Climate Characteristics Flashcards
What are the 7 key climate characteristics?
Temp Precipitation Wind speed Wind direction Relative humidity Atmospheric pressure Air quality
What unit is temp measured in?
°C
°F
Which instruments are used to measure temp?
Thermometers
Stevenson Screen
What unit is precipitation measured in?
mm
What instrument is used to measure precipitation?
Rain gauge
What is wind direction a measure of?
The direction which the wind has come from
What unit is wind direction measured in?
Compass direction (N,S,E,W)
Which instruments are used to measure wind direction?
Wind vane
Compass
What unit is relative humidity measured in?
%
Which instrument is used to measure relative humidity?
Whirling Psychrometer
What is atmospheric pressure?
The amount of pressure exerted on the ground by the atmosphere
What unit is atmospheric pressure measured in?
millibars (unit of pressure)
Which instrument is used to measure atmospheric pressure?
Barometer
What is air quality?
How good the air is
Which units is air quality measured in?
Micrograms per cubic meter
Parts per million
What instrument can be used to measure air quality?
Acetate
Which units is wind speed measured in?
mph m/s knots per hour km/h beaufort scale
What is the beaufort scale?
A scale which allows you to work out wind speed based on observation.
Using the diagrams you are able to see the speed (mph) of the wind
What instrument can be used to measure wind speed?
Anemometer
Explain why in period of high pressure large, urban cities, for example London, can experience poor air quality
Because the pollutants can’t escape the atmosphere and therefore stay close to the surface of the earth
How does a max/min thermometer work?
As the temp increases the alcohol expands and pushes the pin (small iron marker) into place. The opposite is also true for the min temp as the alcohol retracts the mercury falls and the pin follows.
This thermometer reads the current temp and records the max and min temps reached since the last reset.
A magnet is used to reset the readings
Why are max/min thermometers useful?
They measure the temp constantly and record the max/min temps which means that reading can be taken after the event.
What is relative humidity (RH)?
The amount of moisture in the air in relation to the max amount the air could hold at that temp
What is absolute humidity?
The max amount of water vapour the air can hold at different temps
What unit is absolute humidity measured in?
Grams of water per m³
How would you measure RH using a whirling psycrometer
A wet and dry bulb lie side by side
The instrument is spun at shoulder level for around a min
Read and record both the wet and dry bulb readings
Subtract the readings from each other
Compare reading with relative humidity chart
State an advantage and disadvantage of using electronic thermometers?
+ve - Precision - They show tenths of degrees
-ve - Don’t work when they are wet
Why is it necessary to calibrate thermometers used in an investigation?
Because if you are using more than 1 thermometer you could have slightly different readings.
Describe how to calibrate thermometers
Number all the thermometers Place them in cold water/fridge Read and record temps Immerse thermometers in warm water Read and record temps Differences should be consistent so should be able to adjust to norm
What is an area of high pressure called?
Anticyclone
What is an area of low pressure called?
Depression
What is high pressure?
As the air cools is descends leading to high pressure
What is low pressure?
As the air warms it ascends leading to low pressure. This is usually associated with unstable weather conditions
How would you measure cold cover?
By taking a photo and observing you can estimate the % of the sky covered by cloud.
By convention, cloud cover is expressed as the number of eighths (oktas) of sky covered by cloud.
