Unit D: Energy Flow in Global Systems. Biosphere and Climate

Transcription

1 Unit D: Energy Flow in Global Systems Biosphere and Climate

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4 CLIMATE: the average weather conditions of a region over a long time (at least 30 years). WEATHER: conditions of temperature, air pressure, cloud cover, precipitation, humidity, etc that occur at a particular place at a particular time.

5 Southern Alberta Summer of 2005

6 Weather and climate result from interactions between the different parts of our biosphere. BIOSPHERE: the parts of Earth that have the conditions suitable for supporting life. It is made up of three parts. ENERGY FROM THE SUN ATMOSPHERE: air LITHOSPHERE: earth HYDROSPHERE: water

7 Biosphere Zones Lithosphere: outer solid portion of Earth s crust Hydrosphere: water portion of Earth s crust Atmosphere:

8 The Lithosphere The solid part of Earth floats on the semi-molten mantle layer Life is found to depths of several kilometres

9 Lithosphere Highest point on Earth = Mt. 8,848 metres above sea level Lowest point on Earth = Dead 399 metres below sea level 9

10 The Hydrosphere All of Earth s water that supports life 97% marine saltwater 3% freshwater (most of which is frozen as mountain glaciers and continental ice sheets)

11 The Hydrosphere 23% of the sun s energy is used to move water around Earth via the hydrologic cycle 11

12 Atmosphere N 2 : 78% O 2 : 21% CO 2, dust, other gasses

13 Layers of the Atmosphere: Thermosphere Gets really hot Auroras (caused by Earth s magnetic field) Mesosphere Temp decreases Stratosphere (10 to 50 km) Temp increases as you go up in this layer Troposphere (0 to 10 km) Average temp (15 C) Nearly all life contained in this layer Contains ozone (O 3 ) gas

14 Stratosphere Contains the ozone (O 3 ) layer which absorbs much of the high energy radiation (UV, X-rays, and gamma rays) and protects living organisms 14

15 Auroras are caused by charged ejected by the sun. These particles are deflected by the Earth s magnetic field. These particles accumulate at the poles where they excite air molecules to produce beautiful streams of plasma called auroras.

16 Altitude and Temperature In the troposphere, temperature decreases with altitude. This is one reason for the upper limit of plant growth on mountains and the formation of glaciers at high altitudes.

17 Changing temperatures in our atmosphere The atmosphere gets thinner as we move away from Earth, the troposphere is thickest at the equator and thinnest at the poles As we move up the troposphere the temperature drops but as we move up the stratosphere the temperature rises again. Why? 17

18 Answer Earth warms the air close to its surface so as we move away the temperature drops At the stratosphere, the ozone layer absorbs energy from the sun so the temperature increases 18

19 Answer At the mesosphere there is not much going on so the temperature drops Once we get to the thermosphere the few particles that exist in this area absorb energy from the sun so more energy will be absorbed by the few particles making them hotter! 19

20 Altitudes and Temperatures In areas near mountains, cool air can be trapped close to the ground by a layer of warmer air (temperature inversion) 20

21 Climate In general, regions with severe climates (either very hot or cold) have far fewer people than regions with more moderate climates.

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23 Climate Affects All Organisms Species of plants, for example, that can survive in a region are determined by the climate. 23

24 Climate Affects All Organisms Adaptation any change in the structure or functioning of an organism that makes it more suited to its environment. Different plants and animals have various adaptations that make them more suited or less suited to a particular climate. 24

25 Many plants undergo a period of dormancy during the winter. Dormancy is a period in which growth of the plant ceases or becomes very slow. Example: deciduous trees shed their leaves when dormant. This helps protect them from freezing and minimizes the amount of moisture they need. 25

26 Climate change Today, the average surface temperature of Earth is increasing, according to two kinds of evidence anecdotal and scientific. Anecdotal evidence of climate change relies on reports from people about particular weather events and how they interpret these events over time.

27 Collecting data Farmers in Alberta report that the growing season begins earlier now than it did years ago. Aboriginal and Inuit elders and leaders in Canada s north have reported changes in weather events over time. First frost date, start of animal migration, and thickness of ice.

28 Scientific evidence agrees with anecdotal evidence that the average yearly temperature in Canada tends to be higher now than in the past.

29 Interpreting Climate Data Graphs of collected weather data sometimes makes it difficult for scientists to detect change in climate. Not all regions of Canada experienced the same variations in temperature, which make analysis even more difficult. 29

30 Presenting data Circle graphs are useful when looking at data and comparing it to a whole

31 Bar graphs Bar graphs are useful when the manipulated variable is a category. Per capita means the total amount divided by the number of people

32 Line Graphs Used when both the manipulated and responding variable change

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34 Climatographs Climatographs consist of both a bar graph and a line graph. The bar graph shows the precipitation. The line graph shows the average temperature.

35 Edmonton and Vancouver Climate

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