Earth Science Exam Notes

Earth Science Review

Key Relationships

• Warm air is less dense, causing it to float.
• Increased pressure leads to increased density: $M = DV$, $V = M/P$

Atmospheric Gases

• Earth's early atmosphere gases primarily originated from volcanic eruptions.

Latitude and Longitude

• Latitude is determined by Polaris' altitude.
• Latitude: North or South, reference line is the Equator.
• Longitude: East or West, reference line is the Prime Meridian.

Seasons

• Reasons for seasons: Tilt, Revolution, and Parallelism.
• Distance from the sun and rotation do NOT cause seasons.
• Perihelion (Jan 3rd): Earth is closest to the sun.
• June 21st: Greatest sun angle, longest day, greatest intensity, highest/longest path.
• Dec. 21st: Lowest sun angle, shortest day, lowest intensity, lowest/shortest path.
• Equinoxes: 12 hours day and 12 hours night.
• Sun rises N of E and sets N of W in spring and summer.
• Sun rises S of E and sets S of W in fall and winter.
• Sun rises due E and sets due W on equinox dates.
• Direct ray is only between 23.5° N and 23.5° S.
• New York never gets a direct ray; face south to see the sun at noon.
• Earth revolves and rotates counterclockwise.

Moon Phases

• The moon revolves counterclockwise around the Earth.
• New Moon: Moon is between Earth and Sun.

Earth's Orbit

• Eccentricity: More eccentric means less circular orbit.
• Perihelion: Closest Earth/Sun distance on Jan 3rd.
• Aphelion: Farthest Earth/Sun distance on July 4th.

Celestial Observations

• Polaris is the North Star, found at the end of the Little Dipper's handle.
• Pointer Stars in the Big Dipper point to Polaris.

Galaxies and Universe

• Milky Way: Flattened spiral structure containing our solar system.
• Big Bang Theory: Explains the origin of the universe.
• Evidence: Red Shift and Cosmic Background Radiation.

Angle, Temperature, and Shadows

• Increasing angle increases intensity, which increases temperature.
• Temperature lag: Hottest time of day is in the afternoon; hottest time of year is after June 21st.
• High sun angle results in a short shadow; the highest angle at noon creates the shortest shadow.

Gravitational Pull

• Gravitational pull depends on mass and distance.

Models

• Heliocentric: Sun-centered model.
• Geocentric: Earth-centered model.

Tides

• Spring Tides: Occur during new and full moon phases.
• Neap Tides: Occur during quarter moon phases.

Greenhouse Effect

• Sun emits shortwave visible radiation.
• Earth emits longwave infrared radiation.
• CO2 and water vapor trap outgoing infrared radiation.
• Heat is absorbed during melting and evaporation.
• Heat is released during freezing and condensation.

Weather

• Air Pressure representation: If the value on a station model is 196, the air pressure is $1019.6$.
• Wind direction: Defined as the direction the wind is coming from.
• Example: NW wind means the wind is coming from the northwest.
• The closer air temperature is to the dew point, the greater the chance of condensation and precipitation; high humidity.
• When air temperature equals dew point, relative humidity is 100%.

Earth's Rotation and Revolution

• Evidence of Earth's rotation: Coriolis effect, pendulum, day and night, and satellite photos.
• Revolution: Going around the sun.

Rates and Gradients

• Gradient = Amount of Change / Distance (e.g., $\frac{300m - 100m}{17km}$).
• Rate = Amount of Change / Time (e.g., $\frac{70°C - 25°C}{20 minutes}$).
• Closely spaced lines indicate a great rate of change.
• Steep slope on a graph means fast rate.

Hemispheres

• Northern and Southern Hemisphere variations in temperature, intensity, angle, and duration throughout the year.

Coastal vs. Inland

• Inland areas: Big temperature range, more extreme temperatures (hotter summers, cooler winters).
• Coastal areas: Small temperature range, less extreme temperatures (warmer winters, cooler summers).