Climatology Flashcards
MCQ's for final exam
What does the term ‘parcel’ mean in climatology
Describes a body of air that has specific temperature and humidity characteristics
What does the ‘ideal gas law’ tell us
That the pressure, density and temperature of a gas are dependent on each other
What happens to a low hanging warm air parcel
Warm air produces a lower density and rises. As it moves up, the air pressure lessens and the air parcel would expand
What are adiabatic processes?
describes the warming or cooling rates for a parcel of expanding or compressing air NO heat added or taken away, just through a change in air pressure. ANY temperature change is due to the changes in pressure
Which part of our atmosphere contains the most air
The troposphere. It contains 80% of the air in the atmosphere.
(as the air gets closer to earth, it compresses)
Which phase change in water takes the most energy?
From water to vaporized gas (it takes about 540 calories)
Does warmer or colder air have to capacity to hold more water
Warmer. The saturation vapour pressure of water increases with temperature.
Is the winter solstice the longest or shortest day in the year and why?
The shortest day due to the position of Earth in relation to the sun
What drives a lot of the air movement in earths atmosphere and how?
Solar/shortwave radiation from the sun. There is an energy surplus in the equatorial regions and a lack thereof in sub-equatorial regions which pushes movement as this energy surplus tries to equalise
What is sensible heat flux?
Energy that can heat the atmosphere. This heat flux changes the temperature of a substance without changing the phase of the substance
What is Latent heat flux?
Energy used to change the state of a substance. Associated with the evaporation/condensation of water vapour between the surface and atmosphere.
How does the atmosphere equalise the deficit of 30 units (radiation) in the atmosphere and surplus of 30 units at earths surface?
By using sensible and latent heat flux to transport surface energy to the atmosphere.
What happens to long wave radiation (the radiation reflected out of earth)?
Transmission and absorption
The earth tries to maintain equilibrium by emitting as much radiation as it gains from the sun. Some of this radiation escapes directly out into space. Some is absorbed by gases and clouds in the atmosphere. Or the greenhouse effect occurs.
What is the greenhouse effect?
When The earths longwave radiation it absorbed by clouds and other stuff in the atmosphere and then re emitted to earths surface, ‘warming’ the surface.
What is albedo?
Albedo explains how much reflectivity a surface has (as a percentage). High percentage = high reflectivity, Low percentage = low reflectivity (high absorption)
What does high albedo do and what surfaces have high albedo
High albedo has high reflectivity and therefore low absorption. High albedo can be found in fresh snow and light coloured things, such as light coloured roofs
What is low albedo and give some examples
Low albedo in surface means is has low reflectivity and therefore higher absorption of radiation. Examples of this include asphalt, concrete and dark coloured roofing
What happens to shortwave radiation when passing through the atmosphere?
Scattering in the atmosphere. When transmitted to the surface, shortwaves are either absorbed or reflected depending of the albedo present on the surface.
Key reasons for the seasons
-Earths orbit around the sun
-Earths rotations of a tilted axis
About how many watts per metre squared is the Earths Solar Constant?
1367
What are the primary constituents in the homosphere
Nitrogen and oxygen
What is the difference between solar and terrestrial radiation?
Solar originates from the sun and forms as short wave radiation, terrestrial originates from the earth and forms as longwave radiation.
What is Wiens law used for?
Wiens law (λmT = 0.2898 centimetre-degree Kelvin) is used to calculate the maximum wavelength. It tells you what the dominant wavelength will be based on it’s temperature.
What does the Stefan-Boltzmann law state?
Stefan-Boltzmann law (E = σ x T4.) states that the energy emitted (E) by a blackbody is related to its absolute temperature (Kelvin units)
What is radiative equilibrium?
The energy coming into earth/earths atmosphere is the same as what is being emitted out.
What controls the wavelength and total amount of energy emitted by an object?
Its temperature
What is a blackbody and give an example of it?
A blackbody absorbs all of the radiation that strikes it and emits radiation at a maximum rate for its given temperature. The sun acts virtually as a blackbody
What is the range of short to long wavelengths called
“electromagnetic spectrum”
How fast does the sun’s solar radiation travel?
The speed of light
Define weather vs climate (how are they different)
Weather- State of the atmosphere at any given time. Has short term variability (day to day)
Climate- Long term state of the atmosphere. Has long-term and seasonal variability (changes over longer periods of time).
What is the ‘first law of thermodynamics’?
‘Energy can neither be created nor destroyed’ (it just changes forms)
What is radiant energy?
energy from the sun
What is thermal energy
Associated with the changes in temperature and forms of water
What is potential energy
The energy an object possesses
What is kinetic energy?
Energy created from movement
Would a stable or unstable atmosphere create a cumulonimbus cloud (the fluffy one that extends along the low, mid and high atmosphere
Cumulonimbus clouds are created in unstable atmosphere as the air parcels are being carried high and scattered all along
What are the three different types of stability in an atmosphere (and maybe what classifies them)
Stable, unstable and conditionally unstable
If a parcel of air is warmer than the surrounding air, it will….
Continue to rise and be unstable
What does it mean if an environmental lapse rate is described as inversion
It gets warmer with height
What does it mean if an environmental lapse rate is described as isothermal
No change with height
On average, what is the average environmental lapse rate in the troposphere globally?
6.4 degrees Celsius per 1000m
How do we measure the atmosphere vertically?
Using weather balloons
How do we use information about lapse rates
To assess atmospheric stability and predict rain and weather events
What governs adiabatic lapse rates?
The temperature structure of that atmosphere and whether there is moisture
What is the different between moist and dry adiabatic rates?
If the atmosphere contains moisture, it must also be more warm. So in moist adiabatic processes, air cools more slowly as the parcel moves higher more slowly.
what are the three main cloud terms/types
1-cumulus
2-stratus
3-cirrus
These are used to describe the texture and shapes of clouds
What are the characteristics of a stable atmosphere
A stable atmosphere would have air parcels colder than the surround air which makes that air sink. With a stable atmosphere you’d expect to see low hanging clouds
What is the pressure gradient force?
Its kind of the gradient between a high and low pressure systems. As high pressure systems are constantly chasing low pressure systems to equalise pressure.
Why does air move in a clockwise direction around low pressure systems in the southern hemisphere
The Coriolis effect, pressure gradient force and the relationship between these two things
