“ We live in an ocean of the element, air.” - Torricelli Earth from space, Apollo 13 Air and Atmosphere
Earth-rise over moon “It was so ironic, after spending all that money to get to the moon, the most impressive sight was our own Earth in the vast blackness of space. It was the only color we could see in the universe and was a gorgeous, moving sight.” -Edward Anders, Apollo 8, 1968 Moon is dead - it has no atmosphere.
Earth’s atmosphere seen from Earth orbit “For the first time in my life I saw the horizon as a curved line. It was accentuated by a thin seam of dark blue light- our atmosphere. Obviously this was not the ocean of air I had been told so many times in my life. I was terrified by its fragile appearance. - Ulf Merbold, West German astronaut on Columbia, 1983
Composition of Earth’s air (as relative areas of a square)
19.5 % oxygen (O 2 )
1. % argon (Ar)
1.5 % water vapor (variable as humidity)
78. % nitrogen (N 2 )
0.04 % carbon dioxide (CO 2 )
trace of other gases
100.04 % total
Air composition table
A graph of temperature altitude vs. temperature shows that the Earth’s atmosphere has four definite layers (with three boundary lines = . . pauses)
Altitude vs. temp
Layers of the Atmosphere & their uses
Altitude vs. T and altitude vs. P
Atmosphere as concentric spheres around the earth
London smog, 1952 Sulfur dioxide
Mexico city brown photochemical smog Normal conditions: Warm air rises “ Temperature inversion” Warmer air above prevents the cooler, dirtier air from rising. This keeps air pollutants from rising or escaping.
China has 16 of the 20 most polluted cities in the world, due to overpopulation and coal burning. This is Zunyi.
Atmospheres of Stars & Planets
Harold Urey’s Hypothesis: All new planets should have an atmosphere of methane, ammonia, water, and hydrogen (H 2 )
Chemical Evolution of the Planetary Atmospheres
Follow-up to Urey’s Hypothesis: The Miller-Urey Experiment
Stanley Miller with Tesla coil to supply spark to methane, ammonia, water, and hydrogen. Experiment performed at University of Chicago, 1953 Result of this experiment: He detected amino acids (up to 15) of the twenty found in life, “the building blocks of proteins”.
Red beds and BIF (Banded Iron Formations) contain minerals that would react with present level of oxygen. That is evidence that they were deposited when the atmosphere contained much less oxygen than the present concentration.
Graph of the History of the Earth’s Atmosphere Evolution of fermentation, photosynthesis, and respiration 1 2
Berkner-Marshall Model 1 -> 1 2 2 -> Cambrian explosion Life emerges from ocean Origin of life 2 1
Years Before Present (in millions of years) PAL 1 2 1 2 “ Middle life” Era “ Recent Life” Era “ Early Life” Era
Sun and Coronal Holes Seen by UV
The sun sends a full range of electromagnetic radiation (from gamma & X-rays to radio waves) which hits the Earth
Chlorofluorocarbons (CFCs, Freons®) and related compounds
CFCs: Too good to be true
Industrial and formerly home-refrigeration systems In 1930s, these were kept on the back porch; too dangerous to have inside any house.
Table of CFCs, HCFCs, etc. CFCs and some possible replacements
CFC, HCFC, HFC use in Sweden
Energy distribution of EM radiation from sun Absorption by ozone
Three forms of oxygen in our atmosphere Name Formula Structure Oxygen atom O O Oxygen molecule O 2 O = O Ozone molecule O 3
Temperature plot vs. altitude of the atmosphere shows the location of the ozone layer Tropospheric ozone is at the lowest 3 km.
Ozone remover: good buy? Or goodbye?
Carbon dioxide & Future Climate
Carbon dioxide concentration (in parts per million) measured at Mauna Loa, Big Island, Hawaii
“ Keeling graph” 1958 to 2010 The increase in concentration of carbon dioxide as measured at Mauna Loa Observatory, Hawaii (as of 2010). Plotted here as monthly average values so the graph shows the annual variation of growing seasons (Summer) and seasons with less plant growth (Winter).
Keeling graph, 1958 – 2009
Ice Core from Antarctic drilling
Bubbles in Antarctic ice
Greenhouse effect explained
Greenhouse (Hothouse) flowers A Greenhouse lets in light and heat and the glass deters convection, so the greenhouse becomes hot. The atmospheric greenhouse effect is different.
Graph of global temperature with years
Temp. increase has followed carbon dioxide increase
The Greenhouse Gases
Greenhouse effect -> Global warming
The moon’s average distance from the sun is the same as the Earth’s. The average temperature on the Moon is below the freezing point of water. If the Earth had no atmosphere and no greenhouse effect, the Earth would be as cold as the moon.
Mercury Mercury has no atmosphere, so ancient craters are not much weathered, similar to the moon. Most non-experts would have a difficult time distinguishing between pictures of the moon and pictures of Mercury.
The terrestrial planets and their surfaces
Melting of Arctic ice
Greenland ice, 1992, 2002, & 2005
Predicted temp. increase
Coastal flooding predicted from global warming
Lands that will be flooded plus many island countries will be under water
Stronger more powerful storms predicted as global warming makes more humidity to drive hurricanes and tornados.
Hurricane Katrina Jan. 22, 2007
Agreement & Disagreement (skeptics)
Four environmental problems Read this table carefully as it is commonly used to make exam questions .
Greek & Latin roots for air on Blackboard under “ Course Documents”