Why are the tropics differentfrom the midlatitudes rculations not in geostrophicor summer when ITCZ is around Recall that midlatitude cyclones derive their energy from the large temperature gradie ID: 939361
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ATMO 436aHurricanes Why are the tropics differentfrom the mid-latitudes? rculations not in geostrophicor summer when ITCZ is aroun
d Recall that mid-latitude cyclones derive their energy from the large temperature gradientBecause there are virtually no temperatu
re differences in the tropics, a storm in the tropics has to get its energy from a different source.WARM MOIST AIR WHICH RELEASES
ITS ENERGY BY CONDENSATION IN CLOUDS. warm region to a cool region, converting some of that energy to In the hurricane :Warm region
= warm and moist air above oceans surfaceCool region = cold cloud top (the exhaust)Energy conversion takes place by latent heat r
elease in the cloud.WARM REGIONWARM REGIONCOOL REGIONCOOL REGION(Emmanuel)ATENT HEATLATENT HEATRELEASERELEASE Fuel =Favorable envir
onmental conditions Ingredients for a HurricaneFavorable environmental conditions Warm water �(82 °F) through a deep layerCo
nditionallyunstable atmosphere with very Typically a tropical easterly wave, or enhanced area of thunderstorms which propagates we
stward within the ITCZ. FUELEXHAUST African Easterly WavesA Trigger for Atlantic Hurricanes Areas of enhanced thunderstorms propaga
ting westwardThunderstorms originate in west Africa . Westward Propagation Easterly wavesEasterly waves If the cluster of thunders
torms within the easterly wave grow to be large enough, they may start to feel the effects of the Earths rotation.Then they start
to spin about an deepening area of low pressure. Why does the surface pressure drop? LLHH High pressure and divergenceLow pressure
and convergence LATENT HEAT LATENT HEAT RELEASE WARMS AND EXPANDS THE COLUMNCOLUMNOnce this process gets going, the surface low ca
n continue to deepen and the storm can grow so long as the environmental conditions are right! Tropical Depression Low pressure s
ystem and starts to spin about an axis of rotation.Winds : About 20-40 miles per hour. Tropical Storm Winds : 35 75 mph ONCE THE W
INDS EXCEED 75 MPH, THE STORM IS A HURRICANE.Hurricanes are called various other names throughout the world, but it is basically th
e same type of storm. Tropical Cyclone NomenclatureNORTHERN HEMISPHERE: Counterclockwise rotation Cyclone: Northern Indian Ocean (
including Bay of Bengal and SOUTHERN HEMISPHERE: Clockwise rotation Cyclone: South Pacific and Southern Indian Ocean Tropical cyclo
ne genesis regions (red) Observations: starting about 5°latitude Tropical Cyclones hitting Brazil? A symptom of global warming? M
arch 2004 Hurricane Intensity given by the Saffir-Simpson ScaleCategories range from 1 to 5.MAJOR HURRICANE ISCATEGORY 3 OR ABOVE(W
ell look at some from the 2005 season) Category 1 Hurricane : 74-95 mphPressure : A little more than Tree branches, shrubs, and u
nanchored objects.Hurricane Ophelia Category 2 Hurricane : 96-110 mphPressure : 965 979 mb Trees blown down, damage to mobile home
s and roofs of buildings.Hurricane Katrina CATEGORY 3 HURRICANE Winds : 111-130 mphPressure : 945 964 mb Large trees blown down, m
obile homes destroyed, structural damage to buildings.Hurricane Katrina CATEGORY 4 HURRICANE Hurricane RitaWinds : 131-155 mphPress
ure : 920 944 mb and buildings, inland flooding as far as about 5 miles. CATEGORY 5 HURRICANE Hurricane KatrinaAugust 29, 2005Wind
s : 156 mph and greaterPressure : Below 920 mbAs in Category 4, a very symmetrical structure and smaller!Hard to maintain this DAMA
GE INFRASTRUCTURE SEVERELY DAMAGED. NEARLY TOTAL DEVASATION OF ALL COASTAL ZONES WIPED CLEAN BY HIGH STORM SURGE. Structure of
a Mature Hurricane Well organized rain bands, of in : An area of relative clear, calm winds and sinking air. Sinking air warms due
to compression. Where the lowest pressure occurs. LLHHCyclonic inflowCyclonic inflowAnticyclonicAnticyclonicoutflow The Eye from
a Hurricane Hunter Flight Hurricane Tracks: 2005 Each storm has a UNIQUE track that is dependent on the specific weather situation
at the time. tty good up to a few days, but forecasting intensity is still very hard! Asymmetry of hurricane winds:Gulf coast exa
mple (Agudoand Burt) WIND and weak tornadoes (F1 F2)IT IS CAUSED BY THE LOW PRESSURE AND WINDS OF THE HURRICANEAND NOT AN EARTHQU
AKE. Williams, The Weather Book Surge: Hurricane nearing coastline Williams, The Weather Book Surge: Hitting coastline Williams, Th
e Weather Book IN THE METEOROLOGICAL COMMUNITY PRIOR TO KATRINA THAT NEW ORLEANS WAS A MAJOR DISASTER WAITING TO HAPPEN! because:ca
use the eye to fill in.water (like the North Tropical Storm Katrina Hurricane Camille: August 1969 This was a Category 5 storm tha
t was VERY MUCH LIKE KATRINAMade landfall on the Mississippi coast, near Pass Christian. Pass Christian, MSPass Christian, MS Riche
lieu Apartments BEFORE CAMILLEAFTER CAMILLE Hurricane Ike: September 2008 Galveston, TX: Before Hurricane Ike Galveston, TX: After