Transcript ESCI 106 – Weather and Climate Lecture 1

ESCI 106 – Weather and Climate
Lecture 1
8-18-2011
Jennifer D. Small 
Weather Fact of the Day: August 18
2005: 27 tornadoes were documented in
WI, thus establishing its record for the
greatest number of tornadoes reported in
a calendar day.
Most were F0 or F1, but an F3 storm killed
1, and hurt 23 between Fitchburg and
Rockdale. 4 other injuries were reported
FOCUS
Successful students focus on the work to
be done. They are academically selfdisciplined, spending appropriate amounts
of time studying. They come to class on
time and prepared. They complete all
assignments and turn them in on time.
They finish their programs.
ADVANCE
Successful students advance by always
improving. They embrace life-long
learning. They understand that subject
expertise requires a long-term
commitment, and commit to ongoing
development of thinking skills and learning
skills.
LINK UP
Successful students link up to make
connections with the academic community.
They get involved. They get to know their
professors and study in groups,
surrounding themselves with focused
students and mentors. They use college
resources and programs to help them with
their learning.
COMPREHEND
Successful students comprehend. They
study for comprehension. They seek to
understand course content rather than
simply complete requirements. They ask
questions to gain understanding, reflect on
what they are learning as well as if they
are learning.
ORGANIZE
Successful students organize a plan to
succeed. They have an educational goal.
They focus on their educational purposes,
maintain a specific education plan, and
choose classes with an intentional learning
purpose in mind. They are well-organized
to meet all of their commitments and to
achieve their goals.
NEW IDEAS
Successful students nurture new ideas.
They are curious. They seek out new
ideas, perspectives, and skills. They
transfer concepts to new contexts in order
to solve problems. They integrate
concepts and knowledge to form a greater
personal understanding.
How do you envision a scientist?
 Most will picture a white
middle aged man
 White coat
 Chemistry equipment…
 Villians in movies
 Does this look familiar??
TEXT BOOK
 Tarbuck, E.J., and
Lutgens, F.K, 2010,
Textbook: The
Atmosphere – An
Introduction to
Meteorology, 11th
edition.
 Available from the
bookstore.
Reading Assignments!
 Should be completed BEFORE class!!!!
 Come prepared to discuss the material
covered in each chapter!
What topics will we cover??
Too many to list on one slide!! 
Tornadoes
Thunderstorms
Hurricanes
Global Winds
Energy Budget
Natural Disasters
Cloud Types and
Formation
What is Meteorology??
 Meteorology is the scientific study of the atmosphere and
atmospheric phenomena including weather and climate.
 Not just TV Weather People
 Researchers (NASA, NOAA)
 Private Companies (AccuWeather, Weather Channel)
 Academics (Universities, Colleges)
Why do we study Meteorology??
 Daily Weather – affects how we plan our days
 Severe Weather – causes damage, loss of life, loss of
property (memorable)
 Includes, tornadoes, hurricanes, snow storms, floods,
thunderstorms… and much more.
 Climate Change – How will weather and climate change
in the future?
 Affects quality of life, water supplies, food supplies
Did you know??
 On average, ~150 people die each year in the
US from floods and flash floods—more than
any other natural disaster?
 Can you name any recent weather related
natural disasters in the US or Globally?
2004 – Hurrican Ivan
2005 - Hurricane Katrina
2011 Tornadoes - Midwestern US
2011 Blizzards – East Coast Snow Storms
Current heat wave in Central US (TX etc).
Meteorology is a mathematical science!
 Scientific Quantities
and SI Units
 Science has it’s own
language
 Scientific Notation
 To make things easier
when dealing with very
large and very small
numbers
 Significant Figures
 Accuracy and precision
are important!
LETS WORK THROUGH SOME EXAMPLES TOGETHER!
Scientific Quantities and Units!
 Mass – kg
 Distance – m
 Time – s
 Energy – Joules, J = Nm =
kg*m/s2 * m (Force times
distance)
 Pressure – N/m2 = Pascale,
Pa (Force divided by area)
kg*m/s2 *1/m2
 Temperature – K
 Force – Newton, N, kg*m/s2
(Mass times acceleration)
 Density (ρ) – kg/m3 (Mass per
volume)
 Area – m2
 Velocity – m/s (Distance per
unit time)
 Volume – m3
 Acceleration – m/s2 (change
in velocity/change in time)
 Power – Watt = J/s (energy
per time)
 Mole – 6.023*1023 Things
Scientific Notation!
10000 = 1 x 104
1000 = 1 x 103
100 = 1 x 102
10 = 1 x 101
1 = 1 x 100
1/10 = 1 x 10-1
1/100 = 1 x 10-2
1/1000 = 1 x 10-3
1/10000 = 1 x 10-4
24327 = 2.4327 x 104
7354 = 7.354 x 103
482 = 4.82 x 102
89 = 8.9 x 101
0.32 = 3.2 x 10-1
0.053 = 5.3 x 10-2
0.0078 = 7.8 x 10-3
0.00044 = 4.4 x 10-4
Significant Figures!
 No more than 3 sig figs, usually
 2000  2 x 103 has ONE sig fig
 2000  2.0 x 103 has TWO sig fig
 RULES
1) Multiplication & Division
 Round the final result to the least number of significant
figures of any ONE term…. See example
2) Addition & Subtraction
 Round the final result to the least number of decimal
places, regardless of the significant figure of any one
term…. See example
Chapter 1 – Introduction to the Atmosphere
 Weather
 The state of the atmosphere
at any given time
 Climate
 A description of aggregate
weather conditions; the sum
of all statistical weather
information that helps
describe a place or region
“Climate is what you expect, but weather is what you get”
Meteorology every day
 Our typical experience
with meteorology is
through TV, print and
online weather forecasts
 Great resource:
http://www.nws.gov/
National Weather Service
Earth’s Spheres
http://www.its-about-time.com/iesart/iesspheres.jpg
The Geosphere
 Extends from the surface to
the center of the Earth
(6400 km, 4000 miles)
 The largest of the spheres
 Main components are the
crust, mantle, core
http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg
The Biosphere
 Includes all life on Earth
 Ocean life is concentrated near
the surface (sun penetrating)
 Life land can survive a few
meters underground and flying
insects and birds up to 1 km
above the surface
 Extraordinary life found near
deep sea vents, hot springs,
deep rocks, upper atmosphere
Showing different biomes,
forests, deserts, plankton…
http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg
The Hydrosphere
 Evaporation from the
ocean and Transpiration
from plants
 Cloud formation via
condensation
 Precipitation onto land
and ocean
 Runoff and infiltration
The Water Cycle
http://earth.rice.edu/mtpe/geo/geosphere/what_images/interior.jpg
The Atmosphere
 The life giving envelope
of gases
 VERY THIN
 Provides air we breath
 Provides protection
from damaging UV
radiation from the Sun
 All the weather
experiences takes
place within it.
The Layers of the
Atmosphere
NOT TO SCALE!!!!
http://www.theozonehole.com/atmosphere.htm
Evolution of the Atmosphere
 The Earth’s atmosphere is
the product of a lengthy
evolutionary process that
began 4.6 billion years ago
 Solar winds swept away
the Earth’s early Hydrogen
(H) and helium (He)
atmosphere
 Primeval Phase
 An atmosphere unfamiliar
to us
 Modern Phase
 What we live in now
Primeval Atmosphere
 Our Solar System, including the Earth is believed to have
developed from the accretion of dust and gases
 The Earth grew by accretion as the planet swept up cosmic dust
in its path and it was hit by meteorites.
 In time, volcanoes began to
spew forth lava, ash and
gases
 By 4.4 billion yrs ago the
Earth’s gravitational field
was strong enough to retain a
thin gaseous envelope
Primeval Atmosphere
 The principle source of atmospheric gases was OUTGASSING
 The release of gases from rock through volcanic eruptions and
impact of meteorites
 Perhaps 85% of all outgassing took within a million years of
the planet’s formation
 Primeval Atmosphere was
mostly
 CO2, N2, H2O, little CH4, NH3
(ammonia), SO2, HCl.
 Radioactive decay of an
isotope of potassium added
argon.
 Free Oxygen (O or O2) was
absent!!!
Primeval Atmosphere
 The Primeval atmosphere was rich in CO2 and may have been 10-20
times denser!
 Computer models predict that the average temperature of the earth as
185-230F!!
 After 4 billion years, the Earth (rocks) cooled enough to allow water
vapor to condense into clouds and rain.
 CO2 dissolves in water so the
rain, and oceans, “washed out”
some of the CO2… cooling the
planet further.
 After life emerged, primarily
photosynthetic bacteria (~2.5
billion yrs ago), emerged O2
began building up, since O2 is a
product of photosynthesis (and
removes CO2).
Modern Atmospheric Composition
 78% Nitrogen (N) – basically inert
so it was able to build up in the
atmosphere
 21% Oxygen (O)
 1% Argon (Ar) – also inert
 Carbon Dioxide (CO2) – from
respiration, combustion, GHG
 Methane (CH4) – cows, wetlands, rice
patties, low oxygen environments,
GHG
 Ozone (O3) – in both the stratosphere
(good) and troposphere (bad)
 Water (H2O) – 0-5% variable over the
surface of the earth
 Hydrogen (H2)
 Helium (He)
 Carbon Monoxide (CO)
 Ammonia (NH3)
 Nitrogen Oxide (NO)
 Nitrous Oxide (N2O)
 Sulfur Dioxide (SO2)
 Nitrogen Dioxide (NO2)
 Particles – Aerosols, dust, smoke
Atmospheric Composition
 Where did all the Nitrogen come
from?
 The answer lies mostly in three facts:
1. nitrogen is volatile in most of its
forms
2. it is unreactive with materials that
make up the solid earth
3. it is very stable in the presence of
solar radiation.
 Over geological time, it has built up in
the atmosphere to a much greater
extent than oxygen
 It is an important component of life on
earth (Nitrogen Cycle)
Nitrogen Cycle
http://www.chemicool.com/el
ements/nitrogen.html
Atmospheric Composition
 Why is Argon Third?
 Argon is formed by radioactive decay
within the earth and released into the
atmosphere through volcanic activity.
 It is an inert (and nonradioactive) gas
and does not react chemically, so it
gradually accumulates in the
atmosphere.
 After a few billion years' worth of
volcanoes, it's now the third (or fourth,
depending on the humidity) most
common gas in the atmosphere.
 Fun Fact: Used in Neon Lights!
Atmospheric Composition
 Where does the oxygen
come from?
 The primary way in which the
Earth generates oxygen for the
atmosphere is through
photoshynthesis
 Photosynthesis accounts for
98% of the world's atmospheric
oxygen
 The breakup of water molecules
by ultraviolet radiation composes
the other 1-2%.
Atmospheric Composition
 Carbon dioxide
 News worthy  Global Climate
Change
 CO2 is an efficient absorber of
energy emitted by the sun!
 Present in minute amounts
 ~0.0387% or 387 ppm
 Proportion of CO2 is relatively
constant over the earth
 Steadily increasing since the
1960s….
 Keeling Curve  We’ll talk more about
later
Atmospheric Composition
 Variable Components
 Water Vapor
 Varies from 0-4% by volume
 Clouds and precipitation
 Heats the atmosphere like CO2
 Releases or absorbs energy when
it changes states (gas-liquid-solid)
 Aerosols
 Tiny solid and liquid particles
 Dust, pollution, sea salt, ash,
smoke, biogenic particles
 Ozone
 NEXT SLIDE!
Atmospheric Composition
 Ozone (O3)
 Water Vapor
 Three Oxygen Molecules!
 Concentrated high above the surface
(in the stratosphere)
 Protects us from UV rays from the sun
(what gives us sun burns)
 We’ll go into detail later…
 Ozone Hole
 We’ll spend a whole lecture on this
later…
 Predominantly found in the
Antarctic
 Montreal Protocol – What
happens when the scientists and
politicians of the world come
together. SUCCESS!!!
Atmospheric Composition
Extent of the Atmosphere
 No clear boundary at the upper
atmosphere
 Rapidly thins as altitude
increases
 Half the atmosphere lies below
~5.6 km (3.5 miles)
 Rate of pressure decrease is
not constant
 Air is HIGHLY compressible
Thermal Structure of the Atmosphere
 Troposphere – warmed by earth
decreases with height
 Stratosphere – sun warms
ozone, ozone warms the air,
temperature increases with height
 Mesosphere – returns to normal
temperature decrease with height
 Thermosphere – very high
temperatures, the sun warms N2
and O2 and heats up the rarefied
“air”. The molecules have lots of
energy and that energy is not
necessarily in ‘heat’ energy. Thus,
the temperature is high due to the
interactions of the energized
molecules bumping into one
another.
Troposphere
 Name literally means the region where air “turns over”
 Where “Weather” happens
 Due to vertical and horizontal mixing of air
 Temperature decreases with height
 Environmental lapse rate
 6.5 deg K per km
 3.6 deg F per 100 ft
 Highly variable
 Inversions – when it’s reversed
 Decreases until ~12 km
 TROPOPAUSE!
 Is the main focus of meteorologists
 Often called the “weather sphere”
Stratosphere
 Begins above the tropopause (12 km - ~50 km)
 Temperature remains the same from ~12-20 km
 Temperatures increase from the Stratopause until the
Mesopause (~50km - ~80 km)
 Temperature INCREASES with height
 -60 C to ~ 0 C (-80 F to 32 F)
 Due to the presence of OZONE, which heats the layer
 Ozone absorbs solar radiation
 Maximum from 15-30 km
 We study this layer with
 Weather balloons
 High altitude aircraft
 Satellites
Mesosphere
 COLDEST temperatures in the atmosphere are observed here
 ~80-90 km (Mesopause)
 -90 C (-130 F)
 Pressure is very low
 Is the least studied region
 Difficult to access by
 Aircraft, balloons and satellites
 Still learning more!!
 Noctilucent clouds occur here!
Thermosphere
 Begins after the Mesosphere and has no well defined upper limit
(~80 km and above)
 Temperature begins to increase with height again!
 Counter intuitive, yup
 Minute fraction of the mass
 Extremely high temps (1000 C)
 Temperature is defined as:




Average speed at which molecules move
Gases here move FAST in thermosphere
Even though there are few of them…
What if an astronaut exposed his hand?
 It would not feel hot, not enough particles!
Ionosphere
 The Ionosphere
 Located between 80-400 km
 Overlaps with the Thermosphere
 Is an electrically charged layer
 An ion is a atomic-scale particle
that carries an electric charge
 No influence on daily weather
 Important for long wave radio transmission since it
reflects radio transmissions
 They travel in straight lines and bounce off the Ionosphere
 The ionosphere is also the site of Aurora – Pretty!!
Auroras
 The Auroras




Aurora borealis (northern lights)
Aurora australis (southern lights)
Closely correlated with solar-flare activity
Geographic location (Earth’s magnetic poles)
 Appear in the night sky as overlapping curtains
 Bottom at 100 km (62 miles)
 Tops at 400 km (248 miles or higher)
 Triggered by the Solar Wind
 A stream of electrically charged particles
 Includes protons and electrons
 Earth’s magnetic field deflects that wind
 Magnetosphere (next slide)
 Collisions rip apart molecules and excite atoms.
 As atoms shift down from the excited states or combine with free
electrons they emit radiation (part of which is the visible aurora)
Magnetosphere
 The magnetopshere
 The region of the upper
atmosphere encompassed
by the Earth’s magnetic
field
 Earth’s magnetic field deflects the
solar wind
 Results in it’s characteristic
teardrop shape surrounding the
planet
Problem Solving
 Refer to weather map from
Weather.com from 8-16-11
 Estimate the observed high
temperatures in central New York
State and central Texas
Central NY: 64 F
Central TX: 86 F
 Refer to weather map from
Weather.com from 8-18-11
 Where is the coldest area on the
weather map? Where is the
warmest?
Northern Maine
Death Valley, CA/West Arizona