Chapter 2 - Climate Flashcards
MODULE 1-2:
(T) Distinguish between climate and weather:
look up indian dipole 3rd pattern
MODULE 1-2:
(T) Describe an example of spatial variation in climate
Describe an example of temporal variation in climate
MODULE 1-2:
(T) Solar Radiation:
Why is incoming solar radiation described as shortwave radiation?
Is all of this energy absorbed by the Earth’s surface?
MODULE 1-2:
(T) What is albedo?
(T) Does snow and ice or a forest have a higher albedo?
MODULE 1-2:
(T) As some energy that reaches the Earth is absorbed by the surface, this absorbed energy can then be emitted back into space as terrestrial longwave radiation.
Why is this radiation referred to as longwave radiation?
What is another name for this radiation?
*Much of this longwave radiation is reflected back to the Earth by water vapour and CO2 in the atmosphere.
MODULE 1-2:
(T) Greenhouse effect.
Should we be concerned about the greenhouse effect?
MODULE 1-2:
(T) Latitudinal Trends in Net Radiation:
Explain 2 reasons why the amount of incoming solar radiation is lower at higher latitudes (this leads to a distinct pattern of global temperatures).
(T) Describe the general pattern of global temperatures.
MODULE 1-2:
(T) Seasonal Trends in Net Radiation:
Explain what causes the seasons.
Where are the seasonal differences most apparent?
- Earth’s axis is 23.5 degrees (precession)
MODULE 1-2:
(T) Surface Net Radiation :
What would happen if the average net radiation was less than zero?
Greater than zero?
Where does this surplus of energy at the equator go?
- The average net radiation of the Earth has historically been __________
- There are geographic differences – some areas absorb more than they radiate
MODULE 1-2:
(T) Atmospheric Circulation :
Name the 3 cells of circulation (describe the latitude where the air ascends and the latitude where the air descends)
MODULE 1-2:
(T) Atmospheric Circulation con’t:
- What is caused by this pressure differential? (see below)
- What happens if the humidity is higher than the air saturation point?
- What happens if the humidity is lower than the air saturation point?
- Explain why convection currents cause rain?
MODULE 1-2:
(T) Cells of Circulation:
- For each of the 3 cells of circulation, describe the patten of air circulation & precipitation.
- Describe how the Hadley cells move with the seasons. Consequences of this movement?
- Compare/Contrast the climate in the Northern vs. Southern hemispheres. Why do the patterns exist?
MODULE 1-2:
(T) Cells of Circulation con’t :
The Coriolis Effect includes:
* Latitudinal winds are deflected longitudinally
* Varies with the Earth’s surface speed
(T) Explain how this affects the air movement in the atmospheric cells. What direction are the prevailing winds along the coast of BC?
(T) What 2 climatic variables are most important for predicting the location of terrestrial biomes?
MODULE 1-2:
(T) Ocean Currents :
List 4 variables that affect ocean currents.
- Currents are patterns of water movement
4 variables:
* salinity
* water density
* gravity
* winds
MODULE 1-2: MAY 16 TUESDAY
(T) Ocean Currents :
- What is a gyre?
- @@Describe at least 2 consequences of gyres
- In which direction do the gyres generally rotate in each hemisphere?
- @@What is an upwelling?
- A circular motion of water in major ocean basins.
- a) Environmental Consequence - garbage put in the ocean by humans (plastics float) tend to cycle around into the ‘Great Pacific Garbage Dump’ and it doesn’t simply sink and disappear.
b) Temperature Consequence - the gulf stream comes up from the Gulf of Mexico and warms up the coast of Europe. Creates a warmer climate, despite it being at the same latitude as Canada (which doesn’t get this Gulf of Mexico gyre) - In the Southern hemisphere, the gyre rotates CCW
In the Northern hemisphere, the gyre rotates CW - Upwellings occur when a water current or movement of surface waters produced by winds, brings nutrient-loaded cold water to the surface. Creates very productive aquatic systems due to the cold water + sunlight + nutrients for the photosynthetic organisms.
MODULE 1-2:
(T) Irregular Variations in Climate :
Since the ocean + atmosphere can interact to affect climate, name 2 well-studied examples of these irregular variations in climate.
NORMAL TIMES
- El Nino Southern Oscillation (ENSO) - “this condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds trade winds blow weaker than normal. All winds around the globe go from East to West. The feedback begins when the trade winds weaken (light, grey arrows) and/or the sea surface temperatures warm in the parts of the central and eastern Pacific Ocean. Starting with changes in the ocean, this means that the normally cool eastern Pacific becomes warmer, leading to increased rising motion over the central and/or eastern Pacific and more convection and rainfall. Warm waters should be building up in South Asia, but instead stay near South America. Less upwelling occurs near the coast of SA. Fish and phytoplankton migrate away because the upwelling doesn’t occur, bring nutrients upward. Canada/USA become much hotter and drier on the West Coast. Peru gets unfathomable rainfall, even if it’s normally arid. Australia and South Asia experience drought conditions, leading to famine and massive bush fires. Last 9-12 mos, and should be starting Autumn 2023.
- . The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east trade winds are stronger and brings even more warmer water to Asia. El Nina gets even stronger. More upwelling occurs near South America, producing a feeding frenzy. In Asia, more wet conditions , causing a spike in cyclones. Jet stream gets pushed more north causing wetter and colder in Canada and droughts in the USA. El Niños typically occur every 3 to 5 years” (Source: noaa.gov). As a result, South Asia gets even drier weather b/c the precipitation circulates in the middle of the ocean instead of dropping on the coast of Asia. We just finished 11/2 yrs of El Nina, ending in Feb 2023.
- Pacific Decadal Oscillation (PDO) - we are in the ‘cool’ phase currently. Often described as a long-lived El Nino-like pattern of Pacific climate variability. a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. During a “warm”, or “positive”, phase, the west Pacific becomes cooler and part of the eastern ocean warms; during a “cool”, or “negative”, phase, the opposite pattern occurs.
- Indian Dipole effect : The Indian Ocean Dipole (IOD) is defined by the difference in sea surface temperature between two areas (or poles, hence a dipole) – a western pole in the Arabian Sea (western Indian Ocean) and an eastern pole in the eastern Indian Ocean south of Indonesia
EL NINO :
MODULE 1-2:
(T) Topography :
Explain what happens as air moves over a mountain.
Why is rainfall low just past the Coastal Mountains, but increases over the Rocky Mountains? (why the Okanogan Valley is drier than the lower mainland of BC)
Mountains affect local and regional climate, meaning that as altitude increases, temperature decreases.
- Air moves from Ocean, west to east. (always west to east)
- Moves up mountains. Cools.
- Water vapour falls as snow/rain.
- Air goes up and over mountain, and water is pulled out of the air because it’s cold as altitude increases.
- Air arrives at the other side and pulls moisture from air as it rushes down and over the land because it’s now dry air.
MODULE 1-2: QQQQQQQQQQ
(T) Climate Change :
Since the average surface temperature of the Earth has been increasing since the early 1900s,
list 10 indications that the Earth is warming:
What are 3 consequences of climate change?
QQQQQ: why was ‘thermal expansion’ mentioned here? 3rd consequence of climate change?
- Increasing humidity
- Increasing Temp over the land
- Increasing sea levels
- Increasing Temp over the oceans
- Increasing air temp
- Increasing Temp over seas
- Decreasing sea ice
- Decreasing glaciers
- Decreasing snow cover
- sea levels rising
- less diversity of species
Thermal expansion property of water causing oceans to rise
MODULE 1-2: QQQQQQQQ
(T) Since CO2 levels have been rising since the 1800s, what evidence indicates that CO2 levels have increased?
- LAW DOME: ice cores from Antarctica
- MAUNA LOA: direct meaurements of CO2.
Correlation between CO2 levels and increased temps doesn’t establish causation. “Ice core data agrees with direct measurementswhere both are available gives confidence in the CO2 curve reconstructed from ice cores.”
the Mechanism that links greenhouse gases to climate change: Greenhouse gases (CO2 + water vapour) are causing more radiation to deflect back to the Earth’s surface…and not escape outwards. Absorbed instead by the surface, which increases the temperatures. These gases sit in the atmosphere.
MODULE 1-2:
Greenhouse Effect vs. Global Climate Change.
Are they the same?
QQQQ: Also, Do all greenhouse gases have the same impact?
No. The greenhouse is a naturally occurring and necessary function on Earth. It’s the additional gases that are increasing the temperature unnecessarily.
Greenhouse Gases: CO2 & water vapour (most common), NO, CH4, SO2, O3. All have increased.
MODULE 1-2:
(T) To determine a mechanism: to establish causation of CO2 levels rising, scientists look at isotopic composition of atmospheric CO2.
Describe how the isotopic composition of atmospheric CO2 has increased – what does it indicate?
(T) How do increasing CO2 levels alter the Earth’s climate?
- C12 is increasing (burning of fossil fuels) and C13/C14 are decreasing.
- Human activities have changed the isotopic ratios of the carbons.
