Final Study Guide 9

Question 1

What is Earth systems science?

Answer 1

Earth system science seeks to integrate various fields of academic study to understand the Earth as a system.Earth system science embraces chemistry, physics, biology, mathematics and applied sciences in transcending disciplinary boundaries to treat the Earth as an integrated system and seeks a deeper understanding of the physical, chemical, biological and human interactions that determine the past, current and future states of the Earth. Earth system science provides a physical basis for understanding the world in which we live and upon which humankind seeks to achieve sustainability.

Question 2

What is the greenhouse effect?

Answer 2

trapping of the sun’s warmth in a planet’s lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface.

Question 3

Why is albedo a critical factor in climate-related feedbacks?

Answer 3

• Albedo- used to define the percentage of solar energy reflected back by a surface
• Understanding local, regional, and global albedo effects is critical to predicting global climate change
• The following are some of the factors that influence the earth’s albedo: clouds, ice,snow,surface, oceans and forests
• It is a very strong “positive feedback” (increases an initial warming) that has been included in climate models since the 1970s

Question 4

List some of the long-term climate variability

Answer 4

• solar
  > changes in the intensity of solar radiation reaching earth
• volcanic
  > eruptions add aerosols to the atmosphere, increasing reflection of radiation
  > adds CO2, which increases global warming
• greenhouse gases
  > adds CO2, which increases global warming

Question 5

How do we know past climate before the instrumental era?

Answer 5

Historical records; change in growth (tree rings, speleothems, corals); changes in organism/plant distribution (pollen records); chemical records (changes in isotopic ratios, in ice and sediment cores); geological evidence (glacial sediments)

Question 6

Weather

Answer 6

natural phenomena within the atmosphere at a given time (seconds to hours to days)

Question 7

Climate

Answer 7

the average weather conditions, and their range of variability, over a long period of time (~30 years or more)

Question 8

Radiative Balance

Answer 8

the solid earth + atmosphere receive heat energy from the sun but they also radiate the same amount of heat back into space

Question 9

Frequency

Answer 9

the number of times that something happens during a particular period

Question 10

Wavelength

Answer 10

distance from one wave of energy to another as it is travelling from one point to another point

Question 11

Electromagnetic Spectrum

Answer 11

• is the range of all possible frequencies of electromagnetic radiation; the “electromagnetic spectrum” of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object
• Higher frequency = more energetic

Question 12

Wien’s Law

Answer 12

• relationship between temperature of a black body and the wavelength at which it emits the most light
• wavelength of emitted radiation is shorter for bodies at higher temperatures
• Used to infer the temperature of the sun
• Sunlight wavelengths ~500 nm (UV radiation)  5500-6000 K
• Objects that are cooler radiate longer wavelengths – so Earth radiates long wavelengths (red)

Question 13

Black body radiation

Answer 13

radiation emitted by non-reflective body held at constant temperature- used to approximate radiation from stars and planets

Question 14

Absorption

Answer 14

is the way in which the energy of a photon is taken up by matter, typically the electrons of an atom; thus, the electromagnetic energy is transformed to other forms of energy for example, to heat

Question 15

Spectrum

Answer 15

group of colors that a ray of light can be separated into including red, orange, green, blue, indigo, and violet: the colors can be seen in a rainbow

Question 16

Greenhouse effect

Answer 16

Energy radiated by the sun converts to heat when it reaches earth. Some heat is reflected back through the atmosphere, while some is absorbed by atmospheric gases and radiated back to earth.

Question 17

Solar constant

Answer 17

a measure of flux density, is the amount of incoming solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit (AU) (roughly the mean distance from the Sun to the Earth)

Question 18

Hadley cells

Answer 18

• a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes
• Steps:
  > Moist warm air expands, rises
  > Cools, condenses, rain falls
  > Dense air sinks in sub tropics
  > Warmed, dry air
 spreads at surface

Question 19

Great ocean conveyor

Answer 19

• refers to a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes (salt driven)

Question 20

Climate proxies

Answer 20

preserved physical characteristics of the past that stand in for direct measurements (as statistical proxies), to enable scientists to reconstruct the climatic conditions that prevailed during much of the Earth’s history

Question 21

El Nino (drought)

Answer 21

• refers to the climatic conditions associated with temperatures in the eastern south pacific - in years with weak trade winds, these waters wam, and the warmer water influence global climate
• hard to predict

Question 22

La Nina

Answer 22

• Warm ocean temperature in western pacific

- Opposite of El Nino

Question 23

Paleoclimatology

Answer 23

is the study of changes in climate taken on the scale of the entire history of Earth

Question 24

Forcings

Answer 24

• external boundary conditions or inputs to a climate model
• Main long-term climate forcings:
  > Solar: changes in the intensity of solar radiation reaching the Earth
  > Volcanic: eruptions add aerosols to the atmosphere that increase reflection of radiation over short periods of time, but also add CO2 to the atmosphere that increases greenhouse warming over long periods
  > Greenhouse forcing: addition of CO2 to atmosphere contributes to climate warming

Question 25

Ice Core

Answer 25

• a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from higher mountain glaciers elsewhere
• Lower layers are older than upper layers of snow (and an ice core contains ice formed over a range of years)
• The properties of the ice can then be used to reconstruct a climate record over the age range of the core, normally through isotopic analysis
• This enables the reconstruction of local temperature records and the history of atmospheric composition

Question 26

Milankovitch Cycle

Answer 26

theory describes the collective effects of changes in the Earth’s movements upon its climate; explains the repeating, cyclical changes from glacial to interglacial

Question 27

Orbital Changes

Answer 27

changes solar energy reaching Earth-> changes in global climate

Question 28

Glacial/Interglacial (Cycles)

Answer 28

• the cycles are caused by variations in the Earth’s orbit through time have changed the amount of solar radiation received by the Earth in each season
• Interglacial periods tend to happen during times of more intense summer solar radiation in the Northern Hemisphere

Question 29

Precession

Answer 29

• the trend in the direction of the Earth’s axis of rotation relative to the fixed stars, with a period of roughly 26,000 years; is due to the tidal forces exerted by the Sun and the Moon on the solid Earth, which has the shape of an oblate spheroid rather than a sphere
• The Sun and Moon contribute roughly equally to this effect

Question 30

Obliquity

Answer 30

a deviation from a vertical or horizontal line, plane, position, or direction.

Question 31

Albedo

Answer 31

the proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon. Like the snow that reflects the sunlight to prevent the surface of the earth from overheating.

Question 32

Photons

Answer 32

elementary particles (one of the basic building blocks) characterized by oscillating electrical and magnetic fields that propagate through space. They behave like particles and waves.

Question 33

Boltzmann’s Law

Answer 33

S(amount of energy emitted by black body)= K(constant)x T^4(temperature)

Question 34

Methane

Answer 34

• Driver of Climate Change
• Along with CO2, nitrous oxide, Methane levels have reached levels that are unprecedented in the last 800,000 years
• Green house gas

Question 35

Ozone

Answer 35

• helps make up the atmosphere, especially the stratosphere
• helps filter out incoming UV light from the sun
• acts like greenhouse gas, absorbs outgoing infrared energy from earth

Question 36

Thermo-haline circulation

Answer 36

• large scale ocean circulation driven by global density gradients created by surface heat and freshwater fluxes
• same as ocean conveyor belt

Question 37

ENSO

Answer 37

El-Nino-Southern Oscillation

Question 38

Global Circulation Models

Answer 38

• A computerized model of general circulation of the atmosphere
• Analog for non-linear oscillator system
• Stress vs. time graph (stick slip cycle)

Question 39

Discretization

Answer 39

the process of transferring continuous models and equations into discrete counterparts. This process is usually carried out as a first step toward making them suitable for numerical evaluation and implementation on digital computers

Question 40

Chaotic

Answer 40

sensitive dependence on initial conditions

Unpredictable over long times (weather forecast)

Question 41

Non-linear systems (like Climate) can be

Answer 41

• metastable
• phase state depends on crucially on parameters
• chaotic

Question 42

Control parameter

Answer 42

• parameters that can affect climate

> time of year, ocean temp, albedo, continentality, etc.

Question 43

Periodic Doubling

Answer 43

switching to a new behavior with twice the period of the original system

Question 44

Poincare Section

Answer 44

A method for examining the motion of dynamical systems; essentially the Poincare section provides a means to visualize an otherwise messy, possibly aperiodic, attractor. It the flow has an attractor, we should see it in the Poincare section

Question 45

Attractor

Answer 45

In dynamical systems, an attractor is a set of physical properties toward which a system tends to evolve, regardless of the starting conditions of the system.[1] Property values that get close enough to the attractor values remain close even if slightly disturbed.

Question 46

Phase space

Answer 46

A space in which all possible states in a system are represented

Question 47

Sensitive dependence on initial condition

Answer 47

small changes in one area of a system can result in large changes later

Question 48

Lyapunov Exponent

Answer 48

exponent of a dynamical system is a quantity that characterizes the rate of separation of infinitesimally close trajectories.

Question 49

Lorenz System

Answer 49

Lorenz attractor is a set of chaotic solutions of the Lorenz system which, when plotted, resemble a butterfly or figure eight. Atmospheric convection system in choatic parameter space.

Question 50

Bifurcation

Answer 50

means the splitting of a main body into two parts.

Question 51

Tipping Point

Answer 51

A tipping point is an example of hysteresis in which the point at which an object is displaced from a state of stable equilibrium into a new equilibrium state qualitatively dissimilar from the first.

Question 52

Metastability

Answer 52

describes the extended time spent by an isolated system in a long lived configuration other than the system’s state of least energy.

Question 53

Speleothem

Answer 53

a cave formation or “cave deposit” is a secondary mineral deposit formed in a cave. typically formed in limestone.

Question 54

δ18O

Answer 54

measure of the number of stable isotopes. Used as a measure of temperature of precipitation.

Question 55

Isotopes

Answer 55

variations in an element due to a different number of neutrons (all isotopes of an element have the same number of protons.

Question 56

Medieval Warm Period (MWP)

Answer 56

• Warm period from 950-1250

- Marked some of the warmest weather in those regions for the time, but lower temps than the current global temps

Question 57

Little Ice Age (LIA)

Answer 57

• A period of cooling after the Medieval Warm Period from 1550-1850
• Modest cooling in the Northern Hemisphere
• Consisted of largely independent regional climate changes instead of global cooling

Question 58

Eccentricity

Answer 58

• Parameter associated with every conic (cone) section.
• Measure of how conic the section deviates from being circular
• relates to the Milanokovitch Cycle; eccentricity and the term orbital changes are essentially the same.

Question 59

Climate Proxies

Answer 59

• geological objects sensitive to climate
• Allow us to reconstruct temp before thermometers
  > rock and fossils, glacial evidence, tree rings, historical records, instruments (now)
• often tied to stable water isotopes