Meteorology CH 6

parcel

football shaped object that will increase or decrease in our atmosphere.

parcel theory

cannot mix in air from outside, contained

rising parcels will what?

expand and cool

sinking parcels will?

compress and warm

as an unsaturated parcel increases 1 km how much does the temp decrease

10 degrees Celsius

Adiabatic processes

when air parcels rise and sink in unsaturated conditions and no heat is gained or lost.

Adiabatic processes

air parcel has the same temp at the beginning and the end.

moist parcel

cools around 6 degrees Celsius per km

moist adiabatic lapse rate

6 degrees celsius per km

Environmental lapse rate

Can change between 7, 2, and 11 degrees celsius per km

absolutely unstable atmosphere/ dry adiabatic rate

greater than 10 Degrees C per km

Conditionally unstable atmosphere

Between 6 and 10 Degrees C per km

Absolutely stable atmosphere/ moist adiabatic rate

6< degrees C per km

stable environment

an environment with little or no unexpected or sudden change

absolutely stable environment parcel movement

dry and moist will sink, (sink, sink)

unstable environment

all parcels will be warmer than there environment and once forced will continue to rise.

Unstable environment parcel movement

Both moist and dry parcels will rise.

will warm air rise or sink?

rise

will cool air rise or sink?

sink

conditionally stable/unstable

there is instability, on the condition that the parcel is saturated.

Conditionally stable/unstable parcel movement

unsaturated parcel will sink and saturated parcel will rise (up, down)

Neutrally stable

when environmental lapse rate equals the dry adiabatic lapse rate.

Neutrally stable parcel movement

no parcel movement (=,=)

ways that parcels are lifted

convection, lifting along topography, lifting along weather fronts, and convergence of air.

free convection

caused mostly by afternoon heating that causes hotspots (due to varying albedo)

Free convection

causes blue sky between cumulus clouds from sinking air.

free convection parcel movement

parcels are warmer than environment causing the air to rise.

lifting condensation level

force an unsaturated parcel to rise from the surface.

cloud base height formula for cumulus clouds

T-Td / 2.5C x 1000

The instability of the air above.

what does the depth of a cumulus cloud depend on?

Level of free convection

when the parcels temp becomes warmer than its environment above this point it will rise freely

Equilibrium Level

level above the LFC at which the parcel becomes cooler than the environment.

LCL

The parcel is saturated

unsaturated topography

the temp is the same on the windward and leeward sides of the mountain

6 degrees C

what rate do the temp and dew point temp decrease at once the parcel is saturated?

saturated topography

the temp will be warmer and dew point will be drier on the leeward side compared to the windward side.

rain shadow effect

causes the amount of rain to be noticeably less on the windward side compared to the leeward side.