Precipitation - 4 Categories, Mechanism, Bergeon Process & Measurement YouTube Lecture Handouts

Get top class preparation for competitive exams right from your home: get questions, notes, tests, video lectures and more- for all subjects of your exam.

Get video tutorial on: Examrace YouTube Channel

Precipitation - 4 Categories, Mechanism, Bergeon Process & Measurement

PRECIPITATION

Types, Mechanism & Measurement

Illustration: Types, Mechanism & Measurement

Definition of Precipitation

“Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity.”

“Precipitation occurs when a portion of the atmosphere becomes saturated with water vapour, so that the water condenses and precipitates” .

Types

  • Liquid Precipitation
  • Freezing Precipitation
  • Frozen Precipitation
  • Mixed Precipitation

FROZEN PRECIPITATION

Illustration: FROZEN PRECIPITATION

Mechanism

  • Adding of Water Vapor
  • Coalescence
  • Cooling of Air

Coalescence

Wegener-Bergeron-Findeisen process: Ice crystal growth occuring in mixed phase clouds (with supercooled water and ice) where ambient vapor pressure falls between saturation vapor pressure over water and lower saturation vapor pressure over ice. This is a sub-saturated environment for liquid water but supersaturated environment for ice lead to rapid evaporation of liquid water and rapid ice crystal growth by vapour deposition.

Illustration: Coalescence

Geographical Distribution

  • Orientation of winds, mountain systems, and air mass control play significant roles in the pattern of precipitation.
  • Geographic pattern of precipitation is explained by examining the spatial distribution of:
    • Air masses
    • Water availability through evaporation
    • Uplift mechanisms

Measurement of Rainfall

  • Most rain gauges normally measure precipitation in millimetres equal to litres per square metre.

Manishika