How a cloud is formed.
A cloud is made up of water and millions of tiny solid microscopic particles called condesation nuclei.
When the dew point temp is reached and cloud is formed the tiny particles can connect and grow larger and larger in the cloud.
Since the liquid droplets are heavier than air gravity causes them to fall towards the ground.
Atmospheric drag
The liquid droplets that fall encounter atmospheric drag meaning the water droplets slow down.
Terminal velocity
The faster it falls the more drag is created until it reaches a speed called “terminal velocity” to the point where the drag is so much for such little mass so it prevents them from falling.
Understanding terminal velocity more a good example
Think of it like walking up an escalator that is going down. It’s simply not moving.
How precipitation makes landfall
Water droplets will keep on getting larger and as there size increases there weight does causing a stronger updraft needed. eventually the weight will out do the drag.
Cloud formation Processes.
When dew point is reached in the presense of condesation nuclei cloud will be formed.
although there are different methods that cause the air to rise.
Convection
The air rises if the elapsed rate allows the air to rise until it hits dew point.
The level at this occurs is called the condensation level
Orographic uplift (moutain rise)(pg 56)
If a mountain is present and the air has to rise over it and air parcel rises to dew point temp cloud will form.
Frontal uplift
When cold air and warm air meet it causes a converging effect.
The cold air is heavier and more dense causing it to stay at the bottom while the less heavier warm air rises to hit its dew point.
Convergence
When two airstreams meet head on at the surface and they have nowhere but to go up.
Happens in low pressure systems usually in equatorial trough and the sub polar low.
Turbulence
turbulence is caused by friction with the surface.
As air mixes with the obsacles at the surface the air in the lower levels is in constant vertical motion
convection causes air to rise and sink while the air is rising and expanding the air is also compressing while sinking causing a washing machine effect.
What cloud is most seen to cause turbulence
stratocumulis.
Latitudinal heating of cold air mass
As cold air moves north in the southern hemisphere the cold air will naturually heat causing it to rise and eventually hit dew point.
The more the air moves north the greater the tempreture between the air mass and enviroment will become causing more formation of cumulus and eventually Towering cumulinimbus.
