GES 121 Midterm

Fall 2025 - Mark Cote

Shape of the Earth

oblate ellipsoid (geoid)

Relative location

to locate a place relative to other landmarks

Absolute location

locating a place using a coordinate system

Parallels

parallel to one another, intersect meridians at 90 degree angles, latitude

Meridians

NOT parallel to one another, intersect at the poles, longitude

Location of zero degrees longitude

Greenwich, England

Location of zero degrees latitude

Equator

90 Degrees North Latitude

North Pole

90 Degrees South Latitude

South Pole

Visible radiation

0.4 to 0.7 μm

Near-infrared

0.7 to 1.2 μm

Short-wave infrared

1.2 to 3.0 μm

Middle infrared

3.0 - 6.0 μm

Thermal infrared

6.0 - 13 μm

Stefan-Boltzmann

The warmer the object, the greater amount of radiation emitted

Wien’s Law

The warmer the object, the shorter the wavelength

Sun’s surface temperature

~6,000 degrees C

Solar Constant

1366 W/m²

Clouds _____ reflection and absorption of radiation

increase

Energy emitted from the sun

shortwave radiation

The Greenhouse Effect

Radiatively active (Greenhouse) gases absorb longwave radiation and the energy gained is then radiated, some of it toward the Earth’s surface

Insolation

incoming solar radiation

Daily insolation is at its maximum at the pole when?

Summer solstice

Composition of the atmosphere (Constant gases)

N (78%), O (21%), Ar (~1%)

Composition of the atmosphere (Variable gases)

Water vapour, Carbon Dioxide, Methane, CFCs, dust and particulates

Conduction

molecule to molecule, (surficial heating of soil, air in a shallow layer)

Convection

fluids, temperature-density driven (turning over of water, thermals of air)

Radiation

Emitted in waves/ doesn’t need a medium (from the Sun or Earth)

Sensible heat

heat that can be felt/measured

Latent heat

heat associated with the change of state of a substance (usually water)

Albedo

percentage of radiation reflected

Earth’s albedo

49% direct radiation, 31% reflected back to space (3% by scatter, 19% by clouds, 9% by ground), 20% absorbed by atmosphere

Incoming Shortwave Radiation

originates at sun and arrives through the atmosphere

Reflected (outgoing) Shortwave Radiation

reflected by the ground and atmosphere, determined by albedo

Incoming Longwave Radiation

emitted by the atmosphere, atmosphere heats because it absorbs SW radiation

Outgoing Longwave Radiation

emitted by the surface, surface is heated by absorbing SW radiation

Surface temperature is determined by:

energy balance, sensible heat, conduction, convection, and latent heat transfer

Solar radiation composition

5% ultraviolet, 45% visible, 50% infrared

Rotation

diurnal cycle

Revolution

annual cycle

Perihelion

closest approach of Earth to the sun (January 3rd)

Aphelion

maximum distance from Earth to sun (July 4th)

Earth’s axial tilt

23.43631 degrees

One solar year

365.26 days

The analemma

a plot that shows the position of the sun in the sky at a given time of day at one place measured throughout the year

Equinox

the moment the subsolar point corresponds with the equator, OR, when the sun is at zenith on the equator, OR, the day which the Declination is 0°

Vernal (Spring) Equinox

March 21-22

Autumnal Equinox

September 22-23

Equinox sunrise

due east

Equinox sunset

due west

Solstice sunrise

maximum positive or negative angle north or south of east

Solstice sunset

maximum positive or negative angle north or south of west

Solstice

the moment at which the subsolar point corresponds with the one of the tropics

Winter solstice

December 21-22

Summer Solstice

June 21-22

The troposphere

is the lowest layer of the atmosphere (nearest to the ground)

Order of parts of atmosphere, lowest to highest

troposphere, tropopause, stratosphere, stratopause, mesosphere, mesopause, thermosphere

Temperature inversion

upper air is warmer than lower air

Dew point

temperature at which saturation occurs (under constant pressure and water vapour content)

Adiabatic

no exchange of energy with the environment