8.1: Weather and Climate
pg. 319
Weather – atmospheric conditions, including temperature,
precipitation, wind, and humidity, in a particular location over a
short period of time, such as a day or a week.
Describing the Weather
Scientist who studies the weather is called meteorologists.
They use the following information when describing weather:
- temperature
- wind speed
- atmospheric pressure
- type and amount of precipitation
- relative humidity
- presence of fog, mist, or cloud cover
In some parts of the world, the weather may stay the same for long
period of time (Sahara Desert). In other parts the weather may
change from one day to the next (Canada).
Predicting the Weather
Meteorologists gather information on weather around the world
and use the information to forecast the weather for a specific area.
Data is collect from thousands of weather stations found
throughout Canada and the rest of the world. Data is collected from
weather stations, weather balloons, aircraft, and satellites.
What causes weather? The interactions between water and air o the
Earth and energy from the Sun contribute to the weather. The Sun
energy creates air currents (wind) and the water cycle (evaporation)
produces the precipitation. Water is collected from the rivers, lakes,
ponds, and oceans. Clouds are formed and air is cooled as it rises
and condensation is created (rain or snow).
What is Climate?
Climate – the average of the weather in a region over a long period
of time.
To determine the climate of a given region, Climatologists collect
weather measurements made over 30 years or more and average
the results.
The climate of a region gives a range of temperatures and amount
of precipitation to expect during a specific time of the year. In
Ontario, in the summer the climate is warm and humid, but in the
winter it is cold with snow.
“Climate is what you expect, but weather is what you get”
The climate of a region will also determine the type of plants and
animals that live in that area.
Check Your Learning, questions 1 – 9. Pg. 321