The Carbon Cycle, Greenhouse Effect, Climate Change, Sea Ice & Permafrost & Ocean Currents
![Picture](/uploads/2/0/2/4/20243255/522261318_4.png)
Year 10 Content Descriptor. Earth & Space Sciences: Global systems, including the carbon cycle, rely on interactions involving the biosphere, lithosphere, hydrosphere and atmosphere (ACSSU189)
Instructions
Please watch the following tutorials via the youTube links below and read the articles via the links or uploaded documents. Once you have immersed yourself in the resources and are familiar with the content, write an A4 reflection in your journal that addresses the content descriptor above. ask yourself: Do I know as much as I think I could regarding the content required?
Carbon CycleThe Carbon Cycle - You will see the carbon cycle drawn in many different ways and in exams they nearly always come up with a new diagram. It is really important that you understand the carbon cycle well so that you can interprete any diagram you are given. Here is a nice one.
Please read the article at the following link:
http://earthobservatory.nasa.gov/Features/CarbonCycle/page5.php Climate ChangeClimate change is a change in the statistical distribution of weather patterns when that change lasts for an extended period of time (i.e., decades to millions of years). Climate change may refer to a change in average weather conditions, or in the time variation of weather around longer-term average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming".
Ocean CurrentsAn ocean current is a continuous, directed movement of seawater generated by forces acting upon this mean flow, such as breaking waves, wind, the Coriolis effect, cabbeling, temperature and salinity differences, while tides are caused by the gravitational pull of the Sun and Moon. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength.
Ocean currents flow for great distances, and together, create the global conveyor belt which plays a dominant role in determining the climate of many of the Earth’s regions. More specifically, ocean currents influence the temperature of the regions through which they travel. For example, warm currents traveling along more temperate coasts increase the temperature of the area by warming the sea breezes that blow over them. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude. Another example is Lima, Peru where the climate is cooler (sub-tropical) than the tropical latitudes in which the area is located, due to the effect of the Humboldt Current. |
Greenhouse EffectThe greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
Please read and reflect upon the following article found at:
http://science.howstuffworks.com/environmental/green-science/question7462.htm Sea Ice & PermafrostThe cryosphere comprises of those parts of the surface of Earth where water is in the form of ice. (Cryos = ice, sphere = ball).
Ice caps, glaciers, ice shelves and icebergs are considered to be land derived. They are the result of accumulated snowfall. Sea ice however is frozen seawater. Sea ice regulates exchanges of heat, moisture and salinity in Polar Regions. It insulates the relatively warm underlying seawater except where cracks (leads) permit loss. In the Arctic, sea ice can build up over many years and be well over 3m thick whereas in the Antarctic sea ice melts and reforms every year. Ice in the Antarctic Ocean averages only 0.5m in thickness. “Global Conveyor Belt” activities (in the Ocean Currents section) explain how ice, cold winds, low air temperatures and increased sea salinity at the poles are drivers for the Global Conveyor Belt. This current transfers heat around the world through moving enormous quantities of water at depths of over 200m. Cold winds and water at the pole freeze out (almost) fresh water to form ice. When comparing Arctic and Antarctic sea ice, differences between land based ice (cap, glacier and shelf) in the east and western sea ice have to be factored in. In the Arctic, almost all ice is from frozen sea ice. Arctic sea ice covers between 14 and 16million km2, Antarctic sea ice covers between 17 and 20million km2, About 7% of the world oceans are covered by sea ice. Because ice is less dense than water it floats. About 7% of the ocean or 23 million km2 is covered by sea ice. Sea ice is not pure fresh water but can contain up to 0.5% salt, mostly sodium chloride. NOTE By international convention, seawater salinity is usually expressed without units. |