Tropical Meteorology

Question 1

What is the difference between the Geographic equator and the thermal equator?

Answer 1

Geo: located at 0˚ Latitude.
Thermal: Located at the point of maximum thermal insolation. Where the sun’s noon rays impact the surface vertically

Question 2

How does the equatorial trough move annually?

Answer 2

Moves almost sympathy with the thermal equator.

• In NH summer the whole trough is in the NH
• In SH summer, it is mainly in the SH, with some parts over the pacific and Atlantic being in the NH.

Question 3

Where is the area of maximum cloudiness in relation to the thermal equator? Why?

Answer 3

A few degrees away on the geographic equator side. If the maximum cloudiness was over the thermal equator, it would not have the most thermal insolation, and so wouldn’t be the thermal equator

Question 4

What is the difference between the equatorial trough and the ITCZ?

Answer 4

ET: formed by the thermal equator and is a permanent band of low pressure and convergence. General term of the relative low pressure globally.
ITCZ: Formed by the convergence, which are not constant, and its position within the ET varies. It is a synoptic feature within the ET.

Question 5

What meteorological conditions can be expected in the doldrums?

Answer 5

• Light winds

- Low pressure

Question 6

What weather is associated with an active ITCZ?

Answer 6

• Massive cloud developments
• Turbulence
• Icing
• Precipitation
• Reduced visibility
• Downdrafts
• Altimeter errors as pressure is changing rapidly
• Things associated with Cb activity

Question 7

What is the extent of an active ITCZ?

Answer 7

500 - 600km across

50,000 - 60,000ft high

Question 8

What weather is associated with an inactive ITCZ?

Answer 8

• Some cumulus cloud cover in places, with showers under the more developed ones
• Light, variable winds

Question 9

What causes the SPCZ?

Answer 9

• NE winds off semi-stationary east pacific anticyclone, that have been deflected by crossing the equator
• SE winds off anticyclones in the Tasman, moving eastwards

Question 10

What is the extent of the trade winds? What causes them?

Answer 10

30˚ either side of equator, 800ft high

-Caused by the outflow of subtropical his being deflected by the coriolis force

Question 11

What is the normal strength of the trade winds? When are they normally stronger?

Answer 11

Stronger in Winter

10-20 kts (sometimes 30kts)