Physical Geography
1114-010
NAME:
HOMEWORK ASSIGNMENT #2
CHAPTERS 4 & 5
Due: Friday 9/6
15 points
Ch. 4
1.
What is the difference between heat (thermal energy) and temperature?
Heat is energy that transfers from one object or subtstance to another because of a difference in temperature
whereas temperature is the average kinetic energy of the molecules in a substance. The higher the internal kinetic
energy, the higher the temperature.
2.
Describe and contrast the portions of the electromagnetic spectrum referred to as shortwave radiation and
longwave radiation (terrestrial radiation). What is insolation?
Shortwave radiation and longwave radiation can be seen on the electromagnetic spectrum. Shortwave radiation
starts with cosmic rays and moves towards the longer wavelengths, which ends with long radio waves. Insolation
is incoming solar radiation.
3.
How is scattering different from reflection. Why is the sky blue? Why are sunsets orange and red?
Scattering is the detection of light waves by molecules and particles, whereas during reflection, objects reflect
back the electromagnetic radiation. The sky is blue because the blue portion of the electromagnetic spectrum is
the most scattered. During sunsets, the electromagnetic radiation travels a longer distance with a reduced angle,
and red and orange scatter more.
4.
Describe the processes of conduction, convection, and advection.
Conduction is the movement of energy from one molecule to another without changing the relative positions of
the molecules. It enables the transfer of heat between different parts of a stationary body.
Convection is the energy transfer through the vertical circulation and movement of fluids, such as air, due to
density differences.
Advection is horizontal transfer of energy, such as through the movement of wind across Earth’s surface.
5.
What happens to the temperature of rising air? Of descending air? Why? What is latent heat?
The temperature of rising air decreases because the air expands when it rises and the molecular collissionss
decrease resulting in a temperature decrease. When air descends and compresses, collisions increase so
temperatures and pressure increase. Latent heat is heat that is released or absorbed during a phase change. It is
“latent” because heat is not felt. It is most commonly found in evaporation and condensation.
6.
Why is evaporation considered a cooling process and condensation a warming process?
Evaporation is considered a cooling process because energy is stored, whereas in condensation energy is released
to sensible, or latent, heat.
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8.
What is meant by the angle of incidence of the Sun’s rays?
Why are there greater seasonal temperature differences in the high latitudes than in the tropics?
The angle of incidence of the sun’s rays is the angle at which rays strike the earth. There are greater seasonal
temperature differences in the high latitudes than in the tropics because of the way the sun’s rays strike the earth
along with the tilt of the earth. The temperature differences are also dependent on the time of year.
9.
What are the two dominant mechanisms of heat transfer around the world?
The two dominant mechanisms of heat transfer around the world are atmospheric circulation and oceanic
circulation.
10.
What is an isotherm? Where in the world do we find the greatest average annual temperature ranges and
where do we find the smallest average annual temperature? Why?
An isotherm is a line joining points of equal temperature. Annual temperature range is the difference between the
average temperature of the coldest month and the warmest month. The greatest variations occur in the interiors of
high-latitude continents and continental areas in general experience much greater ranges than oceanic latitudes.
The smallest variations can be found in the tropics especial over tropical oceans.
Ch. 5
1.
What causes a thermal high near the surface? A thermal low?
Very cold surface conditions are often associated with high pressure at the surface and very warm surface
conditions are often associated with relatively low pressure at the surface.
2.
What causes a dynamic high near the surface? A dynamic low?
Strongly descending air is usually associated with high pressure at the surface which causes a dynamic high and
strongly rising air is usually associated with low pressure at the surface and causes a dynamic low.
3.
What is meant by pressure gradient? When referring to air pressure, what is a high, a low, a ridge, and a
trough?
Pressure gradient force is what creates the response to if there is higher pressure in one area than in another and
air will begin to move from the higher pressure towards the lower pressure. A high-pressure area is a ridge, and a
low-pressure area is a trough.
4.
What is a cyclone? An anticyclone?
A cyclone is a low-pressure center and an anticyclone is a high-pressure center. Both are referring to wind-flow
patterns.
4.
What are the Hadley cells and what generally causes them?
The Hadley cells are two complete vertical convective circulation cells between the equator, where warm air rises
in the ITCZ and 25 degree to 30 degree latitudes. This is where much of the air subsides into the subtropical
highs.
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5.
What is meant by the horse latitudes and the doldrums?
Horse latitudes are areas in the subtropical highs that care characterized by warm sunshine and an absence of
wind. The doldrums are the belt of calm ir associated with the region between the trade winds of the Northern
and Southern hemispheres, generally in the vicinity of the equator and the region of the intertropical convergence
zone.
6.
Describe the general location and characteristics of the jet streams of the westerlies.
The jet streams are a rapidly moving current of wind in the upper troposphere. They can be thought of as the
high-speed “cores” of the high altitude westerly wind flow that frequently meander in a north-south direction
over the mid-latitudes.
The westerlies are a great wind system of the mid-latitudes that flows basically from west to east around the
world in the latitudinal zone between about 30 and 60 degrees both north and south of the equator.
7.
What are Rossby waves?
A Rossby wave is a very large north-south undulation of the upper-air westerlies and jet stream.
8.
Describe and explain the South Asian Monsoon.
The South Asian Monsoon is the first of the two major monsoon systems. Prominent onshore winds spiral in
from the Indian Ocean bringing a significant amount of rain to the subcontinent.
9.
What is El Nino? Contrast the oceanic and atmospheric conditions during an El Nino event with hose of a
La Nina event.
El Nino is the periodic atmospheric and oceanic phenomenon of the tropical Pacific that typically involves the
weakening or reversal of the trade winds and the warming of surface water off the west coast of South America.
During El Nino, abnormally warm water appears at the surface of the ocean off the west coast of South America.
La Nina is the opposite of El Nino: the waters off South America become unusually cool, the trade winds become
stronger than usual, the waters off Indonesia are unusually warm and the southwester US is drier than usual while
Southeast Asian and northern Australia are wetter.
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