Climate and Weather - Climate Change Final Unit 1
Acidification. Why and how is the ocean's pH changing?
- Oceans have absorbed about half of the CO2 emitted over the last 2 centuries - Coral, mollusks, and types of plankton secrete calcium carbonate to do this they take carbonate and calcium ions, if there is a lot of hydrogen the concentration of carbonate ions goes down, and the organisms must take energy to pump away hydrogen ions, making it hard to create their shells
ENSO Cycle in years
3-7 years
Pacific Decadal Oscillation
A long lived el nino pattern in the pacific which waxes and wanes every 20-30 years
Convective lift
Air rising (lifting) due to the sun heating the ground which then heats the air
Cause of jetstreams
Because the arctic is warming faster than other parts of the world, the thermal gradient driving the jet streams - jet stream has lost energy and developed large slow-moving meanders that create prolonged extreme weather and storminess
What impact do bodies of water have on climate?
Bodies of water are heat sinks - they try to reach equilibrium This is why coastal towns are warmer in the winter and cooler in the summer - bodies of water trap and then release heat depending on outside weather Variation in water temp affects atmospheric pressure
How long does it take to complete the ocean circulation cycle
Can take over 1000 years
Impacts of jetstream
Causes changes in wind and pressure at higher altitudes which in turn impact lower altitudes the same way - large meanders in polar jet
How do climate and weather differ
Climate → the long-term average weather pattern in a specific region and the result of interactions between land, ocean, atmosphere, water in all forms, and organisms - characterized by temperature, precipitation, humidity, sunshine, wind, and more. Weather → the short-term state of the atmosphere at a specific location - largely due to the sun heating areas of the planet unequally
Formula for pH
Co2 + H2o → H2Co3 → HCo3-+H^+ → H^+ + Co3 Carbon dioxide + water → carbonic acid → bicarbonate ions + hydrogen ions → carbonate ions + hydrogen ions
What gives rise to the predominant wind currents on the planet?
Coriolois effect and Variation in atmospheric pressure and air temperature
How are oceans being affected by global warming
Deadly trio: 1. Warming 2. Acidification 3. Anoxia All disrupt marine plants(highly responsible for oxygen production) and animals
Explain deep ocean circulation
Deep circulation is driven by variations in water salinity and temperature Colder, saltier water sinks to the bottom while warmer water rises, creating a vertical cycle called the thermohaline circulation Thermohaline circulation and surface currents from wind combine to create the ocean conveyor belt
Convergence lift
Differential warming of the Earth's surface results in movement of air masses, which results in vertical mixing (low pressure over high pressure)
El Niño
Easterly trade winds weaken, causing surface currents to slow Occurring along equator in the Pacific ocean Warm water builds up off the coast of South America, causing an increase in precipitation and heat
How do atmospheric pressure and moisture affect the weather?
Equilibrium between dense and light air causes wind that blows from areas of high pressure to areas of low pressure When water vapor changes into liquid or crystal form, heat energy is released Increase in moisture → increase in precipitation
What happens to global and regional climate when there is a pronounced (stronger and more often) el Niño
Influences global temperature and precipitation Precipitation increases in eastern pacific Precipitation decreases in western pacific Global temperature increases
What happens to the global and regional climate when there is a pronounced (stronger and more often) La Niña?
More precipitation in SE Asia Cooler water on eastern pacific Global temperature declines
Anoxia. Why is dissolved oxygen important and how is it changing?
Ocean contains an abundance of dissolved oxygen that all marine organisms breathe to stay alive In the poles, melting glaciers adds more freshwater to the ocean (which is more buoyant), reducing mixing between low and high waters (increase in ocean layer aka stratification) which in turn deprives deeper water of oxygen A rise in ocean temperatures causes a decrease in dissolved oxygen - disrupting marine ecosystems
Explain why climate can vary between two locations along the same latitude (i.e. they receive the same solar radiation but have different climates)?
Ocean currents (therefor temperatures) vary among the same latitudes, which drive wind and precipitation patterns - water vapor fuels weather
How is deep ocean circulation affected by global warming?
Rising sea temperatures have caused the conveyor belt to slow down, less variance in warm and cold water slows thermohaline circulation
How does global warming affect ENSO?
Severe ENSO events will become more frequent and generally stronger They create a positive feedback loop
5 gyres
Surface currents are called Gyres -> 5 gyres: north pacific, south pacific, indian ocean, north atlantic, south atlantic
How is the ocean absorbing heat?
The ocean holds heat better than air and therefore absorbs excess heat The top 6.5 feet of the ocean contains as much heat energy as the entire atmosphere
Global warming took a hiatus from 1998 to 2010 that led to an increase in public skepticism about global warming. Explain what happened?
This period began with a record high el nino year (1998) so global temperatures were extraordinarily high Years following were cooler, which is common after an el nino year Relative to the past decade, global temperatures had cooled, but compared to the past century, temperatures were still rising
La Niña
Trade winds strengthen Warm pool gets warmer
Orographic lift
Warm air moving up a mountain and hitting cold air would cause snow, fog, wind
Explain how ocean currents transfer heat on the planet
Water holds heat much better than air, so when water moves around the globe it brings heat with it
frontal lift
When two air masses meet and warm air is lifted above cold air
Influence of wind currents and Coriolis effect
Wind currents and the coriolis effect are responsible for for surface level ocean currents
Polar vortex
a large area of low pressure and cold air surrounding both poles (90 degrees)
Intertropical Convergence zone (ITCV)
area of low pressure, warm temperatures, and high rainfall that marks where the trade winds from both hemispheres converge - crucial in formation of hadley cells
Polar front
area of rising air, cloud development, and precipitation that forms at a transitional zone separating arctic masses and tropical air masses
Subtropical high-pressure zones
areas of atmospheric high pressure located at about 30 degrees north and south latitude, formed by vertically descending air currents from the Hadley cell - arid desert conditions
3 cell model of atmospheric circulation
polar cell, Ferrel cell, Hadley cell
Does low atm have sinking or rising air
rising hair (warmer, lighter air)
Does High atm have sinking or rising air
sinking air (colder, heavier air)
How does deep ocean circulation affect global climate patterns?
transports both energy (heat) and matter (solids, dissolved compounds, and gases), and in doing so influences global climate
Factors that influence weather
heating by the sun, atmospheric pressure, moisture, topography (change in pressure + heat radiated back out) , lift, vegetation - these factors vary among the same latitudes
Jetstream
high elevation powerful wind currents found in 4 locations - two in the Northern and two in the Southern Hemisphere (polar + subtropical jet) - blow from west to east
Negative phase PDO
warm water concentrates in the pacific, it sinks down and absorbs heat from the air, causing global temperatures to go down
Positive phase PDO
warm water spreads across the pacific ocean, heat escapes and warms the air, causing a global increase in temperature
Atmospheric pressure definition
weight of air above measurement
ENSO neutral year
when winds are normal
Coriolis effect
wind moving from N to S on longitude line pushed to the right b/c earth turns counterclockwise