Flashcards in GEOGR 5210 Exam I Deck (102)
What does the term "theory" mean in science?
Any hypothesis that succeeds in explaining a wide array of observations over a period of time.
What is the difference between weather and climate?
climate - broad composite of the average condition of a region
weather - shorter fluctuations in atmospheric conditions on the order of hours, days, weeks, or a few months
How old is the Earth? How do we know that?
4.55 billion years ago
We know this by radiometric dating.
What is climate forcing? What are some examples?
Climate forcing is a reference to factors that drive or cause changes in the climate system that result in climatic shifts.
Some examples are changes in plate tectonics, changes in the Earth's orbit, and changes in the Sun's strength.
What is a climate response? Examples?
The results of a climate forcing.
Some examples are changes in atmospheric, changes in ice, changes in vegetation, changes in ocean, and changes in land surface.
How do response times differ? Give an example of a response at a short time scale and at a long time scale.
Response times differ due to the specific properties of the substance that is changing.
A fast response is the daily heating and cooling of the atmosphere. A slow response is the advances and retreats of glaciers.
Does the climate system ever reach equilibrium? Why or why not?
No. The system is complex and due to the different time scales of climate response, if an equilibrium is reached it will be short lived.
What is climate feedback? Give an example of a positive and a negative feedback in the climate system. Be able to recognize positive and negative feedbacks.
climate feedback - processes that alter climate changes that are already underway, either by amplifying them or suppressing them.
An example of a positive feedback is a decrease in the amount of insolation entering the climate system will allow more ice to grow on the surface of the earth, which will reflect even more insolation, propagating cooling.
An example of a negative feedback is chemical weathering. As Earth warms, the atmosphere is able to produce more precipitation which will enhance the amount of weathering, which removes CO2, resulting in cooling.
How does ozone in the upper atmosphere protect us from UV radiation?
Energy gets absorbed by an O3 molecule and separates it into O2 and O.
What is latent heat?
The amount of heat associated with a phase change.
What is evapotranspiration?
evapotranspiration - the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants
What causes atmospheric circulation?
Differences in heating from poles to tropics, land to oceans, and surface to top of the atmospheric layer.
Why is there uneven heating of the earth's surface?
- Unequal radiation on a sphere
- Tilt of the earth
- Specific heat of water is much higher than land
- Albedo differences
- Sun angle
Where is there a net gain in radiation? Where is there a net loss? Why?
Poles typically have higher albedos, lower sun angles, less land, etc. Tropics are the opposite.
Be able to explain Hadley cells and trade winds.
Wow. Hadley cell.
Why is there lots of precipitation at the equator? Why dry at 30N?
Generally low pressure at the equator due to the convergence of the two Hadley cells. Low pressure promotes lifting mechanisms and supports precipitation.
Generally high pressure at 30N due to convergence of Hadley and Ferrell cells. High pressure promotes subsidence mechanisms and suppresses precipitation.
Why does the ocean circulate?
To distribute heat from the tropics around the globe.
Where is the "hinge" of thermohaline circulation?
Where the majority of the dense water sinks, northern Atlantic near Greenland
What drives the thermohaline circulation?
Density differences in water due to temperature and salinity.
What is a climate archive?
In what settings are they found?
How do they record climate?
Give pros and cons of different examples.
A type of record that can hold climate information.
They record climate by quantifying climatic indicators like isotopes or fossils and we can deduce information.
Pros - Invaluable direct records of the climate system at that point in time.
Cons - Can be incomplete, can have low resolution, etc.
How are archives dated to produce a chronology?
Counting annual layers
Correlating with other climate archives
What is meant by a climate proxy? Be specific.
climate proxy - a quantifiable indicator of climate change contained in a climate archive and covering an interval that precedes direct instrument measurements of climate
What is a high resolution climatic record? What is a low resolution?
A high resolution record allows fine temporal detail, e.g. a tree ring.
A low resolution record allows low temporal detail, e.g. an ocean sediment core.
What is a climate model?
A computer generation of a climate system derived from numerical representations and simulations of real atmosphere processes.
insolation - incoming solar radiation
the decimal fraction or percentage of incoming solar radiation reflected from a surface
Define greenhouse effect.
the warming of Earth's surface and lower atmosphere that occurs when Earth's emitted infrared heat is trapped and reradiated downward by greenhouse gases
Why SPECIFICALLY is Venus so much hotter than the Earth?
Its CO2 enriches atmosphere creates a much stronger greenhouse effect that traps much more heat.
What is a carbon reservoir? How has carbon been exchanged between reservoirs throughout Earth history?
A carbon reservoir is an effective place for carbon to be stored in the climate system.
Carbon has been exchanged through volcanic input and chemical weathering.