vue - Clouds circa 1920 US Department of Agriculture - US Weather Bureau

more at http://scitech.quickfound.net/weather_news_and_links.html also see: Know Your Clouds https://www.youtube.com/watch?v=alE4lyC8h60 Public domain film from the Prelinger Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied. The film was silent. I have added music created by myself using the Reaper Digital Audio Workstation and the Independence and Proteus VX VST instrument plugins. http://creativecommons.org/licenses/by-sa/3.0/ http://en.wikipedia.org/wiki/Cloud In meteorology, a cloud is a visible mass of liquid droplets or frozen crystals made of water or various chemicals suspended in the atmosphere above the surface of a planetary body. These suspended particles are also known as aerosols and are studied in the cloud physics branch of meteorology. Terrestrial cloud formation is the result of air in Earth's atmosphere becoming saturated due to either or both of two processes; cooling of the air and adding water vapor. With sufficient saturation, precipitation will fall to the surface; an exception is virga, which evaporates before reaching the surface. Clouds in the troposphere, the atmospheric layer closest to Earth's surface, have Latin names due to the universal adaptation of Luke Howard's nomenclature. It was introduced in December 1802 and became the basis of the modern classification system. Synoptic surface weather observations use code numbers to record and report any type of tropospheric cloud visible at scheduled observation times based on its height and physical appearance. The international cloud classification system is based on the fact that these aerosols in their most basic forms can show free-convective upward growth into low or vertical heaps of cumulus, appear in non-convective layered sheets at various altitudes as with low stratus and its higher variants, or take the form of high thin fibrous wisps of cirrus. In the case of low and vertical or multi-level clouds, prefixes are used whenever necessary to express variations or complexities in these basic forms. These include strato- for low cumulus layers with limited convection that show some stratus-like characteristics, cumulo- for complex highly convective vertical nimbus storm clouds, and nimbo- for thick stratus layers with sufficient vertical extent to produce moderate to heavy precipitation. For higher-based cloud types, the prefixes specify middle or high altitude ranges; alto- for middle, and cirro- for high. Cloud types prefixed by altitude range may be of simple non-convective stratiform structure or show slightly to moderately complex stratocumuliform structure due to limited convective activity. Free-convective clouds with potentially more complex forms are not prefixed by altitude range. Whether or not a cloud is classified as low, middle, or high level depends on the altitude range of its base above Earth's surface. In the case of a layer or heap with significant vertical extent, the height of the top is also a factor that defines its altitude classification.. A vertically developed cloud can initially form or have its base in the low or middle altitude range of the troposphere depending on the moisture content of the air, while the top can be in the middle or high range. While a majority of clouds form in Earth's troposphere, there are occasions when they can be observed at much higher altitudes in the stratosphere and mesosphere. These three main atmospheric layers are collectively known as the homosphere. Above this lies the thermosphere and exosphere, which together make up the heterosphere that marks the transition to outer space. Clouds have been observed on other planets and moons within the Solar System, but, due to their different temperature characteristics, they are composed of other substances such as methane, ammonia, and sulfuric acid...