Geography Final: Exam 2

_____are enormous continental masses of glacier ice covering over 50,000 square kilometers

Ice Sheets

When Earth's tilt is small

Ice sheets should grow in the Northern Hemisphere according to the Milankovitch theory

______Forms as a result of the calving and the breakup of glaciers over water

Icebergs

The Medieval warm Period (or Medieval Climate Anomaly) was characterized by significantly warmer conditions

In the North Atlantic AND in western Europe

The correct order of events describing the postulated "Warm Artic Cold Continents Pattern is"

Increased autum snow in Siberia, Jet stream strengthens south, colder winter in U.S and Europe

Large volcanic eruptions inject sulphate aerosols into the troposphere and stratosphere, reducing the amount of solar radiation reaching the surface and resulting in a ______radiative forcing

Negative

More proxy records are located where

Norther Hemisphere

The ______is significantly under-sampled when considering proxy records of the climate for the past 1000 years

Southern Hemisphere

In recent research expeditions to the Cordillera Vilcanta in Southern Peru, Dr. Perry dug a 2 meter snow pit and collected samples from a shallow firm core to analyze

Stable Oxygen isotope ratios (delo 18 or O18)

What aspect of volcanic eruption is most strongly linked to global cooling events that may last up to several years in duration

Sulfate Aerosols

The eruption of what volcano is linked to the famous "Year Without a Summer" in 1816

Tambora

Measured properties form ice cores include

Atmospheric humidity

All of the following are considered astronomical controls on solar radiation except

(axial tilt, axial precession, precession of the equinoxes, precession of the ellipse-ALL OF THESE ARE)

Which horror production is directly associated with Year Without a Summer

*Frankenstein*

Reliable instrumental records of climate are generally only available for the past

100 years

What is the primary periodicity related to solar activity (i.e. the sunspot cycle and time between peaks in sunspot abundance)

11 years

Conditions are likely to be most favorable for northern hemisphere continental glaciation when the hypothetical axial tilt is

20 degrees

The ______is a circulation pattern in which the atmospheric pressure over the polar regions varies in opposition with that over middle latitudes on time scales ranging from weeks to decades, the negative or cold phase of this circulation patter is typically associated with cold and snowy weather in the Easter US

AO

Which of the following has the greatest influence on ice sheets size?

Ablation in the summer

______occurs when the climate system is forced to cross some threshold triggering a transition to a new statee

Abrupt Climate Change

A component of the ENSO Observing system

All of the above: TAO/TRITON array of oored buoys, tide gauges, ship based measurments, satalites

What condition drives the equilibrium line north, in the two-dimensional numerical model of northern hemisphere ice sheet behavior

High values of summer insolation

When glaciers begin to grow, why is there a lag between changes in insolation and changes in ice volume

Changes from high to low insolation are instantaneous, but changes in ice volume are not

Which of the following is the correct sequence of steps in reconstructing past climates using proxy data?

Collection, Dating, Calibration, Validation, Reconstruction

The glaciers of the Central Andes Mountains of Boliva and Peru have been in a state of retreat in the past 30 years primarily as a result of more frequent and intense ______events.

El Nino

The periodic warming of sea surface temperatures off the west coast of Peru and extending into the Eastern Pacific is known as

El Nino

Traditional explanation is that O18 becomes_____during periods of cooling (glacier advance) and becomes _____during periods of warming

Enriched and then depleted

Both the Younger Dryas and the 8.2 ka event are believe to have been caused by

Freshwater influx into the North Atlantic and subsequent disruption of the Oceanic Conveyor Belt

_______forms as a result of snow that accumulates on a land and then through compaction and sow metamorphic turns to ice

Glaciers

Exceptionally vigorous upwelling along the coast of Ecuador and Peru occurs during

La Nina

The periodic cooling of sea-surface temperatures off the west coast of Peru and extending into the Eastern Pacific is known as

La Nina

Which of the following climatic time periods is thought to be more global in extent (either warming or cooling) than others

Last Glacial Maximum (LGM)

All other things being equal, greater eccentricity of Earth's orbit

Leads to increased seasonality

The ______was associated with a period of widespread global cooling from approximately 1500 to 1850 and was particularly intense in the North Atlantic and Europe

Little Ice Age

Which of the following is not associated with the Mideval Warm Period

Lower treelike in Europe (THESE ARE WHAT ARE ASSOCIATED: alpine glacier retreat, rising population, vineyard cultivation, Viking colonies in Greenland)

Longer term, there is an apparent match between global temperatures and sunspot activity, best illustrated by this period of low sun spot activity that was concurrent with the "Little Ice Age"

Maunder Minimum

The Viking settled Greenland and other sections of the North Atlantic during the

Medieval Warm Period

A _________ phase of the AO is typically associated with cold and snow conditions in the Europe and the eastern U.S

Negative

An interglacial climate favors a ______________mass balance

Negative

The most common occurring oxygen isotope is

O16

The ratio of O18 to _____in water changes with climate and is widely used measure to describe climates of the past

O16

The cooling effects associated with volcanic eruptions are typically greatest how many years after the eruption

One year

The Ice Age of past were most likely caused primarily by

Orbital Factors

The ____________ is a long lived oscillation in the Pacific Ocean involving sea-surface temperatures and related air pressure--

PDO

_______ is the study of past climates.

Paleoclimatology

________consists of permanently frozen water in the soil

Permafrost

Most ice cores used in paleoclimatic reconstructions

Polar ice caps

A _________ phase of AO is typically assocated with mild conditions in Europe and the Eastern US

Positive

All of the following are limitations of large-scale climate reconstructions using proxy data except

Proxy records are meaningful records or environmental variable (NOW THESE ARE LIMITATIONS: instrumental record is short, needs to calibrate, the relationship between the proxy data and the climate variable may have varied over tie----there is no consensus among scientist on formulas, its time consuming and expensive)

How are proxy data used to reconstruct climate

Relationship between proxy record and instrumental records are established using statistical techniques

___________Forms the freezing of ocean

Sea Ice

During the Little Ice Age, which of the following did not occur in Europe

Sea ice contraption (WHAT DID OCCUR: decreasing agricultural productivity, lowered treelike, freezing of canals and rivers, settlement abandonment and population decline)

The Little Ice Age was associated with a decrease in______.

Solar Activity

The two most important climate forcing responsible for the Medieval Warm Period and the Little Ice Age include

Solar Activity and Volcanoes

At the June Solstice

The sun is the highest in the sky and the sun is above the horizon the longest in the Northern Hemisphere

Ice cores are excellent climate proxies covering

Thousands of years

Dendroclimatology examines

Tree Growth Rings

El Nino and La Nina are inter-annual variations in Earths climate system occurring in the

Tropical Pacific

How does vertical ice sheet growth serve as a climate feedback

Vertical growth places the top of the ice into higher altitudes where temperatures are colder, making the ice mass balance more positive.

An abrupt period of cooling around 13,000 years came to be known at the _____, after an Arctic flower that become common across Europe

Younger Dryas

Rapid warming of Earth after the Plesitocene maximum began about 15 thousand years before the present, this warming ended about 12,000 years before the present in a time period known as the

Younger Dryas

From oldest to youngest the correct ordering of these climatic time periods is

Younger Dryas, Holocene Climatic Optimum, Medieval Warm Period, Little Ice Age

A relatively warm period during a glacial period is known as

an interglacial

During a negative phase of the North Atlantic Oscillation (Arctic Oscillation) easter North America and wester Europe are typically much _____than normal

cooler

During periods of low sunspot activity, total solar irradiance

decreases

Near the poles atmospheric water is increasingly ______in O18

depleted

Which statement is correct regarding changes in axial tilt

increased tilt amplifies seasonality

Which of the following are not examples of widely used climate proxies of the studies of past climates

moon cores

The National research council recently concluded that tropical ice cores are more complex than previously thought. Recent studies suggest that isotopic composition of Andean precipitation is mainly controlled by local________processes.

precipitation

Recent observations from space suggest that the decrease in_______ irradiance during low sunspot activity may be greater than previously thought

ultraviolet