Global Change Exam 1

What are the 3 main pieces of evidence for the Big Bang?
Redshift, Cosmic Microwave Background Radiation, and the Distribution/Abundance of Elements
What are the long and short wave colors?
Red is longer wave/lower energy, Blue is shorter wave/higher energy
Stefan-Boltzmann Law
Total energy emitted is proportional to the temperature.
Wien’s Law
Peak electromagnetic radiation is inversely related to the temperature of a black body.
Planck’s Law
A hot body emits more energy at shorter wavelengths. All bodies radiate energy over a range of wavelengths.
(Newton’s) Inverse Square Law
Solar flux is inversely proportional to the square of the distance from the Sun
Radiative Equilibrium
Assumes that incoming radiation is equivalent to outgoing radiation.
Albedo
Reflectivity of the Sun’s light of a specific surface.
Band Saturation
Complete absorption of radiation at specific wavelengths.
Radiative Forcing
Change in net (down minus up) irradiance at the tropopause
Solar flux
The rate at which energy reaches a unit of area.
Solar luminosity
Amount of energy radiated per unit of time.
What caused initial oxygen rise?
Volcanoes going off, photosynthesis by early plants.
Lapse Rate
Change in temperature by altitude.
How do the atmospheric layers’ temperatures change?
Troposphere: Temperature decreases with height. Stratosphere: Temperature increases. Mesosphere: Temperature decreases.
What are the terrestrial planet’s atmospheres like?
Venus: runaway greenhouse effect, Earth: just right, Mars: refrigerator.
What caused the decline in atmospheric CO2 in early earth?
The weather of silicate rocks, such as granite, trapped CO2.
How did silicate rocks lower CO2 levels?
Acid interacts with rocks, which strips the mineral apart and all the different components interact, leaving calcium carbonate.
Greenhouse Gas
Atmospheric gas that absorbs in the longwave spectrum.
What determines the effectiveness of a Greenhouse Gas?
-Concentration of the gas in the atmosphere
-Frequency of the absorption band relative to the blackbody spectrum for Earth
-Lifetime
Why is the Greenhouse Effect of CO2 decreasing?
It is decreasing because of band saturation, Co2 concentration is increasing, lowering the marginal Greenhouse Effect.
How is the greenhouse effect of H2O?
It is greater than that of CO2 by about 4x.
What is the age of the Earth?
4.54 billion years old.
What is the age of the solar system?
4.6 billion years old.
What is the formula for the Force of Gravity?
Gravitational constant(m1m2)/(r^2)
Asteroids, Meteoroids, Comets
planetoids (less than planet/bigger than meteoroids), meteoroids are 10m or less across, comet is a collection of dust.
Continental Drift
The hypothesis that continents are mobile.
What does ozone do in the troposphere?
In the troposphere, it’s a GHG that is toxic to organisms, destroys nylon/rubber/and stuff
What are aerosols?
Small particles or droplets in the atmosphere, usually on the size
What are the effects of aerosols?
Direct: Reflect and scatter incoming solar radiation.
Indirect: aerosols influence cloud properties.
Seasonal Changes in Aerosol Production
Summer biomass burning in Southern Africa and Brazil, Industrial aerosols in Europe and US, Mineral dust from Africa.
Doppler Effect
Compression or Relaxation of waves with relative motion. (Whistle of train)
Redshift
Shift in light froma star towards a longer/redder spectra due to Doppler Effect.
Hubble’s Law
Galaxies recede at a rate proportional to their distance: closer means slower, farther it is- faster it recedes.
Hubble’s Constant
Rate of recession of astronomical objects per distance away.
Age of the Universe?
Approximately 13.9 billion years old.
Megaparsec
Unit for measuring distance to neary galaxies.
Cosmic Microwave Background Radiation
Electromagnetic (microwave) radiation that fills the entire Universe and is a relic of the Big Bang.
When could light finally scatter after the Big Bang?
Approximately 300,000 years later in an event known as the Surface of Last Scattering.
How long did it take CBR to reach Earth?
Many billions of years due to the distance.
What is regular matter known as?
Baryonic Matter.
What is dark energy?
Energy responsible for inflation of the universe.
Dark Matter
Hypothetical matter that does not interact with light but does exert a gravitational force.
What produces new stars?
Interstellar dust.
Local group
Cluster of galaxies including the Milky Way Galaxy.
Milky Way Galaxy
Barred spiral galaxy containing 200-400 billion stars.
Interstellar Matter
Mixture of gas, typically hydrogen and helium, and dust (solid particles of heavier elements).
Nebula
Region of dense interstellar dust.
Hydrostatic Equilibrium
Balance between pressure and gravitational forces.
Luminosity
Amount of energy radiated by a body per unit of time.
What is the general life cycle of a star?
Protostar, Main Sequence, Red Giant, Planetary Nebula, White Dwarf.
How are heavier elements formed?
Anything greater than Hydrogen and helim was formed through stellar nucleosynthesis, supernova, etc.
Why do supernovas occur?
Iron is stable, so burning it produces no heat. Gravity overcomes the pressure without heat, so the Red Giant implodes.
Nebular Theory
States that our solar system was formed from gravitational collapse of a giant interstellar gas cloud- the solar nebula.