Module 5 Flashcards
Coefficient of determination (r squared)
Determines how best fit data is to a line
When coefficient of determination is 0….
Data does not fit on a line
When coefficient of determination is 1….
Data perfectly fits to a line
Volcanic eruptions increases…
Greenhouse gases which result in warming
What 3 main gases come from a volcano?
Water vapor, carbon dioxide and sulphur dioxide
Equation for the speed of an object falling due to gravity
Hint: Think of y=mx+c
v=gt, c =0
Least Squares method
Determines line of best fit for a model of data which yields the minimum squared distance between the data and the straight line
Linear Regression Analysis
Using idea of least-squares straight fit line to explore whether or not two or more time series are related
In linear regression what are the variables x and y referred to as?
x- predictor
y- predictand
What has been the trend in temperature in the last 55 years?
Undeniably going upward with an increase of 25%
What are two things covered in this module which affect global average temperatures?
Greenhouse gases
Volcanic eruptions
Sulphate aerosols (from large volcanic eruptions)
Particles which act as a shield against incoming solar radiation, increasing effective albedo of the Earth and reducing the global average surface temperature
How long can sulphate aerosols stay in the stratosphere before settling in the troposphere?
Two years
Carbon dioxide concentration is related to…
The rising global average surface temperature
Remember! Correlation does not prove causation!
Radiative Equilibrium
Net radiation absorbed = net radiation emitted
Temperature is unchanged
If net radiation absorbed is more than net radiation emitted…
Temperature goes up
If net radiation absorbed is less than net radiation emitted…
Temperature goes down
Stefan-Boltzmann Law
A black body is a perfect absorber and emitter of energy
Major Greenhouse Gases
Hint: There are 7
Water vapor, carbon dioxide, methane, nitrous oxide, ozone, freon-11, freon-12
Which Greenhouse Gases have the most concentration?
Water vapor and carbon dioxide
Where does most of water vapor reside?
The troposphere
Greenhouse Effect
Greenhouse gases (and clouds) absorb the infrared radiation emitted by the Earth and re-emit it back to the surface, warming it more
Albedo
Fraction of incident solar radiation that is reflected by clouds
High albedo implies what kind of effect?
A cooling effect
Thick, low altitude clouds have…
A stronger albedo effect than greenhouse effect, which cools the Earth
Thin, high altitude clouds have…
A stronger greenhouse effect than albedo effect, which warms the Earth
All clouds are excellent absorbers of…
Infrared radiation
The net influence of all clouds…
Cools the Earth
The IR flux/temperature feedback
As temperature increases, so does outgoing energy which in turn decreases temperature
Water vapor feedback
As surface temperature increases, so does atmospheric water vapor and the greenhouse effect, which keeps the temperature increasing
Snow/Ice Albedo
As surface temperature decreases, snow and ice increase which results in a decrease in planetary albedo
(works in both directions)
El Nino events result in…
Warmer than average surface temperatures
Brewer-Dobson Circulation
Circulation in stratosphere directed from the equator to the poles. Effective in transporting volcanic gases
Examples of natural forcing
Changes in solar radiation, orbital changes, volcanic activity
Examples of anthropogenic forcing
Increasing greenhouse gas concentrations (particularly carbon dioxide emissions)
Natural climate variability
Variability that is intrinsic to the climate system and independent of climate forcing
(i.e. ENSO, PNA, NAO, etc)
Global Climate Models (GCMs)
Complicated mathematical representations of what we think we know about the planet
What is useful for running GCMs because of uncertainties?
Ensembles
