theories of precipitation

Question 1

what are the 2 theories of precipitation

Answer 1

1. bergeron-findeisen process
2. collision process

Question 2

explain bergeron-findeisen process

Answer 2

clouds at high altitudes (<0°C) contain waterdroplets + icecrystals
ice crystals fracture from fast air currents
hexagonal ice shapes develop(highSA), more water vapour condenses around them
snowflakes become too dense ∴ falling and melting as temp increases = rain

Question 3

explain collision process

Answer 3

“supersized” condensation nuclei(large sea salt particles) provide “seeds” around which water droplets form.
These droplets are heavier and larger than normal droplets.
the larger droplets fall + collide with smaller droplets ∴ absorbing them
high terminal velocity of larger droplets allow them to absorb many smaller droplets, therby causing rapid fusion ∴ raindrop growth occurs