Questions to explore today:
How are we affected by our atmosphere?
How is our atmosphere affected by us?
Absorption of electromagnetic radiation
Why do energies get absorbed at different heights?
Layers of the Atmosphere
Layer heights are NOT TO SCALE
Where the AIR is, and relative pressures...
Composition of Dry Air - ?
Composition of Dry Air
Where our stuff is…
Thinking deeper: Why do you freeze in space if the exosphere is 1700 ͦC?
So what does our atmosphere do for us?
So what does our atmosphere do for us?
Maintains a stable temperature
So what does our atmosphere do for us?
Maintains a stable temperature
Maintains moisture
So what does our atmosphere do for us?
Maintains a stable temperature
Maintains moistureProvides oxygen (and carbon
and nitrogen)
So what does our atmosphere do for us?
Maintains a stable temperature
Maintains moistureProvides oxygen (and carbon
and nitrogen)Blocks harmful
electromagnetic radiation
So what does our atmosphere do for us?
Maintains a stable temperature
Maintains moistureProvides oxygen (and carbon
and nitrogen)Blocks harmful
electromagnetic radiationAnd makes
PROBLEMS IN THE ATMOSPHERE
Problem #1: the Greenhouse effect
Certain gases trap heat energy from the sun in earth’s atmosphere They act like a
greenhouse, keeping earth warm
Natural greenhouse effect keeps earth warm and habitable
Major natural greenhouse gases: carbon dioxide, methane, water vapor, nitric oxide
World population: 7 billionUS population: 300 million , or ~4%, but we emit 20% of C)
YOUR TASKS:
1. Examine the effect of our carbon dioxide output on global climate change with computer models
Complete a “carbon footprint” profile with your own family compared to others Graph with Excel Common task!
Add title, too of course
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Problem #2: holes in the ozone layer
The Earth's ozone layer protects all life from the sun's harmful radiation – UVB - but human activities have damaged this shield
Ozone – O3 - is blue and has a strong odor
Normal oxygen - O2 - is colorless and odorless
Human impact: CFCs (found in
refrigerants, solvents, foam blowing agents) damage ozone layer
CFCs banned in in US in 1970s
Jet exhaust produces nitric oxide, which also breaks down ozone
The good news: Natural ozone
production process will heal the ozone layer in about 50 years