With Best Regards: Closing Your Letter. June 17, 2014 by. When writing professional or informal emails and letters, it is often considered proper etiquette to complete your correspondence with an appropriate closing signature.
What two conditions are needed for clouds to form? Air must be cooled to its dew point and particles must be present in the air When are clouds formed by ice crystals instead of drops of liquid water?
The visible droplets become a cloud, and that altitude (temperature) at which it forms is called the condensation level. There can be some mixing of clouds on windy days, but in general the air mass at the cloud level is moving quite steadily. And again, fluids of slightly different densities do not mix well.