Atmosphere_Climate fdfdfdfdfffdfnffdf.pdf

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1. Chr. Lamnatou, D. Chemisana
Atmosphere and Climate
12-9-2024
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2. UV radiation
Ozone
CFCs
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Part 1

3. Atmosphere and Climate
•Earth’s atmosphere
– A thin layer of gases that surrounds the planet
– Nitrogen (78%) and oxygen (21%)
– Water: solid (snow), liquid (rain) and water vapour
(humidity)
-Troposphere
up to 10 km (above earth’s surface)
-Stratosphere
-Mesosphere
-Thermosphere
Source: http://asd-www.larc.nasa.gov/SOLAR/learningindex.html
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4. Atmosphere and Climate
•Earth’s atmosphere
Source: https://scied.ucar.edu/l earning-zone/atmosphere/layers-earths-atmosphere
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Picture

5. Atmosphere and Climate
•Troposphere
– It is the lowest layer of the Earth's atmosphere
– It contains the mass of the atmosphere and the atmospheric water
– clouds, rain, snow in this region
•Stratosphere
–It contains most of the Earth's
ozone (a gas that absorbs
dangerous UV radiation from the sun)
•Mesosphere and Thermosphere
– A great distance from the Earth
Source: http://asd-www.larc.nasa.gov/SOLAR/learningindex.html
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6. Atmosphere and Climate
Ozone Unstable molecule Earth's atmosphere An ozone molecule is made up of 3 atoms of oxygen
Source: http://asd-www.larc.nasa.gov/SOLAR/learning-ozone.html
However, in the air we breathe, ozone is a harmful pollutant (d amage to human
health, plants and so on)
The amounts of "good" and "bad"ozone in the atmosphere depend on a balance
(processes that create ozone vs processes that destroy ozone)
It has been found that "bad" ozone is increasing and "good" ozone is decreasing
Depending on where ozone resides, it can protect
or harm life on Earth.High in the atmosphere, ozone is a shield which protects
Earth's surface from the sun's harmful ultraviolet
radiation. Without this protective shield, we would be more
susceptible to certain illnesses.
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7. Atmosphere and Climate
In Stratosphere, ozone is created and destroyed mainly by UV radiation
UV rays strike molecules of ordinary oxygenthey split the molecule into two
single oxygen atoms a free oxygen atom can be combined with an oxygen
molecule a molecule of ozone is formed
When an ozone molecule (O
3
) absorbs UV radiation,it splits into O
2
and a free
oxygen atom (O), etc. → O
3
production and destruction, by UV radiation
(Chapman Reactions)
Ozone levels change periodically: changing seasons, winds, etc.
Ozone balance:ozone is being created at the same rate that is being destroyed →
the total amount of ozone remains the same
Source:http://asd-www.larc.nasa.gov/SOLAR/learning-ozone.html
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8. Atmosphere and Climate
Source: https://web.njit.edu/ ~lipuma/Ozone/chap.htm
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•The Chapman Reaction
Pictures

9. Atmosphere and Climate
Early 1970's: human activities are disrupting the ozone balance 
human production of chlorofluorocarbons (CFCs) CFCs:
are made up of chlorine, fluorine and carbon; they are stable m olecules: one of the few forces that can break up CFC molecules is UV rad iation; the mixing processes of the atmosphere carry them into the stratosp here
Source:http://asd-www.larc.nasa.gov/SOLAR/learning-ozone.html
-When CFCs and HCFCs reach the stratosphere, UV from the sun
causes them to break apart and release chlorine atoms which react
with ozonechemical cycles of ozone destructionOzone
depletionone chlorine atom can break apart many ozone
molecules
(Source: http://www.epa.gov/ozone/science/q_a.html)
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10. Atmosphere and Climate
•CFCs
– In the stratosphere, CFCsbombarded by the sun's UV → they release their
chlorine atomsthe free chlorine atoms can react with O
3
molecules,
taking one oxygen atom they form chlorine monoxide (ClO)
–A single atom chlorine destroys many molecules of ozone
•Ozone Depletion
– Ozone loss is exceeding ozone creation
–Using O
3
-destroying compounds (for example, CFCs) the level of
ozone protecting us from UV decreases
– Example: area over Antarctica
Source:http://asd-www.larc.nasa.gov/SOLAR/learning-ozone.html
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11. Atmosphere and Climate
Source: http://www.esrl.noaa.gov/gmd/hats/publictn/elkins/cfcs.html
CFCs are used in the manufacture of products examples: aerosol sprays,
blowing agents for foams, solvents and refrigerants
The environmental concerns about CFCsare related to their
long atmospheric lifetime
(55 yearsfor CFC-11 and 140
yearsfor CFC-12, CCl
2
F
2
)
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12. 12
Upwelling
El Niño Part 2

13. Atmosphere and Climate
What's the difference between Weather and Climate? Weatherconditions of the atmosphere over a short periodof time
Climatehow the atmosphere "behaves" over long periodsof time
Climate change:changes in long-termaverages of daily weather
In addition to long-term climate change, there are shorter term
climate variations:
El Niño, volcanic eruptions, etc.
Source: http://www.nasa.gov/mission_pages/noaa-n/climate/climate_weather.html
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14. Atmosphere and Climate
El Niño Every 3-7 years, the seawater at the surface of the
equatorial Pacificoff the west coast of South America becomes unusually warmEl Niño event
Abnormally warm waters in the eastern equatorial Pacific
negative impacts on marine life
changes in climate
Source: El niño: illustrating the concept, University of Califo rnia
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15. Atmosphere and Climate
El Niño • The trade winds(east-to-west) cease, decrease or reverse 
warm waters(western equatorial Pacific) slosh eastwards
• The relative pressure between west and east reverses winds
reverse
•Thicker than normal layer of warm water(eastern Pacific) 
reducing upwelling. The warm water prevents vertical mixing of
water reduction in biological productivity
Upwelling= the movement of water from deeper layers of the sea to the
surface nutrient generation in the surface; it is wind-driven
(source: http://www.es.flinders.edu.au/~mattom/ShelfCoast/notes/chapter06.html)
Source: El niño: illustrating the concept, University of Califo rnia
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16. Atmosphere and Climate
El Niño and Upwelling • Normally, the cold Peru Current flows offshore from south
to north due to this cold current coastal upwelling
appears upwellingwater is rich in nutrients which stimulate the growth of phytoplanktonfood for small animals (zooplankton). The plankton is eaten by fish which are caught by bigger fish and so on
• During El Niño, upwelling ceases and phytoplankton
production is diminished and fishes move to colder
regions (or they starve)
Source: El niño: illustrating the concept, University of Califo rnia
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17. Atmosphere and Climate
El Niño and Upwelling
Source: https://www.weather.gov/source/zhu/ZHU_Training_Page/tropical_stuff/enso/enso2.htm
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Pictures

18. Additionalinformation
•PHYTOPLANKTONsimilar to terrestrial plants
•They have chlorophyll
•They need sunlight in order to live and grow
•They are the base of aquatic food webs
•If we have a balanced ecosystem phytoplankton = food for sea
creatures (shrimps, snails, etc.).
•If there are too many nutrients algal blooms negative impacts
on fish, shellfish, etc.
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Source: https://oceanservice.noaa.gov/facts/phyto.html

19. Additionalinformation
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Source: https://www.epa.gov/national-aquatic-resource-surveys/indicators-zooplanktonZOOPLANKTON
The zooplankton community plays a pivotal role in the aquatic
food chain
They are intermediary species in the food chain they transfer
energy from planktonic algae (primary producers) to predators
and fish

20. Additional information
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Source: https://oceanservice.noaa.gov/facts/phyto.html
PHYTOPLANKTON
Picture

21. Additionalinformation
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Source: https://www.epa.gov/national-aquatic-resource-surveys/indicators-zooplankton
ZOOPLANKTON
Picture

22. PYRAMID OF ENERGY -Trophic level - each feeding level
-Only 5 to 20% of energy is transferred to the next trophic leve ldue to: not all digestible,
all organisms respire and so on
Source: http://www.rw.ttu.edu/2302_butler/chapter3.htm
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Tertiary
consumers
Additionalinformation
zooplankton phytoplankton