Term 1 Flashcards
Difference between climate and weather
Climate: long term average of the weather at a location
Weather: what we see hour to hour in precipitation, temperatures, cloudiness and wind
What is the keeling curve
-Shows the annual cycle of co2.
-rise in atmospheric co2 since 1950s
What is the intergovernmental panel on climate change (IPCC)
-provide summaries of climate change science for governments.
-they review the science and say what is happening with climate change, future estimates and what we can do
Confidence and likelihood
-qualitative assessment gives confidence
-quantitive assessment gives likelihood
What is global atmospheric circulation
-differential heating of equator and poles (the equator has more concentrated radiation then the poles
-warm moist air raised from E and moves in direction of P with descending cool dry air at the P causing condensation
What is Coriolis effect
-Northern hemisphere wind deflects to the right, southern to the left
-there are Hadley, Ferrell and pole cells in north and Southern Hemisphere with different conditions of atmospheric circulation
What are jet streams
-2 streams in each hemisphere, if the stream isn’t a smooth circular and has wiggles it could cause hot or warm air to move further north of south into a climate that is not used to its temperatures
-polar jet stream: cooler air in the upper part of the hemispheres
-subtropical jet stream: hot air by the equator
What is the intertropical convergence zone
-2 jet stream zone where air is rising and surface winds are convergent
-moves with seasons
What are the 4 layers of the spheres from lower to higher
-troposphere
-stratosphere
-mesosphere
-thermosphere
What is the pro graphic effect
When warm air hits an object liek a mountain causing it to stay on the windward side causing mass rainfall and moisture that can’t go over the object and so the other side experiences dry warm air
What is continentality
The further into the continent the less liek y they are to get rain as tehy tend to be more dry due to lack of coast
What is thermohaline circulation and it’s process
-warm water
-water evaporates as it moves north (surface water gets saltier and denser)
-water cools giving heat to the atmosphere as it flows north to Labrador Sea and Iceland (even more dense)
-cold dense water sinks to form North Atlantic deep water
Importance of Atlantic meridional overturning circulation
-delivers warm air to Western Europe, milder winters and summers
Wave length graphs
-shortwave radiation’s is not absorbed much but that long wave radiation is absorbed much more by co2, water vapor
What is albedo
The proportion of incident radiation that is reflected by a surface. White have high albedo, black low albedo
What is the problem of black carbon on snow/ice
-pollution has caused black carbon to enter into snow causing the ice to be darker so less reflected instead the light is absorbed and turns into heat so snow and ice warms up and melts faster
What are the problems with high and low clouds
High: can cause warming as if doesn’t let out ongoing solar energy and so it returns to the earth causing warming
Low: can cause clouding as the clouds let out more long wave radiation then it reflected back into the earth as a result it doenst cause extensive heating.
What is climate forcing
Measures the imbalance in the earths energy budget caused by a perturbation of the climate system
-radiation hitting the top of the atmosphere and radiation leaving the top of the atmosphere
What is pacific decadel oscillation
A pattern of temperatures in north eastern pacific which can have a + or - phases and they can last for decades
What is the North Atlantic ossicaltion
Described teh variation in the pressure difference between the asides and Iceland
-when pressure difference is high NAO gets strong western winds and frequent storms in NW Europe
-when pressure difference is low, get weaker winds and storms track further south
-causes winter climates
Process of hurricane
-need source of warm moist water and air
-low level convergent winds
-low wind shear
-far from the equator for the Coriolis to cause a spin
Information about greenhouse gases
-the global warming potential: allows comparison of the global warming impacts of different gases
-define as how much energy the emissions of 1 ton of gas will absorb over a given period of time relative to the emissions of 1 ton of carbon dioxide
Long term perspectives to get information of co2
-ice cores
-corals
-trees
-soil
-fossils
-oxygen isotopes
Evidence of co2 rising due to human impacts
-economic data on emissions (amount of co2 released, fuels, industry, land use change, land sink, atmosphere, ocean sink)
-isotopic evidence
-change in oxygen concentration (fall in oxygen shows mass burning)
What does cold water show in relation to gases
-the colder the water the more gas can dissolve, so water can hold more carbon and so the deep ocean holds 50x more co2 than the atmosphere
Effects of acidification in ocean
-due to extra co2 and acid in the ocean it causes deformed shells as they cannot be formed properly, hard for carbonate reforming organisms to live in the ocean
What are the different types of land use in the carbon cycle
-agriculture
-deforestation
-biomass burning
-cement production
What is the global climate indicator and what does each system show
A framework for understanding changes in the climate system. What would you see change in each system
-temperature and energy: surface temperature and ocean heat
-atmosphere: co2
-ocean and water: ocean acidification and sea level
-cryosphere: glaciers, Arctic and Antarctic sea ice extent
How to measure climate
-precipitation, sunshine, wind ect at ground stations but also measure from satellites, ships, buoys and balloons
What is a global observing network
-launch of weather balloons holding a sensor it measures altitude, temperature, wind direction, pressure humidity on the way up and down
What is quality control and what ways do scientists make sure to check data accurately
-detecting and repairing data issues
-they check spikes, flat liners, outliers, excessive range, change points
What is the urban heat island
Urban sites tend to be hotter than rural sites, they are more densely developed causing it to heat up. Areas with Greenland experience lower temperatures
What is energy out and in in rural areas
-vegetation in rural areas leads to greater evaporation, needs heat energy and so this cools the rural area compared to an urban area.
-teh difference in energy balance between urban and rural areas, the wider teh arrow teh larger the flow of heat in a graph
-in rural areas most the energy/ radiation we get from the sun is reflected and more evaporation occurs. In urban areas the left over energy is stored in buildings and roads
What is BEST
Is a procedure that removes outliers or spatial and temporal averaging, they take data from multiple stations and incorporate partial records from the stations
What is uncertainty
Is scientific working that measures any variability in teh data, it is quantitive measure of the accuracy and precision of our results
What is spatial average land
-averaging the results in each grid box and then average of thsoe grid boxes is easier to calculate
Effects of altitude on the cooling of stratospheric
-increased levels of carbon dioxide lead to higher temperatures in the lower atmosphere while teh upper atmosphere gets cooler
What are the trends in temperatures of the layers of atmosphere
-cooling of lower stratosphere
-warming of mid to upper troposphere
-when ghg increase the troposphere is more effective at acting like a blanket which prevents heat reacting up the stratosphere
What would we expect to see if the greenhouse effects was causing warming
-nights to warm faster then days
What would we expect to see if the sun was causing warming
Warming trend to be greatest in daytime
What is the earth seeing with the warming and why
- a decrease in cold nights greater then a decrease in cold days
-an increase in warm nights greater then the increase in warm days
-due to anthropogenic impact (human fault)
What happens in average vs extreme graphs
-change in mean shifts the curve sideways
-change in variation spreads and flattens the curve
What are we seeing with patterns of extreme weather events
-number of events are going up
-financial probsons due to this
-potentially could be because of better recordings but most likely not
What is attribution studies
Robust statistical assessment of whether anthropogenic (human) influences on our climate can be detected and attributed given our current knowledge
-humans have been viable to affect
-droughts, extreme rainfall, tropical storms and hurricane, rising sea levels but an overall decrease in tropical cyclones.
What evidence do we have that humans are causing global warming
-shrinking upper layer
-rising tropospause
-more fossil fuel carbon in trees and corals, oceans
-less oxygen in air
-more carbon in air
-winter warming faster then summer
-nights warming faster then days
-pattern of ocean warming
Where is global warming going in most to least
-oceans
-atmosphere
-continents
-glaciers and ice
Sea levels measurements techniques: tide gauges
-tide pole/staff: (a vertical graduated staff attached to the coast from which readings of the
height of the sea surface were taken, typically at high and low water levels.)
-float tide gauge: measures sea level by means of a float in a stilling well.
-acoustics: measures changes in sea level relative to a datum (a height reference)
-radar gauges: devices are fitted with sensors that record the height of the instantaneous
water level providing a value per minute.
How accurate is gauge network data
-relatively accurate but the data may need correcting when their is missing data, abrupt jumps ect
-there might be rapid changes in data but could be from natural causes or mistakes from the collection of data
What is satellite altimetry
-measures the time taken for a radar pulse to travel from the satellite to the sea surface and back to the satellite. Maps the topography of teh ocean surface with unprecedented accuracy
-measures the input into dynamic models for long term climate forecasting and predicting to improve knowledge of ocean tides and develop global tide models
Why is sea level rise not uniform
-regional variations are caused by when heat is concentrated, regional change (isotopic), shifts in currents and wind, melting ice
How do glaciers influence ocean level s
-if colder temperatures the glaciers increase in mass but if higher temperatures the glacier looses mass.
-1mm of sea level rise per year due to glaciers
How do we measure ice sheet loss
- Radar altimetry
-measure ice surface elevation change, determines ice sheet volume change
2.gravimetry
-measure change in mass of ice sheets
3.input output
-measure input (surface mass balance) minus output (flux across grounding line)
Impacts of terrestrial storage of water
-reservoir impoundment: water retained on land through dams, damns stop water returning to the oceans, can cause damage if dam breaks
-ground water depletion: this involved extraction of water for irrigation and sanitation from aquifers beneath the land surface. Causes sea level rise
How to calculate albedo
-reflected light/ incoming light
What is a marine heatwave
-periods of extremely high ocena temperatures that persist for days to months can extend up to thousands of km
-events taht exceed threshold 90-99% percentile if a probability density function if sst data for 5 days +
-grades accordingly to: intensity, duration, extent
What is paleoclimate
-past climate for which we do not have direct instrumental records so they use proxy data
Long term influences on climate
plate tectonics:
-collision of plates, growth of mountains, increase erosion and weathering, co2 consumed in weathering and locked up in rocks, less co2, cooling
Milankovitch cycle:
-eccentricity (circular shape of orbit)
-processions (rotational axis is unstable causing it to wobble)
-obliquity(change in tilt of axis)
How does eccentricity affect climate
-causes seasons to be slightly different lengths
-difference in solar radiation received on earth between closest and further point
-small affect on total radiation
How does obliquity affect climate
-as tilt increase then seasons become more extreme
-growth in ice sheets with low tilt angles because of milder summers which allow snow to survive, large tilt angels favor deglaciation
How does procession affect climate
-combined effect of precession with eccentricity is that closest approach to sun occurs at different seasons through time
-causes seasons to be more extreme in one hemisphere and less so in the other
What can we use to reconstruct paleoclimate
-tree rings
-corals
-soil
-oxygen isotopes
-ice cores
-cave deposits
-fossil pollen
What is climate
All of the statistics describing the atmosphere and ocean determined over an agreed time interval computed for the global or region
What is a climate model
A numerical representation of some of the statistics describing the atmosphere and ocean determined over an agreed fine interval
What is a hindcast, prediction, projection
-hindcast: draws on observed conditions
-prediction: will often be short term and depend on initial conditions of the modeled systems
-a projection will often be long term and depend on uncertain external forcing and interval variation
How does volcanism cause internal forcing of global warming
- Volcanoes inject particulate matter and gases into the atmosphere
Key climatic contribution is to increase the quantity of H2SOA droplets in stratospheric aerosol layer
Altitude of injection influences type of forcing (different kinds of volcanoes examples)
Small eruption > Troposphere injection > Gravitational fallout or rain out > Minimal forcing
Large eruption > Stratospheric injection > SO, reacts to form sulphate aerosol (1-12year residence time) > Increase albedo > Decrease forcing > Cooling
How does ocean circulation cause internal forcing
Internal forcing : Ocean circulation
Deep Ocean circulation is driven by density changes due to temperature and salinity
(thermo-haline).
Density changes occur in surface waters (colder/saltier enters deep ocean basins replacing deficit produced by warmer/fresher coastal upwelling)
Bulk of the energy absorbed in climate system is in the oceans and its huge thermal capacity allows it to modulate climate on long timescales
How does greenhouse gases cause internal forcing
-Atmosphere is highly absorbent to infra-red radiation
-Greenhouse effect : Opaqueness of atmosphere to infrared versus transparency of atmosphere to shortwave radiation
-Absorption of infra-red is mostly by water vapour, carbon dioxide (CO,), methane (CHa), nitrous oxide (NO), tropospheric ozone (O.)
-Carbon dioxide ~ logarithmic radiative effect with increasing concentration
-Trace gases ~ linear radiative effect with increasing concentration
-Traces gases often more potent absorbers of I but concentrations much lower
How does aerosols and clouds cause internal forcing
Sulohate particles inject into troposphere are produced by industry activity and fossil fuel burning.
-Direct effect > Reflects some solar radiation back into space (local cooling)
-Indirect effect > Increase reflectivity of clouds (incr. albedo > cooling)
-Clouds influence success of radiation reaching surface
-Dependent on thickness and surface area modulated by albedo
How does stratospheric ozone cause internal forcing
-absorbs significant amount of ultra violet and re radiated infer red radiation
-ozone increase or decrease can cause warming or cooling
How does land surface change cause internal forcing of climate change
-interplay of natural and human interactions lead to release or drawdown of greenhouse gases and aerosols which modulate climate
What are the bad secondary effects of this:
-can cause vegetation loss with increase albedo (cooling)
-vegetation loss decreases soil moisture (warming)
-warming dominates cooling leading to limited cloud formation and increasing aridity
Climate model: energy balance
-simplified the complex realities of our planet
-shows the radiation budget on a simple approximation to model earths climate
-it shows radiation fluxes, equator to pole energy transport, albedo, temperatures
Types of climate models: radiative convective
Dissolves layers in teh atmosphere to calculate vertical energy balance, impose more complex radiative interactions/processes than possible
-estimates global averaged temperature profile of atmosphere
Types of models:dimensionally constrained
Models meridional (southern Europe) atmospheric dynamics
-looks at zonal averages of temperatures due to change in atmospheric chemistry
-exploring climate change over millennia
Types of models: general circulation models
-grids of cells that solve for all fundamental equations at their boundaries to exchange and feedback upon each other
What is climate sensitivity: transient
-the amount of warming that occurs when co2 doubled having increased by 1% each year
-it matches how co2 concentration has changed in the past
What is epistemic and aleatory uncertainty
Epistemic:
-systematic, represents things we could in principle know but don’t in practice
Aleatory:
-random, represents the unknown that differs every time we run the same experiment
FLICC framework
-fake experts (manipulate data, fake data)
-logical fallacies (misrepresentation, jumping to conclusions)
-impossible expectations (demands unrealistic standard or proof, ignores data and focuses on uncertainties)
-cherry picking (choose data that matches their argument)
-conspiracy theory (trying to put out ideas that will reduce scientists trust ability)
What is dragons of inaction
-most people could do more for climate, but they are hindered by seven categories of psychological barriers, or “dragons of inaction”
What are the different types of dragons to inaction
-limited cognition (not thinking rationally)
-ideologies (religious or political views taht stop someone believing in the truth)
-comparisons with others (refusing to change if others don’t)
-limited behaviour (the lack of doing something)
-discredence (viewing others in a negative light and so they refuse to do what they say)
-confirmation bias: tendency to search for interpret favor and recall info that confirms their beliefs
What is the intergovernmental panel on climate change
-UN and world meterological organization to provide the world with a clear scientific view on the current state of knowledge in climate change on its impact on environmental, social and economics
-shapes public perspective
-it doesn’t conduct any research or monitor climate data
-focuses on how humans have affected the environment
What is agnothology
-the study of deliberate culturally I funded ignorance or doubt typically to sell a product or win favor through publication of false data
-the ideology to bring down individuals instead of groups of scientists
-discourages researchers from conveying their data to the public
What are extremes
-long term climate signals reflect the regional picture of climate change. Something that goes beyond the normal eg/ temperature, heat, precipitation
What are examples of observations for regional climate information
-climate monitoring
-evaluating and improving climate attribution
-reduce uncertainty of regional climate projections
-
