ATMO 105 - Learning Goals (copy)

How people learn:

- continuous study

- recall

- making graphs/diagrams

- the students who get the lowest grades have the greatest difference in expectation to reality

Define atmosphere

the envelope of gases, suspended particles, and precipitation that surround a planet and is held to it by gravitional force

What are the 3 parts of the atmosphere?

- gases

- suspended particles

- precipitation

Define weather

the short-term condition of the atmosphere at any given time and place

Define climate

the accumulation of daily and seasonal weather events over a longer period

Difference between weather and climate

weather is short term and climate is long term

Define permanent gases

found in (roughly) equal concentration everywhere and are 'well-mixed'

Describe permanent gases

- 'well-mixed' up to 50 miles

- generally have a long lifetime

Define lifetime

the average length of time before a gas molecule is destroyed through chemical or photo chemical reaction at the surface or in the atmosphere

List the major permanent gases in the atmosphere

- Nitrogen [N2] (~78%)

- Oxygen [O2] (~21%)

- Argon [Ar] (~0.93%)

- many others - "trace gases" (Neon, Helium, Hydrogen, Zenon)

Nitrogen - lifetime, sources, & sinks

- lifetime: 13 million years

- sources: decay of plant material

- sinks: soil bacteria, plankton, vegetation

Oxygen - lifetime, sources, & sinks

- lifetime: 5,000 years

- sources: photosynthesis

- sinks: respiration, organic decay, chemical reactions (combustion)

Argon

unimportant for life and chemically inert

define meteorology

the study of the atmosphere and the processes that cause weather

List the major variable gases

- water vapor (H2O) ~0.25%

- carbon dioxide (CO2) ~0.04%

(methane, nitrous oxide, ozone)

Water vapor - lifetime, concentration, sources, & sinks

- lifetime: ~10 day

- concentration: varies - 4% @ equator, 0% at poles

- sources: surface evaporation, transpiration

- sinks: precipitation, condensation

Carbon dioxide - lifetime, concentration, sources, & sinks

- lifetime: ~150 year

- concentration: changing and increasing ~2.5 ppm

- sources: combustion, volcano eruptions, respiration

- sinks: photosynthesis, uptake by oceans

Key features of the hydrologic cycle

Describe the hydrologic cycle

precipitation --> snowmelt runoff --> surface runoff --> evaporation --> transpiration --> condensation --> precipitation

Define intra-annual

processes which occur within a year

Why is there intra-annaul variability of CO2

seasonal changes in vegetation

Long term trends of atmospheric carbon dioxide

What is the carbon cycle?

the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere

Key features of the carbon cycle

Explain why certain atmospheric gases are permanent while others have variability

some are affected by temperature (water vapor - equator vs poles) and the lifetime does not allow for equal distribution (~10 day for H2O)

Define greenhouse gases

gases that trap heat in the Earth's atmosphere

What are the most important greenhouse gases?

- water vapor (~60% of the greenhouse effect)

- carbon dioxide: we are concerned about its change

List the greenhouse gases

- water vapor

- carbon dioxide

- methane

Key idea of greenhouse gases/effect

greenhouse gases absorb thermal energy emitted by the earth and re-emimt the energy towards the earth's surface

greenhouse effect

What is the typical storm track tropical cyclones as they move from the equator to poles?

tropical cyclones move towards the west then towards the poles and 'recurve' to the east in each hemisphere

What tropical cyclones are stronger?

West Pacific typhoons are stronger than Atlantic hurricanes

Where are tropical cyclones/storms more frequent?

Storms are more frequent in the west Pacific then the North Atlantic

What is the location and time of year where you are most likely to find the "ozone hole"?

In the southern hemisphere after winter

Differences between gases and aerosols

Aerosols:

- are small solids or liquid particles suspended in the atmosphere

- much bigger than gas

- aerosols play a major roles in cloud formation

- aerosols can affect optics

What are several effects of aerosols?

- aerosols play a major role in cloud formation (act as a surface for water vapor)

- can affect optics like sky color

List weather elements (6)

- Temperature

- Pressure

- Moisture

- Wind

- Visibility

- Precipitation

Temperature: How is it labeled and what instruments are used to measure it?

units: celsius, fahrenheit, kelvin

instruments: thermometer

Pressure: How is it labeled and what instruments are used to measure it?

units: mb, hPa, in Hg

instruments: barometers

What are the types of moisture?

Relative humidity and dew point temperature

Relative humidity: How is it labeled and what instruments are used to measure it?

units: %

instruments: psychrometer

dew point temperature: How is it labeled and what instruments are used to measure it?

units: celsius, fahrenheit, kelvin

instruments: hydrometer

What are the aspects of wind?

speed and direction

wind speed: how is it labeled and what instruments are used to measure it?

units: mph, kt, ms^-1 (meters per sec)

instruments: anemometer, wind socks

wind direction: how is it labeled and what instruments are used to measure it?

units: degrees

instruments: wind vane

Visibility: how is it labeled and what instruments are used to measure it?

units: miles, ft

instruments: ceilometer, visual observations

Precipitation: how is it labeled and what instruments are used to measure it?

units: in, cm

instruments: rain gage, tipping bucket, radar

Define temperature

related to the average molecular velocity / kinetic energy of molecular motion

Define dew point

the temperature at which condensation occurs (temperature to which a given volume of air must be cooled to achieve saturation)

Define pressure

the force exerted by the atmosphere at any given point per unit area ; the weight of a column of air

Define wind

the three dimension motion of air past a fixed point

Define visibility

measure of the opacity of air

Define precipitation

liquid and/or solid "hydrometeors" that fall from the atmosphere and reach the surface

Why does air density decrease with increasing altitude?

at higher altitudes, there is less air pushing down from above, and gravity is weaker farther from Earth's center

Identify layers of the atmosphere

1. troposphere

2. stratosphere

3. mesosphere

4. thermosphere

How does temperature change within each layer of the atmosphere from the surface to outer space?

Troposphere: temperature decreases with height

Stratosphere: temperature increases with height

Mesosphere: temperature decreases with height

Thermosphere: temperature increases with height

How does temperature change within the Troposphere?

temperature decreases with height

How does temperature change within the Stratosphere?

temperature increases with height

How does temperature change within the Mesosphere?

temperature decreases with height

How does temperature change within the Thermosphere?

temperature increases with height

What percentage of the atmosphere is each layer?

Troposphere: 80%

Stratosphere: 19.9%

Mesosphere: ~0.01%

Thermosphere: very little

Why does stratosphere warm with height?

ozone gas absorbs radiation

Explain the temperature of the Mesosphere

it is heated from the stratosphere

temperature descreases with height

it has the lowest temps in the atmosphere

Explain the temperature of the Thermosphere

- temps increase with height (< 1500C)

- hotness due to the oxygen molecules absorbing high energy radiation from the sun

- the air density is too low to transfer heat

List examples of extreme and hazardous weather

1. Hurricanes (costliest)

2. Heatwaves (deadliest)

3. Flooding, Lightning, Tornados

Extreme weather events summarized

- climate change is partly responsible

- human activity & infrastructure expansion is main cause of losses

- there are ~$100 billion of loses & 500 weather related deaths in the USA each year

Define energy

the ability to do work on some form of matter

Define heat

The energy transferred between objects that are at different temperatures

Define specific heat

amount of heat needed to raise the temp of 1g of a substance by 1C

List what earth surface materials have a greater specific heat to lesser specific heat

1. Water

2. Ice

3. Clay

4. Dry air

5. Sand

Define atmospheric thermals and describe their cause and effects

rising parcels of less dense and hotter air

thermals can lead to cloud formation (if air is saturated)

page 14 in notebook

What are the mechanisms of heat transer?

- conduction

- convection

- radiation

Define conduction

the transfer of heat from molecule-to-molecule (requires direct molecular contact)

Define convection

transfer of heat by fluid flow in some gas or liquid

Define radiation

The transfer of energy by oscillations in electromagnetic waves

how are electromagnetic waves categorized?

amplitude: measurement of trough to crest

wavelength (frequency): measurement between 2 crests

What are the properties of radiation?

1) All objects with a temperature emit radiation

2) Amount of radiative energy is a strong function of temperature

3) Objects emit radiation at different wavelengths based on their temperature

4) Shorter wavelengths are heigher frequency & have greater energy than longer wavelengths

Explain the radiation property: amount of radiative energy is a strong function of temperature

Stefan- Boltzman Law: energy is proportional to temperature^4

Define blackbody

hypothetical substance that absorbs all possible incident radiation and emits the maximum possible radiation for its temperature

Principles of Radiation and Emission

- hotter objects emit more energy

- hotter objects emit most energy energy at shorter wavelengths

- rapid change for shorter wavelengths & broad distribution on longer wavelenghths

- hotter objects emit more energy at ALL wavelengths compared to a cooler object

What are the aspects of solar and terrestrial wavelengths?

- solar wavelengths: shortwave or solar radiation, 0.1-4 micrometers

- terrestrial wavelengths: longwaves or terrestrial radiation, 4-30 micrometers

what do shortwaves appear as?

(0.1 - 4 micrometers) Ultraviolet to Infared

What do longwaves appear as?

(4-30 micrometers) Infered to far infared

Define atmospheric window

portion of the IR spectrum (8-11 micrometers) where energy emitted by the earth can escape to space

How does the atmospheric window relate to selective absorption?

The gases that are selective absorbers only absorb some wavelengths but are transparent to others

Explain how clouds effect the temperature of the surface

- clouds help prevent cooling at night and partly "close" the atmospheric wind

- thicker clouds will have smaller loss of LW radiation & result in warmer night

- a night with high clouds will be colder than a night with low clouds (lower clouds are warmer and emit more energy)

- clouds cool during the day (reflect SW energy)

- thicker clouds reflect more SW energy than thing clouds (higher albedo)

Wavelengths of solar radiation

< 4 μm

Wavelengths of terrestrial radiation

> 4 μm

What is the atmospheric window

8-11 μm (micrometer)

Dirty skies

look red, because aerosols enhance scattering

Clean skies

look yellow

Define geometric scattering

all wavelengths are scattered equally = creating white light

Why do clouds appear white?

cloud droplets scatter all wavelengths of visible sunlight in all directions (resulting in white light)

How is latent heat transported and/or released with the phase change of water?

Define: Radiative Equilibrium

if the energy absorbed (in) is equal to the energy emitted (out), THEN the temperature will not change.

List all the transfer processes in the earth-atmosphere systems

radiation, conduction, and convection. Evaporation, condensation,

Which transfer process in the earth-atmosphere system is the most important?

evaporation-condensation cycle is an important mechanism for transferring heat energy from the Earth's surface to its atmosphere and in moving heat around the Earth

Define selective scattering

small particles can preferentially scatter shorter or longer wavelengths of radiation

List the atmospheric gases in order of longest lifetime to shortest lifetime

1. Nitrogen

2. Oxygen

3. Carbon Dioxide

4. Nitrous Oxide

5. Methane

6. Ozone

7. Water Vapor

Explain the cause of global weather

- differences in radiative energy are what set up our global weather patterns

- tilt of the Earth's axis