Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physical Geography > Climate Variation and Change > Flashcards

Climate Variation and Change Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

What are proxy indicators?

A

ice core data, sediments, coral reefs, ancient pollen, tree-ring…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is the current climate monitored?

A

weather station data, remote sensing data, numerical modeling using General Circulation Models (GCM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how is the future climate monitored?

A

numerical prediction using GCMs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some methods for long term climate reconstruction?

A

Some paleoclimatic techniques yield long-term records that span hundreds of thousands to millions of years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where do long term records come from?

A

Such long-term records come from cores drilled into ocean-bottom sediments or into the thickest ice sheets on Earth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is isotope analysis?

A

a technique that uses the atomic structure of chemical elements, specifically the relative amounts of their isotopes, to identify the chemical composition of past oceans and ice masses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does isotope analysis help us?

A

Helps us understand how much ice the temperature of earth was around /fluctuated over time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is oxygen isotope analysis?

A

So, it’s about measuring the ratio of O18 (heavy compared to O16) and O16.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain oxygen isotope analysis:

A

Because O18 is heavier, it takes longer to evaporate. Like in the subtropics we have more O16 carried (deposited near the poles and frozen), but the O18 will evaporate sooner.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When does the proportion of O18 increase? Why?

A

The proportion of O18 increases in ocean water during cold periods, when more O16 is locked up in glaciers and ice sheets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where do we see oxygen isotope analysis?

A

In ice cores.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are ocean sediment cores?

A

Shell building organisms build their shells from stuff they find in their environment (including oxygen molecules). When they die, they float to the bottom and get buried.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or False: We can see a change in the 18O/16O ratio in the ancient shells of long dead marine organisms, found in these sediment cores, which can be several kms long, yielding data of past conditions which span 70 million years.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some methods of short term climate reconstruction?

A

The tools for short-term climate analysis consist mainly of radiocarbon dating and the analysis of climate proxies (growth rings of trees, speleothems, corals, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is an example of short-term climate reconstruction?

A

Dendrochronology, wide ring in good years.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some methods of natural climate fluctuation?

A

-Solar variability -Earth’s orbital cycles (Milankovitch cycles)
-Continental position and topography -Atmospheric gases and aerosols

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

True or False: earth’s orbit is more elliptic,

A

True

18
Q

What is earths obliquity?

A

23.44°

19
Q

What is Axial Precession?

A

Earth’s axis of rotation points at different points in the sky Impacts the timing of equinoxes and solstices relative to perihelion and aphelion

20
Q

True or False: Currently perihelion occurs during NH winter, at other times it coincides with NH summer.

A

True

21
Q

What are Milankovitch Cycles?

A

ilankovitch cycles describe the collective effects of changes in the Earth’s movements on its climate over thousands of years

22
Q

what are some causes of present climate change?

A

Contributions of greenhouse gases including carbon dioxide, methane, nitrous oxide, halogenated gases, anthropogenic greenhouse gases.

23
Q

What are some mechanisms for natural climate change fluctionation?

A

-Solar variability Earth’s orbital cycles (Milankovitch cycles)
-Continental position and topography -Atmospheric gases and aerosols

24
Q

True or False: -Natural variability in solar insolation cannot explain modern temperature trends. ***

A

True

25
Q

At the peak of the Pleistocene glaciation (18,000 B.P.), sea level was about ______m lower than it is today.

A

130

26
Q

True or False: If Antarctica and Greenland became ice-free, sea level would rise at least 65 m worldwide.

A

True

27
Q

What does GCM stand for?

A

General circulation model

28
Q

What are GCMs’ used for?

A

The general circulation models (GCMs) are used to assess past climatic trends and forecast future climate changes.

29
Q

What do the most sophisticated GCM’s do?

A

They couple atmosphere and ocean submodules and are known as Atmosphere-Ocean General Circulation Models (AOGCMs).

30
Q

What does AOGCM stand for?

A

Atmosphere ocean general circulation model

31
Q

How do scientists use GCMs?

A

Scientists can use GCMs to determine the relative effects of various climate forcing on temperature.

32
Q

What are some AOGCM scenarios for surface warming?

A

-Climate Change and Sea Ice-Albedo Feedback Loop
-Permafrost Thawing and Methane Feedback Loop

33
Q

What are the sea level projections?

A

A rise of only 0.3m would cause shorelines to move inland by about 30m, resulting in a loss of approx. 20,000 km2 of land in North America and trillions of dollars in damages.

34
Q

True or False: Melting of sea ice does not contribute to the rise of sea level.

A

True

35
Q

What are some reasons for change in sea level?

A

-Thermal expansion of ocean water
-Melting of land ice (e.g. glaciers, ice sheets)

36
Q

What are the effects of a 1-metre rise in sea level?

A

-Would flood: 15% of Egypt’s arable land
-17% of Bangladesh Pretty much the entire nation of The Maldives and other low-lying island nations like it.

37
Q

True or False: Climate change is disproportionately impacting northern regions

A

True

38
Q

Where does the most of the warming occur in the in the northern regions?

A

Above 50°N latitude

39
Q

When does most warming occur in Winnipeg?

A

Most marked warming occurring in the winter and spring months (Jan – Mar) 4 – 5°C

40
Q

What is the change of precipitation in Winnipeg?

A

Some months wetting, others drying. Overall minor increase in total annual precipitation over the last 100(ish) years.

41
Q

Why are moisture trends most difficult to predict?

A

-Overall increase in precipitation in Canada
-Regionally defined wetting and drying trends

42
Q

What are some measures of mitigation to slow the rates of climate change?

A

-Reduce carbon emission.
-Plant trees and expand green spaces in urban areas.
-Alter agricultural practices to retain more carbon.
-Increase motor vehicle fuel-efficiency standards.

Physical Geography (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions