Lesson 4 Precip

Question 1

What are three conditions for precipitation to occur?

Answer 1

The atmosphere must become saturated by cooling and/or by addition of moisture

Condensation of water particles must occur

Water or ice particles must coalesce and grow large enough to reach the earth against updrafts.

Question 2

What are mechanisms for saturation (by cooling or moisture addition)

Answer 2

Orographic Storms – mechanical lifting of the air over natural barriers
Convective Storms – caused by surface heating
Frontal Storms (cyclonic storms) – Warm Front or Cold Front (Warm air meets cold air masses)

Question 3

What does leeward mean?

Answer 3

Opposite side of the windward on a wall

Question 4

Convective Precipitation

Answer 4

Surface heating of air-ground surface

Heated air mass cools  condenses  precip.

Question 5

Frontal Systems

Answer 5

Warm Front – warm air lifted over cold air

Cold Front – cold air displacing warm air

Question 6

Mechanism for Condensation

Answer 6

Condensation of water vapour  cloud droplets
Small particles or nuclei are present in the atmosphere (e.g. dust and ocean salt) upon which condensation or sublimation can take place

Question 7

Methods of Measurments (Rainfall)

Answer 7

Standard

Storage Gauge

Recording gauge

Doppler Radar