Tropical Lows

Contribution from Each Product

Question

Which satellite products were most useful for identifying the system and why?

a) WV because tropical moisture can be distinguished from mid-latitude moisture

b) WV because the upper level moisture and divergence (anticyclonic rotation) in the upper levels can be easily identified

c) Airmass RGB because the various levels of cloud and the rotation thereof can clearly be seen

d) Airmass RGB because warm tropical air can be distinguished from cooler polar air

e) IR because the low level cloud can be monitored overnight

f) IR because the various cloud types can be determined from their shape and cloud top temperatures through the day and overnight. There is continuity in the progression of the system.

g) VIS because rotation of the low only takes place during the day, so the vis channel is best used.

h) VIS because during the day the various cloud types are easily distinguishable by the reflectivity, shape and shadowing. The rotation of the system is also able to be determined as the convective cloud circulates around the low pressure.

The correct answers are B, C, F, and H.

Water vapour images show the upper tropospheric flow and moisture, making it easy to identify the tropical low anticyclonic rotation in the upper levels. But they do not provide information about whether the moisture is of tropical or mid-latitude origin.

The airmass RGB provides information about various levels of cloudiness, which let us identify rotation at various levels. It can also be used to distinguish tropical air masses from polar air masses (but polar air masses are not involved in tropical cyclone development).

Infrared images are good for showing cloud shapes and development through both day and night. But they are not the best choice for monitoring low clouds at night.

Visible images are good for showing various cloud types during daytime. The clouds and their reflections and shadows help to distinguish the cloud types. In addition, you can determine the rotation of the system by the convective cloud circulation around the area of low pressure.

Please make a selection.

Produced by The COMET® Program

Navigation Menu

Contribution from Each Product

Question