2.3+-+Weather,+Climate,+and+Ecosystems

__From the syllabus__
Candidates should be able to:


 * Weather**
 * Draw, describe and explain the use and siting of the following instruments at a weather station: rain-gauge, maximum-minimum thermometer, wet and dry bulb thermometer (hygrometer), barometer, anemometer and wind vane.
 * Make calculations using information from these instruments.
 * Use and interpret graphs and other diagrams showing weather data.
 * Describe and explain the characteristics, siting and use made of a Stevenson screen.
 * Describe the main types of cloud and be able to estimate the extent of cloud cover.


 * Climate**
 * Describe and explain the main characteristics of the climate in the regions listed in the syllabus (tropical rainforest and tropical desert):
 * temperature – mean temperature of the hottest month, mean temperature of the coolest month, therefore the annual range
 * rainfall – the amount and seasonal distribution
 * other climate features – wind, cloud, humidity etc.
 * Factors influencing these characteristics should be noted such as: latitude, pressure systems and the winds to which they give rise, distance from the sea, altitude and ocean currents.
 * Candidates should be familiar with climatic graphs showing the main characteristics of temperature and rainfall of the climates in the regions listed.


 * Ecosystems**
 * Describe the characteristics and distribution of the two ecosystems listed in the syllabus (tropical rainforest and tropical desert).
 * Explain the relationship in each ecosystem of natural vegetation and climate.


 * Demonstrate an understanding that the natural environment presents hazards and offers opportunities for human activities. Reference should be made to tropical storms and drought. (NB: This also includes opportunities such as those presented by the various resources of the rainforest)

**__Case studies__**

 * Deforestation in the Amazon (textbook p. 236)
 * Desertification in the Sahel (textbook p. 256)