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EESA09H3 (200)
Lecture

EESA09H3 Lecture Notes - Nimbostratus Cloud, Barometer, Thermosphere


Department
Environmental Science
Course Code
EESA09H3
Professor
Tanzina Mohsin

Page:
of 6
Lecture 1 Notes EESA09H3
May 10 2012
- Specific kinds of winds
- What is the role of wind in hurricanes?
- A: causes the tornado to develop
Why study wind?
Human mythology
Destructiveness tornadoes, hurricanes
165 Tornadoes in 24 Hours, 194 Dead in Alabama , April 2011
Hurricanes: Katrina, Irene, Bill……..
Climatic importance wind chill, local cooling and heating, Chinooks
Power source wind power
Did you ever think of the role of wind in all these?
History of Wind Mythology
Greeks (Euro-centric)
Aeolus designated by
Zeus to look after the four winds
Zephyrus gentle, west wind
Boreas chilly, north wind
Notos southern rain bringer
Eurus ill-tempered east breeze
Chinese mythology:
o Feng Po Po, Wind goddess, replaced Feng Po
Japanese mythology:
o Fujin was one of the earliest gods of Shinto, the God of Wind
North American Indian:
o Navajo (DinE) wind intimately connected to their spiritual life
o Part of creation stories (Holy wind nilch‟i) – links to breathing
Others wind mythology permeates most human societies
Been used as a metaphor, representing change
In the Hindu and Buddhist religions,
o wind is viewed as the nature or state of a god, and referred to as “vayu”, “pavan” and
“godai”
In other religions, such as Judaism, Islam, or Christianity - Wind is viewed as one of the five great
elements of power
The wind power had been used to teach lessons to the followers in the past
Each book of the religions describe the act of wind power in different ways
History of Wind Geologic Control
- 4.6 billion years
- Has the atmosphere always been as it has now?
- No- the atmospheric composition is dynamic not static
o Balance come not from static but because inputs are equal to outputs
In the beginning
- Early earth
o Atmospheric composition largely the result of volcanic emissions (geologic control)
CO2, C04
o Life appeared 3.8 billion years ago
- 2.3 billion years of methane, carbon dioxide atmosphere
o Anaerobic conditions, “age of bacteria”
- Abrupt change 2.3 billion years ago
o Oxygen makes an appearance in the atmosphere and stabilizes at 21%
o Aerobic life appears and flourishes (biological control)
o Links to Gaia hypothesis (James Lovelook)
History of Wind Biological Control
- Basic premise of life that modifies the environment to best suit itself
- 21% oxygen is optimum for life
- Mars and Venus are static equilibrium with high levels of carbon dioxide and methane
- Why switch from anaerobic conditions to aerobic conditions 2.3 billion years ago?
Gaia Hypothesis
- Early sun produced 30% less energy (archea)
- Solar output has been gradually increasing
- Early earth with high levels of methane and carbon dioxide had a strong greenhouse effect
which lead to conditions warm enough for life
- After 2.3 billion years, solar output increased and earth was becoming too warm, the switch to
aerobic life reduced the ghg and cooled the planet
- We now was considerably lower levels of C02 in the atmosphere than the early earth
- The Gaia hypothesis postulates that the atmospheric constituents have been controlled by life
to optimize conditions for life
History of Wind Anthropogenic Control
- During the Carboniferous Period (360 290 million years ago) during the Paleozoic Age life
arrives on land
o The sun’s energy converted to plant material (photosynthesis)
o Decaying plants are not fully oxidized
o Converted coal and oil under geologic pressure
o Stored for millions of years
o Many of today’s air quality problems arise for the release of this stored energy
Story of Coal
- First major anthropogenic modification of the atmosphere
- Britain industrial revolution 19th century
- USA 19th and 20th century
- China 11th century, present
A modern dumping ground
- Fossil fuel (coal, oil, other hydrocarbons), source of emissions
o Acid rain
o Urban air quality
o Urban heat island
o Global warming
- Other industrial emissions
o Ozone hole
Composition
- What phase of matter is air?
o Gas mainly
o Liquid (cloud)
o Solid (particulate matter)
- What are the gas phase constituents of air?
Composition of the Atmosphere
- What is a green house gas?
o An atmospheric constituent that traps outgoing terrestrial radiation
o These include water vapor (H20), carbon dioxide (C02), methane (CH4), nitrous oxide
(N20), ozone (O3), and CFC’s
- Understand the difference between natural greenhouse effect and enhanced greenhouse effect
- Is the composition of the atmosphere static?
o No, paleo-atmispheres were different (as discussed above with the Gaia hypothesis)
- Current changes
o Anthropogenic emissions of greenhouse gases have increased in the past few decades
and have great impacts on the natural atmosphere
Clouds (Liquid constituent)