The Climate System Flashcards
What is a system?
- A set of interacting objects of which there are three elements
What are the three elements of a system?
1) A set of components
2) A flow of energy
3) A process for internal regulation of their functioning via positive or negative feedback
What is an open system?
- Allows energy and mass to pass across the system boundary
What is a closed system?
- Allows energy but not mass across its system boundary e.g. earth
What are the five components of the climate system?
- Atmosphere (all gases and particulates)
- Hydrosphere (all liquid water)
- Cryosphere (all frozen water)
- Biosphere (flora and fauna)
- Lithosphere (surface and subsurface)
Describe the atmosphere
- Most unstable and rapidly changing of the climate system components.
- Changing composition and subsequent climate change is of considerable concern.
- Extreme events
Describe the greenhouse effect in relation to the atmosphere
- Natural process that keeps the earth 15 degrees above freezing.
- Without it the global temperature would be -18 degrees.
- Human activity is increasing the greenhouse effect to an amount that is harmful for the atmosphere.
What makes up the hydrosphere?
- Oceans, surface and subsurface water
- Has a circular system known as the Hydrological cycle.
What makes up the cryosphere?
- Mountain glaciers, ice sheets, snow, sea ice, ice sheets, permafrost and frozen ground
- Consists of liquids in solid form
Describe an area of glacier retreat?
- Cascade mountains- glaciers been retreating since 1928
What is an important part of the biosphere?
- The carbon cycle
What is the energy source for our climate system?
- The sun
What is the radiation spectrum?
- Shows what kind of radiation reaches the earth.
- Radiation can be in the form of short or long waves.
- The visible radiation range is the radiation which we can with the naked eye and is between 0.4-0.8 micrometer
What is the Stefan Boltzmann Law?
- Describes the amount of energy emitted by an object
In radiation what does a lower temperature mean?
- Less temperature is emitted- proportional
What is Wein’s law?
- Describes the relationship between temperature and wavelength
- Sun surface temperature is 6000 degrees, Earth’s is 15 degrees- shows that the sun emits more energy.
What do short waves mean?
- More energy e.g. The sun
What do long waves mean?
- Less energy e.g. Earth
What are orbital varies?
- Things which affect radiation/energy that reaches the Earth’s surface e.g. Different distances from the sun and earth at different times of year.
What is obliquity?
- The tilt of the Earth’s axis
Give an example of a cycle
Milankovitch cycles
What happens to the energy from the sun?
- It can be scattered, absorbed or reflected.
How much solar radiation is absorbed by the Earth’s surface?
- 50%
- 20% reflected by clouds, 19% absorbed by clouds, 4% reflected from surface
- 6% reflected by atmosphere
What happens to short waves?
- A shortwave received at the surface is made up of direct (28) and diffuse (23) components.
- Direct passes uninterrupted through the atmosphere.
- Diffuse is scattered or reflected downwards but does eventually make it to the surface.
What happens to long waves?
- Amount of long waves at the surface is the difference between the long wave received at the surface (96) and the amount of long waves emitted from the surface (117).
96-117= -21
How do you work out the net radiation?
- To find the net radiation we take the net shortwave radiation (Incoming SW-Reflected SW) and add it to the net long waves radiation (Incoming LW- Reflected SW).
What is the equation for net radiation?
- Q= K+ L*
30= 51 (28+23) + -21 (96-117)
What would happen if the earth didn’t get rid of all it’s latent and sensible heat?
- It would heat uncontrollably up to 200 degrees per day
What is albedo?
- Shortwave radiation reflectivity which determines incident shortwave radiation at the surface.
- Greater amounts of snow and ice= greater albedo= greater reflection
What happens when there is a build up of energy?
- Has to be gotten rid of
- Energy surplus in equatorial regions but a deficit in polar regions.
- Must be evened out.
- Mechanism for redistribution is global atmosphere circulations and also ocean circulations.
What is important with regards to the effect of net radiation?
- the nature of the surface has a big impact
- is the surface wet or dry?