Pitt AOC exam 1

Blue marble

• Fully Illuminated Earth

• Able to see Antarctica, Madagascar, Coast of Africa, Arabian Peninsula

• Highly produced

• No other image like this has been taken by humans

Overview effect

• Reported by almost all astronauts while Earth gazing

  • Reported a feeling of profound (spiritual) change

  • Saw the earth as an organism

Weather Vs. Climate

Climate is what you expect

Earth system Web diagram

• Not consistent

• Not predictable

• Not 1:1

System

A set of connected things or parts forming a complex whole in particular.

• Set of things working together as parts of a mechanism, or an interconnecting network.

  • University

  • Government

  • Human body

Definition of Earth system

• The unified set of chemical, physical, biological, and social components, processes, and interactions that determine the state and dynamics of Earth. Including her biota and human components

Stock

The amount of the item in interest (volume of glacier studied)

Reservoir

Where the stock sits (glacier in the side of a mountain)

Flux

Movement of flow of a quantity (water melting off of glacier)

Equilibrium

Flux in = Flux out

Residence time

Stock / flow

Stability

Tendency to return to equilibrium

Equilibrium Diagram

When a system is in equilibrium, only have to pick one flux to find residence time

Stability (ball) diagram

Feedback Loops

Self perpetuating mechanisms of change and response to that change

Positive Feedback

• Causes system to change (and amplifies those changes)

  • Doesn’t mean good

Negative

• Keeps system from changing (eg. diminishes the effects of a disturbance)

  • Doesn’t mean bad

Feedback loop diagram

• Changes in seasons change the CO2 level

• As of jan 17 we are at 426.34ppm

• There is typically a certain range that these fluctuations stay within (even during ice ages), but we are way above the highest level now

Fluctuation diagram

Why is the pliocene relevant in this situation

• Earth’s CO2 has not been this high since that period

• Global and land temps were 5-7 degrees cooler

• sea levels were 100 ft higher (all the ice melted)

• We know it was hot, but we don’t know why. We can assume that it was because of the higher CO2 levels, but we don’t know why they were higher

What is the atmosphere thinner than

The skin of an apple

What is so important about water vapor?

• It is an important greenhouse gas

• It is concentrated differently in different areas

• It is very powerful

• It has a short residence time in the atmosphere

Atmospheric thermal structure

• Troposphere: there is a drop in temp as there is an increase in elevation

  • Instability and that is why we have weather (heating and cooling of air)

• Ozone in the stratosphere

How does atmospheric pressure changer with altitude

• susceptible to gravity

  • Everything settles near Earths surface, so there is more pressure

How does energy, from the sun, change at different altitudes?

• Higher concentration of solar rays at the equator than at the poles

• Same amount of rays at equator as at the poles, but the concentration differs due to Earth’s curvature

Atmospheric patters and energy distribution

• Main curve:

  • Incoming solar radiation

  • Shows concentration of radiation

• Flat curve:

  • Amount of energy going back into atmosphere

  • Fairly consistent

  • earth heats as a whole and there is radiation back

Changes in climate at different altitudes

• Imbalance:

  • there is a net radiation deficit at higher altitudes

Composition of Hydrosphere

• Don’t have to memorize. Just understand

Sea Water composition

• Don’t have to memorize. Just understand

Ocean basin profiles

• Thermocline drops around 1m

• Increased salt content = more dense = will sink

Oceanic Conveyer belt —> Thermohaline circulation

• water that is driven up the north Atlantic cools and gets more salty

• When sea water freezes, salt gets left behind (as water freezes, it rejects salt from its molecular structure)

  • Stronger winds, more aired, more evaporated — leaves behind salt

• The water then sinks and flows south

  • Becomes less slaty and warms (because it is less boyant)

Why is circulation important?

Energy (heat) flow

Gyres

• Circular patterns of surface water movement

  • One in the northern hem and one in the southern hem

    • Driven by winds and Coriolis

Currents

• Connections between gyres

  • Driven by winds and Coriolis

  • Colder on west coast of continent or eastern boundary currents

  • western boundary currents are warmer

ENSO definition

• Coupled ocean atmosphere circulation system centered in the tropical pacific that is relate to changes in global atmospheric circulation and influences temp and precipitation patterns across the globe

ENSO cycle

• normal conditions

  • “normal” arrow sizes and they indicate “normal” winds

• Wind is dragging warm waters to the west

• Also get tropic on western side of pacific

• December - February are when ENSO conditions are most apparent

El nino

• Less wind on water surface (sometimes they change directions)

• Fire weather in Australia, typically very hot, but not wet

• Thermocline is not allowing the cold water to circulate to the surface

• Influencing fishing industry off west coast of south America

• More evaporation over whole pacific because warm air is not being pushed all in one way

La Nina

• lots of rain in wester pacific

• strong winds in every direction

• very steep thermocline

• Deep waters are able to get closer to the surface

• low pressure warm air rising (Australia and Indonesia), high pressure air sinking

What are the effects of El Nino on Canada and Alaska?

• When we have el Nino, Canada and Alaska are quite warm and there are wet conditions in southern us. ( dece- feb)

Trends in this graph

• Typically warmest is el Nino and coolest is Nina

  • 79- didn’t really classify as a Nino, but there were Nino qualities (delayed in 79)

  • 90- Eruptions lead to cooling

• Nino and Nina are hotter than they have ever been and Nina is now warmer than past Ninos

Characteristics of the Cryosphere

• Land and sea cover change because if the seasons

• Northern hem because we have more landmass spread across the northern hem

All of the elements (from cryosphere) shown in this image

Albedo feedback

What is the average albedo of earth

The average albedo of earth is 30% (0.30)

Water cycle Diagram

Precipitation

The change of atmospheric water vapor into a liquid or solid

Evaporation

The exchange of water from a liquid to a vapor

Transpiration

The release of water into the atmosphere by plant and animal cells

Infiltration

The movement of liquid water downward from land surface into and through soil and rock

Runoff

The total amount of water flowing into a stream

What is the residence time of water in the atmosphere?

10 days

What is the residence time of CO2 in the atmosphere?

100 - 1000 years

Biosphere range

• Height of troposphere to deep in the earths crust

  • 3.1 miles deep

  • 7.0 miles high

Prokaryotes

• No membrane bound nucleus

Where might cyanobacteria be found?

• fossil material (churt)

  • There are some rocks from millions of years ago that have oxygen

• Fossil evidence: 3.5 gya

• Chemical evidence: 3.8 gya

Photosynthesis

6H₂O → C₆H₁₂O₆ + 6O₂

Geosphere composition

• Crust varies in thickness depending on location

  • Continental and oceanic crust (vary in rock type and rock density)

  • Granite is much less dense than basalt

What is a geomagnetic dynamo?

• liquid swirling around solid

• Protects us from solar radiation

Mantel characteristics

• like silly putty—> very slow flowing (not like liquid)

• Mobile and convecting

What are tectonic plates

• not equivalent to the size or shape of continent

  

Techtonic diagram

The rock cycle

• Metamorphic: heat and pressure 

• Igneous: formed from melted rock that has cooled 

• Sedimentary: accumulation of sediments that are buried and lithified 

  • Need to break down other rocks to get the sediments 

• Can take any metamorphic rock and subject it to heat and pressure and it becomes another metamorphic (the same with the other types) 

  • Recycling process