EAS 1600 Exam 1
Impact of climate change on hurricane
# of hurricanes hasn't increased More category 4 or 5 because of climate change. More effects like storm surge.
How to calculate average albedo?
(area percentage)*(average albedo)
Planck Function
* Describes shape of a blackbody spectrum * Sun emits visible light * Earth emits infrared only
Daisy World
* James Lovelock * Imaginary planet: how living organisms could unintentionally stabilize a planet's climate. Assumptions: 1) No atmosphere 2) Planet does not rotate --> has no seasons 3) Grey soil 4) White daisies 5) Only responsive to temperature
Hadley Cells
* Tropical air is warmer ->less dense *Rises by convection *Moist air cools, so it condenses to form clouds
Daisy World Albedo and Temperature Relatioship
* White daisies reflect more light--> average albedo increases * Average temperature decreases as Daisy coverage increases
Mesosphere
*Air too thin to absorb solar radiation, so very cold *Highest layer of the atmosphere where gases are mixed **Meteors burn up
Stratosphere
*Heated from above *No convection -> no weather *Ozonle layer located
Troposphere
*Heated from the bottom. *Convection *Weather occurs
30 N and S characteristics because of Hadley Cell
*Less condensation * Few clouds *Low precipitation ***Desserts
Thermosphere
*Low Eaarth orbit Satellites *Gases in lower quantity and layered *Temperature not measurable
Properties of the Equator due to Hadley Cells circulation
*Low pressure *Increased precipitation *Increased cloud cover *Uplift *Rainforests
Eye
*No wind *Temp warmer due to descending air
Eyewall
*highest wind speed --> right side stronger *Strongest pressure *Storm surge strongest --> right side stronger
Where do Hurricanes form?
*low pressure systems that form over warm, tropical waters near the equator. *5ºN and 20ºN (they almost never form in the South Atlantic.
Solar Flux
*the amount of energy coming in from the sun absorbed by a planet per unit area. (W/m^2) *Depends on distance from object and angle of incidence
Albedo
0 - 1 fraction of incoming sunlight reflected back to space. Ice: high albedo (more sunlight reflected) Dark surfaces: Low albedo (absorb more)
Processes to energy balance at each latitude
1) Atmospheric circulation 2) Ocean circulation Results in weather and climate
Environmental Challenges
1) Deforestation and soil loss: Biosphere, Hydrosphere, Litosphere 2) Hypoxia and Fish Kills: Biosphere, Hydrosphere 3) Species Extinction: Hydrosphere, Biosphere, Litosphere 4) Air Pollution: Atmosphere, Biosphere 5) Ocean Acidification: Atmosphere, Hydrosphere, Biosphere
Earth System Spheres
1) Hydrosphere 2) Lithosphere 3) Atmosphere 4) Biosphere 5) Cryosphere: frozen water part of the Earth
Process of a Hadley Cells
1) Intertropical Convergence Zone(ITCZ) at the equator. Merging of air masses moving from low pressure. 2)Uplift: Top of the troposphere (12km) forms barrier to further uplift, air must then diverge horizontally towards poles. 3) Cooler and denser air subsides at 30º N and D, as the air sinks it warms.
Most abundant permanent gas
1) Nitrogen 2) Oxygen
Success Stories
1) Ozone Hole --> Atmosphere and Biosphere 2) Acid Rain --> Atmosphere, Biosphere and Hydrosphere
Disturbances
1) Perturbations(Sudden change): temporary events. System eventually returns to balance. (Tsunami) 2) Forcing: Persistent Change (Anual mean CO2) (slowing of Earth rotation) 3) Periodic: repeats at regular intervals (increases and decreases) (Seasonal CO2) (Photosynthesis)
Progression of a Hurricane
1) Tropical disturbance (North Coas Africa) 2) Tropical depressions (23mph) 3) Tropical storm (39mph) --> named 4) Hurricane (74mph)
Most abundant greenhouse gas
1) Water Vapor
What type of radiation is absorbed by the ozone layer?
100% UV-C 95% UV -B
Permanent vs Variable gases
99% atmosphere composed of permanent gases have larger residence times. 0.01% atmosphere composed of variable gases have shorter residence times.
Chapman Mechanism
A set of reactions representing the formation and destruction of ozone in the stratosphere.
Horizontal movement driven by difference in pressure
Air moves from high to low pressure zones
How are hurricanes named?
Alphabetical order and alternating gender. New list every 6 years. If a big Hurricane, name is retired.
Positive Feedback Loop
Amplifies effect of disturbances. Unstab;e
Why is the temperature in Earth is warmer than expected?
Atmosphere --> Greenhouse Effect
Barometric Law
Atmospheric pressure decreases by a factor of 10 for every 16 km increase in altitude. * Altitude decreases more rapidly on the range 0-10
Daisy World Temperatures
Below: Negative Feedback Loop Above: Positive Feedback Loop
Annual Temperature Range
Continents: Variability --> More variability in North Hemisphere because theirs more land than in South Oceans: remain constant
External forces
Create disturbances in systems
Negative Feedback Loop
Diminishes effect of disturbance. Stable
Why do we have seasons?
Earth's tilt: 23.5
Solstice
Either of the two times of the year when the sun is at its greatest distance from the celestial equator
Incoming solar shortwave radiation
Energy In = S0(1-A)piR^2 S0 = 1372 W/m^2 *Cross section: the sun is only hitting a circle, not a sphere
Outgoing long wave radiation
Energy out: σTeff^4(4piR^2) *Sphere: the earth is giving off radiation from everywhere
How does the sola flux change as latitude increases?
Higher latitude, less solar flux Temperature decreases as latitude increases due to decrease in solar flux.
Earth's Energy Budget
Incoming solar radiation (short wave): 100 Absorbed by atmosphere: 25 Absorbed by surface: 45 Reflected by surface: 5 Reflected by atmosphere: 25 Total reflected solar radiation: 30 + Outgoing infrared radiation (long wave IR): 70 = 100
Greenhouse gases trap ________ radiation that is emitted from the Earth.
Infrared radiation * 33 K warmer
New Stable Equilibrium
Large disturbance from this state can carry the system into a new stable equilibrium state.
James Lovelock: Gaia hypothesis
Living matter on the earth collectively regulates the material conditions necessary for the continuance of life. The planet, or rather the biosphere, is thus likened to self-regulating organism.
Stable Equilibrium State
Modest disturbances from this state followed by return to this state.
Air pressure changes ___________ when moving vertically than it does when moving horizontally.
More
Stratospheric ozone hole over Atlantica Causes
Natural: marine algae, volcanos and evaporation of sea spray, produced by bacteria in agriculture. Anthropogenic: Chlorofluorocarbons (Freons) lifetime 60 to 130 years.
How do we know climate is changing? Sources:
Observational Data: 1) Instrumentation: Keiling Curve and Mauna Loa Observatory. 2) Ice Core Data 3) Tree Ring Data 4) Sediment Core Data
How do we know anthropogenic forcing drives changes in climate?
Observations Not enough evidence climate change affects frequency of climate change.
June Solstice
Occurs when the direct rays of the sun fall along the Tropic of Cancer --> Summer for the northern hemisphere *90ºN 24hours of Sunlight * Solar declination +23.5º N
Permanent gases
Permanent: Variables: Nitrogen Water vapor Oxygen Carbon dioxide Argon Methane
What are the three cells and their location?
Polar: Poles 60º-90º Ferrel: 30º - 60º Hadley: Equator 0º - 30º
Reductionism vs System
Reductionism: understanding a system by breaking system down into parts System: interactions between parts that function as a complex whole
Solar Flux based on Latitude
S = S0 cos(q) q = Latitude - solar declination
The distribution of incoming solar energy varies with:
Season and latitude
Why CO2 rise and falls through a year?
Seasons: fall and winter no leaves so no photosynthesis.
Unstable Equilibrium State
Slightest disturbance from this state will carry it away from this state to a stable state. Temporal.
Blackbody Curves:
Sun has bigger area under the curve because the sun is hotter
Sun vs Earth
Sun: primarily visible light Earth : primarily infrared
Incoming radiation Surplus and Deficit
Surplus: Equator Deficit: Poles
Hadley and Polar cells circulation is driven by ____________
Temperature
What causes changes in the atmosphere?
Temperature -> Horizontal Pressure -> Vertical
Effective Temperature
Temperature planed would have if it radiated as a true black body.
Why we have Coriolis effect?
The equator is rotating faster to keep himself aligned with the poles. -> Creates three individual cells of air circulation. If no Coriolis effect, one big cell.
Wien's Law
The higher the temperature of a body the shorter the wavelength of it's maximum radiation. (hotter = shorter wavelength) λmax(um)= 2898/T --> Kelvin
What is Earth's primary source of energy?
The sun
Stefan-Boltzmann Law
Total Radiative Flux F= σT⁴. σ = 5.68 *10^-8 T = Kelvin F = W/m^2 F ~ T^4 2^4F ~ (2T)^4 = Doubling temperature, results in a 16x increase in F
The Eath's axis points in the same direction all four seasons (23.5)
True
What type of radiation is required to photolyze O2?
UV-C
Which type of UV radiation is more harmful?
UV-C because it has a shorter wavelength so it is more energetic. UV-B causes cancer
Equinox 0º (equal night): direct sunlight at the equator
Vernal ->Spring for north: March 20 --> March Equinox Autumnal -> fall for north: September 22 or 23 --> September Equinox *Lowest during June and December Solstice * Solar declination 0º
To keep balance: ________ air must be carried towards the poles, while ___________ air must be carried towards the equator.
Warmer, colder.
Waves
Wavelength: the distance between two adjacent wave crests. Frequency: the number of wave crests that pass by point per second. Amplitude: the maximum height of wave from equilibrium.
Weather vs Climate
Weather: state of the atmosphere at any given time Climate: overall change. Ex: subtropical
December Solstice
Winter for the Tropic of Cancer --> Northern Hemisphere * Solar declination -23.5º S
Negative Coupling
a change in one component leads to a change i the opposite direction in the linked component. ----------o
Positive Coupling
a change in one component leads to a change in the same direction in the linked component --------->
Solar Luminosity
amount of energy the sun gives off (W=J/s)
Blackbody
an object that emits or absorbs electromagnetic radiation with 100% efficiency at all wavelengths. Blackbody radiations: higher temperature, brighter color. red->orange->yellow->white
What influences the solar flux that is received?
angle of incidence: measured from directly overhead to the geometric center of the sun's disc
Southern Hemisphere deflection
clockwise: to the left
Northern Hemisphere deflection
counterclockwise: to the right
λv = c λ = wavelength (nm) --> Convert to meters to use equation v = frequency (s^-1) c = 3*10^8 (ms^-1) T = Kelvin
higher frequency, shorter wavelength higher temperature, shorter wavelength
GWP (global warming potential)
how much heat a greenhouse gas traps in the atmosphere up to a specific horizon, relative to carbon dioxide.
Inverse Square Law
incoming radiative flux (S) decreases as we go further from the sun (r).
Coupling
mechanism that link the components of a system
Global Climate Change
natural: Short term:Enso (El Niño), Milankovitch cycle. Long term: Volcanism, Rock weathering anthropogenic: Pollution, GreenHouse Emissions. Human changes to natural features.
Coriolis effect
tendency for a fluid or large object that is moving across the Earth's surface to be deflected from its straight path * only effects things at a large scale * Increases as speed object is moving increases * Is zero at the equator * Increases with latitude (towards the poles)
Vertical movement driven by buoyancy
the ability to float in water or air or some other fluid. *Negative: object is more dense so it sinks *Positive: object less dense so it floats *Neutral: object same density as surrounding
Solar declination --> Solar noon
the latitude where the sun is directly overhead at noon June solstice: Tropic of Cancer 23.5ºN December solstice: Tropic of Capricorn 23.5º S
Ferrel cell rotates due __________
the motion of Hadley and Polar cells
Atmospheric Pressure
the wight that the atmosphere exerts over the surface of the Earth
Convective cells
tropical solar heating, ocean water evaporation and conversion to latent heat during vaporization, and then heat released during condensation
Atmospheric Layers
troposphere, stratosphere, mesosphere, thermosphere
Feedback loop
two or more linked coupling.
