Observe and record weather in your area over the coming months. There is resources available to help with:
- measuring temperature,
- wind speed
The first sighting of the swallow or primrose in flower in spring is a significant event. When scientific measurements are taken the significance lies not in the single measurement but in its place as part of a set, or series, of measurements. Temperature measurements are like this. A single temperature measurement does not tell us much. A graph of temperature measurements taken at the same place, but over a period of time, however, can tell us a lot. It is very important that all these temperature measurements are taken in exactly the same way so that they can be compared fairly.
How To Measure Temperature
How To Measure Temperature
- It is important to make sure that the temperature measurements are taken in the same place and at the same time every day.
- The place should be in the shade (so that the sun does not heat the thermometer directly,) and a location where the wind can blow freely (not in a porch or a partially-covered shed, for example).
- The time should be at noon every day (as well as comparing the temperatures in the same place from day to day, this helps to compare simultaneous measurements taken at different places, or in comparing the school measurements with nearby Met Éireann measurements).
- It is also important that the measurements are not accidentally affected. For example, by holding the thermometer in warm hands. The thermometer will also need some time out in the air - about five minutes - for it to adjust properly to the actual outdoor temperature. Now read the thermometer and write down the temperature in degrees celsius on the wall chart provided with this brochure.
Other Things To Notice
- What is the range of temperatures at your school - the difference between the highest and the lowest?
- What was the biggest change from one day to the next?
- Calculate the average temperature for each week/month. How much did it change through the spring?
If you record other weather details you could answer the following questions
- Were the sunniest days always the warmest?
- Were wet days colder than dry days?
- Was there any connection between temperature and the direction / strength of the wind?
Measuring Wind Speed
Wind Speed Task
An anemometer is a device that measures how fast the wind is blowing. As such, it is one of the most important instruments to be found in a weather station. The device you are going to build is a model of a real world 'anemo' that will give you an approximation of how fast the wind is blowing. You'll find instructions for making one below.
How To Measure Wind Speed
How To Measure Wind Speed - Materials
N.B. For this experiment to be of scientific value, you must use the following equipment:
- 4 small paper/plastic cups (like drinking cups)
- A colouring pen - any colour
- 2 strips of stiff cardboard - the same length
- Large drawing pin (thumb tack)
- Sharpened pencil with eraser on the end
- Blu tack or modelling clay
- A hard surface - cardboard or tile
- A watch with a second hand
- Cut off the rolled edges of the cups to make them lighter
- Colour the outside of one cup with the colouring pen.
- Cross the cardboard strips so they make a plus sign. Staple them together.
- Take the ruler and pencil and draw lines form the outside corners of where the cardboard strips come together to the opposite corners. Where the pencil lines cross will be the exact middle of the cross.
- Staple the cups to the ends of the cardboard strips; make sure the cups all face the same direction.
- Push the drawing pin through the centre of the cardboard (where the pencil lines cross) and attached the cardboard cross with the cups on it to the eraser point of the pencil. Blow on the cups to make sure the cardboard spins freely on the pin.
- Place the blu tack or modelling clay on the hard surface. Stick the sharpened end of the pencil into the clay so it stands up straight.
Measuring the Wind
This anemometer cannot not tell the wind speed in miles per hour, but it can give you an idea of how fast the wind is blowing.
Every Friday at 11.30am from the start of February bring your “Anemo” outside and using your watch, count the number of times the coloured cup spins around in one minute. You are measuring the wind speed in revolutions (turns) per minute. Weather forecasters’ anemometers convert the revolutions per minute into miles per hour (or kilometres per hour).
Keep a record of the wind speed you’re measuring for the day on the wall planner sent to your school and upload the data to the website.
Most schools leave their rain gauge out on a Friday afternoon and take a measurement on Monday morning. This measurement is the total rainfall for the weekend. It is important to enter this measurement on your wall chart on Monday so it is included when calculating your weekly rainfall.
How To Measure Rainfall
Calculating rainfall at weekends
As an exercise in class you can also work out an average rainfall for each wet day over the weekend. For example, if it only rained on Friday and Sunday, divide the amount of rainfall you measure on Monday morning by two to calculate an average. If it rained on all three days divide the amount of rainfall you measure on Monday morning by three to calculate an average.
Measuring rainfall is one of the most important jobs in Meteorology (the science of the weather). Every day, tens of thousands of weather observers all over the world go to their rain gauges and empty their collection containers into a graduated cylinder to measure how much rain has fallen - just like you can do for this year's Greenwave experiment.
N.B. For this experiment to be of scientific vaue, you must use the following equipment:
- 2 litre empty bottle (will become your funnel)
- 10ml plastic syringe (available from your local chemist) OR 100ml graduated cylinder
- Metre stick
- Container to collect the rain (i.e.
- Measure 34cm of thread on your metre stick
- Place the 34cm of thread around the 2lt bottle, cut the top of the bottle at this point, this part will now become your funnel. The funnel should look something like that shown here.
- Place the funnel into your collecting container and set it up outside in a place where it won't tip over, and where it is not overshadowed. Ideally it should be more than 5 metres from the nearest building / tree or structure. Make sure it is positioned where it cannot be knocked over accidentally by dogs or cats (or children). If you like, place the container in a plastic bucket and pack sand/mud around it.
- At 9.30am every day, use the plastic syringe or graduated cylinder to measure the amount of rain that has collected in the container. When you are finished measuring, you can throw out the water so that the container is empty and ready to collect rain over the next 24 hours!
- For the purpose of comparison, you will need to convert this to millimetres by dividing the figure by 9.2. Please round the result to two decimal places. Log your daily readings on your wall chart to see how the rain changes from day to day, and at the end of each week calculate and fill in the total rainfall for the week.