Cloud physics vertically developed clouds, the cumulonimbus type is the tallest and can virtually span the entire troposphere from a few hundred metres above the ground up to the tropopause. It is the cloud responsible for thunderstorms. Some cirriform clouds can form at very high to extreme levels above the troposphere, mostly above the polar regions of Earth. Polar stratospheric clouds clouds are seen but rarely in winter at altitudes of 18 to 30 kilometers, while in summer, noctilucent clouds occasionally form at high latitudes at an altitude range of 76 to 85 kilometers. Homospheric types determined by cross-classification of forms and
Tag cloud Tag cloud A tag cloud (word cloud, or weighted list in visual design) is a novelty visual representation of text data, typically used to depict keyword metadata (tags) on websites, or to visualize free form text. Tags are usually single words, and the importance of each tag is shown with font size or color. This format is useful for quickly perceiving the most prominent terms and for locating a term alphabetically to determine its relative prominence. When used as website navigation aids, the terms are hyperlinked to items associated with the tag. In the language of visual design, a tag