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ATMOSPHERE

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Eric Toft

on 16 February 2017

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Transcript of ATMOSPHERE

ATMOSPHERE
a. Composed of the air surrounding earth, which form a cushion of gasses approximately
1,000
miles thick.

b. 99%
Nitrogen
and
Oxygen

I. What is the Atmosphere?
a. The atmosphere is sorted into different layers by temperature, pressure, and chemical composition.

b. We are focused on the lowest layer, that supports life, the
TROPOSPHERE

i. 90% mass of the atmosphere, were weather occurs

ii. Where the atmosphere’s water vapor is stored

II. Layers of the Atmosphere
a.
Insolation
: Energy from the sun

i. Energy Balance in the Troposphere

1. The amount of energy in
equals
the amount out.

III. Influences on Climate
2. Greenhouse Effect

a. Atmosphere absorbs heat energy

b. A real greenhouse traps heat inside

c. Atmosphere
delays
transfer of heat from Earth into space

c. Protects the earth from harmful radiation and intense heat from the sun by reflecting much of it out into space.

d. Also serves as a type of
greenhouse
by holding in enough heat for life to exist.



Figure 3.3

Temperature
in the Troposphere

© 2012 Pearson Education, Inc.

Figure 4.2

Insolation at Earth’s Surface

Actual Greenhouse vs.
Earth’s Greenhouse

Actual Greenhouse vs. Earth’s Greenhouse

© 2012 Pearson Education, Inc.

Figure 4.10

Earth–Atmosphere Radiation Balance

ii. Insolation is not evenly distributed because:

1.
Curvature
of the earth

2.
Axial tilt
means that the sun is directly overhead at different places at different times.

a. Equinoxes and Solstices

Energy Budget
by Latitude

© 2012 Pearson Education, Inc.

Figure 4.4

Refraction

Daily Net Radiation

Figure 2.10

Insolation by Latitude

Figure 2.17

b.
Albedo
: reflectivity of a surface

i. Scale of 0-100 with 0 as least reflective, therefore most absorbent

1. Darker, duller=
lower
albedo

2. Lighter, shinier=
higher
albedo

© 2012 Pearson Education, Inc.

Figure 4.5

ii. Clouds and Albedo

1. Clouds reflect insolation, cooling the earth during the day and delay heat loss, warming the night.

2. Cloud-albedo forcing: increase in albedo caused by clouds.

a. Thicker reflect more,
cooling
the surface

3. Cloud-greenhouse forcing: increase in warming because clouds hold in insolation.

a. Thinner let through more and hold in more surface heat.

4. Pollution, natural or human made (anthropogenic)
increases
cloud cover.

© 2012 Pearson Education, Inc.

Figure 4.7

Atmospheric Aerosols

© 2012 Pearson Education, Inc.

Figure 4.9

IV. Global Temperatures
a. Principal Temperature Controls

i.
Latitude
- colder farther from the equator.

ii.
Altitude
- cools 3.5 degrees for every 1,000 ft

iii.
Cloud cover

iv. Proximity to
water

b. Land-Water Heating Differences

i. Evaporation

1. Most from the ocean

2. Insolation heats water, water vaporizes, absorbing heat and taking it away from the surface and immediate air,
cooling
the surface and air

Figure 4.18

Global Latent Heat

ii. Transparency

1. Soil is
opaque
, water is
transparent
.

2. The more transparent the greater the penetration of heat

a. Beach in the summer---dig!

Radiation Budgets

© 2012 Pearson Education, Inc.

Pitt Meadows,
BC
49˚N

El Mirage,
CA
35˚N

© 2012 Pearson Education, Inc.

Figure 4.5

b. Water can hold
4X
more heat than soil

3. Higher specific heat takes longer to heat up and longer to lose heat.

4. Bodies of water---
lag time
. Long time to heat, long time to lose heat.

Figure 4.18

Global Latent Heat

Figure 4.19

Global Sensible Heat

iii. Movement

1.
Heat rises, cold descends
= for air and water, causing circulation of water and temperature locally and globally.

iv. Marine vs. Continental Effects

1. Climate of land close to water is
moderated

2. Climate of land far from water experiences
extremes

Land–Water Heating Differences  

Sea-Surface Temperatures

Ocean Currents

V. Forces Driving the Atmosphere
Altitude

January Temperatures

July Temperatures

January Temperatures

July Temperatures

Global Temperature Ranges

a.
Gravity

i. Virtually uniform; counteracts outward centrifugal force of spinning planet, pulls on all molecules.


b.
Pressure

i. Drives air from high to low pressure

ii. Warm air is less dense, rises, causing low pressure

iii. Cold air is more dense, descends, causing high pressure

iv.
Cycles
---air close to the surface is warmed, rises, eventually cools, then falls, and repeats.

Pressure gradient determines wind speed.

Large change in pressure over small distance = steep pressure gradient

Small change in pressure over a distance = gradual pressure gradient

c.
Coriolis Effect

i. A deflective force, straight winds appear to turn relative to Earth’s rotating surface (right in N. Hem; left in S. Hem).

Coriolis Force

Effect of Earth’s rotation
Rotational speed varies with latitude; so does Coriolis Force
Zero along the equator
Increases to half the maximum deflection at 30 ̊ N and S
Maximum deflection flowing away from poles
Effect increases with increasing speed

Coriolis Force

d.
Friction
force

i. Earth drags on wind as it moves across surfaces.

e. These forces combine to form wind and water streams called
currents
, that circulate the sun’s heat from eth equator to the poles and back.

Three physical forces produce winds.

i.
Prevailing Winds
: Air circulates from the warm equator to the cold poles and back again.

ii.
Gulf Stream
: Ocean current that brings warm waters from the Caribbean north along the coast of N. America and east along the coast of Britain and Scandinavia.

Figure 6.9

Global Barometric Pressure

Figure 6.9

Global Barometric Pressure

Polar and Subpolar Circulation

© 2012 Pearson Education, Inc.

Figure 6.13

Gulf Stream

VI. Moisture in the Atmosphere
a.
Humidity

i. Amount of H20 in the air.

ii. Warmer air has more space to hold H20, so when it’s hot and humd there is a lot of H20 there, you feel “sticky.”

iii. Cooling causes there to be less space between molecules, so water
condenses
.

Relative Humidity

© 2012 Pearson Education, Inc.

http://www.youtube.com/watch?v=CL5cgXwKUXc


Humidity Patterns

Humidity Instruments

Water Vapor in the Atmosphere

VII. Weather: a snapshot of climate
a. Lifted air (expanding) cools, contracts, hits the dew point / saturation (no room between H20 molecules) and condenses, precipitates.
b. Types of Lifting Mechanism:

i.
Convergent
Lifting (come together)

1. Low pressure areas (sinks) pull in and up

ii.
Convectional
Lifting (heat)

1. Cool air mass from water passes over hotter land

2. Cool air passes over urban heat island or the dark soil of plowed fields, etc.

© 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc.

Figure 7.20

© 2012 Pearson Education, Inc.

Moisture Droplets

Atmospheric Lifting Mechanisms 

Convection over Florida

Local Heating and Convection

Cumulus

iii.
Orographic
Lifting (rain shadow)

1. Migrating air mass forces up by mountains

Orographic Precipitation

Figure 8.8

Orographic Precipitation

Orographic Patterns

Mountain ranges and rain shadows

iv.
Frontal
Lifiting

1. Leading edge of an advancing air mass, a narrow zone forming a line of conflict between two air masses of different temp, pressure, humidity, wind speed, and direction.

2. Cold Front

a. Cold air forces warm air aloft

b. Travel at an average of 25 mph

c. Clouds may build along the front into a characteristic
cumulonimbus
form.

d. Precipitation is usually heavy, containing large droplets, and can be accompanied by hail, lightning, and thunder.

1-2 days ahead of cold front cirrus clouds appear, hinting at approaching lifting mechanism.
Wind shift, temp drop, lowering pressure mark cold front’s advance due to frontal lifting.
As line of intense lifting passes (usually just ahead of the front), pressure drops to local low.
Clouds may build along the front into a characteristic cumulonimbus form.
Precipitation is usually heavy, containing large droplets, and can be accompanied by hail, lightning, and thunder.
After cold front passage, usually winds from N (N. Hem) or from S (S. Hem) as anticyclonic high pressure advances. Temps are lower and pressure rises.
Clouds break and clear.

Cold Front

Fast advancing cold front can cause violent lifting and create a squall line just ahead or along the front.
Can lead to turbulent winds, intense precipitation, and tornadoes.
Shape and size of N. Am. Landmass and its latitudinal position present conditions where cP and mT air masses are best developed and have a lot of interaction.
Resulting contrast often leads to dramatic weather (especially in late spring), with great contrast between temperatures of air masses.

Cumulonimbus

3. Warm Front

a. Leading front of less dense warm air cannot displace colder, denser air, so warm air pushes cooler, underlying air into a wedge shape as warm air slides up over cooler air.

b. Travel at an average of 10-15 mph

c. Cool air is gently lifted, leading to low, dark, clouds and
drizzly precipitation
.

Warm Front

Cirrus (“curl of hair”)

Cirrostratus (stratus: “layer”)

Altostratus (“high” “layer”)

Stratus

Nimbostratus (“rainy” “layer”)

c. Violent Weather
i. Warm and cold air and waters mix, creating storms.

ii.
Thunderstorms

1. Warm air pushed up rapidly condenses, warming air, pulling up more, faster = precipitation.

2.
Cumulonimbus
clouds indicate dramatic weather: squall lines of heavy precipitation, lighting, thunder, hail, blustery winds, tornadoes.

3. Thousands occur on Earth at any given moment.

Cumulus

Cumulonimbus

Liberate tremendous energy through condensation, causing local heating
Leads to updrafts and downdrafts as rising air parcels pull surrounding air into the column and as frictional drag of raindrops pulls air toward ground
Cumulonimbus clouds create dramatic weather: squall lines of heavy precipitation, lighting, thunder, hail, blustery winds, tornadoes.
Thousands occur on Earth at any given moment.
In N.Am., most occur in areas dominated by mT air mass.

Thunderstorms

Average and Actual Storm Tracks

iii.
Lightning

1.
Approx. 8 million
lightning strikes on earth daily

2. Flashes of light caused by enormous electrical discharges (tens of millions to hundreds of millions of volts) briefly superheat the air to between 27,000 54,000 F.

3. Caused by buildup of electrical energy polarity between areas within a cloud air between the cloud and ground.

4. Violent expansion of abruptly heated air sends shock waves through the atmosphere as a
sonic bang
of thunder.

Thunderstorms

 Combined 1995–2003 data from the Optical Transient Detector and 1998–2003 data from the Lightning Imaging Sensor

iv.
Hail

1. Generally form in
cumulonimbus
cloud

2. Raindrops continually circulate repeatedly above and below the freezing level in the cloud.

3. Layers of ice added until wind can no longer support their weight.

Hailstones

© 2012 Pearson Education, Inc.

v.
Tornado

1. Idea-- spinning, cyclonic, rising column of air forms a cyclone that rotates vertically within a supercell cloud, spawning a tornado.

2. Moisture rich air is drawn up, condensing, liberating
latent heat
, warming, pulling up more, faster- positive feedback loop.

3.
Waterspout
: tornado over water.

Tornado Formation

Super Cell
Tornado
and Eye Wall

Tornado Path

Tornadoes

© 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc.

Felled Trees, Canadian Boundary Waters 1999 Derecho

© 2012 Pearson Education, Inc.

© 2012 Pearson Education, Inc.

vi.
Hurricans / Typhoons / Cyclones

1. Easterly waves of low pressure in Trade Wind Belt of the tropics gathers energy into the atmosphere while passing over
warm water
.

2. Because there is so much fuel (evaporation) the sorms are much bigger and more powerful.

Easterly
Wave

Easterly waves of low pressure in Trade Wind belt of the Tropics.
Mechanism that triggers the start of a tropical cyclone.
Tropical cyclones form along leeward (Eastern) side of the migrating troughs of Low P, a place of convergence and rainfall.

Tropical Cyclones

80 per year worldwide
45 powerful enough to be classified as hurricanes, typhoons, and cyclones (30% in Western North Pacific)

Tropical Cyclones

Profile of a Hurricane

Isabel, 2003 from intl. space station

Ivan

sandy

sandy

New Orleans, Katrina

Katrina: Gulfport Miss.

VIII. Climate Regions
a. 4 major regions- Tropical, Mid-Latitude, High-Latitude and Dry.

b. Remember: All vegetation zones have been modified through human use of
fire
and many would not be possible without
irrigation
, therefore climate does not determine what grows where.

i. Example 1: Much of the prairies were covered in forest until people cleared them with fire and continued to do so annually, allowing for only fast growing grasses.

ii. Example 2: Much of the American West has been extensively irrigated in order to grow crops in a dry climate which would not naturally provide enough precipitation.

Climatic Relationships

Generalized Climate Regions

World Climate Classification

Earth’s Climate System

Worldwide Average Precipitation

c.
Tropical
Climates: 30N-30S; climate is warm throughout the year.

i.
Tropical Wet
Climate: Without human intervention continuous rain and heat produce lush vegetation.

1. Often dense rain forests which are home to millions of forms of plant and animal life are found in these regions.

2. The
Amazon Basin
is the largest.

© 2012 Pearson Education, Inc.

Tropical Climates

Tropical Wet (rainforest)

Tropical Wet (Monsoon)

Tropical Dry (Savanna)

ii.
Tropical Dry
Climate: These areas of the tropics have a long dry season and a short, but intense, wet season.

1. This climate, combined with human use of fire, is favorable for
grassland growth
.

d.
Mid-Latitude
Climates: 30N to 60N and 30S to 60S;
most of the world’s people
live in this region. Warm air coming from the equator mixes with cold polar air, resulting in a wide
variety
of climates. This variety is mirrored by the variety of life.
© 2012 Pearson Education, Inc.

Mid Latitude Climates

i.
Humid Subtropical
Climate: Mid-latitude regions near the tropics where rain falls year-round, but is heaviest during the summer. Winters are short and mild, while summers are long, hot, and humid.
Humid Subtropical Hot-Summer

Humid Subtropical Hot-Summer

Humid Subtropical Winter-Dry

ii.
Marine West Coast
Climate: coastal areas where winds blow from the ocean. Winters are rainy and mild, summers are mild.
Marine West Coast

Marine West Coast

iii.
Mediterranean
Climate: Mild rainy winters and dry, hot summers.
Mediterranean Climates

iv.
Humid Continental
Climate: Found far inland from oceans. Winters are long, cold, and snowy, while summers are short and hot.
Humid
Continental
Hot-Summer
Climate

e.
High-Latitude
Climates: 60N-90N, 60S-90S. Climates are cold in these regions.

i.
Subarctic
Climate: Found just
below the Arctic Circle
, the winters are long and bitterly cold, though in the short summers, temperatures do rise above freezing, allowing for immense forests of evergreen trees to grow.

Extreme Subarctic Cold Winter

ii.
Tundra
Climate: Found
within
the Arctic Circle, the climate is harsh and dry. Extensive rolling plains, lacking any trees and very little vegetation is called
tundra
. During the summer months, the top few inches of soil thaw, allowing for some robust grasses and bushes to grow; the lower layer of soil however, remain permanently frozen, and are known as
permafrost
.
Polar and Highland Climates

iii.
Ice Cap
Climate: Located on the polar ice caps, Antarctica and the ece sheets of Greenland, this region is so cold that only some fungus-like plants grow on rocks.
iv.
Highland
Climate: Characterized by mountainous terrain, this climate is cool to cold year-round. The higher the elevation, the thinner the air, and the colder the climate.

1.
Timberline
: elevation above which no tree can grow.

St. Moritz Switerland

f.
Dry
Climates: Arid or semi-arid regions that receive little to no rainfall annually. Temps are generally hot during the day and cold at night. Severely
cold winters
are possible.
Dry Climates   

Desert Landscapes

g.
Desert
Climate: Can be found at any latitude, and receives
less than 10
inches of rain per year. Only plants with extremely deep roots or roots that spread out expansively near the surface survive without human irrigation.
Tropical, Subtropical Hot Desert

h.
Steppe
Climate: Averaging
10-20
inches of rain per year, though these area can support trees, humans have used fire during the dry summers to transform them into grasslands. Central Asia is home to vast steppes, so is
west-river SD
.
© 2012 Pearson Education, Inc.

Figure 10.29

IX. CLIMATE CHANGE
a. Cycles

i. Short term: 30 year
drought cycle
in SD, 7-11 year sun spot cycles.

ii. Long term: Earth has experienced at least five major Ice Ages, dating back over 2 billion years ago to the most recent, approx. 20,000 years ago.

1. Paleocene-Eocene Thermal Maximum-
6
degree increase 56 million years ago.

iii. Global temperature have risen
1.2

to
1.4
degrees F over the past century.

NOAA

b.
Anthropogenic
Global Warming / Climate Change

i. The issue is greenhouse warming due to human-caused CO2

ii. Increased CO2 in the atmosphere hampers long wave radiation from leaving earth.

1. Increase the natural
greenhouse effect

2. Earth’s temperature increases as a result

iii. Assessing the evidence

1. Warmer temps over the past 30 years overall

2. Carbon Dioxide
emission
rise mirrors increase in temp.

3. The UN’s
Intergovernmental Panel on Climate Change
(IPCC) say they are 90% sure climate change is due to CO2 level rise.

4. Approx.
95
% of published earth scientists agree

2000-2009

Vostok Ice Core, Antarctica

1000 Years of CO2 and Temperature Record

Figure 10.31

© 2012 Pearson Education, Inc.

Figure 10.32

© 2012 Pearson Education, Inc.

Figure 10.32

Temperature Anomalies

5. Climate is dynamic and monumentally complex! Very difficult to predict all variables and their impact on the future.

a.
That is ok, the nature of science is to go with what you know, continue investigating, adjust to new evidence when and if it arises.

iv. Negative Consequences of global warming:

1. Scientists predict that global temperature will rise
approx.
6.6-10.6
degrees F by the end of the century (5th IPPC).

2. Climate change is not uniform; some hotter, some colder, some wetter, dryer.

3. Glacial melt and rising sea level

a. 1ft rise in last 100 years

i. IPCC predicts
1-2
ft increase by 2100

b. Changing global temperatures and
growing seasons

c. Changing
precipitation
patterns and amounts

d. Changing, more
extreme storm
patterns

e. Human changes:

i.
Economic
--- some winners, some losers

ii.
Settlement

iii. Health and well-being

c. Possible Positive/Neutral Consequences

i. Majority of plants and animals live in
humid tropics
, far less in arctic regions. http.//en.wikipedia.org/wiki/Biodiversity#Distribution

ii.
Humans
are adapted for the tropics

iii. Cold kills more than warmth (disease associated with cold).

iv. Some will lose coastal territory gradually, those in land will see property values rise.

v. Overall
higher crop yields
as growing season lengthens and favorable conditions expand farmable regions poleward.

vi. Cooling a house costs
less
than heating.

d. Reasons to be Hopeful

i. Population is expected to level off at around
9
billion around
2050
.

ii. Human well-being is in the
best condition it has ever been
and is getting better.

iii. The % of people in poverty continually declines through time.

iv.
Less
violence, better health, wealth, productivity,
cleaner
environment, education, liberty, etc.

Accounts for solar forcing and volcanoes (no anthropogenic forcing)

Accounts for anthropogenic forcing

Explaining Global
Temperature Changes

sea surface height data from the Topex/Poseidon and Jason-1 satellites

NOAA

 http://www.ncdc.noaa.gov/bams-state-of-the-climate/2009.php

Temperatures across the world in the 1880s (left) and the 1980s (right), as compared to average temperatures from 1951 to 1980: U.S. EPA

U.S. Federal Government, National Intelligence Council, using data from WHO

Precipitation during the 20th century and up through 2008 during global warming, the NOAA estimating an observed trend over that period of 1.87% global precipitation increase per century

Gold coast, Australia

Italy

Papua New Guinea

Ghana

 SeaWiFS Project, Goddard Space Flight Center and ORBIMAGE

CDC

Crude death rates for weather-related mortality, by age: United States, 2006–2010 (CDC)

Netherlands delta works


Netherlands


 Maeslantkering storm surge barrier netherlands

v.

vi. Humans are the most
adaptable
species ever

vii. People are acting to improve green energies, etc.! (yea
scientists
!)

viii.
Innovation
continues to reduce the negative affects of fossil fuels and
improve upon
clean energy alternatives
.
© 2012 Pearson Education, Inc.

Figure 4.10

Earth–Atmosphere Radiation Balance

Latent heat of sublimation = 680 cal absorbed as one gram of ice turns into vapor

Latent heat – heat energy released or absorbed in a phase change.
-most cooling agent in energy budget

Phase Changes

Latent Heat

X. Why Are We Still Using Fossil Fuels?
a.
Economics
i. Fossil fuels are
finite
, but
abundant; cheap
.


1. Years of production left in the ground with the most optimistic proved reserve estimates (Oil and Gas Journal, World Oil)
a. Coal:
417
years
b. Oil:
43
years
c. Natural gas:
167
years
ii. They are
cheap
, supply a lot of energy proportionately and are
portable
,
controllable
,
consistent
,
storable
.

iii. People need energy; the more they use the higher their standard of living.

1. The Industrial Revolution, scientific advancements of the past 200 years, Information Age, were impossible without fossil fuels.

iv. Green Energy---

1. Very
costly
and yield comparably little energy currently

2.
Not
portable, controllable, consistent, or storable.

3. Major strides are being made,
costs
are going
down
, energy
production
is going
up
over time.

v. Energy Future

1. Over the foreseeable future
green
energies will
contribute

increasingly
to the energy supply,
fossil
fuels
will remain
a substantial contributor to that supply.

XI. Putting the Problem in Context

a. Top Problems

i. Copenhagen Consensus Project: asked people around the world, particularly in the developing world, and top world economists to rank the top world problems:

1.
Top
of the list: disease, corruption, malnutrition, sanitation, water quality, women’s rights, housing, education, and others
related to poverty
.

2.
Bottom
of the list:
terrorism
,
climate change
,
immigration
.

a. This
doesn’t deny climate change
or its importance!

ii. Top economists, including Nobel Laureates, did a ranking of priorities based on the most good for the money.

1. Bottom of the list
a.
Climate change, immigration


i.
Kyoto
Protocol: climate change goal treaty
1. 5% less emissions than 1960
2. Cost
150
billion per year
3. Benefit: postponing warming
6
years
100
years from now.

2. Top 4
a. 4-
Malaria
: nets, medication
i. Cost
13
bill
ii. Benefit—
5X
the cost, -
500,000 deaths
, -1 mill infections, ½ the incidence of infection.

b. 3-
Free Trade
: drop subsidies, trade barrier, govt. influence on economy
i. Cost,
very low
- policy change, rewrite laws
ii. Benefit--
$2.4 trillion
for world economy,
rich and poor
.

c. #2-
Malnutrition
---1/2 pop. lacks vitamin A, iron, others.
i. Cost: $12 billion
ii. Benefit:
increased survivial rate
, life quality for
millions
.

d. #1-
Disease
---HIV/AIDS in Africa
i. Cost: 27 billion
ii. Benefit:
40X
the cost, 28 million cases prevented.
vi. So Ask Yourself

1. Should we
spend a lot
on something that will do very
little good
in the distant future, a future where people are wealthier and less vunerable, or
spend much less
on things that will do substantial
good
for many people
now
?
2. Or is the very small risk of catastrophic, run-away warming still
so potentially bad
that it is worth focusing all our energy, even if that means neglecting other current problems?
3. No reasonable person thinks that we shouldn't do anything about climate change,
we should, can, and are
.
2. 1.2 bill
lack access
to electricity, 2.7 bill cook and heat with
wood
,
crop residue
, and
dung
.

3. By 2040 .5 bill will lack access,
1.8
will still burn biomass.

a. International Energy Agency’s “World Energy Outlook 2016.”

Changes in global grain yields and global temperatures 1961-2011. Data Sources: FAO, BEST
Deaths from nutritional deficiencies per million persons in 2012, WHO
Estimated percentage of HIV among young adults (15–49) per country as of 2011.[195] No data<0.10 0.10–0.5 0.5–1 1–5 5–15 15–50
Deaths due to HIV/AIDS per million persons in 2012 0 1–4 5–12 13–34 35–61 62–134 135–215 216–458 459-1,402 1,403–5,828
AIDS Clinic, India 2010
If all the world's ice melted: Natl. Geo.
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