The amount of water vapor that exists in the atmosphere varies according to several factors, such as vegetation, hydrography, among others. In general, the atmosphere receives moisture from oceanic and continental waters. In addition to the contribution of plants, which, through the process of evapotranspiration, emit large amounts of moisture into the atmosphere. In the Amazon region, for example, about 50% of the rains come from evapotranspiration promoted by plants.
Water vapor contained in the atmosphere results in atmospheric humidity, which can be relative or absolute. Relative humidity corresponds to the relationship between the percentage of absolute humidity and the saturation point, it is usually indicated by %.
The atmosphere has a limit on the amount of water vapor present. This means that it cannot keep a high amount of water vapor in suspension in its structure, when it reaches its maximum point we say it has reached the saturation point.
Upon reaching this saturation point, any existing water vapor becomes denser and turns into clouds, these can trigger a climatic phenomenon - precipitation - which can come in the form of rain, snow or hail.
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By Eduardo de Freitas
Graduated in Geography
Would you like to reference this text in a school or academic work? Look:
FREITAS, Eduardo de. "Atmospheric humidity"; Brazil School. Available in: https://brasilescola.uol.com.br/geografia/umidade-atmosferica.htm. Accessed on June 27, 2021.