Hurricane Document Notes Flashcards
What are very strong tropical systems referred to as in North America?
Hurricanes
What are very strong tropical systems referred to as in China Sea?
Baguio
What are very strong tropical systems referred to as in Eastern Asia?
Typhoons
What are very strong tropical systems referred to as in India and Australia?
Cyclones
What are the conditions necessary for the development of tropical storms?
SST at least 27 degrees Celcius or 80 degrees Fahrenheight
The Coriolis force is outside of 3 to 5 degrees latitude
Very little vertical shear
The temperature is relatively constant over large surface areas
Relatively high mid-tropospheric moisture
A strong disturbance
What do disturbances that lead to tropical cyclone development include?
Decaying extra-tropical systems (MCC’s and fronts), waves in the ITCZ, and easterly waves
The African waves account for what percent of major hurricanes in the Atlantic and the Eastern Pacific?
85%
Atlantic hurricanes which originate directly off the coast of Africa are known as what?
Cape Verde storms
What happens when thunderstorms release large amounts of latent heat?
The latent heat warms the mid and upper troposphere. As a result of this heating, the air begins to diverge consequently by lowering the surface pressure
Surface convergence is enhanced by what?
Friction
Because of warm waters, the adiabatic cooling as the air crosses the isobars is balanced by what?
Conductive heating
What would happen if there were vertical shear associated with a hurricane?
The heat in the core of the hurricane would be transported away from the center, not allowing further strengthening
How does friction balance a tropical systems strength?
By limiting its intensity but maintaining its fuel supply (latent heat)
What can a body have?
Kinetic and potential energy
The internal energy of a body is a result of what?
The potential and kinetic energy of the molecules
The internal energy of the air parcel increases as a result of what?
Latent heat transferring heat to the gas
The potential energy of a parcel is increased by what?
The lifting of the air
What happens when air radiates to space near the top of the troposphere?
It becomes cooler, losing internal energy and subsides, causing a loss in potential energy
The process of a Hadley cell, likewise a Hurricane, likens a Carnot engine because why?
It loses energy at a cooler temperature than it gains back
In a Hadley Cell and Hurricane, what is the source of energy?
Sensible and latent heat from the sea/ocean
What does the First Law of Thermodynamics state?
A measure of heat transferred into a system will result in an increase in temperature and in the system’s ability to do work
What does the Second Law of Thermodynamics state?
Only in transferring heat from a warmer body to a colder body that heat can be converted into work in a cyclical process
What is the ITCZ defined as?
The result of the equatorial Hadley Cell where air converges near the equator, rises and diverges near the tropopause thereby transporting heat away from the equatorial regions in the upper troposphere
Observations have noted that the rate of precipitation greatly exceeds the rate of evaporation from the ocean in the vicinity of what?
The ITCZ
What is the ITCZ?
A distinct number of cloud clusters separated by large areas of clear air
The ITCZ is rarely over what?
The equator
Cloud clusters in the ITCZ propagate westward with weak wave disturbances over a period of how many days?
4 to 5 days
What does mass continuity dictate?
That regions of convergence at low levels must give way to divergence at higher levels
What is important regarding the Level of Non-Divergence (LND)?
The level where the mass divergence is zero
Where is the Level of Non-Divergence located in the tropics?
Near the 400 millibar level
Large scale convergence will occur in what way?
Cyclonically
Large scale divergence will occur in what way?
Anticyclonically
As storms develop in the tropics, there is considerable entrainment of what?
Relatively dry mid-tropospheric air into the incipient storms
Only a large cluster of cumulonimbus clouds can protect the inner core from what?
Evaporational cooling and the resulting negative buoyancy
Large disturbances off of Northern Africa generate what?
Sufficient thunderstorm activity
In April, African wave disturbances begin to occur in association with what?
Intense surface heating over the Sahara Desert
What is the average wavelength of African wave disturbances in April?
About 2500 kilometers with a period of 3 to 4 days
How many waves occur on average over North Africa each year?
About 60