Geography π | Weather β | Flashcards
What device is used to measure wind speed?
The anemometer
What units are used by an anemometer?
km/h
How does an anemometer work?
It is connected to a meter, and the little cups rotate. This is converted to wind speed.
What device is used to measure air pressure?
The barometer.
How does a barometer work?
A barometer acts like a balance that βbalancesβ the weight of the atmosphere against the weight of a mercury column.
What device is used to measure rainfall?
The rain gauge
How does a rain gauge work?
It measure the amount of rain, hail, sleet, and snow which falls into a metal cylinder, through a funnel and into a collecting bottle.
What units are used by a rain gauge?
mm
What device is used to measure temperature, and what are itβs units?
Themometer; degrees Celcius or Farenheight
What device is used to measure wind direction?
Wind vane
How does a wind vane work?
The wind makes it rotate: if the wind is from the west, it is called westerly wind.
What device is used to measure the amount of sunshine?
Sunshine recorder.
How does a sunshine recorder work?
It records the amount of sunshine in a 24 hour period by having a piece of heat sensitive black card placed under a glass sphere, burning a line that indicates how long there was sunshine.
What device is used to measure humidity?
Hygrometer
In what units does a hygrometer measure humidity?
% (relative humidity)
What site factors are needed for a wind vane to work?
It should be on top of buildings so that the arrow can move in any direction the wind is blowing without interference.
What site factors are needed for an anemometer to work?
It should be on top of buildings so that it can record the true wind speed unaffected by obstacles such as other buildings and trees that slow it down.
What site factors are needed for a rain gauge to work?
It should be away from overhanging buildings and trees that may drip onto it. It should also be put into the ground for stability, or onto a firm base.
How far away from the ground should a rain gauge ideally be?
30cm
What site factors are needed for a sunshine recorder to work?
It should be off the ground, facing south in the northern hemisphere so that it is exposed to the sun.
How is cloud cover measured?
Using the eye, where we judge what portion of our vision is covered by clouds and convert it to oktas that represent certain amounts of cloud cover.
What is the unit of measurement for cloud cover?
oktas.
What are cirrus clouds?
High, atmospheric, and detached clouds - in thin hairlike strands.
Where are cirrus clouds found?
In the high layer.
What are status clouds?
Clouds that are low, smooth sheets - often grey, a precipitator, and blocking the sun.
Where are stratus clouds found?
In the low layer.
What is a cumulus cloud?
Detached and fluffy clouds with clear edges, and a white top bulge.
Where are cumulus clouds found?
At the low layer
What is a cumulonimbus cloud?
A cloud with a large vertical length that forms huge mountains, flat and spread at the top.
Where are cumulonimbus clouds found?
They span all layers.
