Atmosphere Flashcards
What is denitrification?
Conversion of soil nitrates to nitrogen gas by bacteria eg pseudomonas
What is nitrogen fixation?
Conversion of atmospheric nitrogen into ammonia, usually by bacteria
What industrial examples involve the use of nitrogen?
Fresh food preservative (gas)
Refrigeration, lightbulbs, nitrate fertilisers
Describe how uv light travels through our atmosphere
Uv light passes through the mesosphere easily but is absorbed by various forms of oxygen in the stratosphere
How does the temperature change throughout the altitude of our atmosphere
Goes from -50 to 15 degrees between mesosphere and stratopause
15 to -50 between stratopause and tropopause
-50 to 15 between tropopause and sphere
What are the sources of nitrous oxide and what is its mean residence time?
Agricultural fertilisers, combustion of fossil fuels and biomass
120 years
Why does ozone depletion have the most significant effect on Antarctica?
The very low temperatures lead to the formation of ice crystals in the stratosphere which provide a catalytic surface of which reactions between UV and chlorine occur that cause holes in the ozone layer
What is the atmospheric concentration of nitrogen?
78 percent
What is the atmospheric concentration of rare gases? Eg helium and neon
1 percent
What is the atmospheric concentration of co2 and what are some of its industrial uses?
0.04 percent
Industrial uses include fire extinguishers, fizzy drinks etc
What is the atmospheric concentration of water vapour, what are some of its industrial uses and how can it be increased?
0-4 percent
Industrial use steam turbines, heating, cleaning
Can be increased by irrigation, reservoir construction etc
What are some of the industrial uses of ozone and how can its atmospheric concentration be increased?
Industrial uses include water sterilisation, bleaching etc
Chemical reactions involving vehicle exhausts produce tropospheric ozone
What are some of the industrial uses of methane?
Fuel, raw material in haber process to make ammonia and fertilisers
What is the atmospheric concentration of oxygen and what are some of its industrial uses?
21 percent
Breathing gases in healthcare, smelting iron, welding
What are the origins/roles of uv/ir in the atmosphere?
Insolation
Emissions from the earth
Thermal stratification
Chemical processes
Describe how uv is absorbed in the atmosphere and converted to various forms of energy?
All UVC and most UVB is absorbed by ozone, converted to chemical energy and then heat
It can sometimes also be absorbed by cfcs during ozone depletion
How is IR converted and absorbed in our atmosphere?
IR is absorbed by greenhouse gases and is converted to heat
Describe a la Niño year
Stronger surface winds across tropical pacific
Warmer sea surface temperatures in northern Australia area with more rainfall
Cooler/less rainfall in coastal western s America
Describe one of the effects of an El Niño year and how climate change will effect the el/la Nino cycle
Weaker Pacific Ocean currents
Increased severity of el/la Nino events
Describe how gcc effects wind patterns and what the effects of this are worldwide
Changes in heating produce different air pressures changing wind direction and velocity
Potentially monsoon season in India could fail
Stronger hurricanes could occur
Reduced wind velocities in temperature areas
What causes ocean acidification and what effects does this have?
Acidic conditions caused by high dissolved co2 levels reduce deposition of coral
What are some of the effects caused by holes in the ozone layer?
Humans-skin/dna damage/cancer, eye cataracts
Plants-uv leaf damage, reduced photosynthesis
Marine organisms-uv damage to coral polyps and plankton
What are the 6 main greenhouse gases in our atmosphere?
Co2, methane, (CH4), Nitrous oxide (N2O), water vapour, tropospheric ozone, CFCS.
What are some of the ecological impacts of climate change?
Plus 1.5 degree Celsius increase since industrial revolution
Changes in biotic conditions such as fewer pollinators, seed dispersers.
Changes in species distribution, deaths in previous range, (poleward shift).
Population fragmentation
What are some of the main impacts of global climate change?
Sea level rise from thermal expansion, (molecules vibrate more)
Slowing of thermohaline circulation/Gulf Stream
Increased severity/frequency of El Niño
What are some of the main difficulties with predicting future climate change?
Regional variations, (arctic warming 2/3 times faster than ROP
Inaccurate data, proxy data such as tree rings
Unpredictable emissions
Natural drivers, (volcanic activity)
Unpredictable climate control action eg Paris 2015
Feedback mechanisms
What did the Rowland Molina hypothesis on cfcs show about the gg?
Very persistent
Low solubility in water, (not removed by rain)
Dissociation by uv
Reactions of chlorine with ozone
What are some of the cfc control methods?
Montreal protocol 1989-ban on CFCs+other ODS
use of alternative materials eg propane/butane aerosols
Alternative processes-pump action sprays/roll on
Why is ozone depletion greatest over Antarctica?
Very low temps=formation of ice crystals in stratosphere
This provides a catalytic surface for chemical reactions between chlorine and ozone
Polar vortex winds blow around the Antarctic, preventing dispersal of pollutants
Describe how infrared and uv energy is absorbed in the atmosphere
All UVC is absorbed in the ozone layer
Most UVB is absorbed
Some light is absorbed by dark surfaces
Greenhouse gases absorb outgoing infrared energy.
