midlatitude cyclone one quiz

Question 1

characteristics of a midlatitude cyclone

Answer 1

• large-scale low pressure system (1000-6000 km across)
• associated with surface fronts
• ‘Dynamic Low’
• driven by net convergence from the air column
• mature cyclone was a ‘comma’ appearance on satellite and radar
• location of cyclone center annotated by a red L on surface maps

Question 2

POLAR FRONT THEORY PHASE 1: STATIONARY FRONT

Answer 2

• prior to the development of a midlatitude cyclone, a stationary front will exist at the surface (no low pressure yet
• winds of either side of the front will blow in opposite directions

Question 3

POLAR FRONT THEORY PHASE 2: FRONTAL WAVE

Answer 3

• winds blowing in opposite directions trigger a ‘kink’ in the isobars
• surface pressure begins to fall
• surface low forms at the ‘kink’
• rotation around the low spurs the development of a cold and warm front

Question 4

POLAR FRONT THEORY PHASE 3: OPEN WAVE

Answer 4

• cold air advection and warm air advection strengthen ___
• cold front becomes oriented from NE to SW
• surface pressure falls
• defined warm sector exists

Question 5

POLAR FRONT THEORY PHASE 4: MATURE

Answer 5

• distinct cold and warm fronts still exist
• cold front becomes oriented from N to S and nearly intersects warm front
• surface pressure continues to fall
• warm sector shrinks

Question 6

POLAR FRONT THEORY PHASE 5: OCCULUSION OR ADVANCED OCCLUSION

Answer 6

• cold front now intersects the warm front
• occlusion front forms
• low has reached maximum intensity
• warm sector is now removed from surface low

Question 7

POLAR FRONT THEORY PHASE 6: CUT-OF CYCLONE OR DECAY STAGE

Answer 7

• surface low is totally removed from any temperature gradient
• low spins and fills (pressure increases) in the cold air
• residual stationary front is left to the SE

Question 8

‘purpose’ of extratropical cyclones?

Answer 8

• equalize uneven temperature distribution
• mix warm tropical air masses with cold polar ones
• send cold air south and warm air north
• help maintain atmospheric heat balance

Question 9

primary areas of formation (seasonal)

Answer 9

• east of Rocky Mountains (Colorado Low, Alberta Clipper)
• Gulf of Mexico coast (Gulf Low)
• East Coast (Hatteras Low)
• Gulf of Alaska