Tropical

Question 1

Active ITCZ

Answer 1

Most active over continental land masses, during summer, and in the afternoons. Can be up to 300nm wide and with the tropopause near its upper limits Cb’s often penetrate into the lower stratosphere. Larger Cb’s means extra latent heat so TS hazards are often at their worst here, poor vis, heavy precipitation, severe turbulence, icing (engine and airframe), microbursts, tornadoes, and hail are likely to be most severe when the ITCZ sits north of the equator.

Icing usually occurs at a higher alt than in mid-lats however the -40 mark is usually not reached till FL340, Ice crystal engine icing is also likely to be severe due to the extent of the anvils.

Question 2

Inactive ITCZ

Question 3

Monsoon

Answer 3

‘a seasonal cross equatorial change in wind direction’

Question 4

Tropics dimension

Answer 4

Between 23 deg 26’ N/S, however this region is not fixed and moves with season change and the position of the Hadley cell.

Average surface temps in coldest months is 18c

Question 5

Key features in tropics

Answer 5

ITCZ,
Hadley cell
Trade winds
Equatorial trough, thermal equator, doldrums
Sub tropical highs, horse lats

Question 6

Met in tropics

Answer 6

Coriolis weak or non existent
Temp contrasts minimal
Small changes in stability drive major wx
Absence of seasonal variation

Question 7

Horse latitudes

Answer 7

30deg N/S both hemispheres where the Hadley and ferrel cell are both descending, creating anticyclones associated with extended periods of light wind and little to no rainfall

Question 8

Doldrums

Answer 8

Between 5 deg N/S, under the ITCZ. Trade winds converge resulting in light surface winds and frequent heavy thunderstorms triggered by the convergence.

Question 9

Equatorial trough (thermal equator)