Exam 1 - ATOC 1060

what is weather

the state of the atmosphere at a given time and place

what is climate

the aggregate weather conditions over many decades

whats the difference between weather and climate

you expect climate, weather is what you get

how can you figure out the climate of a certain place?

By the average conditions, but also, range, extremes, and types of events (e.g., do tornadoes occur there? Freezing rain? Etc.)

ex) in warmer climates, the avg temp is warm and their is less cold weather. but that doesn’t mean that they can’t get record cold

The Keeling Curve

• Atmospheric carbon dioxide data starts in 1957, upward trend for the entire time period.

• Seasonal cycle due to seasonal cycle of leaves on the trees: in summer when leaves are on the trees, atmospheric carbon dioxide decreases, in winter when leaves are off the trees, carbon dioxide increases.

Feedbacks

sequence of interactions that determines the response of a system to an initial change or perturbation

• Positive feedbacks amplify initial signal

• Negative feedbacks dampen initial signal

5 climate components

1. Atmosphere – the layer of gases around Earth; controls weather, temperature, and circulation.

2. Hydrosphere – all liquid water (oceans, lakes, rivers); stores and moves heat.

3. Cryosphere – frozen water (glaciers, ice sheets, sea ice, snow); reflects sunlight and affects sea level.

4. Lithosphere (Geosphere) – Earth’s land surface and rocks; influences climate through volcanoes, terrain, and carbon storage.

5. Biosphere – all living organisms; affects carbon cycles, albedo, and energy flow.

Atmospheric composition

the gases that make up Earth’s atmosphere

• Nitrogen (78%), Oxygen (21%), Argon (0.9%)

• water vapor, carbon dioxide, and methane are also important to note

4 layers of the atmosphere defined by temperature structure

• Troposphere: closest to the surface, temperature (typically) decreases with height

• Stratosphere: Above the troposphere, contains the ozone layer which absorbs incoming uv radiation which results in heating and therefore temperature increasing with height.

• Mesosphere, thermosphere

Permafrost melt leads to

• Unstable ground

• Methane release

• Makes coastal areas more susceptible to erosion

Glaciers

• Grow by snow accumulation

• Shrink by melting, calving

on land

ice sheets and glaciers

in water

ice shelves and sea ice

6 phase changes

• Freezing : liquid → solid

• Melting: solid → liquid

• Sublimation: solid → gas

• Deposition: gas → solid

• Condensation: gas → liquid

• Evaporation: liquid → gas

Latent heat

• Extra heat removed from or released to the atmosphere during a phase change.\

  • Going from a lower energy state to a higher energy state (e.g., ice -> liquid or liquid -> gas) removes latent heat and cools the surrounding environment.

  • Going from a higher energy state to a lower energy state (e.g., gas -> liquid or liquid -> solid) releases latent heat and warms the surrounding environment.

Saturation

The point at which a given volume of air is holding the maximum amount of water vapor.

Sea level rise occurs because of:

• Thermal expansion

• Melting of land ice

• Vertical movement of land

• Short term changes such as wave action from storms or tides

Radiation

energy associated with vibration of molecules, travels in waves.

• There is a spectrum of wavelengths which depends on the speed of the motion of the molecules.

  • The peak wavelength of radiation from the sun is in the visible part of the spectrum.

  • The peak wavelength of radiation from the earth is in the infrared part of the spectrum.

Wien’s displacement law

relates temperature to peak wavelength, inverse relationship (i.e., the warmer the temperature, the shorter the wavelength of peak radiation).

Stefan-Boltzmann law

relates temperature to how much energy an object emits. The greater the temperature, the greater the amount of energy emitted.

Radiation can be:

• Transmitted

• Absorbed

• Reflected/scattered/refracted

Albedo

• a property of a surface that tells us the fraction of incoming solar radiation that is reflected.

  • The higher this number the more that is reflected.

  • The brighter the surface, the higher the albedo (e.g., fresh snow has very high albedo, asphalt has very low albedo)

Latitude

• controls the angle incoming solar radiation is spread over an area.

  • At low latitudes, incoming solar radiation is more concentrated than at high latitudes.

  • There is a surplus of heat at low latitudes and a deficit at high latitudes.

  • This imbalance of heat across the planet is the fundamental driver of all of our weather

The greenhouse effect:

• The atmosphere absorbs outgoing longwave radiation from the surface and that is how it is heated.

• The atmosphere is largely transparent to incoming solar radiation but opaque to outgoing longwave radiation.

• Not all gases absorb this outgoing longwave radiation. Those that do are called greenhouse gases.

Greenhouse gases:

• Carbon dioxide

• Ozone

• Water vapor

• Methane

Not Greenhouse gases:

• Oxygen

• Nitrogen

• Argon

Global energy budget

• Ultimate source of all of our energy is the sun

• 30% of incoming solar radiation is reflected (another way of saying this is the planetary albedo is 30%).

• Majority of outgoing longwave radiation is absorbed by the atmosphere or clouds, some of which is remitted back towards the surface.

• A small amount of outgoing longwave radiation escapes directly to space through an atmospheric window.

Aerosols

• Mostly lead to cooling

• Water vapor condenses best when there is a surface on it can condense, when this happens a cloud droplet is formed.

• Clouds that form in an environment with a large number of aerosols have a large number of small droplets. In an environment with a smaller number of aerosols, clouds have a smaller number of larger droplets.

Positive climate feedbacks:

• Water vapor feedback

• Sea/ice/albedo feedback

Negative climate feedbacks:

• Lapse-rate feedback

• Planck feedback

Why does the temperature increase with height in the stratosphere?

This is the layer that contains the ozone layer which absorbs incoming solar ultraviolet (uv) rays which increases the temperature.

In a warming climate, there will not be any more record cold temperatures.

false

Which of the following of these would be part of the way the climate of Boulder is defined?

A. Boulder experiences severe downslope winds.

B. The average high temperature of Boulder in August is 84℉

C. The average precipitation in Boulder is ~19 inches

D. The average date of the first snow in Boulder is October 17th.

E. All of these are examples of how we define the climate of Boulder, CO.

E. All of these are examples of how we define the climate of Boulder, CO.

Praise for an achievement causes more interest in learning which causes more praise for achievement. This is an example of a

Positive feedback

If you get cold, your body starts to shiver to try to warm yourself back up. This is an example of a

Negative feedback

Which of the following are a consequence of melting permafrost?

A. Unstable ground

B. Release of methane to the atmosphere

C. Makes areas near coastlines more susceptible to erosion

D. All of these are consequences of melting permafrost

E. None of these are consequences of melting permafrost

D. All of these are consequences of melting permafrost

Which of these is on land?

A. Ice sheet

B. Ice shelf

Ice Sheet

The phase change of condensation _____________ heat from/to the environment.

A. Adds

B. Removes

Adds

The warmer the air, the _________ the amount of water vapor it can hold.

A. Less

B. More

More

How do ice shelves contribute to sea level rise?

they don’t

When people step out of the shower, their skin will often feel cool. Why?

The water evaporating from their skin removes heat from their body for the phase change

Why does it take longer for bodies of water to warm than land?

A. It takes more energy (i.e., more solar radiation) to heat water 1℃ than land.

B. Solar radiation is able to penetrate a deeper layer of water than land, so the available energy is spread over a larger area.

C. Movement of water by wind action mixes the warmed water, further spreading the energy over a larger area.

D. Some of the solar radiation is used to evaporate the water rather than heat it. So there is less energy available to raise the water temperature.

E. All of these are reasons for water taking longer to warm than land.

E. All of these are reasons for water taking longer to warm than land.

This is Frannie. She is awesome. She is also emitting radiation. In what part of the electromagnetic spectrum is her peak radiation?

Infrared

Which of the following emits peak radiation at the shortest wavelength?

A.The sun

B.The Antarctic ice sheet

C.Frannie

The Sun

Which of the following has the lowest albedo?

A. Old sea ice

B. Open water

C. Fresh snow

D. Sand

Open Water

The atmosphere is largely ________ to solar radiation, but __________ to terrestrial radiation.

A. Opaque; opaque

B. Opaque; transparent

C. Transparent; opaque

D. Transparent; transparent

C. Transparent; opaque

Globally, approximately how much solar radiation is reflected back to space?

30%

Which of these is NOT a greenhouse gas?

A. Carbon dioxide

B. Water vapor

C. Methane

D. Oxygen

Oxygen

Which of the following gives rise to the seasons?

A. The tilt of the earth which gives rise to more direct solar radiation in the summer hemisphere.

B. The amount of vegetation

C. Distance to the sun.

D. Companies being able to sell both swimsuits AND winter jackets.

A. The tilt of the earth which gives rise to more direct solar radiation in the summer hemisphere.

What does the greenhouse effect tell us about how atmosphere is heated?

Incoming solar radiation is absorbed by the earth’s surface, which then reemits heat in the longwave spectrum which then gets absorbed by the atmosphere, thus heating the atmosphere.

Everything else being equal, how do clouds impact daily high temperatures?

On a cloudy day, high temperatures are lower than they otherwise would be on a clear day

How does the number of aerosols in the atmosphere affect cloud reflectivity?

The size of clouds droplets tends to decrease with increasing aerosol counts, thus increasing reflectivity

What makes the radiative forcing from the water vapor feedback a positive feedback?

The addition of water vapor to the atmosphere enhances warming.