Precipitation

Precipitation is a significant aspect of the water cycle, and is responsible for depositing most of the fresh water on the planet. It provides suitable conditions for many types of ecosystems, as well as water for hydroelectric power plants and crop irrigation.

Overview

The main ways precipitation occurs are through convection, stratiform deposition, and orographic lift. Convection occurs when air rises into the atmosphere which can cause areas of lower pressure below. Stratiform (layered) precipitation occurs when a layer of warmer air is above a layer of cooler air. Orographic precipitation is caused when moist air is lifted upwards over a mountain.

Types of precipitation

There are many types of precipitation. These include rain, snow, sleet, and hail; 'drizzle' and 'freezing drizzle' are two other types. Precipitation can be characterized by its size, volume, intensity, duration, and the area in which it falls.

Measurement

Precipitation is measured using a rain gauge. It is expressed in millimeters (mm), inches or centimeters (cm). An alternative way of measuring is through the use of a weather radar which can calculate the intensity of the precipitation.

Factors affecting precipitation

Several factors can affect precipitation including the temperature, humidity, and wind speed and direction. Other factors include the geographical location, season, and time of day.

See also

• Water cycle
• Cloud
• Rain
• Snow
• Sleet
• Hail

• 
  Precipitation
• 
  Precipitation