cloud often attached to the underside of Cb. Stratus fractus (WMO genus and species) – ragged detached portions of stratus cloud that usually form in precipitation (see also scud cloud). Striations (informal term for WMO supplementary feature velum) – a groove or band of clouds encircling an updraft tower, indicative of rotation. Tail cloud (informal term) – an area of condensation consisting of laminar band and cloud tags extending from a wall cloud towards a precipitation core. Towering cumulus (TCu) (aviation term for WMO genus and species cumulus congestus) – a large cumulus cloud with great vertical development, usually with a cauliflower-like appearance, but lacking the characteristic anvil of a Cb. Wall cloud (informal term) – distinctive fairly large lowering of the rain-free base of a Cb, often rotating.
Posted on: Sun, 12 Oct 2014 08:44:27 +0000
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