Karteikarten
Earth's Climate System
Karten in diesem Stapel (88)
- 1List the four external forces that may affect the climate systemNatural Causes:
Changes in plate tectonics
Changes in Earth's orbit
Changes in sun's strengths
Anthropogenic Causes:
Combustion of fossil fuels
Land use changes - 2Draw a rough diagram illustrating the internal interactions in our Climate system
- 3What is meant by the sun's coronaThe corona is the sun's "atmosphere"
It is much hotter than the sun's surface but due to its low density it radiates much less energy into space - 4What is meant by a magnetic storm?a magnetic storm is another word for a solar flare
These emit large quantities of UV radiation and energised charged particles - 5List facts about the sun~150 million km away from Earth
15 million °C at the core
6000K at the surface (photsphere/chromosphere) - 6List three facts about sunspotsSunspots are cooler regions
The average area of a sunspot is five times the size of Earth
The 11-year sunspot cycle has a measurable but small impact on solar energy output - 7Define radiationradiation is energy that travels
- 8What untis do we use to quanitfy energyJoules
Joule per second = Watt
Watt per square unit of area = Energy flux density - 9What is meant by a black body in the physical sciences?A "black body" is a term for an idealised object that absorbs and transmits EM radiation over all wavelengths
At room temperature such a body looks black
Both the sun and the Earth are approximately like black bodies - 10What is Planck's law?Planck's Law describes the amount of energy emitted at a given wavelength at a given temperature
In theory it describes the spectral distribution of emitted EM radiation of a black body at a given temperature - 11What is meant by radiant exitance?Radiant energy that is emitted, transmitted, received or reflected (radiant flux) by a surface per unit of area
- 12What does the Stefan-Boltzmann Law describe?This law describes the power radiated from a black body in terms of its temperature
Specifically, the radiant exitance of a black body is directly proportional to the fourth power to the black body's absolute temperature - 13What does the Wien's displacement law describe?It states that the black body radiation cruve for different temperatures peaks at a wavelength inversely proportional to the temperature (i.e. the hotter the temperature, the shorter the wavelength)
- 14Explain differences we'd see if there were no atmosphereNo air to breathe
No lakes or oceans
Extreme temperature rnages without atmosphere (like on the moon)
No sound without air
No protection from meteorites
No protection from UV radiation - 15Describe Earth's second atmosphereformed 4.0-3.3 billion years ago
Earth cooled and developed a solid crust
convective magma activity contributed to the formation of magnetic field capable of deflecting solar wind and cosmic rays
high volcanic activity
atmosphere contained (co2, h2o and n2)
very high atmospheric temperatures (>100°C) due to volcanic & tectonic activity, frictional heating from meteorites and strong greenhouse gas effect - 16How did the oceans form?Once temperatures cooled down below 100°C condensation of water vapour and precipitation became possible (3.8-3.9 billion years ago)
expanding oceans served as a CO2 sink
anaerobic bacteria began to develop near volcanic hydrothermal vents - 17Describe what is meant by the 'Oxygen Catastrophe'3.8-3.5 billion years ago prokaryote cyanobacteria appeared as first O2 producing organisms
Stromatolites must have lived deep enough (>5m) to be protected from harmful radiation but still within the rnage of sunlight
1.3 billion years ago eukaryotic cells were more efficient at producing oxygen
1 billion years ago the oceans were saturated with oxygen and O2 could subsequently build up in the atmoosphere forming an ozone layer
dissolved oxygen was toxic to anerobic organisms - 18Describe the formation of Earth's "Third Atmosphere"with development of more sophisticated forms of plant life oxygen levels iun the atmosphere continued to increase
the present day atmosphere (oxygen-nitrogen) formed approximately 400 million years ago
formation of ozone layer and the protection from harmful solar radiation were key to the formation of plant life on land - 19What are the four layers of the atmosphereFrom Earth to space:
Troposphere
Stratosphere
Mesophere
Thermosphere - 20Describe the atomspheric vertical profile in relation to pressurethe global average atmospheric pressure decreases near-exponentially in vertical direction
99.9% of the atmospheric mass is below 50km
90% is below 10km - 21What does the atmospheric vertical profile look like in relation to temperatureTroposhere: decreasing with height
Stratosphere: increasing with height
Mesosphere: decreasing with height
Thermosphere: increasing with height - 22Why does temperature decrease with height in the troposphere?An air parcel cools and expands when rising vertically
Conversely, an air parcel warms and is compressed when descending - 23Name the three main gases that make up the airs compositionNitrogen : 78.08%
Oxygen: 20.95%
Argon: 0.93% - 24What are three effects aerosols may have on us?Reduction in visibility through a haze effect
They can scatter incoming light
They can absorb outgoing thermal radiation (like GHGs) - 25Outline the processes involved in the hydrological cycleEvaporation: solar energy transforms liquid water into water vapour
Transpiration: Moisture given up by plants (in form of water vapour)
Condensation: Water vapour reverts back to liquid phase (formation of droplets)
Precipitation: liquid or solid forms of water falling from clouds - 26Where is most of the water held?97% Oceanic system
2.999% in the land system
0.0001% in atmospheric system - 27Describe the evaporation processStage 1: -evaporation can occur at any temperature
-at the surface, water molecules with sufficient kinetic energy will break away from the surface and evaporate into the air
-with time the amount of water vapour in the air increases
-condensation also will occur, however the condensaiton rate is slower than the evaporation rate - 28What is meant by the dynamic equlibrium in the evaporation processStage 2: - the rate of condensation depends on the amount of water vapour in the air
-once the air above the water is saturated, for every molecule that evaporates, one condenses
-the amount of water vapour therefore stays the same
-wind enhances evaporations as water vapour molecules are carriued away by it thus never reaching saturation - 29Why is cold are dryer and warm air more humid?At higher tempreatures the water molecules will have more kinetic energy and therfroe the rate of evaporation will be higher
The dynamic equilibrium will therefore be reached at higher concentrations of water vapour - 30Deifne relative humidityRelative humidity is the ratio of the amount of water vaoupr in the air to the maximum amount of water vapour required for saturation at that particular point
- 31What is meant by the dew point temperatureThe Dew point temperature represents the temperature to which air would have to be cooled foor saturation to occur
Warm dew points indicated high relative humidity and cold low - 32Explain trends of relative humidity variationDiurnal: -water vapour amounts can remain unchanged with changing RH
-RH changes mainly due to diurnal temperature variations which affect the water vapour capacity
Meridional:
-high RH values at tropics and cold 60° and above
-low RH values at the tropics of cancer and capricorn - 33Define cloudA cloud is a visible aggregate of tiny water droplets or ice crystals supsended in the air
- 34What are the different types of clouds?High clouds:
Cirrus (Ci), Cirrostratus (Cs), Cirrocumulus (Cc)
Middle clouds:
Altostratus (As), Altocumulus (Ac)
Low clouds:
Stratus (St), Stratocumulus (Sc), Nimbostratus (Ns)
Clouds with vertical development:
Cumulus (Cu), Cumulonimbus (Cb) - 35How does latitude variation in solar irradiance affect the flow of air (winds)?-winds are involved with the transfer of heat, as there is a surplus of heat at the equator which has to be distributed around the globe
-these vary in intensity with the Earth's tilt and its seasons - 36How does the pressure gradient force (PGF) affect the flow of air (winds)?the pressure gradient force is directed from higher toward lower pressure at right angles to the isobars
closely spaces isobars on a map indicate steep pressure gradients and a alrge PGF - 37How does the coriolis force affect the flow of air (winds)?the coriolis force describes an apparent force due to the rotation of the Earth
in the northern hemisphere wind deflects to the rihgt of its intended path and to the left on the southern hemisphere
the higher the wind speed the stronger the deflection
the force increases with latitude with zero at the equator - 38What is meant by geostrophic wind?Geostrophic wind is where PGF and CF are in balance
As a consequence the wind will flow parallel to the isobars and will not further accelerate - 39What is meant by the centripetal force?The combination of PGF and CF results in a Centripetal force component which forces the wind in a circular motion
Consequently wind motion is anticlockwise around a low-pressure system (cyclone) and clockwise around a high-pressure system (anticyclone) in the Northern hemisphere --> the opposite for the Southern hemisphere - 40How does firction in the planetary boundary layer affet the flow of air (winds)?the planetary boundary layer refers to a layer of the troposphere in which winds are affected by friction with the ground
This friction reduces the wind speed which in turn reduces the CF leading to winds being able to blow across isobars
At stable stratification and smooth terrain the layer is quite thin whereas when the air is unstable and the terrain rough the effect extends far further upwards due to vertical mixing - 41What is the intertropical convergence zone?The zone at which the trade winds meet
The problem with this is that heat is desperately trying to be redistributed therefore most of the heat at the equators is distributed via ocean surface currents - 42What are the westerlies?The westerlies are the winds which go towards the poles at 30° north and south
- 43What is meant by thermal cicrulations?Local circulations brought on by changes in air temperature
- 44What factors result in the heat island effect?The interaction of the follwoing factors:
-release and reflection of heat from buildings
-absoprtion of heat by concret, brick and tarmac by day and the release of it at night
-enhanced cloud formation as pollution traps heat
-relative absence of water means that less energy is used for avapotranspiration and more for heating of the lower atmosphere
-absence of strong winds to disperse heat and bring in cool rural air - 45How does the mountain and valley breeze form?-During the day sloped valley walls will receive more insolation and so the air above the valley warms
-this air rises and cuases a gentle valley breeze
-at night the cooler denser air descends the slope which is known as the mountain breeze - 46What is a possible impact of a subsidence inversion?Increased pollution:
-during a strong anti-cyclone (high pressure) warm air is compressed and warmed, pushing toward the land
-below, the colder denser air collects and creates a thick layer which traps the pollution - 47What is the adiabatic process?Wehn an air parcel cools and warms or expands and compreesses without exchange of matter and energy of the surrounding air
- 48What is the environmental lapse rate (ELR)?The rate at which the temperature of an air parcel decreases with altitude
the rate depends on the temperature of the surface air and whether the atmosphere is stable or not because unstable atmospheres allow vertical development
It is crucial is determining the extent of vertical motion in the atmosphere - 49What is the dry adiabatic lapse rate (DALR)?10°C for 1km of change in elevation
This only counts for unsaturated air (RH below 100%) - 50What is the moist adiabatic lapse rate (MALR)?6°C for 1km
This only counts for saturated air
As moist air rises temperature cools more slowly for the water vapour condenses giving off latent heat countering the temperature loss caused by the expanding air parcel - 51What are the two processes respoinsible for carbon uptake on land?Photosynthesis
Weathering - 52What are the two broad processes carried out by the oceans in the carbon balance?Biological pump (through phytoplankton into food chain)
Physical pump (deep water formation and ventilation/upwelling) (the warmer the oceans the less able they are to dissolve CO2) - 53What is a consequence of increased CO2 uptake in oceans?Uptake of increased CO2 reduces surface ocean pH value --> increasing the ocean's acidity
this affects:
-coral reefs (decling calcification/weaker)
-cold water corals
-ecosystems where aragonite is essential (aragonite)
-temperature increase (coral bleaching) - 54What is meant by Insolation?Incoming Solar Radiation
mostly at an oblique angle and not vertical
average insolation equals to a quarter of the solar constant
342 W m^-2 - 55What is the solar constant?the rate at which energy from the Sun reaches the Earth
1370 W m^-2 - 56What are the four different atmospheric solar radiation pathways?Absorption 19%:
radiative energy turned into other forms by gases or particles in the atmosphere
Reflection 30%:
radiative energy is reflected back into space when hitting a surface
Scattering:
Radiative energy is (at least partly) redirected by air molecules and particles
Transmission:
radiative energy passes through the atmosphere - 57What is the distinguishing factor between geometric scattering, Mie scatering and Rayleigh scattering?The size of the object on which he sunlight falls on
- 58Which type of particle induces which type of scattering?Air particles --> Rayleigh scattering --> blue sky, red sunsets
Aerosols (pollutants) --> Mie scattering --> Brownish smog
Cloud droplets --> geometric scattering -> white clouds
Darker clouds have larger water droplets which absorb some of the incoming light - 59Explain the effects by Rayleigh scatteringAir molecules (N2) scatter shorter (blue) wavelengths more efficiently than longer ones (red)
The longer the path length of light through the air, the more blue light is scatter, which results in remaining red light turning the sky red
Equally the sky appears blue because of this too - 60What is Albedo?the ratio of reflected radiation to incoming radiation
The albedo of Earth and its atmosphere is roughly 30% - 61What are the three types of thermal energy transfer?Conduction: through contact
Convection: gases & fluids
Radiation: also works in a vacuum - 62What are greenhouses gases?Greenhouse gases are atmospheric gases which absorb thermal radiation emitted by the Earth's surface
this blanketing effect leads to increased temperatures
H2O is responsible for most of the greenhouse warming, but its atmospheric proportion is not changing directly as a consequence of humans - 63Which are the important GHGs which are influenced by humans?Carbon dioxide, methane, nitrous oxide, chloro-fluorocarbons and ozone
Carbon dioxide is the most important because after water it has the largest greenhouse effect - 64Outline the global pressure distributionThe average surface wind and pressure distribution is largely determined by semi-permanent highs and lows
E.g. the pressure difference between the icelandic low and the bermuda high determines the severity of European winters (the bermuda high drives the golf stream)
interseasonal variability in the inter-tropical convergence zone which affects monsoon seasons - 65What are monsoons?Monsoons seasons are experienced by those countries that lie where the inter-tropical convergence zone (ITCZ) shifts
India, for example, receives warm moist air from the indian ocean in july and colder dry wind from the north during winter - 66What factors determine climate?Latitude: determines how much solar radiation a location receives
Land and water: determines continentality
Ocean currents: can provide additional heat
prevailing winds: moisture and thus precipitation
Pressure cells: cloud coverage
mountain barriers: rain shadow
altitude - 67Outline the NAO (North Atlantic Oscillation)determined by the pressure difference between the bermuda high and the icelandic low
Positive phase: strong pressure difference resulting in warm wet winters for Europe and mild and wet winters in the US
Negative phase: weak pressure difference resulting in more cold air invasions
phase changes take decades - 68What factors influence the natural variability in the Earth's global average surface temperatures?Changes in insolation
Continental drift
Changes in Earth's albedo
Changes in outgoing terrestrial radiation (GHG effect) - 69Outline the Milankovitch cyclesChanges in the Earth orbit's eccentricity vary with a period of about 100,000 years
Variations in the obliquity (angle of tilt) of the Earth's axis have a period of about 41,000 years
Changes in precession (direction of tilt) and point of perihelion (proximity to the sun) change with a period of about 23,000 years - 70What are the four natural influences on the energy imbalance?Plate tectonics: millions of years; regional scale
Volcanic Activity: years, but longer for 'mega-eruptions'; regional/global
Changes in solar irradiance: 11 years, but also much longer; global
Long-term outgassing from oceans volcanoes: millenia; global - 71What are the four anthropogenic influences on the energy imbalance?Land-use change: instantaneous; regional/continental
Aerosol emissions: instantaneous/constant; regional
Ozone depletion: decades; mostly at poles but small effect globally
Fossil fuel emissions: decades/centuries; global - 72What is radiative forcing?-one of the most commonly used climate metrics
"Radiative forcing is a measure of how the energy balance of the Earth-atmosphere system is influenced when factors that affect climate are altered"
it allows for the comparison of different climate mechanisms - 73What are two ways to describe the absolute quantity of a gas?Density - microgram per cubic metre
Concentration - molecules per cubic centimetre (cm-3) - 74Name 2 sources and sink of methaneNatural:
-Wetlands
-Termites
Anthropogenic:
-mining (petroleum)
-enteric fermentation (rumenants)
Sinks:
-Atmoshpheric removal
-removal by soils - 75Where can the ozone layer be found?at an altitude of 20km to 30km
it contains about 90% of atmospheric ozone, which is produced via photolysis of molecular oxygen - 76What is tropospheric ozone?it's an air pollutant
produced from oxidisation of hydrocarbons in presence of nitrogen oxide (photolysis of nitrogen dioxide) - 77Outline how tropospheric ozone formsozone is formed in the presence of sunlight (never at night)
Carbon monoxide (CO) or volatile organic compounds, water vapour, nitrogen oxides (NOx) and sunlight is needed
pollutants must be available in the right concentration, especially NOx
urban environment usually contains pollutants in the right concentration
ozone production requires a reaction chain - 78Outline how stratospheric ozone formsozone forms at 20km to 50km of altitude through the photodissociation of oxygen molecules
it requires shortwave solar radiation (<240nm); shortwave UV-radiation (<280nm) is completely filtered out during the process - 79What are two instruments used to measure ozone?Total Ozone Mapping Spectrometer (TOMS)
Ozone Monitoring Instrument (OMI)
total ozone in the atmosphere is measured in Dobson units (DU) - 80What are the conditions for efficient ozone depletion at the poles?Low temperatures (formation of PSCs (polar stratospheric clouds))
Isolated conditions (for chemical processes)
PSCs (reaction on surface of cloud crystals increases destruction efficiency by 100x) - 81When and where is ozone depletion strongest?Ozone Depletion is storngest in polar regions during the onset of spring when sunlight reaches the polar regions again (halogen gases are made reactive)
Ozone depletion occurs globally but most efficient in polar regions as meteorological conditions there enhance the depletion process - 82What are some of the environmental impacts of ozone depletion?decrease in stratospheric ozone layer has small cooling effect (minimal compared to proportion lost due to GHGs inefficiency)
Significant increase in UV radiation leading to increase skin cancer and plant damage especially in Southern Hemisphere - 83What are the indirect effects from aerosols?impact on cloud droplet size which affects both the cloud's albedo and the amount of precipitation
other effects include impacts on heterogeneous chemistry, cloud condensation processes, etc. - 84What are atmospheric brown clouds (ABCs)?Indoor and outdoor pollution consisting of paerticles and gases (Nox, CO, SO2, NH3 and many other VOCs and acids)
- 85Where are the regional hotspots for ABCs?East Asia
Indo-Gangetic Plain in South Asia
Southeast Asia
Southern Africa
the Amazon Basin
Also in the Hindu Kush-Himalayan-Tibetan glacier region
can also occur in East USA and Europe but dissipate quickly due to washout processes such as precipitation - 86What are the impacts of ABCs?-dimming of solar irradiance at the surface (sulphate aerosols)
-increase in atmoshperic solar heating (black carbon, soot)
-Dimming effect about 6% in China and India
-black carbon is responsible for a 15% increase in average annual mean of solar absoprtion in troposphere
-change in rainfall patterns
-increased receding and thinning of glaciers
-rainfall in northern half opf india has decreased, shift in patterns in china
albedo changes and temperature increase affects glaciers and snowpacks in the Hindu Kush - Himalayan - Tibetan region - 87What are the consequences of ABCs?-changes in monsoon rainfall and glacier extent will affect water levels required for irrigation of crops
-ground level ozone increases will affect crop yields
-1985-1998 rice production decreased by 6.2 million tonnes in 9 South and East Asian countries
-health effects from indoor and outdoor pollution (affecting pulmonary and cardiovascular systems leading to chronic respiratory problems) - 88Distinguish between Climate Change and Global WarmingGW refers to an increase in globally and annually averaged air temperature near the surface (also observed in oceans and soils)
GW is a good proxy for CC but it does not describe the complexity of the individual changes nor the regional differences
CC refers to a significant and persistent change to the mean state of the climate or its variability.
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- Undergraduate Earth Climate System Karteikarten am Earth's Climate System, erstellt von Aqib G am 28/04/2016.
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- Erstellt von R S · 28 Apr 2016
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