Chapter 2: Warming and Cooling and the Atmosphere

What is potential energy?

Stored energy due to an object's position or state. In the atmosphere, potential energy is associated with air masses at different altitudes (higher altitude = more potential energy)

What is Kinetic energy ?

The energy of motion.

How is kinetic energy defined in the atmosphere?

In the atmosphere, kinetic energy is represented by the movement of air molecules and is directly related to temperature; faster-moving molecules result in higher temperatures.

Warm air

less dense, causing it to rise. It holds more moisture and has lower pressure.

Freezing point in Fahrenheit (°F)?

32°F

Boiling Point in Fahrenheit (°F)?

212 °F

absolute zero in Fahrenheit (°F)?

-459.67°F

Freezing point in Celsius (°C)?

0°C

Boiling Point in Celsius (°C)?

100°C

Absolute zero in Celsius (°C)?

-273.15°C

Freezing Point in Kelvin?

273.15 K

Boiling Point in Kelvin?

373.15 K

Absolute Zero in Kelvin

0 K

Heat capacity?

The total amount of heat required to change the temperature of a substance

Specific Heat

The amount of heat needed to change the temperature of one unit mass of a substance by one degree Celsius.

Cold air

denser, making it sink. It holds less moisture and has higher pressure.

Which has a higher heat capacity? Water or Land?

Water heats and cools more slowly which is why oceans help regulate Earth’s climate, water can absorb and store more heat without a significant temperature change.

Latent J

The heat absorbed or released during a phase change of a substance, such as evaporation or condensation, without changing its temperature.

What is Latent heat of evaporation?

The amount of heat required to convert a unit mass of a substance from liquid to vapor without a change in temperature.

What is Latent heat of condensation?

Heat is released when water vapor turns into liquid (warming process)

longwave energy

High-energy radiation from the Sun (e.g., ultraviolet, visible light).

shortwave energy

Lower-energy radiation emitted by Earth (infrared heat radiation).

Electromagnetic Spectrum

representsthe range of all types of electromagnetic radiation, including visible light, infrared, and ultraviolet.

What are the primary types of solar radiation?

mostly shortwave energy (UV, visible, near-infrared)

What are the primary types of Earth radiation?

mostly longwave infrared energy

Natural greenhouse effect

certain gases trap some of Earth’s outgoing heat, keeping the planet warm (~33°C warmer)

Man-made greenhouse effect

Excess greenhouse gasses (CO₂, CH₄) from human activities enhance the greenhouse effect, leading to global warming

Albedo

the amount of light reflectivity a surface has (higher = more reflection)

Average Earth albedo

~30% (.30)

Surfaces with high albedo

ice, snow, clouds

surfaces with low albedo

oceans, forest, asphalt

Absolute Zero

The lowest possible temperature (0 K), where molecular motion stops

Heat

energy transfer due to temperature differences

Kelvin Scale

a temperature scale starting at absolute zero, used in scientific studies

Fahrenheit Scale

a temperature scale mainly used in the U.S.

Celsius Scale

a temperature scale used worldwide, based on water’s freezing and boiling points

Latent Heat

Heat energy absorbed or released during phase changes (condensation, evaporation, etc.)

Sensible Heat

can be felt; heat that changes temperature but not phase

Conduction

heat transfer through direct contact

convection

heat transfer through fluid movement (air or water currents)

Thermals

rising columns of warm air due to convection

Advection

The horizontal transfer of heat, moisture, or air properties; typically by wind.

Radiant Energy

energy emitted as electromagnetic waves

What is another word for “Radiant Energy”?

Radiation

Electromagnetic waves

waves that transfer energy without needing a medium

Micrometer (µm)

unit of measurement for radiation wavelengths

Photon

particles of light carrying electromagnetic energy

Visible region

The part of the EM spectrum detectable by the human eye

Ultraviolet Radiation

radiation with wavelengths shorter than visible light, often causing skin damage, and is absorbed by the ozone layer

Infrared Radiation

radiation with wavelengths longer than visible light, primarily associated with heat energy.

What is shortwave radiation?

Shortwave radiation refers to the high-energy radiation emitted by the Sun, including ultraviolet (UV), visible light, and near-infrared.

What is longwave radiation?

Lower-energy radiation emitted by Earth, mainly in the infrared spectrum.

What is a blackbody?

An idealized body that absorbs all radiation and emits a characteristic spectrum based on its temperature.

What are selective absorbers?

Materials that absorb radiation at certain wavelengths while allowing others to be transmitted or reflected.

What is Radiative Equilibrium Temperature?

The temperature at which the incoming energy from the Sun is equal to the outgoing energy emitted by the Earth, resulting in no net energy gain or loss.

What is the greenhouse effect?

The process by which certain gases in Earth's atmosphere trap heat, keeping the planet warmer than it would be without these gases.

What are greenhouse gases?

Gases in the Earth's atmosphere that trap heat, including carbon dioxide (CO2), methane (CH4), and water vapor (H2O).

What is the atmospheric window?

The range of wavelengths in the infrared spectrum that can escape the Earth's atmosphere without absorption, allowing heat to radiate into space.

What is the solar constant?

The amount of solar energy received per unit area at the top of the Earth's atmosphere on a surface perpendicular to the Sun’s rays, approximately 1361 W/m².

What is scattering?

The process by which solar radiation is redirected in different directions upon encountering particles in the atmosphere.

What does reflected (light) refer to?

Light that bounces off surfaces instead of being absorbed, contributing to the overall energy balance of the Earth.

What is albedo?

The measure of reflectivity of a surface, expressed as a fraction or percentage; higher albedo surfaces reflect more sunlight.

What is the summer solstice?

The longest day of the year in the Northern Hemisphere, occurring around June 21, when the Sun is directly over the Tropic of Cancer.

What is the autumnal equinox?

The date in September when day and night are approximately equal in length, marking the beginning of fall in the Northern Hemisphere.

What is the winter solstice?

The shortest day of the year in the Northern Hemisphere, occurring around December 21, when the Sun is directly over the Tropic of Capricorn.

What is the vernal equinox?

The date in March when day and night are approximately equal in length, marking the beginning of spring in the Northern Hemisphere.