Lecture 22: Climate Flashcards
What is Forcing?
When there is an imbalance between the absorption of solar radiation and energy emitted by the top of the earth’s atmosphere
What is Feedback?
The reaction of the climate system to forcing. It can be positive or negative
What is a Proxy?
A source of information from natural and human records that can be used to estimate past climate conditions
What are examples of Natural Proxies?
Pollen, plant macrofossils, shells, and tree-rings
What are Ice Cores?
One of the most important records of past environments that preserve gas bubbles
How do Marine Cores provide detailed records?
they make their shells out of calcium carbonate with different isotopes of oxygen which represents different temperatures of water
What is Long Term Climate controlled by?
Configuration of tectonic plates and it referred to as tectonic forcing
What controls climate on short term scales?
Milankovitch cycles which are modified by feedbacks in the earth’s system
What are Internal Climate forcings?
Greenhouse gases, aerosols, albedo, ocean-atmospheric circulation patterns
What are External Forcings?
Tectonic, Orbital, Solar, Volcanism, Anthropogenic changes (people)
How does Climate change during Greenhouse and Icehouse times?
they change due to things like orbital and solar changes and greenhouse gasses and albedo feedback
What external factors control short term climate?
Solar Variation and Milankovitch cycles (changes in the earth’s tilt and axis)
What is Eccentricity?
The measure of earth’s orbits departure from circularity and effects the amount of solar energy reaching the sun
What does Tilt control?
The strength of the seasons
What is Precession?
The direction of tilt of the earth’s rotation relative to earth’s elliptical orbit
