New Geography in Action Junior Cycle Geography Weather stations
A weather station is a place with equipment and instruments for observing and recording the weather. Information from the weather stations in Ireland is sent to Met Éireann, the Irish National Meteorological Service.
The information gathered from weather stations is put onto weather maps called synoptic charts. Synoptic charts use lines and symbols to show what is happening with the weather at a given time. The lines on the charts show areas that have equal atmospheric pressure, temperature, sunshine or rainfall, depending on what is being measured.
Measuring weather We will now examine the instruments that are used to measure the elements of weather. It is important that you know: 1. What it measures 2. The name of the instrument 3. What the unit of measurement is 4. How it is shown on the synoptic chart
5.5 °C
Temperature 1. Temperature measures how hot or cold the air is.
2. The instrument used to measure air temperature is a thermometer.
A thermometer consists of a glass rod with a very thin tube in it. The tube contains a liquid that is supplied from a reservoir, or ‘bulb’, at the base of the thermometer. The liquid may be mercury or red- coloured alcohol. As the temperature of the liquid in the bulb increases, the liquid expands and rises up the tube.
3. The unit of measurement is degrees Fahrenheit or degrees Celsius.
4. Isotherms are lines on a weather map that join places of equal temperature.
Maximum and minimum thermometers
A maximum thermometer measures the highest temperature. The mercury in the thermometer rises as the temperature increases and pushes a pin in the tube upwards. As the temperature drops again, the pin stays at the highest point.
A minimum thermometer contains alcohol and shows the lowest temperature. As the temperature drops, the pin in the tube drops and stays at the lowest point.
240 4.5 °C 6.5 °C 5 °C 7 °C 5.5 °C 6.5 °C 7 °C : Figure 13.25 Isotherms 6 °C 5.5 °C 4 °C 6 °C 4.5 °C
