Chapter 2 Flashcards
A measure of the average kinetic energy of the molecules in a substance. Higher temperatures correspond to more energetic molecules.
Temperature
The transfer of energy from a warmer object to a cooler one. It is transferred in the atmosphere by:
Heat
The direct transfer of heat through a substance, mainly affecting the surface of the Earth.
Conduction
The transfer of heat by the movement of fluid (air or water), such as rising warm air and sinking cool air.
Convection
The transfer of energy by electromagnetic waves. All objects emit radiation depending on their temperature.
Radiation
The heat absorbed or released during a phase change (e.g., from solid to liquid or liquid to gas), without changing temperature. It plays a significant role in atmospheric processes:
Latent Heat
Water absorbs latent heat and changes from liquid to vapor, cooling the surroundings.
Evaporation
Water vapor releases latent heat and changes back to liquid, warming the surroundings.
Condensation
Energy from the sun primarily in the form of shortwave radiation (visible light and UV radiation). It heats Earth’s surface, driving weather patterns.
Solar Radiation
Why the Earth Has Seasons
Earth emits longwave radiation (infrared) back to space. This energy is what balances the incoming solar radiation.
Terrestrial Radiation
The balance between incoming solar energy and outgoing terrestrial radiation, which maintains Earth’s average temperature.
Radiative Equilibrium
Around June 21, the Northern Hemisphere is tilted towards the sun, receiving more sunlight and experiencing summer.
Summer Solstice
Gases such as water vapor, carbon dioxide (CO₂), methane (CH₄), and ozone (O₃) that absorb longwave radiation from Earth’s surface and reradiate it back, trapping heat in the atmosphere.
Greenhouse Gases
The increase in greenhouse gases, especially due to human activities like burning fossil fuels, leading to additional warming of the Earth.
Enhanced Greenhouse Effect
Around March 21 and September 21, day and night are approximately equal because neither hemisphere is tilted towards or away from the sun.
Equinoxes
Around December 21, the Northern Hemisphere is tilted away from the sun, leading to winter.
Winter Solstice
Factors Affecting Earth’s Seasonal Variations
Sun Angle
Daylight
Distance from the sun
Clouds reflect incoming solar radiation, reducing the amount of energy that reaches Earth’s surface and contributing to cooling.
Clouds and Solar Radiation
Clouds also trap outgoing longwave radiation, contributing to warming at night. This dual effect makes clouds important regulators of temperature.
Clouds and Terrestrial Radiation
Caused by Earth’s axial tilt and its orbit around the sun, leading to variations in sunlight and day length
Seasons
Solar radiation, including visible light and ultraviolet, that is absorbed by the Earth’s surface.
Shortwave Raadiation
The percentage of incoming sunlight reflected by a surface.
Albedo
Radiation emitted by the Earth, primarily in the form of infrared radiation.
Longwave Radiation
The rate at which solar energy reaches the Earth, approximately 1367 watts per square meter.
Solar Constant
