WEEK 4- DYNAMIC PLANET

Question 1

what are extra tropical cyclones?

Answer 1

also called mid-latitude Cyclones or simply low pressure systems

they are the dominant weather systems that bring us rain and snow in the mid-latitude
regions of the world
-in some places over 80% of wintertime precipitation due to this

Question 2

What is the intertropical Convergence Zone?

Answer 2

a band of persistent convective storms along the Equator

caused by the rising warm air in the tropics

Question 3

What are conditions like north and south of the Intertropical Convergence Zone in the subtropics?

Answer 3

regions are relatively cloud free
associated with the desert regions of the world
associated with large scale descending motion, which is why they tend to be relatively free of clouds at the surface
at the surface we find regions o high pressure= subtropical anticyclones

Question 4

What are the mid latitudes characterised by?

Answer 4

location= poleward of the subtropical highs
characterized by relatively strong flow from west to east above the surface of the Earth= jet streams

Question 5

How does satellite imagery work?

Answer 5

infra red radiation emitted by the Earth but viewed by a satellite placed 35,000km above the equator.

The satellite has an instrument that detects infrared radiation and converts it into a grey shading from black (highest temperatures) to white (lowest temperatures).

white areas= high clouds- mostly serious and deep convective storms
black areas= earth surface and the tropics
grey areas= tops of low clouds or cooler land surfaces

Question 6

How does the jet stream control the weather of the mid latitudes?

Answer 6

within the jet stream disturbances form= mid latitude cyclones
These are regions of low pressure and they
have circulations that as a result tend to evolve comma shaped cloud patterns

Winds around these mid-latitude Cyclones blow counterclockwise in
the Northern Hemisphere and clockwise in the southern hemisphere

These Cyclones tend to move along with the jet stream from west to east with the comma shape becoming more pronounced and wrapped up

As the Cyclone involves the jet stream forms along
the strong gradient in temperature between cold polar air and warm.
Tropical air in each hemisphere. Thus the jet stream also is a manifestation of
the strong gradient in temperature. So poleward of the jet stream the air tends
to be cold and equator word of the jet stream the air tends to be relatively warm