Stability And Cloud Formation

Question 1

Initial causes of vertical motion.

Answer 1

Convection, Orographic, Convergence, frontal, Wind.

Question 2

Atmospheric stability

Answer 2

Following initial vertical motion, depending on environmental temperature, the environment is either:
Stable - parcel of air returns to normal position
Neutral - No tendency to move
Unstable - moves further away

Question 3

Environmental lapse rate

Answer 3

Rate at which temperature chnages with height.
2 degrees per 1000ft, rangers 0.6>4 degrees per 1000ft
0.65 degrees per 100m

Question 4

Adiabatic cooling

Answer 4

When air rises, it enters low pressure, parcel will expand as a result of losing temperature.

Question 5

Adiabatic warming.

Answer 5

Air sinks and enters high pressure, air compresses resulting in temp increase.

Question 6

Dry Adiabatic lapse rate

Answer 6

Provided water vapour does not condense when it rises, air cools at 3 degrees/1000ft or 1 degree/100m

Question 7

Rising saturated air

Answer 7

Air which condensation has occurred cools at the saturated rate adiabatic 1.8 degrees/1000ft.

Question 8

DALR and SALR

Answer 8

DALR is below the dewpoint.
Above this, in SALR, clouds begin to form.
SALR varies with altitude, due to less water vapour to condensate, less latent heat is released, the SALR increase.

Question 9

Absolute stability

Answer 9

ELR - 1degree/1000ft,
DALR - 3degree/1000ft
SALR - 1.8degree/1000ft

Air does not rise buoyantly.
Little icing, little turbulence, drizzle, poor visibility.
Stratus, nimbostratus, altostratus.
Any ELR between X-Axis and SALR curve causes absolute stability. Smaller lapse rate

Question 10

Absolute instability

Answer 10

ELR - 4degree/1000ft
DALR - 3degree/1000ft
SALR - 1.8degree/1000ft
Air rises buoyantly,
Any ELR left of DALR causes absolute instability. Bigger lapse rate.
Turbulence, bad icing, good vis, microburst, hail.
Cumulus, towering cumulus, cumulonimbus, stratocumulus, altocumulus.

Question 11

Conditional instability

Answer 11

DALR - 3degrre/1000ft
ELR - 2degree/1000ft
SALR - 1.8degree/1000ft
Unsaturated air does not rise buoyantly.
Saturated air rises buoyantly. Anywhere between DALR and SALR.

Question 12

Measuring cloud base and tops

Answer 12

Cloud base - top of DALR
Cloud tops - SALR and ELR intersect

Question 13

Advection and stability

Answer 13

Cooled from below - stable
Warmed from below - unstable

Question 14

Dispersal of cloud

Answer 14

Warming through subsidence (adiabatic warming.
aBSORBING SOLAR AND TERRESTRIAL RADIATION