Weather and climate Flashcards
Which instrument is used to measure
max and min daily temps
A maximum-minimum thermometer.
What is a rain gauge used for?
Measuring precipitation over a period of
time.
Millimetres
What is a barometer used for?
Measuring air pressure.
millibars
Which instrument is used to measure wind speed?
An anemometer.
mph, kph, m/s
Which instrument is used to measure wind direction? (blowing from)
A wind wane.
Where should a Stevenson screen be situated?
- Clear from trees or buildings that create shade.
- On grass so this will not absorb heat/alter temperature.
What is the advantage of using a digital thermometer over a maximum-minimum thermometer?
- Quick/instant reading
- Accurate to a decimal point
Suggest why temperatures should be taken each morning and afternoon (digital thermometer)?
Temperature will change during the day
/
To show the range of temperature during a day.
Why are temperature different at different sizes?
- Buildings/tarmac/concrete absorb heat from sun
- Internal heating system of the buildings
- Buildings radiate heat around them
- Funneling effect of buildings
- Aspect/south facing/facing sun
- Shade from sun by trees/buildings
Some students measures the relative humidity at different sites. What are the improvements the the students could make to his data collection method?
- Collect datas on more than three days.
- Collect data on twice a day.
- Collect data in different months/seasons.
- The students check other students’ reading.
- Reading should be taken by the same student so there is less height difference.
Where should a rain gauge be placed and why?
On grass. Because if they are placed on concrete, extra water can splash in.
Why should rain gauge be checked regularly?
To avoid evaporation.
What is a wet-dry bulb thermometer (hygrometer) used for?
Humidity
Cirrus cloud
Thin and wispy
High atmosphere - 5500 metres
Doesn’t bring any type of weather
Stratus cloud
Low level - sometimes reaching ground
Below 2000m
Grey, fast
Rain, snow
Cumulonimbus cloud
Large, fluffy
up to 10km high and across
Rain, thunder, lighting
Cumulus
Low - 600 and 1200m
Light rain
Features of the Stevenson Screen and why
White: reflect sun
Double lid: insulation
Slanted sides: let the air circulated
Slanted downwards: Prevent light getting in
Legs 1m long: prevent heating from ground
Short grass: standardised. ie: same amount of reflectivity
How a hygrometer is used to work out relative humidity
read off wet and dry bulb temperatures
use relative humidity table
subtract wet bulb from dry bulb
read off figure at intersection of dry bulb and wet bulb depression figures
Why are instruments placed in a Stevenson Screen?
not heated by sun
not affected by wind
measure condition of air not ground
standard height above ground
not affected by concrete
avoid tampering
Instruments that are put inside Stevenson Screen
Barometer
Hydrometer
Maximum-minimum thermometer
Intruments that are put outside Stevenson Screen
Rain gauge
Wind vane
Anemometer
Explain how wind speed and direction measurements are obtained at a weather station.
You may include diagrams of the instruments used.
wind direction - wind vane
labelled diagram
arrow points to where the wind blowing from
wind speed - anemometer
labelled diagram
both connected to computer
check instruments every X hours to get reading
location: high up + away from trees
