Solar Energy & Seasons Lecture Review

Vocabulary flashcards covering topics from the lecture on solar energy and seasons, including geographic coordinates, solar system characteristics, electromagnetic radiation, and Earth's orbital dynamics related to seasonality.

Thomas Richardson

A San Antonio native and UTSA B.A. (2023) in Geography and Environmental Sustainability, currently an M.A. candidate, who studied freshwater salinization in the San Antonio River.

Freshwater Salinization

The topic Thomas Richardson has studied in the San Antonio River, concerning the river's ecological health and impacts from urban wastewater.

Parallels of latitude

Lines on a map or globe that run east to west, defining positions North or South of the Equator.

Meridians of longitude

Lines on a map or globe that run North to South, defining positions East or West of the Prime Meridian.

Northern Hemisphere

The half of Earth north of the Equator.

Southern Hemisphere

The half of Earth south of the Equator.

Equator

The imaginary line around the middle of Earth, equidistant from the North and South Poles, at 0° latitude.

Tropic of Cancer

A parallel of latitude at 23°26' N.

Tropic of Capricorn

A parallel of latitude at 23°26' S.

Arctic Circle

A parallel of latitude at 66°34' N.

Antarctic Circle

A parallel of latitude at 66°34' S.

North Pole

The northernmost point on Earth, at 90° N latitude.

South Pole

The southernmost point on Earth, at 90° S latitude.

Solar System

Located in the Milky Way Galaxy, consisting of eight planets and over 100 moons, condensed from a nebula.

Nebula

A large, slowly rotating, collapsing cloud of dust and gas from which the Solar System condensed.

Perihelion

The point in Earth's elliptical orbit where it is closest to the Sun (around Jan 3).

Aphelion

The point in Earth's elliptical orbit where it is furthest from the Sun (around July 4).

Sun

The primary energy source for Earth's atmosphere and biosphere, creates energy through fusion reactions by forcing hydrogen atoms together to form helium.

Fusion Reaction (Sun)

The process in the Sun where high temperatures and pressure force hydrogen atoms together to form helium, releasing energy.

Solar Cycle

Captures the variation of solar output, characterized by an 11-year cycle between solar minimum and solar maximum.

Sunspots

Magnetic storms that appear as dark areas on the Sun; more sunspots generally mean more solar radiation.

Solar Winds

Clouds of electrically charged particles constantly emitted by the Sun.

Magnetosphere (Earth's)

Deflects charged particles from solar winds towards the poles.

Auroras

Produced in high latitudes when solar winds interact with Earth's upper atmospheric layers.

Electromagnetic Waves

Waves with electrical and magnetic properties emitted by the Sun, enabling them to pass through the vacuum of space.

Electromagnetic Spectrum

Captures all the different wavelengths of electromagnetic energy.

Longer Wavelength (Electromagnetic Radiation)

Associated with lower energy and lower frequency.

Shorter Wavelength (Electromagnetic Radiation)

Associated with higher energy and higher frequency.

Visible Light (Solar Emission)

Accounts for approximately 47% of the Sun's emitted energy.

Infrared (Solar Emission)

Accounts for approximately 45% of the Sun's emitted energy.

UV, X-Ray, & Gamma (Solar Emission)

Account for approximately 8% of the Sun's emitted energy.

Temperature

The average kinetic energy (speed of molecular movement) of individual molecules.

Heat

The transfer of kinetic energy between objects due to temperature differences (from hot to cold).

Shortwave Radiation

Emitted by the Sun, concentrated around 0.5 μm in the visible portion of the spectrum.

Longwave Radiation

Emitted by the Earth, concentrated around 10 μm in the infrared portion of the spectrum.

Insolation

Incoming solar radiation intercepted by Earth, measured in watts per square meter (W/m²).

Solar Constant

The average insolation received at the top of the atmosphere, approximately 1372 W/m².

Total Solar Irradiance (at Earth's distance)

Approximately 1360 W/m² at Earth's distance from the Sun.

Solar Irradiance (at sea level)

Roughly 1000 W/m² at sea level, after absorption by atmospheric gases and water vapor.

Insolation Distribution (Earth's Curved Surface)

Uneven across latitudes due to Earth's curved surface.

Subsolar Point

The only place where insolation arrives perpendicular to the surface, occurring between 23.5°N/S, where energy is most concentrated.

Net Radiation

The balance between incoming shortwave and outgoing longwave radiation, with positive values in lower latitudes and negative values in higher latitudes, driving atmospheric and oceanic circulations.

Seasonality

Describes changes in insolation throughout a given year, influenced by Sun Altitude and Daylength.

Sun Altitude

The angle between the horizon and the Sun, influencing seasonality.

Daylength

The duration of insolation between sunrise and sunset, influencing seasonality.

Earth's Orbital Characteristics

Revolution, Rotation, and Tilt, which produce seasonal and diurnal variations.

Plane of Ecliptic

The plane in which Earth orbits the Sun.

Revolution

Earth's 365.2-day elliptical orbit around the Sun, defining the year and seasons, but not a significant factor in seasonality due to small distance variation.

Rotation

The turning of Earth on its own axis every ~24 hours, determining daylength and creating the apparent deflection of winds/currents.

Circle of Illumination

Divides areas experiencing day and night; at the equator, daylight is always evenly divided between 12 hours of day and night.

Tilt (Earth's Axis)

The axis of Earth is tilted 23.5°, which is the most important orbital parameter for seasons; causes hemispheres to receive more direct insolation when tilted towards the Sun.

Winter Solstice

Occurs in December (Dec 21 or 22) when the sun is directly overhead 23.5°S (Tropic of Capricorn); the North Pole is in complete darkness, and the Northern Hemisphere receives less intense insolation.

Vernal Equinox

Occurs in March (March 20 or 21) when the sun is directly overhead at the Equator; the circle of illumination passes through both poles, and all locations on Earth experience 12 hours of day/night.

Summer Solstice

Occurs in June (June 20 or 21) when the sun is directly overhead 23.5°N (Tropic of Cancer); the North Pole experiences daylight for 24 hours, and the Northern Hemisphere receives more intense insolation.

Autumnal Equinox

Occurs in September (Sept 22 or 23) when the sun is directly overhead at the Equator; the circle of illumination passes through both poles, and all locations on Earth experience 12 hours of day/night.