Podcast
Questions and Answers
The optical depth τ for some path of light through a gas depends on...
The optical depth τ for some path of light through a gas depends on...
- The length Δz of the light path
- The density ρ of the gas
- A constant k describing how readily the gas tends to absorb or scatter radiation
- All of the above (correct)
Why is the sky blue?
Why is the sky blue?
Gas molecules scatter short wavelengths more than long wavelengths.
What does optically thin mean?
What does optically thin mean?
Transparent
Small optical depth τ ≪ 1 corresponds to being?
Small optical depth τ ≪ 1 corresponds to being?
What do we call the layer of the sun that emits light to space?
What do we call the layer of the sun that emits light to space?
Large optical depth τ ≫ 1 corresponds to being?
Large optical depth τ ≫ 1 corresponds to being?
From what optical depth into the Sun does the Sun emit light to space?
From what optical depth into the Sun does the Sun emit light to space?
How deep into a gas does the gas emit radiation like a solid surface?
How deep into a gas does the gas emit radiation like a solid surface?
What color are clouds as seen from space?
What color are clouds as seen from space?
What does optically thick mean?
What does optically thick mean?
Which of the following is not a greenhouse gas?
Which of the following is not a greenhouse gas?
Who is credited with identifying the gases responsible for the greenhouse effect?
Who is credited with identifying the gases responsible for the greenhouse effect?
The effective height of long wave emission to space is at 9km where the temperature is 210K on a planet. If the lapse rate in the planet's dry atmosphere is 10K/km, what is the surface temperature?
The effective height of long wave emission to space is at 9km where the temperature is 210K on a planet. If the lapse rate in the planet's dry atmosphere is 10K/km, what is the surface temperature?
What is Rayleigh scattering?
What is Rayleigh scattering?
What is Mie Scattering?
What is Mie Scattering?
Which gas is transparent to long wave radiation?
Which gas is transparent to long wave radiation?
Who is credited with postulating the existence of a greenhouse effect and thereby kicking off the field of climate science?
Who is credited with postulating the existence of a greenhouse effect and thereby kicking off the field of climate science?
What strongly absorbs long wave radiation?
What strongly absorbs long wave radiation?
What gas is relatively opaque to long wave radiation?
What gas is relatively opaque to long wave radiation?
In what year was the greenhouse effect postulated, thereby initiating the field of climate science?
In what year was the greenhouse effect postulated, thereby initiating the field of climate science?
On planet Cruftulon, the effective height of long wave emission to space is 3 km where the temperature is 310 K. If the lapse rate in this atmosphere is 10 K/km, what is the surface temperature?
On planet Cruftulon, the effective height of long wave emission to space is 3 km where the temperature is 310 K. If the lapse rate in this atmosphere is 10 K/km, what is the surface temperature?
What best describes the atmospheric greenhouse effect?
What best describes the atmospheric greenhouse effect?
Which causes the greater amount of additional warming?
Which causes the greater amount of additional warming?
If Earth's mean temperature increases from 288 K to 291 K when CO2 is doubled from its preindustrial concentration, what mean temperature would you expect if CO2 were quadrupled from its preindustrial concentration?
If Earth's mean temperature increases from 288 K to 291 K when CO2 is doubled from its preindustrial concentration, what mean temperature would you expect if CO2 were quadrupled from its preindustrial concentration?
What is the modern estimate for the likely range of Earth's climate sensitivity?
What is the modern estimate for the likely range of Earth's climate sensitivity?
Climate sensitivity is the...
Climate sensitivity is the...
Who is credited with alerting the public to global warming with his congressional testimony?
Who is credited with alerting the public to global warming with his congressional testimony?
What is the mean of 0, 4, and 8?
What is the mean of 0, 4, and 8?
What was the preindustrial concentration of carbon dioxide?
What was the preindustrial concentration of carbon dioxide?
Who first predicted global warming and made a calculation of Earth's climate sensitivity?
Who first predicted global warming and made a calculation of Earth's climate sensitivity?
Why is the amount of oxygen in the atmosphere decreasing?
Why is the amount of oxygen in the atmosphere decreasing?
What is the modern best estimate of Earth's climate sensitivity?
What is the modern best estimate of Earth's climate sensitivity?
Who is credited with alerting scientists to global warming by documenting the rising concentrations of carbon dioxide in the atmosphere?
Who is credited with alerting scientists to global warming by documenting the rising concentrations of carbon dioxide in the atmosphere?
The first prediction of global warming was made in what year?
The first prediction of global warming was made in what year?
In what year did congressional testimony first raise public awareness about global warming?
In what year did congressional testimony first raise public awareness about global warming?
In what decade did measurements on Mauna Loa first document rising concentrations of CO2?
In what decade did measurements on Mauna Loa first document rising concentrations of CO2?
What was the preindustrial CO2 concentration?
What was the preindustrial CO2 concentration?
Equation for surface temperature is...
Equation for surface temperature is...
What do we call a situation where wind is actively blowing sand onto and off of the sand dune, but the height of the sand dune is not changing in time?
What do we call a situation where wind is actively blowing sand onto and off of the sand dune, but the height of the sand dune is not changing in time?
A positive forcing is...
A positive forcing is...
What word do we ascribe to a sand dune that has no grains of sand being added or removed?
What word do we ascribe to a sand dune that has no grains of sand being added or removed?
A positive perturbation is...
A positive perturbation is...
A negative forcing is...
A negative forcing is...
A negative perturbation is...
A negative perturbation is...
If the Earth suddenly becomes warmer than its steady-state temperature, the Planck feedback tends to make the Earth?
If the Earth suddenly becomes warmer than its steady-state temperature, the Planck feedback tends to make the Earth?
Which of the following is not a positive feedback?
Which of the following is not a positive feedback?
The radiative forcing by extra greenhouse gases is best described as causing...
The radiative forcing by extra greenhouse gases is best described as causing...
As the Earth warms, the atmosphere holds ____ water vapor and that tends to cause the Earth to emit ____ radiation to space.
As the Earth warms, the atmosphere holds ____ water vapor and that tends to cause the Earth to emit ____ radiation to space.
What is the Earth's biggest negative feedback?
What is the Earth's biggest negative feedback?
Why does burning fossil fuels cause global warming?
Why does burning fossil fuels cause global warming?
With respect to Earth's temperature, an increase in CO2 in the atmosphere can be described as a ____
With respect to Earth's temperature, an increase in CO2 in the atmosphere can be described as a ____
What is the Earth's biggest positive feedback?
What is the Earth's biggest positive feedback?
If the Earth suddenly becomes cooler than its steady-state temperature, the Planck feedback tends to make the Earth?
If the Earth suddenly becomes cooler than its steady-state temperature, the Planck feedback tends to make the Earth?
As the Earth cools, the atmosphere holds ____ water vapor and that tends to cause the atmosphere to emit ____ radiation to space.
As the Earth cools, the atmosphere holds ____ water vapor and that tends to cause the atmosphere to emit ____ radiation to space.
Is the ice-albedo feedback a positive or negative feedback?
Is the ice-albedo feedback a positive or negative feedback?
Final perturbation = ...
Final perturbation = ...
If a sand dune's feedback parameter is +1 kg/s/m, what is the final perturbation if a forcing of -2 kg/s is applied?
If a sand dune's feedback parameter is +1 kg/s/m, what is the final perturbation if a forcing of -2 kg/s is applied?
Net rate = ...
Net rate = ...
If a sand dune's feedback parameter is +25 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of −5 m?
If a sand dune's feedback parameter is +25 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of −5 m?
If a sand dune's feedback parameter is −5 kg/s/m, what happens if we suddenly add 4 m of sand?
If a sand dune's feedback parameter is −5 kg/s/m, what happens if we suddenly add 4 m of sand?
If a sand dune's feedback parameter is −3 kg/s/m, what is the final perturbation if a forcing of −9 kg/s is applied?
If a sand dune's feedback parameter is −3 kg/s/m, what is the final perturbation if a forcing of −9 kg/s is applied?
If a sand dune's feedback parameter is +24 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of 2 m?
If a sand dune's feedback parameter is +24 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of 2 m?
If a sand dune's feedback parameter is −15 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of 3 m?
If a sand dune's feedback parameter is −15 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of 3 m?
If a sand dune's feedback parameter is −8 kg/s/m, what is the final perturbation if a forcing of 4 kg/s is applied?
If a sand dune's feedback parameter is −8 kg/s/m, what is the final perturbation if a forcing of 4 kg/s is applied?
If the height of a sand dune is 50 meters and the net inflow of sand is 10 kg/s, what can we say about this sand dune?
If the height of a sand dune is 50 meters and the net inflow of sand is 10 kg/s, what can we say about this sand dune?
If a sand dune's feedback parameter is +8 kg/s/m, what happens if we suddenly reduce the height of the dune by 2 m?
If a sand dune's feedback parameter is +8 kg/s/m, what happens if we suddenly reduce the height of the dune by 2 m?
If a sand dune's feedback parameter is −20 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of −4 m?
If a sand dune's feedback parameter is −20 kg/s/m, by what amount does its net rate of inflow change if we apply a sudden height perturbation of −4 m?
Who created the cloud classification scheme that we still use today?
Who created the cloud classification scheme that we still use today?
When was most coal formed?
When was most coal formed?
What is the empirical formula for coal?
What is the empirical formula for coal?
Photosynthesis is best described by what chemical reaction?
Photosynthesis is best described by what chemical reaction?
What is another way to write 300 Mya?
What is another way to write 300 Mya?
Oil is...
Oil is...
What is peat?
What is peat?
What is plankton?
What is plankton?
What is 3 Gya?
What is 3 Gya?
What is the empirical formula for gas?
What is the empirical formula for gas?
Natural gas is...
Natural gas is...
When was the universe formed?
When was the universe formed?
Atmospheric CO2 decreases most rapidly in...
Atmospheric CO2 decreases most rapidly in...
What is the empirical formula for oil?
What is the empirical formula for oil?
Coal is...
Coal is...
When was most oil formed?
When was most oil formed?
Respiration is best described by what chemical reaction?
Respiration is best described by what chemical reaction?
January is during the Southern Hemisphere's...
January is during the Southern Hemisphere's...
Which is not a contributing factor to the seasonal cycle in atmospheric CO2?
Which is not a contributing factor to the seasonal cycle in atmospheric CO2?
When the Northern Hemisphere is in summer, the Southern Hemisphere is in...
When the Northern Hemisphere is in summer, the Southern Hemisphere is in...
What causes the seasons?
What causes the seasons?
When was the Earth formed?
When was the Earth formed?
Roughly how much of the recoverable coal have humans used?
Roughly how much of the recoverable coal have humans used?
What is roughly the per-capita consumption of coal in the United States?
What is roughly the per-capita consumption of coal in the United States?
How much fossil fuel have humans burned?
How much fossil fuel have humans burned?
Roughly at what rate are the ocean and plants absorbing CO2 at present?
Roughly at what rate are the ocean and plants absorbing CO2 at present?
Roughly how much of the recoverable oil have humans used?
Roughly how much of the recoverable oil have humans used?
What is a GtC?
What is a GtC?
How many GtC were there in the preindustrial atmosphere?
How many GtC were there in the preindustrial atmosphere?
What is the current concentration of atmospheric CO2?
What is the current concentration of atmospheric CO2?
If the concentration of atmospheric CO2 increases by 100 ppm, roughly how much more carbon is there in the atmosphere?
If the concentration of atmospheric CO2 increases by 100 ppm, roughly how much more carbon is there in the atmosphere?
In a business-as-usual scenario, what is a likely concentration of atmospheric CO2 in the year 2100?
In a business-as-usual scenario, what is a likely concentration of atmospheric CO2 in the year 2100?
If the amount of CO2 in the atmosphere increases by 100 GtC, roughly how much does the concentration of CO2 increase?
If the amount of CO2 in the atmosphere increases by 100 GtC, roughly how much does the concentration of CO2 increase?
Study Notes
Optical Depth and Light Interaction
- Optical depth (τ) is determined by the light path length (Δz), gas density (ρ), and a constant (k) specific to the gas's absorption/scattering characteristics.
- Optically thin means the medium is transparent; this corresponds to a small optical depth (τ ≪ 1).
- Optically thick means the medium is opaque, corresponding to a large optical depth (τ ≫ 1).
Atmospheric Phenomena
- The sky's blue color results from gas molecules scattering short wavelengths of light more effectively than long wavelengths.
- Clouds appear white from space as water drops and ice scatter all wavelengths of light.
Greenhouse Effect and Climate Science
- The layer of the sun emitting light into space is called the photosphere; emission occurs at an optical depth of τ = 1.
- John Tyndall identified gases responsible for the greenhouse effect; Joseph Fourier postulated the greenhouse effect's existence, founding climate science.
- Major greenhouse gases include water vapor and carbon dioxide, with nitrogen not classified as a greenhouse gas.
Climate Sensitivity and Global Warming
- Climate sensitivity measures temperature changes in response to doubling CO2 levels; modern estimates range from 1.5 to 4.5K, with a best estimate of 3K.
- James Hansen raised public awareness of global warming through congressional testimony in 1988; Svante Arrhenius first predicted global warming in 1896.
- CO2 concentration preindustrial levels were around 280 ppm; currently approximately 400 ppm.
Feedback Mechanisms
- Positive feedback examples include water vapor feedback and ice-albedo feedback, causing amplifying warming effects.
- Negative feedback is exemplified by Planck feedback, which acts to cool the planet in response to warming.
- Changes in atmospheric conditions due to fossil fuel combustion elevate the CO2 layer to colder atmospheric levels, increasing greenhouse effect impact.
Perturbations and Steady States
- Perturbations can be either positive (adding stock to the system) or negative (removing stock); final perturbation is calculated using forcing and feedback parameters.
- Steady state exists when inflow and outflow are balanced, while static equilibrium occurs with no change in stock.
Carbon and Fossil Fuels
- Fossil fuels like coal and oil originate from ancient organic materials; coal is fossilized peat formed mainly during the Carboniferous period, while oil is from fossilized plankton predominantly from the Jurassic period.
- A significant portion of CO2 reduction occurs in the Northern Hemisphere summer, as plant photosynthesis peaks.
Temporal Context and Historical Data
- The Earth formed about 4.5 billion years ago (Gya), while most coal was created around 300 million years ago (Mya).
- Humans have utilized only a few percent of recoverable coal, with per-capita consumption in the U.S. roughly 3 tons/year.
- Approximately 400 gigatons of carbon (GtC) have been burned by humans, with current absorption rates by oceans and plants around 5 GtC/year.
Environmental Implications
- Future projections suggest atmospheric CO2 could reach 1000 ppm by 2100 without changes in environmental policies.
- An increase of 100 ppm CO2 concentration correlates with an addition of about 200 GtC to the atmosphere, affecting climate conditions.
Chemical Reactions and Biological Processes
- Photosynthesis is represented as CO2 + H2O + photon → O2 + CH2O, while respiration reverses this process: O2 + CH2O → CO2 + H2O + photon.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge with these flashcards from UC Berkeley's EPS 7 course. This quiz covers key concepts related to optical depth, light scattering, and atmospheric phenomena. Perfect for reviewing essential terms and definitions before your midterm exam.
