Chapter 1 Introduction to the Atmosphere. Weather Influences Our Lives a Great Deal. The United...
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- Slide 1
- Chapter 1 Introduction to the Atmosphere
- Slide 2
- Weather Influences Our Lives a Great Deal. The United States
likely has the greatest variety of weather of any country in the
world. Severe weather events such as tornadoes, flash floods, and
intense thunderstorms, as well as hurricanes and blizzards, are
collectively more frequent and more damaging in the United States
than in any other nation.
- Slide 3
- Few Aspects of Our Environment Influence Our Daily Lives Like
Weather Beyond its direct impact on the lives of individuals, the
weather has a strong effect on the word economy, by influencing
agriculture, energy use, water resources, transportation, and
industry. Weather clearly influences our lives a great deal. Yet it
is also important to realize that people influence the atmosphere
and its behavior as well. There are, and will be, significant
political and scientific decisions to make involving these
impacts.
- Slide 4
- A Typical Newspaper Weather Map Meteorology the scientific
study of the atmosphere and the phenomena of weather. Weather the
state of the atmosphere at a given time and place 1) Weather is
constantly changing, day-to-day or even hour-to-hour 2) Weather is
acted on by the combined effects of Earths motions and energy from
the Sun. Climate an aggregate of weather conditions, the sum of all
statistical weather information that helps describe a place or
region
- Slide 5
- Map Showing Percentage Chance of Sunshine in Different Areas
The nature of both weather and climate is expressed in terms of the
basic elements, those quantities or properties measured regularly.
The most important elements are: air temperature, humidity, type
and amount of cloudiness, type and amount of precipitation, air
pressure, and speed and direction of the wind.
- Slide 6
- Costs of Weather Disasters in the United Sates Natural hazards
are apart of living on Earth. Everyday they adversely affect
millions of people worldwide and are responsible for staggering
damages. Some, like earthquakes and volcanic eruptions, are
geological in nature, but a greater number of hazards are related
to the atmosphere. Occurrences of severe weather have a fascination
that ordinary weather cannot provide. Hurricanes and tornadoes
attract a great deal of attention as a single one of these events
can cause billions of dollars in property damage, much human
suffering, and many deaths. The four hurricanes that struck the U.
S. in August and September 2004 caused more than $40 billion in
damages and 152 deaths. Hurricane Katrina (2005) is estimated to
have caused $130 billion in damages and more than 1,800
deaths.
- Slide 7
- Scientific Inquiry Science is based on the assumption that the
natural world behaves in a consistent and predictable manner can be
understood through careful and systematic study. The development of
new scientific knowledge involves some basic logical processes that
are universally accepted. Scientists collect facts through
observation and measurement that serve as springboards for the
development of scientific theories. The scientific method is a
process used by scientists to answer questions about the natural
world. The method involves the collection of facts, the development
of a hypothesis, tests of the validity of the hypothesis, and the
use of newly acquired information to accept, reject, or modify the
hypothesis.
- Slide 8
- Automated Surface Observing System (AOSS) Observing the
Atmosphere Scientific study of the atmosphere began in the
seventeenth century as instruments were developed to measure
different elements of the atmosphere. Galileo invented a type of
thermometer in 1593, and in 1643 Torricelli built the first
barometer. By 1661 Robert Boyle discovered the basic relationship
between pressure and volume in a gas. During the eighteenth
century, instruments were improved and standardized, and extensive
data collection began.
- Slide 9
- Helium Weather Balloon High Altitude Observations Gathering
data from ground-level sites only significantly limited an
understanding of Earths atmosphere. Kites were first used to obtain
data above Earths surface. In the late eighteenth century manned
balloon flights were attempted in an effort to collect information.
Today unmanned balloons play a significant role in the systematic
study of the upper atmosphere. Modern weather balloons are equipped
with radiosondes, lightweight packages of instruments fitted with
radio transmitters that send back data on temperature, pressure,
and relative humidity in the lower portions of the atmosphere.
Radar and Satellites Other tools used to study the atmosphere
include radar and satellites. Recent technological advances have
greatly enhanced the value of weather radar for the purpose of
storm detection, warning, and research. Satellites give
meteorologist a big picture view of weather. Images from satellites
allow scientists to study the distribution of clouds and the
circulation patterns that they reveal. Additionally, they let
scientists see the structure and determine the speed of weather
systems over the oceans and other regions that are sparsely
populated. Satellites also enable scientists to monitor storms from
space, and measure and monitor variables such as winds, solar
radiation, temperature, precipitation, and changes in atmospheric
composition.
- Slide 10
- Earth; Viewed from Space Describing our Planet Earth can be
divided into four independent parts that can be called spheres.
They include: the geosphere solid Earth; the atmosphere gaseous
envelope; the hydrosphere water portion; and the biosphere life.
These spheres are not separated by well-defined boundaries. Each
sphere is intertwined with all of the others, and these spheres can
be thought of as being composed of numerous interrelated
parts.
- Slide 11
- A Shoreline is an Interface between Two Parts of the Earth
System; Land and Water The geosphere is the solid Earth. It extends
from the surface to the center of the planet, a depth of about
6,400-km. It is the largest of the Earths four sphere. The
geosphere can be divided into three principal regions: the core,
the solid, dense center of Earth; the mantle, much less dense than
the core; and the crust, the light, thin outer skin of the Earth.
Soil a thin layer of material on Earths surface that supports the
growth of plants, may be thought of as part of all four spheres. It
is solid, so it is part of the geosphere; it contains organic
matter, so it is part of the biosphere; and it is part of the
hydrosphere and geosphere because soil is a product of weathering
which involves air and water.
- Slide 12
- The Atmosphere Is only a Shallow Layer Compared to the Radius
of the Solid Earth The atmosphere is a life-giving gaseous envelope
that surround the Earth. Compared to the radius of the Earth
(6,400-km), the atmosphere is very shallow. More than 99 percent of
the atmosphere is within 30-km of Earths surface. The atmosphere
not only provides the air we breathe, but also acts to protect us
from the dangerous radiation from the Sun. The energy exchanges
that continually occur between the atmosphere and Earths surface
and between the atmosphere and space produce the effect we call
weather.
- Slide 13
- Distribution of Earths Water The hydrosphere contains all the
water that exists on this planet. The oceans account for 97 percent
of all water, and covers 71 percent of Earths surface. Fresh water,
although just a small fraction of the total amount, is vital to
life on Earth. In addition, the movement of fresh water on Earths
surface is responsible for creating many of the planets varied
landforms.
- Slide 14
- Mt. St. Helens The biosphere includes all life on Earth. Most
life, whether land- or water-based, occurs near Earths surface. In
the oceans most life is concentrated in the sunlit surface waters.
On land, tree roots and burrowing animals reach a few meters
underground, while flying insects and birds reach a kilometer or so
above the surface. While plants and animals depend on the physical
environment for the basics of life they do more than just respond
to the physical environment. Through countless interactions, life
forms help maintain and alter the physical world around them.
- Slide 15
- The four spheres that make up Earth are not separate
entities,but are highly interactive, forming a dynamic body that
can be called the Earth system. A system can be any size group of
interacting parts that form a complex whole. Most natural systems
are driven by sources of energy that move mater and/or energy from
one place to another. Closed systems are systems where matter and
energy move through the system but the total amount of matter and
energy never changes. When matter and energy can flow into and out
of a system that system is described as an open system. A weather
system like a hurricane is an example of an open system. Systems
are controlled by feedback mechanisms. Negative feedback mechanisms
work to maintain the system as it is, while a positive feedback
mechanism encourage or enhance change in the system.
- Slide 16
- The Carbon Cycle The Earth system has a nearly endless array of
subsystems in which matter is recycled over and over again..
Examples of recycling subsystems include: the water cycle, in which
water continually moves from the atmosphere to Earths surface and
back; the rock cycle, in which, by a variety of processes, rock is
changed from igneous to metamorphic and/or sedimentary, which can
then be recycled as igneous rock; and the carbon cycle, where
carbon is moved through the four spheres of the Earth system. The
different recycling systems can interact with each other. The
common boundary where different parts of a system come in contact
and interact is known as an interface. Two sources of energy that
power the Earth system are: (1) the Sun, which drives the external
processes that occur in the atmosphere, hydrosphere, and at Earths
surface, and (2) heat from Earths interior that power the internal
processes that produce volcanoes, earthquakes, and mountains.
- Slide 17
- Composition of the Atmosphere Air is a mixture of many discrete
gases, and its composition varies from time to time and place to
place. After water vapor, dust, and other variable components are
removed, two gases, nitrogen and oxygen, make up 99 percent of
clean, dry air. While carbon dioxide accounts for about 0.02387
percent of the air, it is an efficient absorber of energy emitted
or reflected from Earth, and the recent increase (over the past 100
years) of this gas in the atmosphere is likely warming the lower
atmosphere and could trigger global climate change.
- Slide 18
- Satellite Image of a Dust Storm and Human-Generated Air
Pollution The variable components of air include water vapor, dust
particles, and ozone. Water vapor can absorb heat given off by
Earth. When water vapor changes state it absorbs or releases
energy. In the atmosphere, water vapor transport heat from one
place to another, a source of energy that drives many storms. Tiny
solid and liquid particles are called aerosols and are important
because these often invisible particles act as surfaces on which
water can condense and are also absorber and reflectors of incoming
solar radiation. Ozone, a form of oxygen that combines three oxygen
atoms into each molecule (O 3 ), is a gas concentrated in the 10-
to 50-km height range in the atmosphere that absorbs the
potentially harmful ultraviolet radiation from the Sun.
- Slide 19
- Changes in the Antarctic Ozone Hole Over the past half century
(50 years) the insertion of chlorofluorocarbons (CFCs) into the
atmosphere has threaten the ozone layer in Earths atmosphere. Ozone
is critical to life on Earth as it protects all life on Earths
surface from overexposure to ultraviolet radiation from the Sun.
Ozone concentrations take a sharp drop over Antarctica during the
Southern Hemisphere spring (September and October). Ozone thinning,
although less severe than over the South Pole, also occurs neat the
North Pole during spring and early summer. The Montreal Protocol
represents a positive international response to the ozone
problem.
- Slide 20
- Atmospheric Pressure Changes with Altitude No sharp boundary to
the upper atmosphere exists. The atmosphere simply thins until
there are too few gas molecules to detect. The change that occurs
in atmospheric pressure depicts the vertical extent of the
atmosphere. One-half of the atmosphere lies below an altitude of
5.6-km (3.5 miles) and 90 percent lies below 16-km (10 miles).
- Slide 21
- Thermal Structure of the Atmosphere Using temperature as the
basis, the atmosp0here is divided into four layers: 1)The
troposphere closest to Earths surface. Generally, temperature
decreases with altitude. Essentially all important weather
phenomena occur here. The troposphere is thicker at the tropics and
thinner in the polar regions. 2)The stratosphere above the
troposphere, the temperature remains constant until an altitude of
about 20-km and then begins to increase sharply due to the
absorption of ultraviolet radiation 3)The mesosphere temperatures
again decrease with an increase in altitude. 4)The thermosphere
temperatures increase with an increase in altitude.
- Slide 22
- Height of the Tropopause Varies with Latitude Based on
composition, the atmosphere can be divided into two layers: the
homosphere and the heterosphere. The homosphere extends from Earths
surface to an altitude of of about 80- km (50 miles). The makeup of
the air is uniform in terms of the proportions of it component
gases (Fig. 1-21, page 20). The heterosphere located above 80-km
altitude is not uniform. The gases are arranged into four roughly
spherical shells, each with a distinctive composition. In order:
lowest shell is dominated by molecular nitrogen (N 2 ), then a
shell of atomic oxygen (O), followed by a layer of dominated by
helium (He) atoms, and finally a regions consisting of hydrogen (H)
atoms.
- Slide 23
- The Aurora Borealis (Northern Lights) Occurring in the altitude
range between 80- and 400-km is an electrically charged layer of
the atmosphere known as the ionosphere. Molecules of nitrogen and
atoms of oxygen are readily ionized (gain an electric charge) as
they absorb high energy, shortwave solar energy. Three layers of
varying ion density make up the ionosphere. The auroras ( aurora
borealis and aurora australis) occur within the ionosphere. Auroras
form as clouds of protons and electrons ejected fro the Sun during
solar- flare activity enter the atmosphere near Earths magnetic
poles and energize the atoms of oxygen and molecules of nitrogen,
causing the to emit light.