Measuring and Forecasting of weather Flashcards
What is used to measure the following? Temperature precipitation wind speed wind direction humidity sunshine atmospheric pressure
Temperature: thermometer precipitation: rain gauge wind speed: anemometer wind direction: wind vane humidity: Hygrometer sunshine: Campbell stokes recorder atmospheric pressure: barometer
what is weather?
Weather is the state of the atmosphere
What is a weather station?
A weather station is a facility that uses equipment and instruments to measure and observe the weather
What is atmospheric pressure?
How is atmospheric pressure measured?
atmospheric pressure is the weight of the atmosphere pushing down on the earth.
It is measured in units called millibars (mb) and by a barometer.
how does a barometer work?
A very sensitive vacuum chamber inside the barometer responds to atmospheric pressure and as it increases or decreases, the main needle on the face moves accordingly. The second needle is only a marker which marks existing pressure.
What displays atmospheric pressure on weather maps?
The lines used on weather maps to display atmospheric pressure are called isobars.
How does a maximum and minimum thermometer work?
The maximum and minimum thermometer is a U shaped glass tube on which temp readings are marked. The tube contains alcohol on its minimum side, a vacuum (space) on its maximum side and mercury in between. There are two metal markers on either side of the mercury which shows the minimum and maximum temperatures when the alcohol expands when warm or contracts when cold.
How does a rain gauge work?
The rain gauge consists of an outer cylinder which contains a funnel that directs water into a measuring cylinder. The cylinder is graduated to show precipitation levels in millimetres. It is partially buried in the ground in an open space away from buildings or trees.
What are the three main cloud types? At what height are they found?
Cirrus clouds are high clouds that form above 8000m.
Cumulus clouds form below 5000m.
Stratus clouds are usually low clouds that form below below 2000m
How does an anemometer work?
Three cups rotate when the wind blows. The stronger the wind, the faster they move. The number of times the cup rotates is used to calculate wind speed. It is recorded and displayed on the meter.
How does a wind vane work?
The wind vane is a free moving arrow on a high mast. The tail of the arrow is wide and blown forward by the wind. This allows the head of the point of the arrow to point in the direction from which the wind is blowing.
