Atmosphere
Stratospheric ozone's important functions
- Absorbed energy warms stratosphere - Temperature increases with elevation - Protects life on earth's surface (UV radiation damages live tissues, skin cancer, etc.)
Climate of temperate and polar altitudes is largely determined by
air masses
Movement wind
air moves from high-pressure areas → low-pressure areas
High pressure
air warms and sinks, available moisture evaporates (rainfall is rare)
Hadley cells
an air circulation cell; the circulation of air that rises at the equator, spins poleward, sinks at subtropical latitudes, and returns to the equator
What path do jet streams follow?
an undulating path where vertical convection currents (Hadley and Ferrel cells) meet
Tropopause
area where air is no longer warmer than its surroundings → ceases to rise
The Greenhouse Effect
atmosphere comparable to glass of a greenhouse that transmits light while trapping heat inside
Why does cooling occur?
bc of changes of pressure with altitude
How is absorbed heat used?
- Evaporation of water - Heat the Earth's surface - Energy for photosynthesis
Stratosphere
- Extends from troposphere to 50km - Vastly more dilute than troposphere, but has similar composition - No water vapor - Almost 1000x more ozone than troposphere - Relatively calm because warm layers lie above colder ones
Thermosphere
- Heated layer - Begins at approx. 80km - Northern lights = in lower part
What can the Earth's energy budget change?
- Increased CO2 (traps outgoing heat at the Earth's surface = global warming) - Melting of glaciers and sea ice (changes the albedo of the Earth's surface from a light reflecting surface to a dark surface = absorb more heat = global warming) → changes albedo - Volcanoes erupt (aerosols from the ash that stay in the stratosphere reflect incoming solar radiation = global cooling)
What influences the climate of an area?
- Latitudinal distribution of sunlight (most important) - Proximity to ocean - Elevation - Presence of mountains
Troposphere
- Layer of air immediately adjacent to earth's surface - Air absorbs energy from the sun-warmed earth's surface and from moisture evaporating from oceans - Warmed air circulates in great horizontal and vertical convection currents - Depth: 18km over equator to 8km over poles - Consists mainly of large, heavy molecules held close to earth's surface by gravity - Contains approx. 75% of atmosphere's total mass - Temps drop rapidly with increasing distance from earth - Composed of 78% nitrogen (N₂) and 21% oxygen (O₂) and CO2 (0.035%).
What is the atmosphere?
- Retains solar heat - Protects us from deadly radiation in space - Distributes the water patterns of temp and moisture that result from the circulation
Characteristics of terrestrial energy
- lower-intensity, lower-wavelength radiation in far-infrared part of spectrum - atmospheric gases (CO2 + water vapor) absorb much of the long-wavelength energy and re-release it in lower atmosphere - provides most of the heat in the lower atmosphere
End of atmosphere
- not marked by any sharp boundary - density of gas molecules decreases with distance from earth until it becomes indistinguishable from near-vacuum of interstellar space
What happens to earth's energy?
- reflected back to space by clouds, atmospheric particles (aerosols) and bright ground surfaces like sea ice and snow - absorbed by clouds, atmospheric gases - passes through the atmosphere and is absorbed by the surface - reflected back to space
Condensation nuclei
- tiny particles of smoke, dust, sea salts, sports and volcanic ash - particles form a surface on which water molecules can begin to coalesce - without them, even supercooled vapor can remain in gaseous form - even clear air can contain a large number of these particles - generally too small to be seen by naked eye
CO2 comprises what percentage of the Earth's atmosphere?
.035%
The atmosphere is only about what % CO2?
0.04%
Examples of airbuses
1. Continental polar/Arctic 2. Maritime polar 3. Maritime tropical 4. Continental tropical
In what three ways does climate change "crank up the odds" of the occurrence of disastrous storms such as the hurricanes in Texas and Florida in 2017?
1. Our emissions of heat-trapping gases have already increased the likelihood and severity of heat waves, extreme rainfall and storm surges. 2. A warmer atmosphere can hold more water, increasing the potential for heavy downpours. Storm surge now occurs on top of sea level rise, increasing flooding risk. 3. Warmer oceans can produce more intense hurricanes, as has occurred in the North Atlantic and the Gulf.
The progression of hadley cells
1. The hot/moist air at the equator rises (updrafts). 2. It cools and releases moisture (rains). The resulting cool/dry air moves poleward (N and S). 3. At subtropical latitudes (20-30º N and S) the cool/dry air descends (downdrafts). (By the time it reaches the earth's surface it is hot, as well as dry; forming the earth's major desert regions.) 4. The warm/dry air returns to the equator (the trade winds). As they cross the ocean, they pick up moisture. 5. They arrive at the equator as warm/moist air.
Four zones of temperature in atmosphere
1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere
How do hurricanes happen?
1. Warm moist air near surface rises into the cold and as it does more air rushes in to take its place 2. The warm air condenses, forming clouds and releasing heat that accelerates the process 3. As more air rushes in, the rotating earth gives it a nudge and everything starts to spin 4. In a warming world with warmer oceans, there will be a greater temp difference between the sea and the upper air → adds more fuel → engine produces more power → storm gets bigger → winds spin faster 5. Air will also hold more moisture → storm will produce more rain → sea levels will be higher → storm surge will start from a higher baseline
_____ of solar energy that reaches the outer atmosphere is reflected by clouds and atmospheric gases; ____ is absorbed by CO2, water vapor, ozone, methane and other gases; ____ reaches earth's surface (some reflected by bright surfaces, other absorbed by earth's surface and water)
1/4; 1/4; 1/2
1g of evaporating water absorbs how many calories of energy?
580 (liquid --> gas)
When water vapor condenses what happens?
580 calories released (gas --> liquid)
Earth's Energy Budget
Amount of solar energy and how it balances
What effect explains why winds seem to curve?
Coriolis effect
Ozone (O3)
Depending on where it is determines whether it's a good thing or bad thing Tropospheric ozone = brown cloak over cities, bad for breathing Stratospheric ozone = good, has ability to block out harmful UV radiation, protecting living creatures
Too strong a greenhouse effect can cause what?
Ex: Burning fossil fuels, deforestation → destabilization of known environment
T or F? Winter CO2 is much less than growing season
FALSE. It's much higher.
What is a natural atmospheric process necessary for life?
Greenhouse Effect
Physical conditions in the atmosphere
Humidity, temperature, air pressure, wind, precipitation) over short time scales, usually days or weeks
How does temperature change with altitude in each layer?
It fluctuates. Troposphere = decreases from 15 → -43 degrees. Stratosphere = increases from -43 → -3 degrees. Mesosphere = the temp decreases even more drastically, plummeting from -3 → -97 degrees. Thermosphere = increases even more drastically than the stratosphere, skyrocketing from -97 → 80+ degrees.
Polar Vortex
Large area of low pressure and cold air surrounding both of the Earth's poles.
Over days, CO2 levels are:
Low in morning, high at night
T or F: Absorbed energy warms our world
TRUE
T or F? Air Masses drive much of the weather in temperate latitudes such as in North America
TRUE
T or F? Weather has regional patterns
TRUE
T or F? You can measure these CO2 fluctuations
TRUE
Airmass
a large body of air that has characteristic properties of temperature and humidity
Water is extremely efficient at what? And why is this matter concerning scientists?
absorbing and storing energy. concerning because historically Article is all white and reflect energy but now it is melting because water is storing and absorbing more and more energy
Low pressure
air cools and rises
How do jet streams play a key role in determining weather?
bc they usually separate colder air and warmer air, generally push air masses around, moving weather systems to new areas and even causing them to stall (ex., stalled rain causes floods)
Maritime polar
brings cold/wet air from North Pacific and Labrador
Maritime tropical
brings warm/wet air from Pacific or Gulf of Mexico.
Volcanic emissions
carbon, nitrogen, oxygen, sulfur and other elements
Convection currents lead to what?
cells in the atmosphere (hadley cells)
What about the atmosphere contrasts from the climate?
climate is long-term patterns of temp and precipitation whereas atmosphere is temporary
What is another ingredient pessary to initiation condensation of water vapor?
condensation nuclei
Air rises in ______ where solar heating is intense (equator)
convection currents
A gas allowed to expand becomes _____ whereas a compressed gas becomes ____
cooler; warmer
Cells + coriolis effect -->
creates weather patterns that we have on our planet
Weather
current state of our atmosphere
El Nino Southern Oscillation (ENSO)
cycle of warm and cold temperatures, as measured by sea surface temperature, SST, of the tropical central and eastern Pacific Ocean
Coriolis effect
deflection of a body of air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, caused by the rotation of the earth
Carbon Dioxide in the atmosphere varies on what kind of scales?
diurnal, seasonal, annual, centennial and millennial
Pacific trade winds that blow over regions typically move from ____ to ____, pushing water at ocean's surface towards _____ and _____
east to west; South Asia; Australia
Terrestrial energy
energy re-released from earth's warmed surface
Much of incoming solar energy used to...
evaporate water
Absorbed energy heats absorbing surface does what?
evaporates water or provides energy for photosynthesis in plants
El Nino occurs how often?
every 2-7 years
The bigger the temp/pressure difference between two air masses, the _____ the air moves. The less difference between the air masses = ______ and ______ wind.
faster; slower and weaker
Continental polar/Arctic
forms over N. Canada and the Arctic; can pour cold/dry air down the continent
Greenhouse gases
gases that capture/trap long-wave radiation (heat) at the Earth's surface.
Atmosphere selectively absorbs ______ wavelengths
greater
Atmospheric pressure near the ground is ______ than at higher altitudes
greater
Convection constantly redistributes what around the globe?
heat and moisture
El Nino is accompanied by _____ pressure in the _______ and ________ pressure in the _________.
high air in western Pacific; low air pressure in eastern Pacific
Air wants to move from regions of _____ pressure to _____ pressure (or hot to cold) in order to equalize. This creates the _____
high to low; wind
Jet streams
hurricane-force winds that circle the earth
Insolation
incoming solar radiation; much stronger near equator than high latitudes
Characteristics of solar energy
intense, high-energy light or near-infrared wavelengths, passing easily through atmosphere to earth's surface
What happens after absorbed energy hates absorbing surface?
it is then gradually re emitted as lower-quality heat energy
Why does curving or spiral motion occur?
jet streams
What surface is the interface between the atmosphere and the biosphere?
leaf surface
Southern Hemisphere winds/ocean currents bend which way?
left
Cool air holds _____ moisture than warm air
less
As air nearest surface warms and expands →
less dense than air above it
What did the earliest atmosphere likely consist of?
lightweight hydrogen and helium → later diffused into space
Where do polar vortex's always exist?
near the poles, but weakens in summer and strengthens in winter
Positive feedback loop
melting --> further melting
Mesosphere
middle layer where meteors are burning up
Aerosols
minute particles and liquid droplets suspended in the air
If air is _____, rainfall is likely
moist
As the warmest weather evaporates, the air fills with _____ and contributes to the monsoon seasons in Asia and Australia
moisture
How can you increase reflectivity?
more volcanic activity
Greenhouse gases: H20
most abundant greenhouse gas, always present in atmosphere
Greenhouse gases: CO2
most abundant human-caused greenhouse gas followed by CH4 (methane), N2O (nitrous oxide) and more
"Vortex"
refers to the counter-clockwise flow of air that helps keep the colder air near the Poles.
U.S.'s jet stream
northern hemisphere polar jet stream
Energy supplied by sun is ____ evenly distributed throughout the globe
not
Cells of our planet
on equator we're heating up air --> convection cells
Albedo
reflectivity of light and other forms of radiative energy
What type of regions tend to receive a great deal of precipitation?
regions with intense solar heating, frequent colliding air masses or mountains
High albedo
surfaces that reflect energy (i.e. snow, ice)
All O2 that we breathe was produced by what?
photosynthesis in blue-green bacteria, algae and green plants
Another name for polar vortex
polar jet streams
On a Global scale, the coriolis effect produces what?
predictable wind patterns and currents
What's an important cause of wind?
pressure differences
Uneven heating leads to what?
pressure differences → intense weather
On a Regional scale, the coriolis effect produces what?
produces cyclonic winds, or wind movements controlled by earth's spin
What holds the atmosphere near the Earth's surface?
pull of earth's gravity
Continental tropical
pushes north from Mexico and southwest US; brings warm/dry air
As hot air rises it expands and cools →
rain
Northern Hemisphere winds/ocean currents bend which way?
right
Evaporated water _______ energy, wind ______ it
stores; redistributes
Because the Arctic is very cold compared to mid-latitudes, there is a great temp and pressure difference, therefore, the jet stream is _______
strong
Air circulation occurs as the sun....
sun warms earth's surface
Low albedo
surfaces that absorb energy (i.e. black soil, pavement)
Fuel for hurricanes arise from what?
temp difference between sea and upper air = fuel
Wind does not flow directly from the hot to the cold area, but is deflected by ________ and flows along the boundary between the two air masses
the Coriolis Effect
Front
the boundary between two different air masses
We're going to increase density the closer we are to where?
the earth (gravity)
Latent heat
the heat required to convert a solid into a liquid or vapor, or vise versa without change of temperature.
The higher the temperature -->
the higher the pressure
All of the weather occurs in which layer of the atmosphere?
the troposphere
What determines climate?
tilt of our axis and where we are on the orbit around the sun --> seasons
Where are jet streams located?
top of troposphere
What sphere do we live in?
troposphere
A jet stream runs between what?
two air masses of different temperatures
Hurricanes
typhoons in the Pacific
Most major weather patterns result from:
uneven solar heating → areas of high and low pressure, together with spinning of the earth
Rising warm air → vertical convection currents
vertical convection currents
What does uneven heating look like?
warm air close to equator, cold air at higher latitudes
Why does it rain?
water condenses as air cools, air cools as it rises → clouds, rain, snow
Weather vs. climate
weather = deals with short-term variations, which is what happens when the polar vortex visits your hometown climate = refers to the long-term averages and trends in atmospheric conditions over large areas
Climate
weather over a long period of time
Barometric pressure
weight of air, Barometric pressure drops with increasing altitude (gravity)
When do convection currents occur?
when low-density air rises above a cooler, denser layer
Convection currents
when low-density air rises above a cooler, denser layer, the warmed air circulates in great horizontal and vertical currents.
When does El Nino occur?
when trade winds stop happening
Why is the redistribution of heat and water around the globe is a necessity?
without, earth would undergo extreme temperature fluctuations
