It’s been the coldest start to December since 1976. Very cold Decembers are not uncommon but a little unusual as our coldest months in the UK are usually January and February. I was talking about the cold weather to some friends over Christmas and we got on to talking about why we can feel hot or cold. I don’t mean that the heating isn’t on or there’s a freezing wind outside, I mean where the sensation of heat actually comes from.
Well, something feels hot to us because the atoms inside it are moving fast, and when it feels cold they are moving slowly. We interpret this movement through the feeling of something being hot or cold, and a thermometer interprets as a certain temperature, in for example degrees Centigrade of Fahrenheit.
Scientists often use Kelvin as a measure of temperature rather than deg C or deg F. The bottom of the Kelvin scale is 0 K or Absolute Zero. What got me thinking about this recently was my God Son who asked me what is Absolute Zero. I was able to give the temperature 0 K or -273.15°C, but not the definition. It’s one of those things that I am sure I did know and could make a reasonable guess of what I thought it was, but to be precise I looked it up for myself. And it is as you might guess a point at which no more heat exists.
What that means specifically in classical kinetic theory is that there should be no movement of individual molecules at Absolute Zero. In practice we don’t of course know this as we have never been able to observe anything at 0 K, but we have come close in the laboratory. The experimental evidence shows us that as we reduce temperatures close to 0 K molecules do slow right down, but there is still movement.
Sunday, 28 December 2008
Wednesday, 22 October 2008
Mountain Meteorology in Action
I was lamenting on what a bad decision it was not to take my new watch (re Blog of 12th October 2008) on my recent trip to Peru and the chance I would have had to give it a good test out in the Andes and to take a meteorological observation in Machu Picchu (what a fantastic place to visit by the way – twice as good as any photos you might have seen).
Fortunately the plane I travelled in was an Airbus with one of those screens that gives you temperature at different altitudes, so on take-off and landing I had the chance to record some upper air observations, and here are a couple below relating to my landing and then take-off at Lima airport:
You can see that they certainly do not conform to the ‘standard atmosphere’ (as defined by the International Civil Aviation Authority) of temperature changing by around 6°C per kilometre. Coming into Lima (blue line) you can see a warm layer of air just below 2 km that extends right down to about 700 m.
The flight from Lima into Cusco was an example of some of the challenges that aircraft have at high altitude. The landing is very spectacular as the plane circles around the mountains and comes into land in a shallow valley at around 3,600 m. You can hear the engines at high revs in the closing turns to maintain the lift they need to turn in the much thinner air (lower air pressure).
I was hoping to see some of my favourite lenticular clouds in the mountains, but not this time. However I did see some amazing cloud formations. Here is one example below; along with a picture I took at sunrise coming through the clouds as I travelled out of Cusco on a train to Machu Picchu.
Fortunately the plane I travelled in was an Airbus with one of those screens that gives you temperature at different altitudes, so on take-off and landing I had the chance to record some upper air observations, and here are a couple below relating to my landing and then take-off at Lima airport:
You can see that they certainly do not conform to the ‘standard atmosphere’ (as defined by the International Civil Aviation Authority) of temperature changing by around 6°C per kilometre. Coming into Lima (blue line) you can see a warm layer of air just below 2 km that extends right down to about 700 m.
The flight from Lima into Cusco was an example of some of the challenges that aircraft have at high altitude. The landing is very spectacular as the plane circles around the mountains and comes into land in a shallow valley at around 3,600 m. You can hear the engines at high revs in the closing turns to maintain the lift they need to turn in the much thinner air (lower air pressure).
I was hoping to see some of my favourite lenticular clouds in the mountains, but not this time. However I did see some amazing cloud formations. Here is one example below; along with a picture I took at sunrise coming through the clouds as I travelled out of Cusco on a train to Machu Picchu.
Sunday, 12 October 2008
My New Meteorological Watch
With one thing and another it has been a while since I last put ‘finger-to-keyboard’ so to speak, but felt I should share a few thoughts about my new meteorological watch.
At my age it is not often I get excited about my birthday (perhaps that is just because I am a bit miserable, as my wife reminds me), but this year I had a very exciting present – no not a vintage Harley Davidson bike, an antique Les Paul guitar, or tickets to see Catherine Jenkins in concert (front row seats); it was a meteorological watch. Yes, you did read correctly a watch that makes observations of the weather. I have had much fun with this, making observations of temperature pressure and altitude. It reminded me of a few things apart from how hopeless I am at finding out how it all works.
The first was how careful you have to be when making observations, to understand what is being observed (like the temperature of the atmosphere, or my wrist), and that the observations are well calibrated. I am waiting to my next blue sky day at the coast to set my altitude and pressure calibrations.
The second was that what I am measuring is all inter-related. Pressure, temperature and humidity are all related. For example in the troposphere, a very small layer of the earths atmosphere relatively speaking that is closest to the surface of the earth and where we have all of our weather, pressure decreases with height in the atmosphere and so does temperature, by roughly 6oC per kilometre (if we make some assumptions about what we call a standard atmosphere). I wonder whether my watch really does measure temperature, pressure and altitude independently or whether, as I suspect, it uses some of our understanding of how these things are linked.
At my age it is not often I get excited about my birthday (perhaps that is just because I am a bit miserable, as my wife reminds me), but this year I had a very exciting present – no not a vintage Harley Davidson bike, an antique Les Paul guitar, or tickets to see Catherine Jenkins in concert (front row seats); it was a meteorological watch. Yes, you did read correctly a watch that makes observations of the weather. I have had much fun with this, making observations of temperature pressure and altitude. It reminded me of a few things apart from how hopeless I am at finding out how it all works.
The first was how careful you have to be when making observations, to understand what is being observed (like the temperature of the atmosphere, or my wrist), and that the observations are well calibrated. I am waiting to my next blue sky day at the coast to set my altitude and pressure calibrations.
The second was that what I am measuring is all inter-related. Pressure, temperature and humidity are all related. For example in the troposphere, a very small layer of the earths atmosphere relatively speaking that is closest to the surface of the earth and where we have all of our weather, pressure decreases with height in the atmosphere and so does temperature, by roughly 6oC per kilometre (if we make some assumptions about what we call a standard atmosphere). I wonder whether my watch really does measure temperature, pressure and altitude independently or whether, as I suspect, it uses some of our understanding of how these things are linked.
Friday, 29 August 2008
Paint the whole world with a Rainbow
When you have lots of sunshine and showers around like we’ve had recently (well OK we’ve had more showers than sunshine) then it’s ideal conditions for rainbows. We see rainbows when the sun shines through the raindrops. More precisely the sunlight is refracted in the raindrop and is split into the different colours that make up the sunlight – you might remember doing something similar in the school science lesson when you shine a bright light through a prism (a glass pyramid). The refracted light is then reflected off the back of the raindrop at an angle of around 42o, which defines the angle in the sky that we see the rainbow. The blue light is a shorter wavelength and so is refracted at a bigger angle than the longer wavelength red light, which means that in the bow you see the red at the top and the blue near the bottom.
Sometimes you can see a secondary rainbow and I’ve included a picture above I took of a primary and secondary rainbow this year in Cornwall. The secondary rainbow occurs when the light undergoes a double reflection in the raindrop. Because this is a second reflection the colours occur upside down compared to the primary rainbow, and they are dimmer. We call the area in between the two bows Alexander’s band after the ancient Greek Alexander of Aphrodisias who wrote about it. It is possible on very rare occasions to see a third bow, but as by this stage the light is very dim and it appears in the direction of the Sun it is extremely difficult to spot.
There are a few different mnemonics that help you remember the seven colours of the rainbow, but my favourite is ‘Richard Of York Gave Battle In Vain’ – that’s Red, Orange, Yellow, Green, Blue, Indigo, Violet.
Rainbows have been talked about for many years. The ancient Greeks wrote about rainbows as a path made by Iris (the messenger of the Gods) between heaven and earth. Chinese mythology speaks of a slit in the sky sealed by the Goddess Nüwa using stones of five different colours. The Bible in the story of Noah talks about the rainbow of a sign from God that life would never again be destroyed by floods. But perhaps the most famous is that the Leprechauns keep their pot of gold at the end of the rainbow. Unfortunately you will never reach the end of the rainbow for two reasons. The first is that because it’s an optical effect then it moves as you move and so you can never reach the bottom. Secondly, and perhaps more importantly, a rainbow is really a circle, it’s just that we see half of it.
There are two things that stick in my mind most about rainbows. The first is the fantastic painting by Constable of Salisbury Cathedral from the Meadows. I first saw it in the National Gallery, and read about the painting of it in a great book by John Thornes (called John Counstable’s Skies, which I can definitely recommend to you). My second abiding memory is from the Wordsworth poetry I studied at school. His 1802 poem "My Heart Leaps Up When I Behold The Rainbow" begins:
My heart leaps up when I behold
A rainbow in the sky:
So was it when my life began;
So is it now I am a man;
So be it when I shall grow old,
Or let me die!…
Wednesday, 13 August 2008
How do I follow a career in Meteorology and do I need a degree in Meteorology to become a Meteorologist
Download Paul's BBC Radio interview on careers in meteorology
With exam results out and lots of young people thinking what they might do next, we thought it would be a good idea to say a bit about how to become a meteorologist. You can’t do a GCSE or A-level in meteorology so what should you be thinking about choosing to study?
Well, many people who end up in Meteorology come from a science background and in particular have studied subjects such as Maths, Physics and Chemistry at GCSE, A-level, and for a degree. Increasingly there are organisations that are employing people from backgrounds in environmental science and geography, but often there will be a requirement to undertake further studies to give people the scientific background needed, whether working as a meteorological researcher or an operational forecaster. Check out our ‘Spotlight on Careers’ page to see how just a small cross-section of our community ended up in meteorology ‘http://www.rmets.org/activities/careers/spotlight.php’.
Very few Universities offer Meteorology degrees, but there lots of related courses that will equip you well – and a number of MSc courses that give an opportunity to convert over to meteorology if you feel you would like to understand more about the science. The Society accredits Undergraduate degree and MSc courses and you can find a list on our website at ‘http://www.rmets.org/activities/careers/courses.php’.
I’m conscious that I am biased, but meteorology offers some great career opportunities, often involving travel within the UK and internationally – meteorology is a very international community. You can work as:
• an operational weather forecaster – and there are many facets to a role like that, including TV and radio presenters if that’s something that interests you.
• a weather observer - either taking observations or working in the development of instrumentation from simple rain gauges right through to aircraft equipment, weather radar and the development of new satellite technologies.
• consulting services - which is an increasing area of growth within the community that brings in business skills to provide advice to companies whose bottom line is affected by the weather.
• research scientist – either working in a university group or at one of the UK’s meteorological research institutes and centres, working at the forefront of weather and climate science.
You can find out more about the range of employers across both the public and the private sector in our section about ‘Who Employs Meteorologists’ (http://www.rmets.org/activities/careers/index.php).
For those working in meteorology already we also offer Vocational Qualifications and you can find out about the NVQs/SVQs in weather forecasting and weather observing, and how to become a Chartered Meteorologist at ‘http://www.rmets.org/activities/careers/index.php#qualifications’.
With exam results out and lots of young people thinking what they might do next, we thought it would be a good idea to say a bit about how to become a meteorologist. You can’t do a GCSE or A-level in meteorology so what should you be thinking about choosing to study?
Well, many people who end up in Meteorology come from a science background and in particular have studied subjects such as Maths, Physics and Chemistry at GCSE, A-level, and for a degree. Increasingly there are organisations that are employing people from backgrounds in environmental science and geography, but often there will be a requirement to undertake further studies to give people the scientific background needed, whether working as a meteorological researcher or an operational forecaster. Check out our ‘Spotlight on Careers’ page to see how just a small cross-section of our community ended up in meteorology ‘http://www.rmets.org/activities/careers/spotlight.php’.
Very few Universities offer Meteorology degrees, but there lots of related courses that will equip you well – and a number of MSc courses that give an opportunity to convert over to meteorology if you feel you would like to understand more about the science. The Society accredits Undergraduate degree and MSc courses and you can find a list on our website at ‘http://www.rmets.org/activities/careers/courses.php’.
I’m conscious that I am biased, but meteorology offers some great career opportunities, often involving travel within the UK and internationally – meteorology is a very international community. You can work as:
• an operational weather forecaster – and there are many facets to a role like that, including TV and radio presenters if that’s something that interests you.
• a weather observer - either taking observations or working in the development of instrumentation from simple rain gauges right through to aircraft equipment, weather radar and the development of new satellite technologies.
• consulting services - which is an increasing area of growth within the community that brings in business skills to provide advice to companies whose bottom line is affected by the weather.
• research scientist – either working in a university group or at one of the UK’s meteorological research institutes and centres, working at the forefront of weather and climate science.
You can find out more about the range of employers across both the public and the private sector in our section about ‘Who Employs Meteorologists’ (http://www.rmets.org/activities/careers/index.php).
For those working in meteorology already we also offer Vocational Qualifications and you can find out about the NVQs/SVQs in weather forecasting and weather observing, and how to become a Chartered Meteorologist at ‘http://www.rmets.org/activities/careers/index.php#qualifications’.
Tuesday, 12 August 2008
The Planning for our Climate Change Question Time
We are just in the final planning stages for this year’s Society event at the British Association’s Festival of Science – a Climate Change Question Time. The Festival moves around the country and this year, in part I suspect to mark its status of European City of Culture, we are in Liverpool.
In preparation for the event we did some filming on the streets of Liverpool in late July, asking members of the public about climate change. I have to say that we had a very warm and friendly welcome and we collected quite a number of excellent and interesting interviews which we hope to be able to put up on the Society’s website before the end of September. We will be using a small selection of these to open our Question Time event. I promise to put a link to these in my blog when we have them ready as I know that you will enjoy watching them and hearing what people have to say – I am sure you will find that many of their thoughts and questions are similar to the ones you have.
The event will be in the style of Question Time and we are delighted to have a panel of very distinguished and internationally respected meteorological scientists who have been very actively involved in, amongst other things, the work of the Intergovernmental Panel on Climate Change (IPCC). The panel includes:
• Professor Sir Brian Hoskins, Director of the Gratham Institute for Climate Change and a newly appointed member of the Government’s Climate Change Committee;
• Dr Peter Stott, the Head of Climate Monitoring and Attribution at the world renowned Met Office’s Hadley Centre, and a lead contributor to the IPCC’s Fourth Assessment Report;
• Professor Jo Haigh, Professor of Atmospheric Physics at Imperial College, whose area of expertise includes the Sun’s impact on our climate;
• Professor Piers Forster, the Roberts Research Fellow and Professor of Climate Physics at the University of Leeds, working in the field of climate forcing and feedbacks.
The aim of the event is to allow members of the public to ask the questions directly of the scientists that they want answered about climate change. The event will be followed by a reception where people will be able to meet with the members of the panel on a one-to-one basis and also see meteorological experiments demonstrated by the Society’s school Met Ambassadors.
It’s a meeting open to the public and if you would like to come we would be delighted to see you there – we are in the Quaker House (22 School Lane) in Liverpool city centre from 6-8pm on Tuesday 9 September. There is a small charge on the door, but if you register with us in advance (with Sue Brown at sue.brown@rmets.org or on 0118 956 8500) we will be able to provide you with a ticket for free entry. You can find out more details of our and other Festival activities at ‘http://www.the-ba.net/the-ba/FestivalofScience/’.
In preparation for the event we did some filming on the streets of Liverpool in late July, asking members of the public about climate change. I have to say that we had a very warm and friendly welcome and we collected quite a number of excellent and interesting interviews which we hope to be able to put up on the Society’s website before the end of September. We will be using a small selection of these to open our Question Time event. I promise to put a link to these in my blog when we have them ready as I know that you will enjoy watching them and hearing what people have to say – I am sure you will find that many of their thoughts and questions are similar to the ones you have.
The event will be in the style of Question Time and we are delighted to have a panel of very distinguished and internationally respected meteorological scientists who have been very actively involved in, amongst other things, the work of the Intergovernmental Panel on Climate Change (IPCC). The panel includes:
• Professor Sir Brian Hoskins, Director of the Gratham Institute for Climate Change and a newly appointed member of the Government’s Climate Change Committee;
• Dr Peter Stott, the Head of Climate Monitoring and Attribution at the world renowned Met Office’s Hadley Centre, and a lead contributor to the IPCC’s Fourth Assessment Report;
• Professor Jo Haigh, Professor of Atmospheric Physics at Imperial College, whose area of expertise includes the Sun’s impact on our climate;
• Professor Piers Forster, the Roberts Research Fellow and Professor of Climate Physics at the University of Leeds, working in the field of climate forcing and feedbacks.
The aim of the event is to allow members of the public to ask the questions directly of the scientists that they want answered about climate change. The event will be followed by a reception where people will be able to meet with the members of the panel on a one-to-one basis and also see meteorological experiments demonstrated by the Society’s school Met Ambassadors.
It’s a meeting open to the public and if you would like to come we would be delighted to see you there – we are in the Quaker House (22 School Lane) in Liverpool city centre from 6-8pm on Tuesday 9 September. There is a small charge on the door, but if you register with us in advance (with Sue Brown at sue.brown@rmets.org or on 0118 956 8500) we will be able to provide you with a ticket for free entry. You can find out more details of our and other Festival activities at ‘http://www.the-ba.net/the-ba/FestivalofScience/’.
Monday, 11 August 2008
What is it about Young People and Umbrellas?
On Thursday evening last week it was absolutely chucking it down. I was checking the weather radar to plan my best time to make a break for home and realised that I wasn’t going to get away with it – so I got out the umbrella and headed off.
I just couldn’t believe how many people were walking around just getting soaked because they didn’t have an umbrella. Now this is where I’m going to sound a bit like an old fogy, but there were all young people! My very unscientific survey suggested that 100% of people over 60 were brollied-up, some 50% of 60-30 year olds (of which I fall into) had umbrellas, but to my great dismay, not a single young person was carrying an umbrella (excuse my arbitrary definition of ‘young’).
So when did it become uncool to carry an umbrella. I was trying to think back to my younger days and whether I carried a brolly around with me. I did, but I then realised that this wasn’t much help as I could never have been described as cool.
Is the answer that we need Apple - the makers of the iPod and iPhone – to design the new iBolly or perhaps persuade Posh and Becs to carry around one of our Society unbrellas (which by the way are very reasonably priced for that special someone in your life). Or should we resign ourselves to the fact that the younger generation would rather be at one with the elements that be seen dead carrying one of our most British of traditions – and to think, they will never have that life experience of getting half way home and remembering that they have just left there nice new umbrella on the bus.
I just couldn’t believe how many people were walking around just getting soaked because they didn’t have an umbrella. Now this is where I’m going to sound a bit like an old fogy, but there were all young people! My very unscientific survey suggested that 100% of people over 60 were brollied-up, some 50% of 60-30 year olds (of which I fall into) had umbrellas, but to my great dismay, not a single young person was carrying an umbrella (excuse my arbitrary definition of ‘young’).
So when did it become uncool to carry an umbrella. I was trying to think back to my younger days and whether I carried a brolly around with me. I did, but I then realised that this wasn’t much help as I could never have been described as cool.
Is the answer that we need Apple - the makers of the iPod and iPhone – to design the new iBolly or perhaps persuade Posh and Becs to carry around one of our Society unbrellas (which by the way are very reasonably priced for that special someone in your life). Or should we resign ourselves to the fact that the younger generation would rather be at one with the elements that be seen dead carrying one of our most British of traditions – and to think, they will never have that life experience of getting half way home and remembering that they have just left there nice new umbrella on the bus.
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