FACTORS NECESSARY FOR FORMATION OF TC: WEATHER PATTERNS ASSOCIATED WITH TROPICAL CYCLONE: GENERAL CHACTERISTICS:
• HOT MOIST AIR – develop at the ITCZ where the hot, • Cyclone Covers a diameter of 500 km. • Isobars around central low-pressure are circular
moist air from the tropical easterlies converge. A warm • The eye covers 25km, associated with subsiding air. the air • Pressure in center is low = 960 hPa, can go as low as 870
sea surface, with a temp of 27° (results in hot, humid, subsides thus, no clouds form in the region of the eye, sky is • Diameter= 600km – 1000km (smaller than MLC)
unstable air)water evaporates and rises quickly at this clear, air is still and calm. No rain falls • Develop in warm moist air mass, DOES NOT HAVE A
temp. this is why TC form in summer because • In the eye There is hot humid calm weather caused by FRONT
temperatures are high. descending warming here • In tropical easterlies, tropical cyclones travel westwards
- Occur in early autumn – late summer at 20km/h and cover 200km of land a day
• Dramatic weather is in the eyewalls, there is a rapid uplift of
- In southern hemisphere occur from February to April • Once a mature cyclone develops, it lasts a week, it will
air. temperature rapidly falls to dew point and huge
• This helps to initiate the low the low-pressure center. • last less when it reaches land
100 km thick cumulonimbus clouds develop to heights over 15
Energy used for evaporation is releases as latent head • form in late summer and early autumn, when water
km
when the water vapor condenses. Does latent heat surface is warmest. In southern hemisphere, they are
• Heavy rain and thunderstorms, rough seas due to strong wind common in February and march
provide the energy needed for the tropical cyclone. To • Either sides of the eyewall, dense cirrus, altostratus, cumulus
continue developing. It warms the air, causing it to rise • Cause damage to coastal areas, strong winds and heavy
clouds extent for 500 km =steady rain rainfall
further, and reduce the central the central low
pressure. This leads to further surface convergence
AREAS WHERE TC FORM:
and uplift of air.
• 30° 𝑵 & 30°𝑺 latitude, do not occur between equator
• INTENSE LOW-PRESSURE CELL: the hot air rising forms
5°𝑁 & 5°𝑆 because they depend on Coriolis force and
an intense low-pressure cell on the surface. The
at the equators the Coriolis force is 0
tropical jet stream in the upper air causes an upper air
• Occur on east side of continents – east side is warmed
low-pressure cell and this intensifies the low-pressure
by warm ocean currents
cell on the surface. Air is sucked into the low-pressure
• Move from region near equator toward coast of a
cell.
country, when they reach land they turn eastwards
• CORIOLIS FORCE: is necessary for the rotation of air Compare each factor in the eye away from the coast and out to sea
around the low-pressure center. Coriolis force is zero is
• Only occur over oceans that are warm.
the equator and weak close to it. Thus, tropical
cyclones do not form between 5° north and south
• HOW A TROPICAL CYCLONE GETS ITS ENERGY:
condensation releases latent heat into atmosphere
provides energy to sustain the cyclone. It makes the air
more unstable and contributes to the more air rising.
This causes large cumulonimbus clouds to form and
torrential rain. This leads to further surface
convergence and uplift of air
• Upper air diverges to remove the rapidly rising air in
the center of the cyclone and thus encourage
continues rising
• HOT MOIST AIR – develop at the ITCZ where the hot, • Cyclone Covers a diameter of 500 km. • Isobars around central low-pressure are circular
moist air from the tropical easterlies converge. A warm • The eye covers 25km, associated with subsiding air. the air • Pressure in center is low = 960 hPa, can go as low as 870
sea surface, with a temp of 27° (results in hot, humid, subsides thus, no clouds form in the region of the eye, sky is • Diameter= 600km – 1000km (smaller than MLC)
unstable air)water evaporates and rises quickly at this clear, air is still and calm. No rain falls • Develop in warm moist air mass, DOES NOT HAVE A
temp. this is why TC form in summer because • In the eye There is hot humid calm weather caused by FRONT
temperatures are high. descending warming here • In tropical easterlies, tropical cyclones travel westwards
- Occur in early autumn – late summer at 20km/h and cover 200km of land a day
• Dramatic weather is in the eyewalls, there is a rapid uplift of
- In southern hemisphere occur from February to April • Once a mature cyclone develops, it lasts a week, it will
air. temperature rapidly falls to dew point and huge
• This helps to initiate the low the low-pressure center. • last less when it reaches land
100 km thick cumulonimbus clouds develop to heights over 15
Energy used for evaporation is releases as latent head • form in late summer and early autumn, when water
km
when the water vapor condenses. Does latent heat surface is warmest. In southern hemisphere, they are
• Heavy rain and thunderstorms, rough seas due to strong wind common in February and march
provide the energy needed for the tropical cyclone. To • Either sides of the eyewall, dense cirrus, altostratus, cumulus
continue developing. It warms the air, causing it to rise • Cause damage to coastal areas, strong winds and heavy
clouds extent for 500 km =steady rain rainfall
further, and reduce the central the central low
pressure. This leads to further surface convergence
AREAS WHERE TC FORM:
and uplift of air.
• 30° 𝑵 & 30°𝑺 latitude, do not occur between equator
• INTENSE LOW-PRESSURE CELL: the hot air rising forms
5°𝑁 & 5°𝑆 because they depend on Coriolis force and
an intense low-pressure cell on the surface. The
at the equators the Coriolis force is 0
tropical jet stream in the upper air causes an upper air
• Occur on east side of continents – east side is warmed
low-pressure cell and this intensifies the low-pressure
by warm ocean currents
cell on the surface. Air is sucked into the low-pressure
• Move from region near equator toward coast of a
cell.
country, when they reach land they turn eastwards
• CORIOLIS FORCE: is necessary for the rotation of air Compare each factor in the eye away from the coast and out to sea
around the low-pressure center. Coriolis force is zero is
• Only occur over oceans that are warm.
the equator and weak close to it. Thus, tropical
cyclones do not form between 5° north and south
• HOW A TROPICAL CYCLONE GETS ITS ENERGY:
condensation releases latent heat into atmosphere
provides energy to sustain the cyclone. It makes the air
more unstable and contributes to the more air rising.
This causes large cumulonimbus clouds to form and
torrential rain. This leads to further surface
convergence and uplift of air
• Upper air diverges to remove the rapidly rising air in
the center of the cyclone and thus encourage
continues rising
