Unit 3 - Our Changing Climate Flashcards
1
Q
Factors of Weather
A
- Temperature
- Type and amount of precipitation
- Wind speed
- Relative humidity
- Atmospheric pressure
2
Q
Weather
A
- Atmospheric conditions in a particular location over a short period of time
- Caused by interactions between water and air with energy from the Sun
3
Q
Methods for Prediction of Weather
A
- Weather stations
- Weather balloons
- Aircraft
- Satellites
4
Q
Climate
A
- Average of weather in region over long period of time
- Determined over weather measurements made over 30+ years
5
Q
Climate system
A
Components that interact with each other to produce Earth’s climate
6
Q
Energy from the Sun
A
- Almost all energy on Earth comes from sun
- Ultraviolet radiation (shorter wavelength; higher energy)
- Infrared (longer wavelength, lower energy)
- Visible light
7
Q
Energy Absorbed by Earth
A
- 51% absorbed by land and oceans
- 19% absorbed by atmosphere and clouds
8
Q
Outgoing Solar Radiation (30%)
A
- 6% reflected by atmosphere
- 20% reflected by clouds
- 4% reflected from Earth’s surface
9
Q
Energy from the Sun (by location of the Earth)
A
- More intense near Earth’s equator because it receives energy more directly
- Less intense at the poles, since it hits Earth’s surface at an angle and spreads over a larger area
- Earth’s global temperature remains fairly constant
10
Q
Atmosphere
A
- The layers of gases surrounding earth
- Reaches +100 km above Earth’s surface
- Part of atmosphere closest to Earth’s surface called the troposphere
11
Q
Ozone in the Stratosphere
A
Ozone absorbs high energy UV radiation from Sun and prevents from reaching Earth’s surface
12
Q
Hydrosphere
A
- Climate system including all water on and around Earth
- Solid water: Polar ice caps, icebergs
- Liquid water: lakes, streams, rivers, oceans, underground reservoirs
- Gaseous water: water vapour, clouds
13
Q
Ozone in the Troposphere
A
Ozone doesn’t provide UV protection and can combine with car exhaust to produce photochemical smog
14
Q
Photochemical Smog
A
Harmful to human health, buildings, plants and animals
15
Q
After Evaporation
A
Transpiration
16
Q
After Transpiration
A
Clouds Form
17
Q
After Clouds Form
A
Precipitation
18
Q
After Precipitation
A
Accumulation
19
Q
Large Bodies of Water and Climate
A
- Affect climate of nearby regions by absorbing and storing thermal energy
- Regions near ocean or lake cooler in the summer and warmer in the winter than inland locations
20
Q
Ice and Climate
A
- 2% of earth’s water frozen and can be found in Arctic sea ice, Glaciers, Permafrost and Mountaintops
- Surfaces covered in ice and snow have more albedo
21
Q
Albedo
A
The ability for a surface to reflect light
22
Q
Lithosphere
A
- Climate system made up of the rock, soil and minerals of Earth’s crust
- Mountains or cliffs can affect how air moves over an area
23
Q
Troposphere Gases
A
78% nitrogen; 21% oxygen; 1% argon, carbon dioxide, helium, hydrogen and ozone traces
24
Q
High Altitudes and Climate
A
- Atmospheric pressure lower because of less air pushing down
- Air rises and cools more easily, causing cooler temperatures
25
Photosynthesis
Plants take carbon dioxide and release oxygen
26
Cellular Respiration
Plants and animals take in oxygen and release carbon dioxide
27
Heat sink
Reservoir (ex: ocean) absorbing and storing thermal energy
28
Energy Transfer in Atmosphere
- Air is warmer than ocean, ocean absorbs energy from the air
- When the air is cooler than the ocean surface, the ocean releases energy back into the air
29
Convection currents
Created in air or other fluids when warm fluid (less dense) rises and cold fluid (more dense) sinks
30
Creation of clouds
- Air at the equator heats up and rises, which later cools and falls
- When air rises, a low pressure area is created, forming clouds
31
Thermohaline Circulation
Flow of water around world’s oceans by differences in water temperatures and salinity
32
Energy Transfer in Hydrosphere
- Water at poles cools and becomes more salty as ice forms
- Saltier, colder water sinks, causing another convection
33
Energy Transfer across Oceans
Ocean currents move water and heat carried around the world
34
Outgoing Lower-Energy Infrared Radiation
- 64% radiated to space from clouds, atmosphere and indirectly from Earth
- 6% radiated directly to space from Earth
35
Studying Clues to Past Climates
- Data climate is currently being kept on temperature, rainfall, precipitation
- Informal climate records kept through journals, paintings, farming records, oral histories
36
Proxy record
Information in tree rings, ice cores and fossils that can be measured to what climate was like in past
37
Ice Core Testing
- Measure air bubbles trapped in Greenland and Antarctica for thousands of years
- Ice at the bottom is 80 000+ years old
- Thin slices of ice tested for gases (CO2, CH4, N2O)
- Ice cores tested for oxygen isotopes (“lighter” oxygen found higher at lower temperatures)
38
Ice Cores: Additional Info Provided
Provide information on precipitation and volcanic eruptions as layers of dust are preserved
39
Tree Rings
- Thick tree rings formed in good growing conditions
- Warm, wet conditions = thick tree rings
- Cold, dry conditions = thin tree rings
- Can assemble data from living and dead trees to determine climate up to 10,000 years
40
Coral Reefs
Coral reefs grow at different rates depending on temperature of water
41
Rocks
- Pollen preserved in rock is indicator of plants species present at the location
- Can determine if there was warmer climate based on different species of plants
42
Ocean Sediment Clues to Climate
- Cores of sediment from ocean floor
- Fossils of marine organisms that lived in a warmer climate than today
43
Caves
Rock formations from stalactites (from the roof) and stalagmites (from the floor) are indirect evidence of precipitation patterns
44
Feedback Loops
- Positive feedback loop: Effect increases original cause
- Negative feedback loop: Effect decreases original cause
45
Low & High Clouds
- Low clouds involved in positive feedback loop between Earth’s temperature and water vapour.
- High clouds involved in negative feedback loop between temperature and water vapour.
46
Natural Changes in Climate
The result of changes in Earth’s Energy Balance
47
Plate Tectonics Basics
- Plates in constant motion, few cm per year
- Ocean floors continually moving, spreading from centre and sinking at edges
- Caused by convection currents fuelled by radioactive decay in Earth’s core
48
Continental Drift
Theory that parts of Earth’s crust slowly drift atop a liquid core (1912)
49
Plate Tectonics and Climate
- When continents move, ocean currents and wind patterns change, so heat transfer changes
- Uplifting of mountain ranges affect local and regional climates
50
Eccentricity Basics
From gravity of other planets, Earth’s orbit changes from circular to more elliptical over cycle of 100,000 years
51
Eccentricity Effects
- Doesn't fully cause seasons (ex: Earth is furthest from sun in summer)
- Variation in distance from sun causes solar radiation received by Earth to vary
52
Eccentricity and Climate
- When orbit more elliptical, Earth receives more solar radiation when near the sun
- When orbit more circular, amount of radiation doesn’t vary much and seasons more equal in length
53
Earth's Tilt - Basics
- Earth’s tilt on its axis changes 2.4˚ over 41,000 years
- Greater tilt, greater temperature differences between summer and winter
54
Earth's Present Tilt
Currently tilt is 23.44˚ and decreasing (midway between extremes - 22.1 to 24.5˚)
55
Wobble (Precession of Tilt)
- Change in direction of axis of rotation or angle of tilt
- Earth is not perfect sphere, so it wobbles a little as it rotates
- Affects amount & intensity of solar energy received by Northern and Southern hemispheres at different times of year
56
Wobble and Climate Effects
- E.g. one hemisphere having contrasted seasons while other showing smaller temperature difference between seasons
- Occurs every 26,000 years and caused by pull of sun and moon acting on non-spherical shape of Earth
- Changes "North Star"
57
Effects of Long Term Natural Climate Variation
- Cause cycles of ice ages and interglacial periods
- Cause of the 100 000 year climate cycle.
58
Changes in Solar Energy
Amount of radiation produced by sun varies
59
Sunspot
Regular solar cycle that occurs every 11 years - if no. of sunspots is high, Sun is emitting more radiation
60
Volcanic Eruptions
- Aerosols (needed for cloud formation) spewed from volcanoes shade Earth’s surface - Earth cools for years up to decades
- Particles settle out or washed away with precipitation
- Volcanoes may cause temperature increase if lots of greenhouse gases emitted
61
Ocean Currents and Climate
- Changes to Earth’s thermohaline circulation can change climate
- As ice sheets melt, vast fresh water dumped into oceans
- Fresh water less dense than salty water, so it stays near surface, changing ocean currents
62
El Nino & La Nina
- Middle of South Pacific Ocean: periodic warming and cooling of seawater (El Nino and La Nina respectively)
- Can impact weather and climate change across North America
- Occurs every 3-8 years
63
Intro. Climate Change
Changes are being observed that have not happened for thousands of years
64
Rising Temperatures
- Earth’s average temperature increased from 1880 to present - most of warming occurred in last 50 years
- Small areas (over oceans) have seen temperature decreases
65
Melting Glaciers, Ice Sheets and Sea Ice
- Twice amount of ice in Greenland and Antarctica is melting in summer compared to 20 years ago
- Glaciers supply water to most rivers and lakes
66
Rising Sea Levels
- From 1993 to present, sea levels have risen twice speed as in previous 30 years
- - Increase in sea levels due to melting of glaciers and thermal expansion
67
Changes in Severe Weather
- Intensity of heat waves and hurricanes increased
68
Changes in Precipitation
- Increase in precipitation as rain, less as snow
- W. North America experienced decrease in annual precipitation (resulting in drought and wildfires)
69
Changing Seasons
- Amt. of snow remaining on ground in winter decreases
- Decrease in # of very cold days
- Very cold days coming later in year and ending earlier in spring
70
Changes in Ecosystems
- Plants, trees, shrubs flowering earlier in the spring - results in longer allergy season
- Animals (ex. squirrels) breeding earlier in year & more often
- Animal and plant species migrating to higher altitudes and latitudes
71
Anthropogenic Definition
Human caused
