ERS 121 UMaine Final
Warming in the stratosphere is mainly caused by: (1) absorption of ultraviolet radiation by ozone, (2) frictional heating caused by meteorites, (3) release of latent heat energy during condensation
(1) absorption of ultraviolet radiation by ozone,
Over the past 100 years or so, it appears that average global temperatures have: (1) increased slightly (2) fluctuated widely but shown no overall change (3) decreased slightly (4) remained constant
(1) increased slightly
The age of the universe is approximately _______ billion years.
(13.8) billion years.
Which one of the following is a significant contributor to increased levels of atmospheric carbon dioxide? (1) refrigerant leakage (2) deforestation (3)aerosol spray can gases (4) large rice paddies
(2) deforestation
Everything else being equal, a gradual increase in atmospheric CO2 would most likely bring about: (1) no change in global climate (2) a decrease in evaporation from the earth's oceans (3) a marked decrease in plant growth (4) an increase in surface temperature
(4) an increase in surface temperature
Earth is approximately _________ billion years old.
(4.5) billion years old.
. The dry adiabatic lapse rate is _____ ˚C/km.
(9.8/10) ̊C/km
In the troposphere, the air temperature normally: (a) decreases with increasing height, (b) increases with increasing height, (c) remains constant, (d) cannot be measured
(a) decreases with increasing height
Surface zones of low pressure are usually associated with: (a) near surface convergence, (b) descending air, (c) clear or nearly clear weather, (d) upper level convergence
(a) near surface convergence
Surface zones of high pressure are usually associated with: (a) near surface convergence, (b) descending air, (c) cloudy or rainy weather, (d) upper level divergence
(b) descending air
In the stratosphere, the air temperature normally: (a) decreases with increasing height, (b) increases with increasing height, (c) remains constant, (d) cannot be measured
(b) increases with increasing height
If the average temperature of a star decreased, the wavelength of peak solar emission would: (a) shift to a longer wavelength, (b) shift to a shorter wavelength, (c) remain the same, (d) impossible to tell from given information
(b) shift to a shorter wavelength
Deserts on Earth occur at about 30 degrees latitude because of: (a) the position of the intertropical convergence zone (ITCZ), (b) the convergence of the prevailing westerlies and northeast trades, (c) the sinking air of the subtropical highs, (d) the position of the doldrums
(b) the convergence of the prevailing
The primary force that causes all winds is: (a) coriolis force, (b) geostrophic force, (c) pressure gradient force, (d) centrifugal force
(c) pressure gradient force
What is the thermocline? (a) the coldest part of the ocean, (b) the hottest part of the ocean, (c) the zone of greatest temperature change, (d) the zone of greatest salinity change
(c) the zone of greatest temperature change
Without greenhouse gases, globally averaged surface temperature on Earth would be approximately ________ degrees Celsius.
-22
How much lower that now was global average temperature during the Little Ice Age?
0.75 degrees
How much has global temperature risen during the past 150 years?
0.85C (about .75)
Earth's atmosphere is approximately _____ % nitrogen and ________ % oxygen.
1. 78 2. 21
Globally, the ELA fell about ___________ meters during the Little Ice Age.
100 M
The dominant cycle of climate change over the last 900,000 years is about __________ thousand years.
100,000 thousand years.
When did agriculture arise?
11-12 thousand years ago
How many hours of daylight occur at the equator on June 21st?
12 hours
When did the Little Ice Age occur?
1300 to about 1850
The Viking settlements in Greenland were abandoned in around ________ A.D
1450
With greenhouse gases at present-day levels, the globally averaged surface temperature on Earth is approximately __________ degrees Celsius.
15
What was the concentration of atmospheric CO2 at the LGM in parts per million by volume (ppmv)?
180
When was the "Dust Bowl"?
1930s
When did modern humans (homo sapiens) arise?
200,000 years ago
Where is the Tropic of Cancer?
23.5 degrees North
The ozone layer is at an altitude of approximately _____________ km.
25 km
What was the pre-industrial concentration of atmospheric CO2 in parts per million by volume (ppmv)?
280
Globally, the ELA fell about_____ meters during the Younger Dryas.
300 M
The average salinity of seawater is _____ parts per thousand (by weight).
35
When did the 3 step-like cooling events of the Cenozoic occur?
36, 14, and 3 MYA
What is the present-day concentration of atmospheric CO2 in parts per million by volume (ppmv)?
400
Much of Tibet lies at altitudes over 5000 meters, where the pressure is about 500 millibars. At such altitudes, the Tibetans are above roughly ____ of the air molecules in the atmosphere.
50%
When did humans first arrive in Australia?
50,000 years ago
Approximately how deep is the ocean surface mixed layer?
50-100m
Earth's average global temperature has risen about ____ ˚C since the last glacial maximum
6 C
Earth's axis of rotation is tilted relative to its orbital plane by _____ degrees
66.5 degrees
When did the Vikings settle Iceland?
874 AD
When were the Viking settlements in Greenland founded?
985 AD
Who was Roald Amundsen?
A Norwegian explorer of polar regions led the Antarctic expedition of 1910-12, which was the first to reach the South Pole
What is a glacial erratic?
A glacial erratic is a piece of rock that differs from the size and type of rock native to the area in which it rests.
What is the Younger Dryas climate reversal?
A late glacial abrupt climate event characterized by cold, dry conditions in the northern hemisphere.
What is the Medieval Warm Period?
A time of warm climate in the North Atlantic region (900-1300 AD)
Where did modern humans arise (homo sapiens)?
Africa
What is a polynya?
An area of open water surrounded by ice
What shape is the orbit of Earth?
An elipse, similar to a circle but stretched.
What is an esker?
An esker is a long ridge of gravel and other sediment, typically having a winding course, deposited by meltwater from a retreating glacier or ice sheet
Name two places on the planet where ocean deep water forms today?
Antartica and the North Atlantic
When did paleoindians enter North America?
Around 15,000 years ago
When did humans first arrive in Siberia?
Around 25,000 - 30,000 years ago
Where is the largest monsoon system on earth?
Asia
Is the Southern Oscillation Index (SOI) a measure of atmospheric or oceanographic variability?
Atmospheric
At what time of the year does the ozone hole form?
Austral Spring (october)
What is the most likely reason for the abandonment of the Viking settlements in Greenland?
Beginning of the little ice age
What human-produced compounds lead to the destruction of ozone?
CFCs (chlorofluorocarbon)
What day of the year has the fewest hours of daylight in the northern hemisphere?
Dec. 21
What has been the trend in levels of atmospheric ozone over the past 15 years?
Decreasing in stratosphere, increasing in lower troposphere
The coriolis force in the northern hemisphere deflects winds in what direction?
Deflects winds to the right
Ocean water is stratified as a result of_____ differences that are related to salinity and temperature.
Density
Is vertical motion at the ITCZ or inter-tropical convergence zone up or down?
Down
Why do seasons occur on Earth?
Earth's axis of rotation is tilted
Lower tropospheric winds in the tropics in both hemispheres generally blow in what direction?
Easterly
When was the Norse discovery of America?
First spotted in AD 985 first visited in 1000 AD
When did the Younger Dryas occur?
From approximately 12,900 - 11,500 years ago
How do we know that land was depressed under large ice sheets at the LGM?
Glacial Erosion, Striations, and deposits.
What are striations?
Glacial striations are scratches or gouges cut into bedrock by glacial abrasion
What are the two types of australopithecines?
Gracile and Robust
The most important greenhouse gas in Earth's atmosphere is
H2O
List three greenhouse gases.
H2O, CO2, CH4, N2O,
Why were Viking ships superior to others of the day?
High bows, light weight, tillers in back, sails to go against wind, open design
What was the first hominid species to spread out of Africa?
Homo Erectus
What has been the trend in the concentration of atmospheric CO2 during the 20th century?
Increasing
What was been the overall trend in global surface temperature through the 20th century?
Increasing
What is the evidence for global warming during the past 150 years?
Instrument record, melting glaciers and sea ice
When was it stormier in the North Atlantic - during the Medieval Warm Period or the Little Ice Age?
Little Ice Age
What is a marine ice sheet?
Marine ice is ice grounded to the sea floor or floating in the ocean
Why is eustatic sea level rising at present?
Melting glaciers and thermal expansion
When did the first modern humans (Cro-Magnon) enter Europe?
Modern humans (Cro-Magnon) entered Europe around 40,000 years ago
Western boundary currents are___ (wider or narrower) than eastern boundary currents
Narrower
Is the global warming of the past 150 years unique to the present interglacial period?
No, around 7000-3000 BC we reached our climatic optimum (temps 1-2 degrees celsius warmer)
Where did the ice age theory originate?
Northern Europe
What did the northern Europe landscape look like during the last ice age maximum?
Northern Europe was a polar desert and tundra teeming with large mammals
By what process do stars generate energy?
Nuclear Fusion
Where does the ozone hole form?
Over Antarctica
How do we know that eustatic sea level was 120 meters lower at the LGM?
Raised Beach
Explain the difference between relative and eustatic sea level.
Relative: is defined as the sea level that is observed with respect to a land-based reference frame Eustatic: is a measure of the total mass or volume of the oceans.
Name two types of flood.
Riverine, Coastal
Eastern boundary currents are ____ (shallower or deeper) than western boundary currents
Shallower
Who was Leif Eriksson?
Son of Erik the Red. Explored North America before Columbus
What time of the year is wet in India?
Summer
What time of the year is wet in northern Australia?
Summer
What is a terrestrial ice sheet?
Terrestrial ice sheets are land based or sprawled over land
When did the greatest global warming of the last 50,000 years occur?
The Holocene Climate Optimum (HCO) was a warm period about 9,000 to 5,000 years ago, with a thermal maximum around 8000 years ago.
What is the Little Ice Age?
The Little Ice Age (LIA) - was a period of cooling that occurred after the Medieval Warm Period.
What is a termination?
The end of a glacial period
The prevailing winds in the middle latitudes of both hemispheres generally blow in what direction?
The prevailing winds generally blow from the west towards the east
How did paleoindians first get to North America?
They crossed the Beringia land bridge between eastern Siberia and present-day Alaska.
What is the most likely reason that Vikings from Greenland visited North America?
Timber
Where did trees grow in Europe during the last ice age maximum?
Trees grew south of the Alps
In what portion of the electromagnetic spectrum does ozone absorb energy?
Ultraviolet and infrared
Is vertical motion in the region of the subtropical highs up or down?
Up
During an El Niño event does equatorial upwelling in the eastern and central Pacific strengthen or weaken?
Upwelling Weakens
The sun emits the greatest intensity of radiation in the portion of the spectrum.
Visible portion of the spectrum.
What is the driving force for surface ocean currents?
Winds
What are katabatic winds?
Winds that blow high density air down a slope due to the force of gravity
What time of the year is wet in western Africa?
Winter
How many times per year does the sun pass directly overhead at Bangor, Maine (45 degrees north latitude)?
Zero
Who was Erik the Red?
a Norse explorer, described as having founded the first settlement in Greenland.
What is a greenhouse gas?
a gas that can absorb infrared wavelengths
What is a monsoon?
a seasonal reversal of wind direction
Name two possible mechanisms that can cause a drought
a. an above average prevalence of high pressure systems b. reduced sea surface temperature
Which came first, large brains or bipedalism?
bipedalism
Winds spiral out from a surface high-pressure system in the northern hemisphere in what direction (clockwise or counterclockwise)?
clockwise
Winds spiral into a surface low-pressure system in the northern hemisphere in what direction (clockwise or counterclockwise)?
counterclockwise
Did average global temperature increase or decrease between 1940 and 1970?
decrease
During an El Niño what happens to sea surface temperature in the eastern Pacific?
sea surface temperature increases
Why is the north coast of Peru a desert?
sea surface temperature is cool, and it is in the rain shadow of the Andes
During a La Niña event do the trade winds strengthen or weaken?
strengthen