GGH1501 - Learning Unit 3
,Learning Unit 3 (Key processes in the physical
environment)
Units left out:
Coastal processes and landforms, PB Sect B: 84-85
Glacial processes and landforms, PB Sect B: 86-89
The physical environment of the Earth is both diverse and dynamic. It is diverse in
the sense that no two locations are exactly the same and it is dynamic due to the
variety of processes that are constantly shaping the physical environment. All the
individual physical processes are interconnected, but also interact with a variety of
other processes that are occurring within the Earth’s four major physical systems
(namely the atmosphere, hydrosphere, lithosphere and biosphere) and ultimately
contribute towards the creation of one system which sustains life on Earth.
Key Terms:
Weather, Climate, and Climate Change: Section B, pages 32 to 63.
Adiabatic cooling:Cooling of air as a result of the expansion of the rising air.
Adiabatic means “without heat being involved”.
Advection: Horizontal movement of air or substances by the wind or
ocean currents.
Angle of The angle where solar radiation strikes a specific place at a
incidence: point in time.
Autumnal equinox: In the Northern Hemisphere Sept 22/23. At noon the
perpendicular rays of the sun strikes the equator. The Sun
is directly above the equator.)
Carbon dioxide: A gas found in the atmosphere, CO ; a major contributor to
the greenhouse effect.
Climate: The weather conditions prevailing in an area in general or
over a long period.
Cold front: The boundary formed when a cold air mass advances
against a warmer one.
Condensation: Water changing from a gas state (vapor) to a liquid or solid
state.
Convection: Circulation in a fluid caused by temperature-induced density
differences, such as rising of warm air in the atmosphere.
Coriolis effect: The tendency of an object moving across Earth’s surface to
be deflected from its apparent path as a result of Earth’s
rotation.
Cyclone: Large low-pressure areas in which wind converge in a
counterclockwise swirl in the Northern Hemisphere, or
clockwise in the Southern Hemisphere.
Desert climate: A climate with low precipitation and temperatures warm
enough to cause potential evapotranspiration to be
substantially higher than precipitation.
,El Niño: A circulation change in the eastern tropical Pacific Ocean,
from westward flow to eastward flow, that occurs every few
years.
Front: Boundary between warm air and cold air.
Global warming: A general increase in temperatures over a period of at least
several decades caused primarily by increased levels of
carbon dioxide in Earth’s atmosphere.
Greenhouse Trace substances in the atmosphere that contribute to the
gasses: greenhouse effect, water vapor, carbon dioxide, ozone,
methane, and chlorofluorocarbons are important examples.
Gyre: A circular ocean current beneath a subtropical high-
pressure cell.
Hurricane: An intense tropical cyclone that develops over warm ocean
areas in the tropics and subtropics, primarily during the
warm season. Hurricanes in the Pacific Ocean are called
typhoons, in the Indian Ocean they’re called cyclones.
Insolation: The amount of solar energy intercepted by a particular area
of Earth.
Intertropical A low-pressure zone between the Tropic of Cancer and the
Convergence Zone Tropic of Capricorn where surface winds converge.
(ITCZ):
Latent heat: Heat stored in water and water vapor, not detectable by
people, latent means “hidden”.
Little Ice Age: The period between 1500-1750, when climates on Earth
were especially cool.
Longwave energy: Energy reradiated by Earth in wavelengths of about 5.0 –
30.0 microns. Includes infrared radiation, which we sense
as heat.
Methane: A trace gas found in the atmosphere with chemical formula
CH ; a major contributor to the greenhouse effect.
Midlatitude A storm characterized by a center of low pressure in the
cyclone: midlatitudes usually associated with a warm and cold front.
Midlatitude low- Regions of low pressure and air converging from the
pressure zones: subtropical and polar high-pressure zones.
Monsoon Seasonal reversal of pressure and wind in Asia, in which
circulation: winter winds from the Asian interior produce dry winters and
summer winds blowing inland from the Indian and Pacific
oceans produce wet summers.
Orographic Precipitation caused by air being forced to rise over
precipitation: mountains.
Ozone: A gas composed of molecules with 3 oxygen atoms; it’s
highly corrosive gas at ground level, but in the upper
atmosphere essential to protecting life on Earth by
absorbing ultraviolet radiation.
Polar front: A boundary between cold polar air and warm subtropical air
that circles the globe in the midlatitudes.
Polar high- Regions of high pressure and descending air near the North
pressure zones: and South poles.
, Quaternary Period: The period of geologic time encompassing approximately
the last 3 million years.
Radiation: Energy in the form of electromagnetic waves that radiate in
all directions.
Relative humidity: The actual water content of the air compared to how much
water the air could potentially hold, expressed as a
percentage.
Semiarid climate: A climate with precipitation slightly less than potential
evapotranspiration for most of the year.
Sensible heat: Heat detectable by sense of touch, or with a thermometer.
Shortwave energy: Radiant energy emitted by the Sun in wavelengths about
0.2-0.5 microns.
Solar energy: The radiant energy from the Sun.
Storm surge: An area of elevated sea level in the center of a hurricane
that may be several meters high, and which does most of
the damage when a hurricane comes ashore.
Subtropical high- Regions of high pressure and descending air at about 25°
pressure (STH) north and south latitudes.
zones:
Summer solstice: For places in the Northern Hemisphere, June 20/21 is the
date when at noon the Sun is directly overhead along the
parallel of 23.5° north latitude; for places in the Southern
Hemisphere, December 21/22 is the date when at noon the
Sun is directly overhead at places along the parallel of 23.5°
south latitude.
Tornado: A rapidly rotating column of air usually associated with a
thunderstorm, often having winds in excess of 300km/h.
Trade wind: The prevailing wind in subtropical and tropical latitudes that
blows toward the Intertropical Convergence Zone, typically
from the northeast in the Northern Hemisphere and from the
southeast in the Southern Hemisphere.
Tropic of Cancer: The parallel of 23.5° north latitude.
Tropic of The parallel of 23.5° south latitude.
Capricorn:
Typhoon: The name applied to a hurricane in the Pacific Ocean.
Vernal (spring) In the Northern Hemisphere March 20/21, one of two days
equinox: when at noon the perpendicular rays of the Sun strike the
equator(the Sun is directly overhead along the equator).
Warm front: A boundary formed when a warm air mass advances
against a cooler one.
Water vapor: Water in the air in gaseous form.
Wavelength: The distance between successive waves of radiant energy,
or of successive waves on a water body.
Winter solstice: For places in the Southern Hemisphere, June 20/21 is the
date when at noon the Sun is directly overhead at places
along the parallel of 23.5° north latitude; for places in the
Northern Hemisphere, December 21/22 is the date when at
noon the Sun is directly overhead at places along the
parallel of 23.5° south latitude.