***Study Guide 9: Paleo Climate

Methane

1. Driver of Climate Change 2. Along with CO2, nitrous oxide, Methane levels have reached levels that are unprecedented in the last 800,000 years 3. Green house gas

Ice Core

1. 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 2. Lower layers are older than upper layers of snow (and an ice core contains ice formed over a range of years) 3. 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 4. This enables the reconstruction of local temperature records and the history of atmospheric composition

Tipping Point

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.

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

Albedo- (snow that reflects the sunlight to prevent the earth from overheating...light reflected by a surface, for example that of a planet) 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, 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

Climate system is NON LINEAR which means it can fluctuate back between metastability and chaos.

Climate system is NON LINEAR which means it can fluctuate back between metastability and chaos.

La Nina

Cold ocean temperature in western pacific

What is Earth systems science?

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.

Greenhouse effect

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.

How do we know past climate before the instrumental era?

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

Boltzmann's Law

S(amount of energy emitted by black body)= K(constant)x T^4(temperature) Determines how much energy is coming from the sun

Chaotic

Small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for such dynamical systems

Control parameter

The factors that are kept the same

List some of the long-term climate variability

Variability in climate (tropics at low latitudes, bands of desserts at mid-latitudes) as a consequences of uneven solar energy and convection transport.

Obliquity

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

Hadley cells

a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes Steps: 1. Moist warm air expands, rises 2. Cools, condenses, rain falls 3. Dense air sinks in sub tropics 4. Warmed, dry air spreads at surface

Global Circulation Models

a mathematical model of the general circulation of a planetary atmosphereor ocean and based on the Navier-Stokes equations on a rotating sphere with thermodynamic terms for various energy sources (radiation, latent heat)

Solar constant

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)

δ18O

a measure of the ratio of stable isotopes

Eccentricity

a parameter associated with every conic section. It can be thought of as a measure of how much the conic section deviates from being circular

Thermo-haline circulation

a part of the large-scale ocean circulation that is driven by global density gradientscreated by surface heat and freshwater fluxes.

Little Ice Age

a period of cooling that occurred after the Medieval Warm Period (Medieval Climate Optimum).

Lyapunov Exponent

a quantity that characterizes the rate of separation of infinitesimally close trajectories

Speleotherm

a secondary mineral deposit formed in a cave. Speleothems are typically formed in limestone or dolostone solutional caves

Phase space

a space in which all possible states of a system are represented, with each possible state of the system corresponding to one unique point in the phase space

Lorenz System

a system of ordinary differential equations (the Lorenz equations) first studied by Edward Lorenz. It is notable for having chaotic solutions for certain parameter values and initial conditions.

Medieval Warm Period

a time of warm climatein the North Atlantic region that may also have been related to other climate events around the world during that time, including inChina[1] and other countries, lasting from about AD 950 to 1250

Wien's Law

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

Glacial/Interglacial (Cycles)

a. 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 b. Interglacial periods tend to happen during times of more intense summer solar radiation in the Northern Hemisphere

Forcings

a.) external boundary conditions or inputs to a climate model b.)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

Ozone

an inorganic compound with thechemical formula O3. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O2, breaking down in the lower atmosphere to normal dioxygen

Orbital Changes

changes solar energy reaching Earth-> changes in global climate

Wavelength

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

Photons

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. Makes up electromagnetic radiations.

Spectrum

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

Electromagnetic Spectrum

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

Paleoclimatology

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

Absorption

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

Weather

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

Climate proxies

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

Black body radiation

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

Isotopes

re variants of a particular chemical element such that, while all isotopes of a given element have the same number of protonsin each atom, they differ in neutron number.

Great ocean conveyor

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

Attractor

set of physical properties toward which a system tends to evolve, regardless of the starting conditions of the system.

Non-linear systems

system that does not satisfy the superposition principle, which means that the output is not directly proportional to the input

Climate

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

Sensitive dependence on initial condition

the butterfly effect

Enso

the cycle of el niño and la niña (?)

Metastable

the extended time spent by an isolated system in a long lived configuration other than the system's state of least energy. During a metastable state of finite lifetime all state-describing parameters reach and hold stationary values.

Poincare Section

the goal of a Poincaré section is to detect some sort of structure in the attractor.

Frequency

the number of times that something happens during a particular period

Discretization

the process of transferring continuous models and equations into discrete counterparts

Albedo

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.

Radiative Balance

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

Bifurcation

the splitting of a main body into two parts.

Periodic Doubling

the system switches to a new behavior with twice the period of the original system.

Precession

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

Milankovitch Cyle

theory describes the collective effects of changes in the Earth's movements upon its climate; explains the repeating, cyclical changes from glacial to interglacial the tilting of the earth's axis affects it. ECCENTRICITY: OBLIQUITY: PRESSION:

What is the greenhouse effect?

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.

El Nino

warm ocean temperature in Eastern Pacific ( Indonesia..) when ocean surface gets too warm, it forms hurricane