Weather Watch

Our school has a professional weather station that transmits weather data from our roof to this web site pretty much in real time and, yes, you can check the weather here wherever you can get online.

These charts show the readings transmitted from our own weather station. What you see is what happened right here! Feel free to interact with the chart, using the ‘sliders’ in the top margin to focus in on any period from the whole past month, down to any one hour in it.

web_station-e1438786911781-250x300A bit of background on our weather station:

  • What is it?
  • What it is used for?
  • And most importantly, what do you do with it?

Well, a weather station is often used for Meteorology, which is the study of the atmosphere. The atmosphere is the layer of gases (oxygen, water vapour and carbon dioxide to mention a few) surrounding Earth. The mix of these gases is continuously changing as they move around the world, driven mainly by the energy in sunlight but also by other natural and man-made processes.

Why is the atmosphere above us always changing?

One answer is: the weather. So, what is weather? Of course you see the weather news on TV. What do they talk about? “It is cold and it will rain tomorrow but the weekend is going to be very sunny and hot” or “this summer has been the wettest in 10 years”. But how do they know that? You guessed it: because they have weather stations all over the country that have been collecting weather data for many, many years. Now we have one like those on our school!

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All this data that the “weather people” are collecting is very important in helping us learn more about the climate. The climate can be defined as the properties of a space at a given point in time. You will have heard scientists (and politicians) talking about “climate change” on TV. What they are referring to is how the Earth’s atmosphere and therefore the weather conditions are changing noticably compared to Meteorologists’ historic records.

Today, Earth’s climate is getting gradually warmer, which could be not great news for us. We believe one of the reasons the climate is getting warmer is because of a steep rise in Carbon Dioxide (CO2) in the atmosphere, increasing the ‘Greenhouse Effect’. But let’s go back to the weather. How do we measure weather changes? How do we know how the local climate of the school is changing over time? First of all, we need to measure and record the weather conditions. Can you think about different types of weather conditions?

Ask yourself if you feel cold or hot when you go outside, or maybe just right. That is a weather condition: “temperature”. Maybe it is just right temperature-wise but impossible to enjoy because it is so windy that you have to hold onto something! This is another one: “wind”.

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The weather station on our roof measures these conditions with the following sensors:

WIND the spinning anemometer measures its speed and the vane reads its general direction
TEMPERATURE it tries to take account of the effect of direct sunlight
RAIN COLLECTOR it estimates the depth of water falling over the area, in millimeters
PYRANOMETER it measures the sun’s energy absorbed by a single square meter of roof

 

WIND


Here you can see the wind right now over the school. Read it like the speedometer of a car.

Wind speed is often measured in meters per second but also in miles or kilometres per hour. At sea they use the Beaufort Scale, ranging from 0 “Calm” to 12 “Hurricane”. When we measure wind speed, the spinning anemometer tells how fast the atmospheric gases are moving from one place to another. To gauge from where to where they are travelling we measure the direction using the vane you can see always pointing upwind.

Real time wind speed information from your school

A sensor measures how fast the 3 little cups are spinning to calculate the wind speed. You may be asking yourself why gases move from one place to another. What is it that makes them move? Well, part of the answer is being measured by our school’s weather station: temperature and solar radiation. Then there’s the rotation of the Earth.

Do you know how fast the surface of the Earth moves around its centre, if we measure it at the Equator? About 1,040mph!! That’s almost 25,000 miles in a day, to get back to where it started.

 

TEMPERATURE


The Sun sends us its light and heat energy every day so there can be life on Earth. When the Sun heats up the water in the sea, water vapour ascends to the sky and clouds are formed. These clouds then get between the Sun and different areas of the Earth’s surface so it cannot heat those areas as much. This makes the temperatures change continuously. However, the biggest impact on temperature is even simpler: day and night times. Below you can see the temperature on our school’s roof over the last 7 days. You may see it change quite a bit between day and night.

Real time outdoor temperature at your own school

At night we don’t receive any sunlight so it gets colder and as the Sun rises it starts to warm up the ground and the air again. This warmth is also carried from place to place in the wind. We measure this with our weather station’s digital thermometer. Wind and Temperature; how are they connected? You may need a bit of help from your teacher to explain this but air (the gases making up the atmosphere) expands and becomes lighter when it warms and becomes heavier with falling temperatures. Air rises off the warmed surface and cooler air moves in below to replace it, creating the wind. Since different parts of the Earth’s surface heat up differently (mountains, sea, houses), small variations in temperature are always present, the biggest caused by changes between day and night.

 

RAIN


tipping-bucket-255x300What happens when you boil water? It vaporises into steam. When the Sun is warming the water on rivers, lakes, the sea and the moist ground all day, part of this is vaporised into the air and when it cools and gets denser it forms clouds. These clouds may have formed near you or come from very, very far away on the wind. As more vapour gets together and cools, the clouds become heavier and greyer. When they become too heavy to stay in the sky, they precipitate into water or ice which falls back to Earth as rain, snow or hail.

The interesting part here is that some of the rain that has fallen on your school may have come from the other side of the Earth thanks to wind and temperature changes.

Rainfall is often recorded as the amount of water that falls over a known area during a measured period of time. Our rainfall sensor uses a tipping bucket mechanism. When enough rain has filled up one of the buckets, its weight makes the balance tip over, emptying its water, and the other bucket starts to fill. The sensor counts the number of times the buckets empty every 10 minutes. You can see below the rainfall here over the last 7 days and over this past day.

Historical and real time rain information from your school

 

SOLAR RADIATION


The word “Pyranometer” comes from the Greek: “Pyr” is fire and “ano” is sky. This sensor measures the amount of solar energy reaching the school in Watts per square meter. Think about it as like a tiny photovoltaic cell, like the ones on some pocket calculators. The brighter the light, the more energy the calculator has to work with, exactly as with the pyranometer; the more intense the solar radiation, the higher the measurement. The amount of sunlight our pyranometer will receive depends on our climate and on our latitude – where we are located between the Equator and the North Pole. The farther away from the Equator, the less intense the solar radiation is. You can probably guess from the picture below where the Equator is.
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Now you know a bit more about how the weather works, can you make more sense of the chart at the top of this page? Can you see any connections between the different weather readings being displayed?