Professor Mandia's Extra Help

CHAPTER 1

Temperature

Temperature - the measure of average kinetic energy (KE) of a gas, liquid, or solid. KE is energy of motion.
All three temperature formulas must be known for quizzes and tests.
The Kelvin temperature scale is called the absolute temperature scale because it is the only scale that directly measures energy. There are negative temps on the other two scales and it is impossible to have a negative energy. Units are K (Kelvins) with no degree symbol.

Time Scales

Earth is approx. 4.55 billion years old. The text covers only the last several million years. See Fig. 1-3.

Hypothesis vs. Theory

A hypothesis is an informal idea that has not been thoroughly tested by the scientific community. Most are discarded.
A hypothesis becomes a theory when it can explain and predict observations and it also has been thoroughly tested by the scientific community. Even theories, over time, can be disproved and discarded.
If a theory stands the test of time (years and decades) it may be called a law or unifying theory and is the closest approximation to "the truth" possible. Keep in mind that it is impossible to prove that a theory is true, only that is is untrue.

Forcing and Response

In climatology, cause and effect are called forcing and response. Forcing refers to those factors that cause change and responses are the effects - the climatic changes that occur.
Fig. 1-5 shows the earth's climate system and the interactions of its components.
There are three kinds of climate forcing in the natural world:
1. Tectonic Processes - processes that alter the basic geography of Earth and are summarized as plate tectonics. These include movements of continents, uplifting of mountains, and the opening and closing of ocean basins. These are slow processes that occur over millions of years.
2. Earth-Orbit Changes - result from the variation of Earth's orbit around the sun. This causes a variation in the amount of solar radiation reaching the earth by season and by latitude. Orbital changes occur over tens and hundreds of thousands of years.
3. Changes in the Strength of the Sun - affect the amount of radiation reaching the Earth. There are various ways the Sun's strength can be changed and these changes occur over all time scales.
A fourth forcing which is not "natural" is called anthropogenic forcing and is the result of human activities.

Feedbacks

A climate feedback is a process that alters climate changes already underway.
Positive feedbacks amplify (strengthen) the climate changes already underway. An example: When there is less incoming solar radiation reaching the earth's surface, temperatures cool. Cooler temperatures mean more ice can be formed. Ice reflects incoming sunlight which further cools the temperature - allowing even more ice to form, etc.
Negative feedbacks suppress (weaken) the climate changes already underway. An example: When there is more incoming solar radiation reaching the earth's surface, temperatures warm. Warmer temperatures mean more surface water evaporates into the atmosphere. More water vapor in the atmosphere leads to more clouds. Clouds block incoming solar radiation which, in turn, cools the earth.

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