The Climate System Flashcards
Effects of differential heating of the
Earth
• Energy surplus at the equator and deficit at the poles leads to heat transfers • Convection – the dominant process for transferring heat upwards from the Earth’s surface • Mass balance dictates that as some air masses rise some must also fall – hence the atmosphere is continually turning • This overturning occurs in the troposphere
What are jet streams?
• Fast-moving bands of air embedded in Rossby waves caused by sharp temperature differences (speeds up to 140 kms-1)
What is subtropical westerly jet stream?
– Poleward boundary of the tropical Hadley cell
– Just below tropopause
– In winter it divides around the Tibetan Plateau
What is polar front jet stream?
- Associated with the warm and cold fronts of temperate-latitude depressions
– Considerable day-to-day variation
What leads to heat transfers?
Energy surplus at the equator and deficit at
the poles leads to heat transfers.
The large-scale circulation of the atmosphere is organised into what?
Cells.
Where do jet streams form?
Jet streams form at the boundaries of the cells and play a major role in storm development.
Jet streams form into standing waves that affect the positions of major air masses.
What does the term climatic system refer to?
An interactive system consisting of 5 major components: atmosphere, hydrosphere, cryosphere, land surface and biosphere.
What is the present day atmosphere makeup?
78.1% nitrogen
20.9% oxygen
0.035% carbon dioxide
Surface pressure of 1 atmosphere
What would the atmosphere be like if there was no life?
Like Venus- 1.9% nitrogen 0% oxygen 98% CO2 Surface pressure of 70 atmospheres
What is biomass?
The tissue formed in plant material as a result of solar radiation providing energy for photosynthesis- vegetation converts co2 into carbon and o2, the carbon is then combined with other elements to form the tissue.
Where is most of the carbon on earth?
Contained in solid rocks such as limestone.
What would happen if 0.03% of the buried carbon was returned to remain in the atmosphere?
The atmospheric conc would double, with devastating results for climate change.
Atmospheric Co2 conc before and after industrial revolution…?
Before- 280 parts per million
383 ppm in 2007.
Who is the largest consumer of energy globally?
China has overtaken the US.
However even after years of growth to 2035 China will still use less energy per person than countries in OECD.
Statistics about those without energy?
- 4 billion do not have access to electricity
2. 7 billion still use wood or other biomass to cook.
Temperature rise over the past 30 years?
Risks!?
0.2 degrees per decade
Once temperature increases rises above 2 degrees up to 4 billion people could be experiencing water shortages.
This rise in temperature could see 40-60 million more people exposed to malaria in Africa.
Agriculture could cease to be viable in some locations, particularly in the tropics.
The melting of the Greenland ice sheet would contribute to sea level rise.
What have the IPCC (2007) concluded needs to be achieved by 2050?
50% reduction in global Co2 levels compared with 2000 levels to limit the long term global average temperature rise to between 2.0 and 2.4%.
What are the two major causes of the global wind circulation?
Inequalities in the distribution of solar radiation over the Earth’s surface, particularly in a north-south direction (more received at the equator), and the Earths rotation.
What is global atmospheric circulation?
Global wind and ocean current circulation redistribute heat from equatorial regions where it is in surplus to polar regions where it is deficit
What provides the energy for global atmospheric circulation?
Solar radiation received mainly at the equatorial East’s surface and reradiated back from the whole surface.
What are the fundamental causes of seasonal differences in climate across the globe?
The approximately spherical shape of the Earth and the way the Earth’s axis of rotation is tilted at 23.44 degrees in relation to a perpendicular to the plane of the Earth’s orbit around the sun.
The greater the tilt of the axis the greater the difference between winter and summer.
Why is there a sharp north-south temperature difference?
The same amount of solar radiation is spread over a larger area nearer the poles and also has a thicker layer of atmosphere to penetrate because of the angle at which the solar radiation is recieved.
What causes the month by month changes in the amount of solar radiation reaching each part of the planet?
The tilt in the earth’s rotation.
