Chapter 21 Flashcards Preview

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Flashcards in Chapter 21 Deck (40):
1

Climate system

multidemensional system of many interacting parts
includes: atmosphere, hydrosphere, geosphere, biosphere, cryosphere

2

Climate impacts geologic processes

weathering, flooding, mass wasting

3

Geologic process affect climate

volcanism and mountain building

4

paleoclimatology

reconstructing past climate change
Instructional records only go back a couple of centuries

5

Scientists use proxy data

indirect evidence of climate change

6

Seafloor Sediments

Storehouse of Climate Data: Abundance and types of organic remains are indicative of past sea-surface temperatures

7

Oxygen Isotope Analysis

precise measure of the ratio of O18/O16
Higher ratios indicate climate was colder
-ratios trapped in calcium carbonate shells of marine organisms
-ratios vary with amount of sea ice and water temp

8

ice can be analyzed for

-oxygen isotope analysis
-Carbon dioxide ad methane (air bubbles trapped in the ice)
-Dust, volcanic ash, pollen

9

Tree Rings

Archives of environmental history
-growth rings are added each year (thickness and density of rings reflect environemental conditions

10

Other types of Proxy Data

-Fossil Pollen: Pollen can provide high-resolution records of vegetation
Best type of paleovegetation indication
-Corals- Through oxygen isotope analysis, corals are used as paleothermometers and precipitation proxies
-Historical Data

11

Composition of the Atmosphere

-Air is a mixture of many discrete gases
-Clean dry air: mostly nitrogen and oxygen, carbon dioxide is a minute component of air but can absorb and affect global climate

12

Water Vapor in atmophere

-amount varies from none to 4% of air
-source of clouds and precipitation
-can absorb heat and affect global climate

13

Ozone (Atmosphere)

-A combination of three oxygen atoms in one molecule in one molecule
-Thin layer of gas concentrated in the stratosphere
-Absorbs harmful ultraviolet radiation

14

Aerosols in atmosphere

-tiny solid and liquid particles found in the air
-Can attract moisture for cloud formation
-can block sunlight from reaching earth

15

Pressure changes with ____

height

16

Pressure in the atmosphere structure

is the weight of the air above
-Pressure at higher altitudes is less
-Average sea level pressure is 1 kilogram per centimeter

17

Earth's atmosphere is divided into four layers based on temperature

Troposphere
Stratosphere
Mesosphere
Thermosphere

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Troposphere

-Bottom layer of atmosphere
-We live in it
-Temp decreases with increase in altitude
-Where weather occurs
-Bounded on top by tropopause

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Stratosphere

-Temp remains constant until 20 Km then it increases
-Ozone is concentrated here
-Bounded on top by stratopause

20

Mesophere

-Temp decreases with height to mesopause
-Coldest temperatures in atmosphere

21

Thermosphere

-tiny fraction of atmosphere
- Temp increases due to absorption of solar radiation
-no defined upper limit

22

The sun emits _______ ______ in the form of rays and waves

electromagnetic radiation

-as an object absorbs radiation, molecule movement increases causing temp to rise
-key difference among electromagnetic radiation is the wavelengths

23

Basic laws governing radtiation

-All objects emit radiant energy
-Hotter objects radiate more total energy than do colder objects
-The hotter the radiating body, the shorter the wavelengths of maximum radiation
-Objects that are good absorbers of radiation are good emitters as well

24

50% solar energy passes through

atmosphere and is absorbed on Earth's surface

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20% solar energy

is absorbed by clouds and atmospheric gases

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30% solar energy is

reflected back to space by clouds, atmosphere, snow and ice

27

Greenhouse Affect

-Shortwave solar radiation passes through the atmosphere and heats Earth
-Longwave radiation emitted by Earth is absorbed by gases in the atmosphere (CO2 and water vapor)

28

Selective absorption and reheating of Earth is called ______ _____ and results in warming of the atmosphere

greenhouse effect

29

Plate Movements

-landmasses move closer or further from equator
-can affect ocean circulation

30

Volcanic Activity and Climate Change

effects volcanic aerosols on climate
Sulfuric acid droplets
lowered global temps
increase in atmospheric CO2

31

Sunspots

huge magnetic storms on the sun
cycle is too short to have effect on global temps
Changes in temperature and precipitation

32

Humans modifying the environment

fire, overgrazing, burning fossil fuels, deforestation
Causing temps to rise

33

Trace Gases

Methane
Nitrous Oxide
CFCs

34

Methane

trace gas
Less abundant than carbon dioxide, but more effective at absorbing outgoing radiation

35

Nitrous Oxide

trace gas
Greenhouse gas that lasts for 150 years in atmophere

36

CFCs

trace gas
commercially produced chemical that depletes ozone

37

different possible outcomes of climate change

climate-feedback mechanisms

38

Changes that reinforce the initial change

positive-feedback mechanisms

39

Produce results that are opposite of the initial change and tend to offset it

negative-feedback mechanisms

40

Possible consequences of global warming

-temp increase not uniform
-precipitaion changes
-sea level rise driven by melting glaciers and thermal expansion
-Changing arctic (loss of sea ice and melting of permafrost)
-Increasing Ocean Acidity