Cirrus cloud tropopause prevents the warm, moist air forming the thunderstorm from rising any higher, thus creating the flat top. In the tropics, these thunderstorms occasionally produce copious amounts of cirrus from their anvils. High-altitude winds commonly push this dense mat out into an anvil shape that stretches downwind as much as several kilometers. Individual cirrus cloud formations can be the remnants of anvil clouds formed by thunderstorms. In the dissipating stage of a cumulonimbus cloud, when the normal column rising up to the anvil has evaporated or dissipated, the mat of cirrus in the anvil is all that is left. Contrails
Cloud computing weigh the benefits of cloud computing against the risks. In cloud computing, the control of the back end infrastructure is limited to the cloud vendor only. Cloud providers often decide on the management policies, which moderates what the cloud users are able to do with their deployment. Cloud users are also limited to the control and management of their applications, data and services. This includes data caps, which are placed on cloud users by the cloud vendor allocating certain amount of bandwidth for each customer and are often shared among other cloud users. Privacy and confidentiality are big concerns in