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110 Cards in this Set

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Age of Earth?


Age of Solar System?


Age of the Universe?

4.54 x 10^9 a


4.57 x 10^9 a


13.8 x 10^9 a

Diameter of Universe?


Number of stars in Milky Way?


Number of galaxies in Universe?


Number of atoms in Universe?

93 x 10^9 light years or 4.3 x 10^23 km


4 x 10^11


5 x 10^11


10^78 - 10^82

The sun is a [blank] type main sequence star with [blank] surface temperature?

G-type and 5500C

List the 3 key properties of a habitable Earth

1. presence of liquid water over extended (evolutionary) period of time


2. continuous protection from cosmic radiation


3. sufficiently low rate of highly disruptive impacting bodies (comets, asteroids, etc)

Describe the Milankovitch cycles

Eccentricity: Earth encounters more variation in energy it receives when orbit is elongated than when it is circular


Tilt: Greater the tilt, the more solar energy the poles receive


Precession: Gradual change, or wobble, in orientation of Earth's axis affects relationship b/w tilt and eccentricity

What determines concentration of CO2 in Earth's atmosphere?

CO2 pumped into atmosphere through terrestial and submarine volcanism

Deterministic Chaos and it's equation

Behavior exhibited by a system that is infinitely sensitive to initial conditions


Examples: turbulence in fluid flows, meteorology, insect populations


xnext = rx(1-x)


x is population in particular year, r is growth rate

What are implication of deterministic chaos?

Complex patterns of change do not necessarily arise from complex causes


Complex effects can arise from simple non-linear relationships


Some natural systems may be inherently 'unpredictable'

What is the concept of the exposome?

Developed to draw attention to critical need for more complete environmental exposure assessment in epidemiological studies


Complements the genome by providing a comprehensive description of lifelong exposure history

What is the Anthropocene Concept?

Captures the quantitative shift in the relationship between humans and the global environment.


Used as a synonym for the Quaternary for several decades

What is temperature?

Determines which way heat flows and is a manifestation of the amount of heat a body contains.


Response of an object to the heat it contains


Measures typical speed of motion of the molecules in an object


Mass of objects determine how it absorbs heat and also different material

What is Heat (energy)?

Quantity of energy required to give an object its temperature. Form of energy measured in joules

What is (Heat) Flow / Flux?

Rate of energy transfer (between objects) possibly per unit area.


Stronger the light, the more energy is transferred in a given time

What determines temperature of a planet?

Heating by incident sunlight. As distance from the Sun increases, the power of the incident light weakens. Variation in heating due to orbit of Earth around Sun (which is elliptical).


Net power absorbed by sun is incident power x (1-albedo)

What is infrared?


What is Earthshine?

Form of light, but at wavelengths longer than our eyes can see.


Planet cools to space by radiating electromagnetic radiation

What is the calculation for Earth?

T^4 = (340 Wm^-2 / 5.67x10^-8 Wm^-2k^-4) x 0.7


= 4.2 x 10^9 K^4

Where Earthshine comes from

Clouds and greenhouse gases absorb radiation from surface, impeding the surface cooling to space


Radiate up and down, adding additional heating to the surface


Surface temp is warmer so that it radiates more in order to balance the heating by sunlight and downward IR

Describe Troposphere, Tropopause and Stratosphere

Troposphere is heated from below (rising warm air, descending cool air)


Tropopause is the height where vertical mixing stops (temp stops decreasing with height)


Stratosphere is heated by absorbing UV light, heated directly and warms with increasing height



Describe pressure in the atmosphere

Pressure always decreases with increasing altitude. Density follows pressure quite closely

What is the radiation constant?

5.67 x 10^-8 Wm^-2K^-4

What is climate forcing?

Perturbation of the climate


Change that is externally imposed on the climate system, as measured by the impact the change has on the top-of-atmosphere radiation balance



Describe Ocean warming

Most absorbed near surface (20 m)


Heated from above


Stabilize oceans


Ocean deeps are the coolest


Convection (downward) happens when surface is cooled and saline



Describe Thermal Radiation

1. Overall behavior: hotter objects radiate a more intense flux


2. Idea that the fundamental scale of temperature is kelvin


3. Dependence is steep

Recipe for Planetary Temperature

Calculate solar heating at planet using distance from sun (incident heating)


Multiply by (1-albedo) to get flux into planet's climate system


Find temperatur that gives a matching flux using


CONST x (t + 273C)^4 where CONST = 5.67x10^-8WM^-2K^-4

Characteristic Timescale

t = C/F where F is flux and C is reservoir


If F is one component of a balanced flux, t is an average residence time in the reservoir


If F is the net flux (imbalance b/w influx and efflux), t is the time-scale for change in the reservoir

Describe Climate Feedback

Climate system is highly interconnected


Various components that affect the global temp in themselves depend on temperature (i.e. water vapor, cloud cover and ice/snow)



Water Vapor Feedback

If output of initial forcing (here temp rises) can initiate a chain of events that leads to an additional forcing in same direction, then feedback is POSITIVE

What is the effect of extra GHG

Increase the altitude pegged to -18degC, thus, assuming the atmospheric lapse rate is unchanged the surface temperature increases


Increases the mean height of radiation to space

Describe Water Vapor

Determined by the fast processes of meteorology


Human activity has tiny direct control on WV globally


Involved in an efficient, fast acting feedback on climate


Feedback is positive if any changes (warming or cooling) get amplified


Humans do not affect directly

What is pressure?

Enormous numbers of air molecules hitting a surface. These molecules exert a force.


More mass -> more molecules -> more force -> greater pressure


Warmer -> molecules hit faster -> more force -> greater pressure


Measured in Pascals

Describe pressure gradient force

Air tends to flow from high to low pressure


Pressure falls with height, so air accelerates vertically


Pressure forces balanced by gravity = hydrostatic equilibrium



Describe Convergence

Low pressure - air is flowing inwards


Generates vertical motion which then diverges aloft

Describe the Coriolis effect

Overall effect of rotating Earth is, in Northern Hemisphere, deflecting motion to the right


Southern Hemisphere to the left


Behaves like a force and is proportional to the speed and directed at right angles to motion


Arises because we want to measure things relative to rotating Earth

Describe some climatic features

Troposphere air cools as it rises


As air cools it can hold less water vapor. The excess water vapor precipitates as rain or snow. Rain happens when air rises

Name the three cell zones

Hadley


Ferrel


Polar

Describe the Hadley Cell (Equatorial Circulation)

Sun overhead -> lots of solar heating and surface air rises giving convergence


Water condenses as air cool so lots of cloud and rain


Convergent flow, if over oceans, brings in moisture


Dry air diverges aloft and flows away from equator


Air descends around 30deg away from upflow and then flows equatorwards ("trade" winds)

Describe Polar circulation

Poles are very cold - little incoming radiation from sun and most energy provided by atmosphere


Cold air is dense and sinks -> high pressure and divergent flow at the surface and convergent flow aloft

Describe the Ferrel Cell (Mid Latitudes)

Mid latitudes have warm descending air on the equatorial side and cold air on polar side


Cell is weak and discernible with much averaging


Flow through Coriolis effect, generates flow that south westerly (from SW)

Describe Anticyclones

Hidden dangers: cold, extreme temps and air pollution


High pressure gives low pressure gradients so winds are weak


High pressure = diverging air = descending air


descending air is dry, so little clouds


Winds low so little mixing and air stays where it is for a long time

Describe mid-latitude flow

Gradients give rise to pressure gradients and thus flow


Strong temperature gradients exist


Speed increases with height - pressure gradient is larger and is Westerly (low pressure on left, wind on back in NH)

What are the three types of air streams?

Warm conveyor


Cold conveyor


Dry conveyor

Describe the Warm Conveyor Belt

Rises over the cold air (warm air being less dense than cold air)


Provides warm wet air which drive the clouds/rain on the cold front

Describe the Cold Conveyor Belt

Runs parallel to the warm front and spirals into the center.


Provides the center of the system with wet air

Describe the Dry Conveyor Belt

High air (thus dry) being pulled down


Sometimes get cloud clear areas in a depression because of Dry Belt - so called dry slots

What is the ITCZ?

Inter-tropical Convergence Zone. Warm wet air converges here, convects and rises all to the tropopause


Air drives the Hadley Circulation with descending air at 30deg

Describe the Life Cycle of a Tropical Cyclone

Need some upper level divergence


Divergence generates upwelling and convergence which generates convection (move slowly west)


some patches grow to tropical depression - low pressure with organized convection

What windspeed is needed for a tropical depression to grow to a storm? cyclone?

16ms^-1 and 33ms^-1

Describe New Orleans in relation to Hurricane Katrina

City is vulnerable


Located in the delta of the Mississippi


Largely below sea level


Surrounded by "levees"


Area vulnerable to flooding from rain, hurricanes or Mississippi

Describe the Fatality Rate of Hurricane Katrina

80% of New Orleans population evacuated outside the risk area


10% evacuated to shelters


10% remained in flood zone


Fatality rate was about 1% similar to other flooding events

What are some criticisms?

Trend in some climate observation doesn't mean it is due to human activities


Could be due to natural drivers rather than human induced warming


Data records are not homogenous


Human driven increase in TCs is not proven

Heat Wave Human Impacts

Excess mortality throughout all of Summer 2003


Big peak in early August


Total excess deaths was about 70,000 (7% of "normal" summer death rate)


No evidence of "harvesting" as death rate later in year are slightly elevated

Describe Eccentricity

"Stretch" of Orbit


Large values correspond to more elliptical orbit


More insulation at Perihelion (when Earth is closest to the Sun) and less at Aphelion


Average radiation over a year is about the same


Northern summers colder when eccentricity large and occurs at Aphelion

Describe Obliquity

Tilt of Axis


High (low) obliquity gives more (less) extreme summers and winters

Describe Precession

Where the axis points


Changes the dates of the equinoxes, perihelion and aphelion


effect to change amplitude of seasonal cycle - modulated by eccentricity

CO2 during Glacial/ Interglacials

Methane (CH4) thought to be a proxy for wet tropics. When the tropics are wet then there is a larger emission of CH4 and so larger atmospheric concentrations

Describe some Early Anthropocene Mechanisms

CH4 has short lifetime in the atmosphere so concentration largely reflects source rate


CO2 has long lifetime but on 100 to 1000 year timescales is taken up by deep ocean


Early farming caused considerable deforestation and CO2 emissions


Rice farming causes large CH4 emissions

Describe how Parameterization works

Many processes occur below the grid resolution


These need to have their effects represented in terms of the large-scale (resolved) flow


Since there is uncertainty in how these processes are represented it leads to uncertainty in model feedbacks and climate sensitivity

What are the types of fluxes?

Evaporation


Transpiration (release of water vapor to the atmosphere from plants, largely through pores (stomata) on leaves


Evapotranspiration (combined effect of evaporation and transpiration)


Precipitation


Lateral atmospheric transport

What are the factors controlling mean annual runoff?

R = P - E


R is mean annual runoff from drainage basin


P is mean annual precipitation across drainage basin


E is mean annual evapotranspiration across drainage basin

Describe Evaporation

Kinetic energy of molecules


Direction of movement - can be away from surface


Increase of kinetic energy with temperature


Loss of molecules lowers temperature (evaporative cooling)


Balance of molecules into and out of water surface produces water vapor layer that is saturated


Availability of water to be evaporated

Describe Transpiration

Water movement from soil -> root -> stem -> leaf -> atmosphere, due to


root pressure, capillary action and transpirational pull


Leaf area, density of stomata, light (affects opening of stomata), temp, relative humidity, wind, water supply to plant, fine hairs on leaf surface to create high humidity layer

Describe potential and actual evapotranspiration

Potential evapotranspiration: rate of evapotranspiration that would occur under a specific set of conditions given a limitless supply of water


Actual: rate of evapotranspiration under a specific set of conditions (rate that actually occurs)

What is the Water Balance equation

P = Q + E + Delta(I + M + G + S)


Where p is precipitation, Q is river discharge, E is evapotranspiration, I is interception and biological water storage, M is soil water storage, G is groundwater storage and S is channel/surface storage

How was the Salton Sea formed?

In 1905, heavy rain and snowmelt in the Colorado catchment led to poorly constructed canal system being swamped


Lake did not disappear even though it should've.


Identified as a useful repository

Hoover Dam

Used to tame the Colorado River

What has been the impact on the Grand Canyon?

Geomorphological impacts: 'beaches' of the Grand Canyon


Ecological impacts: habitat changes for fish species and vegetation

What were the key impacts in the river regime?

1. removal of annual spring/early summer snowmelt flood


2. much lower magnitude diurnal flood regime related to HEP generation


3. water flow erosive as 'under-charged' with sediment (clear-water erosion)

Why did the 1983 flood occur?

Water released at the Glen Canyon Dam in 1983 due to risk of overtopping (level of Lake Powell reached just 1.8m below the dam crest) and potential dam collapse


Arose b/c inadequate lowering of the lake level in the previous season, long winter and rapid snowmelt, inaccurate weather forecasts and late decision to release water

Response to the 1983 flood

Appreciation of the role of 'natural' flooding in maintaining the geomorphological and ecological characteristics of the Colorado River in the Grand Canyon


Prompts move to an approach to river management that attempts to incorporate ecological processes


High flow experiments involved controlled flooding

Consequence of decline in Arctic sea ice extent

1. Reduction in albedo (radiation reflected back into space)


2. Change in heat budget through absorption of energy by sea water resulting in changes to patterns of atmospheric pressure


3. Weakening of pressure difference b/w Arctic and mid-latitudes which encourages movement of Arctic air to lower latitudes

What are some possible implications for climate of norther Europe?

Southerly displacement of jet stream in summer associated with wetter summers


Higher frequency and persistence of large meanders in jet stream associated with longer periods of similar weather


Impact in terms of temp and precipitation of persistent patterns of weather depends on precise location of jet stream meanders

Describe the Subak irrigation

Water irrigation system for rice paddy fields comprising dams, channels, tunnels and flow dividers


Water is distributed equally b/w farmers (topographically) higher up and lower down

Why is cheating rare at the Subak?

Everyone belongs to the Subak organization


Decisions are made by consensus about irrigation schedule (relates to planting schedule and pest control)


Those who do not attend are subject to fines


Water supplies can be cut off depending on responsibilities met

What is regolith?

unconsolidated material found overlying bedrock


may have formed in situ or been transported by water, wind or ice


soil is part of the regolith, and is usually the top part which contains a high concentration of organic material and is affected by weathering

Describe O, H, A and E soil profiles

O: unsaturated organic layer at surface


H: saturated organic layer at surface


A: mineral horizon at or near surface with humified organic matter associated with mineral


E: mineral horizon just below the surface which has lost clay, organic material or iron by downward movement

Describe B, C and R soil profiles

B: subsurface mineral horizon resulting from the change in situ of soil or the washing in of materials from above


C: unconsolidated or weakly consolidated mineral horizon which has evidence of rock structure and lack properties of A, E or B


R: continuous hard or very hard rock

What factors control soil formation?

Pedological processes: climate


biological activity


relief


parent material (e.g. rock)


time


S = f(Cl, o,r, p, t)


S is any soil property, Cl is climate, o is organism, r is relief/topography, p is parent material, t is time and f is function

What is the influence of climate on soil

Rainfall: lower -> salt crusts/lime layer


higher -> leaching of soluble salts, more clays, organic matter, cation exchange and nutrients increase


Temp: heavy rain and high temp lead to rapid breakdown of organic material


small increase in clay minerals with temp


evaporation (impact depends on rainfall)


weathering (temp and rainfall)

What is the influence of biological activity on soil (micro-organisms)

Micro-organisms (bacteria, fungi, algae, protozoa)


Anaerobic and aerobic bacteria


Nitrifying bacteria


Denitrifying bacteria


Fungi - break down organic material

What is the influence of biological activity on soil (macro-organisms)

Earthwords mix organic and mineral matter


arthropods also mix soil


slugs and snails breakdown organic material


small animals loosen and mix soils

What is the influence of biological activity on soil (plants)

litter and roots supply soil with nutrients and organic matter


different types of tree produce different soils


seasonal vegetation


Rhizosphere around roots important site for exchange nutrients


Symbiotic relations with fungi and bacteria

What is the influence of relief?

Altitude: in UK, colder and wetter conditions lead to accumulation of organic material


Aspect: warmth of soil


Slope: mass movement, overland flow, throughflow, creep


Catena: Relationship of soils of similar age with varying characteristics due to variation in relief drainage

What is the influence of time?

Young soils: tend to share features with parent material


Pedological begin to mask parent material with time


Older soils (mature): in equilibrium with environment


often very different from parent


old soils can be nutrient poor

What are Histosols, Anthrosols and Vertisols?

Histosol: more than a defined amount of organic material, organic soils


Anthrosols: influence of human activities dominates soil formation


Vertisols: Clayey soils which crack widely when dry and swell when moist

What are Fluvisols, Gleysols, Andosols and Podzols?

Fluvisol: Soils developed on river deposits showing alluvial stratification


Gleysol: Soils dominated by the effects of poor drainage and anaerobic conditions


Andosols: Soils composed of volcanic materials, often with a dark colored surface horizon


Podzols: Soils with a bleached, ashy colored horizon immediately beneath the surfacce and a spodic B horizon

What are Chernozoms and Cambisols?

Chernozems: Dark colored, deep soils rich in organic matter, and calcareous lower in the profile, associated with prairie/steppe


Cambisols: Moderately developed soils with lower horizons and a cambic B horizon

Describe Peats (Histosols)

Form in areas with poor drainage


Paludification: organic material undergoes limited decomposition, builds up to form peat deposit


Blanket bog: high rainfall, high water table, low temps, acidic


Basin bog: low lying damp area, ponds can become bogs as they fill in


Raised bog (ombrogenous): domed shape bog which grows above water table, acid, brown peat, maintained solely by rainfall


Progressions: basin peats can become raised bogs, blanket bogs can grow to cover landscape


Importance: wildlife habitats, carbon reservoirs

Describe Gley Soils

Mineral soils characterized by waterlogging


Little water movement and bioturbation


Anaerobic conditions lead to iron changing from red/brown to greys


Base of slopes, hollows and often have a high clay content


Range from all mineral to peaty gley


Common on poorly drained ground

Describe Podzols

Formed on acid, coarse grained, well drained materials


Surface organic material not broken down (coniferous and heather vegetation difficult to decompose)


Iron, Al, nutrients and organic matter are leached from upper horizons and deposited in B horizon (spodic horizon)

Describe Brown (Earths) Forest Soils

Fertile deep soils


Deciduous woodland


Bioturbation leads to organic material being rapidly broken down


Not very acidic or slightly alkaline


Important agricultural land (artificially fertilized, aberdeenshire, fife, lothians, SE Scotland)

What are the four constituents of soil?

Mineral (45%)


Organic Matter (5%)


Water (20-30%)


Air (20-30%)



Describe Minerals (inorganic content of soil)

Produced by weathering of parent material


In situ or transported from elsewhere


Important size ranges from 2mm to < 0.002mm


Variations in particle size lead to soil texture

What are some primary minerals?

Quartz, micas and feldspars


Sand and slit fraction of soil


Persistent products of physical weathering

What are some secondary minerals?

Silicate clays, iron oxides - clays (colloidal organic material)


Formed by breakdown and weathering of minerals in soil


Clays - kaolinite, smectite and hydrous micas


Fine platey minerals which swell when wet


Important sites for exchanging (ions) cations and anions

Describe Soil Organic Matter

Living organisms (soil biomass)


Remains of organisms


Organic compounds


Generally only forms 1-6% of mineral soil


Forms granular loose soil structure, source of phosphorous, sulphur and nitrogen, Increase amount of water the soil can hold


Important part of carbon cycle


twice as much carbon stored in soil as vegetation

Describe Soil Organic Matter as an Active Pool

Microbial biomass and easily decomposed compounds


Small % of total C, but major role in Carbon Cycle


Active fraction declines rapidly when vegetation is cleared



Describe Soil Organic Matter as a Passive Pool

Most of the organic carbon (60-90%)


Stable, can remain in soil for 10^3 or 10^4 years


Cation exchange sites and water retention

Describe Clay-Humus Complex

Colloidal organic material


Complex organic compounds


Resistant to decay


Important sites for exchanging ions and cations


Attract and hold nutrient ions and water


Contain hormone-like compounds with aid plants


Crucial to soil structure

Describe soils influence on organic content

Climate: Organic content high in cool moist conditions


Drainage: Organic content high in poorly drained soil


Biomass: Organic content high where root biomass is high

Describe soil water

Moisture regime of soils depends on climate, vegetation, organic content, texture of soils


Water held in pores: gravitational water - freely drains, capillary water in fine pores, water molecules attached to minerals, not all soil water is available to plant


Soil solution: dissolved compounds and elements

What is a biome?

An intercontinental formation of similar climate and vegetation


Characteristic animal and plant adaptations


Contains functionally distinct biota


Land and water

Is it only climate that determines Why What Where?

No. Soils (nutrients, texture), species (physiology, ecology), history and chance (fire, volcano, humans)

Why is it useful to think about WWW and natural systems?

Classify the biosphere to identify key properties so that we can start to:


Identify and analyze causes of change


Predict Change

How do we classify the biosphere?

Ecosystem concept: exchange as well as organisms


Relationships among organisms (biota) in a given area and their interactions with the physical (abiotic) environment

What is Biodiversity?

Diversity of plant and animal life, as represented by the number of extant species


Functional and taxonomic diversity of organisms across all spatial and temporal scales

What are the 3 types of species patterns?

1. Historical factors determine regional pool of species (evolution, climate change)


2. Abiotic factors govern distribution and abundance within the region (pH, rainfall)


3. Biotic factors further govern distribution and abundance within the community

What came before the Pleistocene?

Tectonic movements affecting climate, ocean currents, marine and land area, biotic interactions

What are some changes in species patterns?

Historical processes affecting present patterns


Future patterns: possible impacts of change during the 21st century


Impact of climate change


History a guide to the future


Human impacts

Biogeographic dynamics in the Pleistocene

Environment: location, extent, configuration of habitat


Changes in nature of climatic zones


Formation/ dissolution of dispersal routes


Biotic responses: move


remain: tolerate or adapt


reduction in range, eventual extinctions

Predicted rates of change from IPCC?

Boreal zone: loss or gain in total area


Temperate zone: overall gain in area


Tropical mountains: upwards by 2-5m/ yr, loss in area


Rates of migration larger than Pleistocene changes


Scenarios of initial losses: different migration, migrate through fragmented landscapes