Download Measuring the weather

How can we measure the
weather?
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Learning objectives
Which instruments are used to
measure the weather?
How can you measure the weather?
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Rainfall
Rain is a type of precipitation.
Precipitation is where water vapour in the air is cooled and
condenses into water droplets.
Other types of precipitation are snow, sleet, hail, dew or fog.
Rainfall is measured with a rain gauge.
rain gauge
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Rainfall
Rain facts!
The greatest amount of rain recorded worldwide in 24 hours
was in La Reunion in the Indian Ocean, when 1825mm fell
between 7th and 8th January 1966.
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Temperature
Temperature is how hot or cold it is.
How is temperature measured?
Temperature can be measured using a
thermometer such as the liquid-in-glass
type, where the liquid (mercury or spirit) in
the bulb expands and rises up a capillary
tube.
Temperature is measured in either oCelsius
or oFahrenheit.
Temperatures are measured in the shade,
so that the heat of the sun does not heat up
the instrument being used.
Thermometer
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Temperature
The highest temperature recorded in the UK
was 38.5°C in Brogdale, near Faversham,
Kent, on 10 August 2003.
The lowest temperature recorded in the UK
was -27°C at Braemar in the Grampians, on
January 10 1982.
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Wind
Wind is simply moving air.
Wind speed is how fast the air is moving.
How is wind speed measured?
Wind speed is measured by an
anemometer. This has metal cups
which rotate in the wind.
The stronger the wind, the faster the
anemometer turns.
anemometer
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Wind speed
Wind facts!
The strongest winds ever measured were gusts of 372 km/h
(231 mph) at Mount Washington, New Hampshire, USA on 12
April 1934.
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Beaufort scale
The Beaufort Scale is a measure for the intensity of the wind
based on conditions. It can be used to estimate wind speed.
The Beaufort scale is divided into a series of values, from
0 for calm winds to 12 and above for hurricanes.
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Wind direction
How is wind direction measured?
Wind direction is measured using a wind vane.
In this case, the wind has come from the north.
It is a northerly wind.
the arrow points
into the wind
See if you can spot a wind vane
in your local area.
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Sunlight
Sunlight is the amount of daylight.
How is sunlight measured?
The duration and the intensity of
sunlight is measured using a
Campbell-Stokes sunshine
recorder.
These focus light from the sun
onto a piece of card where it
leaves a burnt trace. The more
sunshine there is, the longer the
line.
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Sunlight
Sunlight facts!
In December 1890, Westminster in London, there was no
sunshine for the entire month.
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Air pressure
Air pressure is the force exerted on
the Earth by the weight of the air
above.
How is air pressure measured?
It is measured with a barometer.
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Weather instruments
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Cloud types
There are four main cloud types:
cirrus - the Latin for 'hair' for clouds that are wispy
cumulus - the Latin for 'pile' for heaped looking clouds
stratus - from stratum, the Latin word for 'layer‘, for sheets
of cloud
nimbus - the Latin word for 'cloud' for low, grey rain cloud
How would you classify these clouds?
cumulus
cirrus
nimbus
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Cloud cover
Cloud cover is the fraction of the
sky covered in clouds.
Cloud cover can be measured
by observation.
It is measured in oktas.
clear sky
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Which instrument?
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