Ch 7b: Atmosphere

Question 1

Climate:

Answer 1

time-average weather conditions at a place on the Earth’s surface.

Question 2

climate records typically include

Answer 2

temperature, precipitation, humidity, wind, cloud cover

Question 3

Climate change over geological time

Answer 3

cenozoic record of cooling, cretacenous warm interval.

Question 4

Koppen scheme of climate classification:

Answer 4

tropical, dry, temperate humid (mesothermal), temperate cold (microthermal), polar

Question 5

Deserts:

Question 6

Semi-deserts:

Answer 6

250-500 mm

Question 7

Distribution of deserts:

Answer 7

belts of low rainfall correspond to regions of divergence.

Question 8

Types of deserts:

Answer 8

subtropical, continental, rainshadow, coastal, polar

Question 9

Subtropical desert eg

Answer 9

Sahara, Kalahari, Great Australian

Question 10

Continental desert eg

Answer 10

Gobi, Takla Makan

Question 11

Rainshadow desert eg

Answer 11

Sonoran

Question 12

Coastal desert eg

Answer 12

Atacama, Namib

Question 13

Polar desert eg

Answer 13

Antarctica

Question 14

Instrumental records

Answer 14

Short term, weather records

Question 15

Proxy records

Answer 15

short to long term: historical, biological, geological, chemical

Question 16

Average weather records

Answer 16

Global correlation, overall warming trend over last 150 yrs.

Question 17

Geological: Glacier ice records

Answer 17

records of glacier extents, geological or historical.

Question 18

Longer-term change: hundreds to thousands of years

Answer 18

climate is inferred indirectly, requires validation by other sources. Similar proxy data types as earlier changes.

Question 19

Historical proxy records include

Answer 19

agriculture or shipping records, pictures, sketches, paintings, writings, personal letters.

Question 20

Biological Climate proxies:

Answer 20

dendrochronology: ring widths show correlation with climate

Question 21

Palynology

Answer 21

pollen: record of land vegetation

Question 22

Last 2 Ma: Quaternary Period

Answer 22

marked by cold climates worldwide, glacial erosion and deposition in areas no longer glaciated

Question 23

Extent of ice cover:

Answer 23

records indicate at least 4 advances and retreats, separated by interglacial periods.

Question 24

Ocean sedimentary records:

Answer 24

6 layers of ice-rafted debris deposited during last glaciation (between 70-10ka)

Question 25

Heinrich events:

Answer 25

catastrophic calving of ice sheet

Question 26

Ocean sediment records: marine micro-organisms

Answer 26

many species of plankton have restricted temperature range. Species alternate in cores, indicating changing temperature changes.

Question 27

Isotopes:

Answer 27

O18:O16.

Question 28

When water evaportes:

Answer 28

vapor contains slightly less O18.

Question 29

As ice sheets grow, O18:

Answer 29

increases in ocean water, decreases in continental ice sheets.

Question 30

O18 is heavier

Answer 30

land rain is O16 enriched.

Question 31

Cycles of climate change:

Answer 31

isotopes record many glacial and interglacial intervals in last 2Ma. Dominant period in last 800000 years is 100000 years.

Question 32

Earlier glaciations:

Answer 32

late paleozoic, late proterozioc time

Question 33

Late paleozoic

Answer 33

gondwanaland, glacial and interglacial intervals

Question 34

Late proterozoic time

Answer 34

difficult to reconstruct, snowball Earth hypothesis

Question 35

Milankovitch cycles

Answer 35

affect the distribution of solar energy over Earth's surface. Affect climate: global totals, seasons

Question 36

Causes of Climate change:

Answer 36

milankovich cycles, changes in solar energy output, plate tectonics, volcanic events, degassing of sediments, asteroid/comet impact.

Question 37

Plate tectonics:

Answer 37

position of continents, redistribution of heat

Question 38

Volcanic Events:

Answer 38

short term: dust particles in atmosphere reduce solar energy reaching the ground. Long term: major volcanic episodes, ash to the atmosphere: cooling effect, carbon dioxide: greenhouse warming effect.

Question 39

Degassing of sediments

Answer 39

hydrocarbons, esp methane, trapped in sediments may be released. Gas hydrates on continental margins. Methane burps.

Question 40

Asteroid

Answer 40

triggering of the younger dryas cooling by ET impact.