Transcript ch. 6 part II - OCPS TeacherPress

CHAPTER 6
THE PHYSICAL ENVIRONMENT
OVERVIEW OF CHAPTER 6
Biogeochemical Cycles
 Solar Radiation
 The Atmosphere
 The Global Ocean
 Weather and Climate
 Internal Planetary Processes

BIOGEOCHEMICAL CYCLES
 Matter
moves between
ecosystems, biotic & abiotic
environments, and
organisms

Unlike energy
 Biogeochemical
involves

Biological, geologic and
chemical interactions
 Five

cycling
major cycles:
Carbon, Nitrogen, Phosphorus,
Sulfur and Water (hydrologic)
THE CARBON CYCLE
THE NITROGEN CYCLE
THE PHOSPHORUS CYCLE
THE SULFUR CYCLE
THE WATER (HYDROLOGIC) CYCLE
EARTH SYSTEMS AND RESOURCES
o
SOLAR RADIATION
Sun provides energy for life, powers
biogeochemical cycles, and determines climate
 69%
of incoming solar
radiation is absorbed by
atmosphere and earth

Remainder is reflected
 Albedo
The reflectance of solar
energy off earth’s surface
 Dark colors = low albedo
(more sunlight absorbed)



snow-temperature feedback example
Forests and ocean
Light colors = high albedo

Ice caps
TEMPERATURE CHANGES WITH LATITUDE

Solar energy does not hit earth uniformly

Due to earth’s spherical shape and tilt
Equator (a)
High concentration
Little Reflection
High Temperature
Closer to Poles (c)
From (a) to (c)
In diagram below
Low concentration
Higher Reflection
Low Temperature
TEMPERATURE CHANGES WITH SEASON
 Seasons
determined
by earth’s tilt
(23.5°)
 Causes each
hemisphere to
tilt toward the
sun for half the
year
o
Northern Hemisphere tilts towards the sun
from March 21- September 22 (warm season)
CHECK FOR UNDERSTANDING
4 - I can explain how solar radiation impacts earth to
my peers
 3 - I understand how solar radiation impacts earth
 2 - I understand that solar radiation impacts earth,
but I don’t really get how it happens.
 1 - I am lost about solar radiation

THE ATMOSPHERE
 Invisible
layer of gases around
earth
 Content
 21% Oxygen
 78% Nitrogen
 1% Argon, Carbon dioxide,
Neon and Helium (+
pollutants like methane,
ozone, dust, CFCs)
 Density decreases with distance
from earth
 Shields earth from high energy
radiation
ATMOSPHERIC LAYERS
 Troposphere
(0-10km)
Weather occurs
 Temperature decreases with
altitude

 Stratosphere

(10-45km)
Ozone layer absorbs UV
 Mesosphere
(45-80km)
ATMOSPHERIC LAYERS
 Thermosphere
(80-500km)
Gases in thin air absorb x-rays
and short-wave UV radiation =
very hot
 Source of aurora

 Exosphere
(500km and up)
Outermost layer
 Atmosphere continues to thin
until converges with
interplanetary space

OZONE (O3)
Tropospheric ozone
Bad
 Formed by UV light
reacting with nitrogen
oxide – from burned
fossil fuels
 Irritates respiratory
problems, slows
photosynthesis and
plant growth

Stratospheric ozone
Good
 Shields UV rays
 Destroyed by chlorine
compounds; CFCs
(chlorofluorocarbons)
in refrigerants,
aerosol sprays,
making of Styrofoam.

ATMOSPHERIC CIRCULATION – DISTRIBUTES
THERMAL ENERGY
 Near




Equator
Warm air rises, cools and splits
to flow towards the poles
(convection)
~30°N&S sinks back to surface
Air moves along surface back
towards equator
Hadley Cell
 This
occurs at higher
latitudes as well

Moves heat from equator to the
poles
SURFACE WINDS
High
Atmospheric gases exert
pressure; changes with
temperature, altitude,
humidity
 Winds blow from high to
low pressure; greater
difference creates
stronger wind


Low
High
Low
High
Low
Right side of diagram
High
CORIOLIS EFFECT

Earth’s rotation influences direction of wind



Earth rotates West to East
Deflects wind from straight-line path
Coriolis Effect



Influence of the earth’s rotation on movement of air and fluids
Turns wind Right in the Northern Hemisphere
Turns wind Left in the Southern Hemisphere
CORIOLIS EFFECT
 Visualize
below)
it as a Merry-Go-Round (see
CHECK FOR UNDERSTANDING
4 - I can explain how atmospheric conditions impact
earth to my peers
 3 - I understand how atmospheric conditions impact
earth
 2 - I understand that, atmospheric conditions impact
earth
 but I don’t really get how it happens.
 1 - I am lost atmospheric conditions

GLOBAL OCEAN CIRCULATION
Prevailing winds produce surface ocean currents
and generate gyres
 Example: the North Atlantic Ocean

Trade winds blow west
 Westerlies blow east
 Creates a clockwise gyre in the North Atlantic


Circular pattern influenced by coriolis effect and
land masses
GLOBAL OCEAN CIRCULATION
Westerlies
Trade winds
POSITION OF LANDMASSES
Large landmasses in
the Northern
Hemisphere help to
dictate ocean
currents and flow
Very little land in
the Southern
Hemisphere
VERTICAL MIXING OF OCEAN (OCEAN
CONVEYOR BELT)
OCEAN INTERACTION WITH
ATMOSPHERE- ENSO
 El

Niño-Southern Oscillation (ENSO)
Def: periodic large scale warming of surface waters of
tropical eastern Pacific Ocean
 Normal
conditions- westward blowing tradewinds
keep warmest water in western Pacific
 ENSO conditions- trade winds weaken and warm
water moves eastward to South America
Big effect on fishing industry off S. America – prevents
upwelling of cold (nutrient-rich) water
 Causes abnormal weather: cooler/wetter  Southeast US;
dry  Southern Africa/Southeast Asia

ENSO CLIMATE PATTERNS
Normal trade winds vs trade winds with El Nino
CHECK FOR UNDERSTANDING
4 - I can explain how the atmosphere interacts with
the ocean (including El Nino) to my peers
 3 - I understand how the atmosphere interacts with
the ocean (including El Nino)
 2 - I understand how wind influences currents, but I
don’t really get El Nino or just need more practice.
 1 - I am lost. What’s my name?

WEATHER AND CLIMATE
climagraph
 Weather


The conditions in the atmosphere at a given place and time
Temperature, precipitation, cloudiness, wind, etc.
 Climate



The average weather conditions that occur in a place over a
period of years
2 most important factors: temperature and precipitation
 Other factors: albedo, angle of sunlight, altitude, distance to
oceans, mountain ranges, pollution
Earth has many climates
RAIN SHADOWS
Mountains force humid air to rise
 Air cools with altitude, clouds form and precipitation
occurs (windward side)
 Dry air mass moves down opposite leeward side of
mountain

TORNADOES




Powerful funnel of air associated with a severe thunderstorm
Formation
 Mass of cool dry air collides with warm humid air
 Produces a strong updraft of spinning air under a cloud
 Spinning funnel becomes tornado when it descends from cloud
Wind velocity= up to 480 km per hour
Width ranges from 1m to 3.2km
TROPICAL CYCLONE/HURRICANE
 Giant
rotating tropical storms, where trade winds
merge
 Wind >119km per hour
 Formation
Strong winds pick up moisture over warm surface waters
 Starts to spin due to Earth’s
rotation (coriolis effect)
 Spin causes upward spiral
of clouds

 Damaging
on land
High winds
 Storm surges

CHECK FOR UNDERSTANDING
4 - I can explain various weather patterns (rain
shadow, tornadoes, hurricanes) to my peers
 3 - I understand weather patterns
 2 - I understand weather patterns, but I just need
more practice.
 1 - I don’t know the difference between weather and
climate.

INTERNAL PLANETARY PROCESSES

Layers of the earth
Lithosphere
 Outermost rigid rock layer
composed of plates; major
element (crust) = oxygen
 Asthenosphere
 Lower mantle comprised
of hot soft rock
 Core : solid, mainly nickel,
some iron (dense)

Plate Tectonicslithospheric plates move
over the asthenosphere
 Plate Boundary- where 2
plates meet


Common site of
earthquakes and volcanoes
PLATES AND PLATE BOUNDARIES
TYPES OF PLATE BOUNDARIES

Divergent Plate
Boundary-2 plates move
apart = mid-oceanic
ridges

Convergent Plate Boundary-2 plates move together 2
continental plates = mountains (ex: himalayas); 1 ocean/1
continental (subduction)= volcano/earthquakes
Mount St. Helens,
Washington on May 18, 1980
MAJOR VOLCANIC AIR POLLUTANT: SULFUR
plus lots of CO2
May 17, 1980
August 13, 2005
TYPES OF PLATE BOUNDARIES



Transform Plate
Boundary- 2 plates
move horizontally in
opposite, parallel
directions
Get stuck, pressure
builds, breaks apart =
earthquake
Ex: San Andreas Fault
EARTHQUAKES

Caused by the release of accumulated energy as rocks
in the lithosphere suddenly shift or break
Occur along faults
 Energy released as seismic wave

Focus- the site where the earthquake originates below
the surface
 Epicenter- located on the earth’s surface, directly
above the focus
 Richter scale and the moment magnitude scales are
used to measure the magnitude; size 8 is 10x greater than

a 7 in shaking amplitude/ 31.6 times greater in energy release
TSUNAMI

Giant undersea wave caused by an earthquake,
volcanic eruption or landslide

Travel > 450mph
Not all ocean earthquakes create tsunamis
 Importance of mangroves vs. human development
 Tsunami wave may be 1m deep in ocean



Becomes 30.5m high on shore
Magnitude 9.3 earthquake in Indian Ocean (9.0
caused Japanese tsunami)

Triggered tsunami that killed over 230,000 people in
South Asia and Africa
CHECK FOR UNDERSTANDING
4 - I can explain tectonic plate movement and they
create earthquakes and tsunamis to my peers
 3 - I understand tectonic plate movement and how
they create earthquakes and tsunamis
 2 - I understand plate tectonic movement,
earthquakes and tsunamis, but I just need more
practice.
 1 - Plate tectonics??????
