Archive for the ‘Protons for Breakfast’ Category

Hazards of Flying

November 17, 2019

Radiation Dose

Radeye in Cabin

RadEye Geiger Counter on my lap in the plane.

It is well-known that by flying in commercial airliners, one exposes oneself to increased intensity of ionising radiation.

But it is one thing to know something in the abstract, and another to watch it in front of you.

Thus on a recent flight from Zurich I was fascinated to use a Radeye B20-ER survey meter to watch the intensity of radiation rise with altitude as I flew home.

Slide1

Graph showing the dose rate in microsieverts per hour as a function of time before and after take off. The dose rate at cruising altitude was around 25 times on the ground.

Slide2

During the flight from Zurich, the accumulated radiation dose was almost equal to my entire daily dose in the UK.

The absolute doses are not very great (Some typical doses). The dose on flight from Zurich (about 2.2 microsieverts) was roughly equivalent to the dose from a dental X-ray, or one whole day’s dose in the UK.

But for people who fly regularly the effects mount up.

Given how skittish people are about exposing themselves to any hazard I am surprised that more is not made of this – it is certainly one more reason to travel by train!

CO2 Exposure

Although I knew that by flying I was exposing myself to higher levels of radiation – I was not aware of how high the levels of carbon dioxide can become in the cabin.

I have been using a portable detector for several months. I was sceptical that it really worked well, and needed to re-assure myself that it reads correctly. I am now more or less convinced and the insights it has given have been very helpful.

In fresh air the meter reads around 400 parts per million (ppm) – but in the house, levels can exceed this by a factor of two – especially if I have been cooking using gas.

One colleague plotted levels of CO2 in the office as a function of the number of people using the office. We were then able to make a simple airflow model based on standard breathing rates and the specified number of air changes per hour.

Slide5

However I was surprised at just how high the levels became in the cabin of an airliner.

The picture below shows CO2 levels in the bridge leading to the plane in Zurich Airport. Levels around 1500 ppm are indicative very poor air quality.

Slide3

Carbon dioxide concentration on the bridge leading to the plane – notice the rapid rise.

The picture below shows that things were even worse in the aeroplane cabin as we taxied on the tarmac.

Slide4

Carbon dioxide concentration measured in the cabin while we taxied on the ground in Zurich.

Once airborne, levels quickly fell to around 1000 ppm – still a high level – but much more comfortable.

I have often felt preternaturally sleepy on aircraft and now I think I know why – the spike in carbon dioxide concentrations at this level can easily induce drowsiness.

One more reason not to fly!

 

 

 

Getting there…

November 14, 2019

Life is a journey to a well-known destination. It’s the ‘getting there’ that is interesting.

The journey has been difficult these last few weeks. But I feel like I am ‘getting there

Work and non-work

At the start of 2019 I moved to a 3-day working week, and at first I managed to actually work around 3-days a week, and felt much better for it.

But as the year wore on, I have found it more difficult to limit my time at work. This has been particularity intense these last few weeks.

My lack of free time has been making me miserable. It has limited my ability to focus on things I want to do for personal, non-work reasons.

Any attention I pay to a personal project – such as writing this blog – feels like a luxurious indulgence. In contrast, work activities acquire a sense of all-pervading numinous importance.

But despite this difficulty – I feel like I am better off than last year – and making progress towards the mythical goal of work-life balance on the way to a meaningful retirement.

I am getting there!

Travelling 

Mainly as a result of working too much, I am still travelling too much by air. But on some recent trips to Europe I was able to travel in part by train, and it was surprisingly easy and enjoyable.

I am getting there! By train.

My House

The last of the triple-glazing has been installed in the house. Nine windows and a door (around £7200 since you asked) have been replaced.

Many people have knowingly askedWhat’s the payback time?

  • Using financial analysis the answer is many years.
  • Using moral and emotional analysis, the payback has been instantaneous.

It would be shameful to have a house which spilt raw sewage onto the street. I feel the same way about the 2.5 tonnes of carbon dioxide my house currently emits every winter.

This triple-glazing represents the first steps in bringing my home up to 21st Century Standards and it is such a relief to have begun this journey.

I will monitor the performance over the winter to see if it coincides with my expectations, and then proceed to take the next steps in the spring of 2020.

I am getting there! And emitting less carbon dioxide in the process

Talking… and listening

Physics in Action 3

Yesterday I spoke about the SI to more than 800 A level students at the Emmanuel Centre in London. I found the occasion deeply moving.

  • Firstly, the positivity and curiosity of this group of group of young people was palpable.
  • Secondly, their interest in the basics of metrology was heartwarming.
  • Thirdly, I heard Andrea Sella talk about ‘ice’.

Andrea’s talked linked the extraordinary physical properties of water ice to the properties of ice on Earth: the dwindling glaciers and the retreat of sea-ice.

He made the connection between our surprise that water ice was in any way unusual with the journalism of climate change denial perpetrated by ‘newspapers’ such as the Daily Mail.

This link between the academic and the political was shocking to hear in this educational context – but essential as we all begin our journey to a new world in which we acknowledge what we have done to Earth’s climate.

We have a long way to go. But hearing Andrea clearly and truthfully denounce the lies to which we are being exposed was personally inspiring.

We really really are getting there. 

What it takes to heat my house: 280 watts per degree Celsius above ambient

August 16, 2019

Slide1

The climate emergency calls on us to “Think globally and act locally“. So moving on from distressing news about the Climate, I have been looking to reduce energy losses – and hence carbon dioxide emissions – from my home.

One of the problems with doing this is that one is often working ‘blind’ – one makes choices – often expensive choices – but afterwards it can be hard to know precisely what difference that choice has made.

So the first step is to find out the thermal performance of the house as it is now. This is as tedious as it sounds – but the result is really insightful and will help me make rational decisions about how to improve the house.

Using the result from the end of the article I found out that to keep my house comfortable in the winter, for each degree Celsius that the average temperature falls below 20 °C, I currently need to use around 280 W of heating. So when the temperature is 5 °C outside, I need to use 280 × (20 – 5) = 4200 watts of heating.

Is this a lot? Well that depends on the size of my house. By measuring the wall area and window area of the house, this figure allows me to work out the thermal performance of the walls and windows. And then I can estimate how much I could reasonably hope to improve the performance by using extra insulation or replacing windows. These details will be the topic of my next article.

In the rest of this article I describe how I made the estimate for my home which uses gas for heating, hot water, and cooking. My hope is it will help you make similar estimates for your own home.

Overall Thermal Performance

The first step to assessing the thermal performance of the house was to read the gas meter – weekly: I did say it was tedious. I began doing that last November.

One needs to do this in the winter and the summer. Gas consumption in winter is dominated by heating, and the summer reading reveals the background rate of consumption for the other uses.

My meter reads gas consumption in units of ‘hundreds of cubic feet’. This archaic unit can be converted to energy units – kilowatt-hours using the formula below.

Energy used in kilowatt-hours = Gas Consumption in 100’s of cubic feet × 31.4

So if you consume 3 gas units per day i.e. 300 cubic feet of gas, then that corresponds to 3 × 31.4 = 94.2 kilowatt hours of energy per day, and an average power of 94.2 / 24 = 3 925 watts.

The second step is to measure the average external temperature each week. This sounds hard but is surprisingly easy thanks to Weather Underground.

Look up their ‘Wundermap‘ for your location – you can search by UK postcode. They have data from thousands of weather stations available.

To get historical data I clicked on a nearby the weather station (it was actually the one in my garden [ITEDDING4] but any of the neighbouring ones would have done just as well.)  I then selected ‘weekly’ mode and noted down the average weekly temperature for each week in the period from November 2018 to the August 2019.

Slide3

Weather history for my weather station. Any nearby station would have done just as well. Select ‘Weekly Mode’ and then just look at the ‘Average temperature’. You can navigate to any week using the ‘Next’ and ‘Previous’ buttons, or by selecting a date from the drop down menus

Once I had the average weekly temperature, I then worked out the difference between the internal temperature in the house – around 20 °C and the external temperature.

I expected that the gas consumption to be correlated with the difference from 20 °C, but I was surprised by how close the correlation was.

Slide2

Averaging the winter data in the above graph I estimate that it takes approximately 280 watts to keep my house at 20 °C for each 1 °C that the temperature falls below 20 °C.

Discussion

I have ignored many complications in arriving at this estimate.

  • I ignored the variability in the energy content of gas
  • I ignored the fact that less than 100% of the energy of the gas is use in heating

But nonetheless, I think it fairly represents the thermal performance of my house with an uncertainty of around 10%.

In the next article I will show how I used this figure to estimate the thermal performance – the so-called ‘U-values’ – of the walls and windows.

Why this matters

As I end, please let me explain why this arcane and tedious stuff matters.

Assuming that the emissions of CO2 were around 0.2 kg of CO2 per kWh of thermal energy, my meter readings enable me to calculate the carbon dioxide emissions from heating my house last winter.

The graph below shows the cumulative CO2 emissions…

Slide4

Through the winter I emitted 17 kg of CO2 every day – amounting to around 2.5 tonnes of CO2 emissions in total.

2.5 tonnes????!!!!

This is around a factor of 10 more than the waste we dispose of or recycle. I am barely conscious that 2.5 tonnes of ANYTHING have passed through my house!

I am stunned and appalled by this figure.

Without stealing the thunder from the next article, I think I can see a way to reduce this by a factor of three at least – and maybe even six.

Gravity Wave Detector#1

July 6, 2017
Me and Albert Einstein

Not Charlie Chaplin: That’s me and Albert Einstein. A special moment for me. Not so much for him.

I belong to an exclusive club! I have visited two gravity wave detectors in my life.

Neither of the detectors have ever detected gravity waves, but nonetheless, both of them filled me with admiration for their inventors.

Bristol, 1987 

In 1987, the buzz of the discovery of high-temperature superconductors was still intense.

I was in my first post-doctoral appointment at the University of Bristol and I spent many late late nights ‘cooking’ up compounds and carrying out experiments.

As I wandered around the H. H. Wills Physics department late at night I opened a door and discovered a secret corridor underneath the main corridor.

Stretching for perhaps 50 metres along the subterranean hideout was a high-tech arrangement of vacuum tubing, separated every 10 metres or so by a ‘castle’ of vacuum apparatus.

It lay dormant and dusty and silent in the stillness of the night.

The next day I asked about the apparatus at morning tea – a ritual amongst the low-temperature physicists.

It was Peter Aplin who smiled wryly and claimed ownership. Peter was a kindly antipodean physicist, a generalist – and an expert in electronics.

New Scientist article from 1975

New Scientist article from 1975

He explained that it was his new idea for a gravity wave detector.

In each of the ‘castles’ was a mass suspended in vacuum from a spring made of quartz.

He had calculated that by detecting ‘ringing’ in multiple masses, rather than in a single mass, he could make a detector whose sensitivity scaled as its Length2 rather than as its Length.

He had devised the theory; built the apparatus; done the experiment; and written the paper announcing that gravity waves had not been detected with a new limit of sensitivity.

He then submitted the paper to Physical Review. It was at this point that a referee had reminded him that:

When a term in L2 is taken from the left-hand side of the equation to the right-hand side, it changes sign. You will thus find that in your Equation 13, the term in L2 will cancel.

And so his detector was not any more sensitive than anyone else’s.

And so…

If it had been me, I think I might have cried.

But as Peter recounted this tale, he did not cry. He smiled and put it down to experience.

Peter was – and perhaps still is – a brilliant physicist. And amongst the kindest and most helpful people I have ever met.

And I felt inspired by his screw up. Or rather I was inspired by his ability to openly acknowledge his mistake. Smile. And move on.

30 years later…

…I visited Geo 600. And I will describe this dramatically scaled-up experiment in my next article.

P.S. (Aplin)

Peter S Aplin wrote a review of gravitational wave experiments in 1972 and had a paper at a conference called “A novel gravitational wave antenna“. Sadly, I don’t have easy access to either of these sources.

 

Not everything is getting worse!

April 19, 2017

Carbon Intensity April 2017

Friends, I find it hard to believe, but I think I have found something happening in the world which is not bad. Who knew such things still happened?

The news comes from the fantastic web site MyGridGB which charts the development of electricity generation in the UK.

On the site I read that:

  • At lunchtime on Sunday 9th April 2017,  8 GW of solar power was generated.
  • On Friday all coal power stations in the UK were off.
  • On Saturday, strong winds and solar combined with low demand to briefly provide 73% of power.

All three of these facts fill me with hope. Just think:

  • 8 gigawatts of solar power. In the UK! IN APRIL!!!
  • And no coal generation at all!
  • And renewable energy providing 73% of our power!

Even a few years ago each of these facts would have been unthinkable!

And even more wonderfully: nobody noticed!

Of course, these were just transients, but they show we have the potential to generate electricity which has a significantly low carbon intensity.

Carbon Intensity is a measure of the amount of carbon dioxide emitted into the atmosphere for each unit (kWh) of electricity generated.

Wikipedia tells me that electricity generated from:

  • Coal has a carbon intensity of about 1.0 kg of CO2 per kWh
  • Gas has a carbon intensity of about 0.47 kg of CO2 per kWh
  • Biomass has a carbon intensity of about 0.23 kg of CO2 per kWh
  • Solar PV has a carbon intensity of about 0.05 kg of CO2 per kW
  • Nuclear has a carbon intensity of about 0.02 kg of CO2 per kWh
  • Wind has a carbon intensity of about 0.01 kg of CO2 per kWh

The graph at the head of the page shows that in April 2017 the generating mix in the UK has a carbon intensity of about 0.25 kg of CO2 per kWh.

MyGridGB’s mastermind is Andrew Crossland. On the site he has published a manifesto outlining a plan which would actually reduce our carbon intensity to less than 0.1 kg of CO2 per kWh.

What I like about the manifesto is that it is eminently doable.

And who knows? Perhaps we might actually do it?

Ahhhh. Thank you Andrew.

Even thinking that a good thing might still be possible makes me feel better.

 

Science in the face of complexity

February 4, 2016
Jeff Dahn: Battery Expert at Dalhousie University

Jeff Dahn: Battery Expert at Dalhousie University

My mother-in-law bought me a great book for Christmas: Black Box Thinking by Matthew Syed: Thanks Kathleen 🙂

The gist of the book is easy to state: our cultural attitude towards “failure”- essentially one of blame and shame – is counter productive.

Most of the book is spent discussing this theme in relation to the practice of medicine and the law, contrasting attitudes in these areas to those in modern aviation. The stories of unnecessary deaths and of lives wasted are horrific and shocking.

Engineering

But when he moves on to engineering, the theme plays out more subtly. He discusses the cases of James Dyson, the Mercedes Formula 1 team, and David Brailsford from Sky Cycling. All of them have sought success in the face of complexity.

In the case of Dyson, his initial design of a ‘cyclone-based’ dust extractor wasn’t good enough, and the theory was too complex to guide improvements. So he started changing the design and seeing what happened. As recounted, he investigated 5,127 prototypes before he was satisfied with the results. The relevant point here is that his successful design created 5,126 failures.

One of his many insights was to devise a simple measurement technique that detected tiny changes in the effectiveness of his dust extraction: he sucked up fine white dust and blew the exhaust over black velvet.

Jeff Dahn

This approach put me in mind of Jeff Dahn, a battery expert I met at Dalhousie University.

Batteries are really complicated and improving them is hard because there are so many design features that could be changed. What one wants is a way to test as many variants as quickly and as sensitively as possible in order to identify what works and what doesn’t.

However when it comes to battery lifetime – the rate at which the capacity of a battery falls over time – it might seem inevitable that this would take years.

Not so. By charging and discharging batteries in a special manner and at elevated temperatures, it is possible to accelerate the degradation. Jeff then detects this with precision measurements of the ‘coulombic efficiency’ of the cell.

‘Coulombic efficiency’ sounds complicated but is simple. One first measures the electric current as the cell is charged. If the electric current is constant during charging then the electric current multiplied by the charging time gives the total amount of electric charge stored in the cell. One then measures the same thing as the cell discharges.

For the lithium batteries used in electric cars and smart phones, the coulombic efficiency is around 99.9%. But it is that tiny of amount (less than 0.1%) of the electric charge which doesn’t come back that is progressively damaging the cell and limiting it’s life.

One of Jeff’s innovations is the application of precision measurement to this problem. By measuring electric currents with uncertainties of around one part in a million, Jeff can measure that 0.1% of non-returned charge with an uncertainty of around 0.1%. So he can distinguish between cells that 99.95% efficient and 99.96% efficient. That may not sound much, but the second one is 20% better!

By looking in detail at the Coulombic efficiencyJeff can tell in a few weeks whether a new design of electrode will improve or degrade battery life.

The sensitivity of this test is akin to the ‘white dust on black velvet’ test used by Dyson: it doesn’t tell him why something got better or worse – he has to figure that out for himself. But it does tell him quickly which things were bad ideas.

I couldn’t count the ammeters in Jeff’s lab – each one attached to a test cell – but he was measuring hundreds of cells simultaneously. Inevitably, most of these tests will make the cells perform worse and be categorised as ‘failures’.

But this system allows him to fail fast and fail often: and it is this capability that allows him to succeed at all. I found this application of precision measurement really inspiring.

Thanks Jeff.

 

 

 

 

 

Explanations are not always possible.

April 28, 2015
I asked Google how to get from NPL to Richmond and it assumed I meant Richmond Virginia instead of Richmond upon Thames which is 5 kilometres away.

I asked Google how to get from NPL to Richmond and it assumed I meant Richmond, Virginia, USA instead of Richmond upon Thames which is 5 kilometres away. 

I have spent a fair amount of time in my life trying to explain things to people. But I think now – in all but the most basic of cases – explanations are impossible.

The reason I feel this is because I think that giving an explanation is like giving directions. And most people will acknowledge that unless you know where someone is ‘starting from’, it is impossible to give general directions to a given ‘destination’.

But while we accept that every set of directions should start with the question: “Where are you now?“, people are reluctant to acknowledge that logically every explanation should start with the question: “What do you know now?”.

Instead there seems to be a widespread belief that explanations can exist ‘by themselves’.

Of course we can draw maps and then explain how to navigate the map. And if someone can follow this, then they can learn the route to a particular ‘destination’. Or someone might already be familiar with the ‘landscape’. In these cases explanations are possible.

But many people find maps difficult. However:

  • Getting someone to drive you to a destination does not in general teach you the route.
  • And programming a ‘sat-nav’ to take someone to a particular location will also – in general – fail to teach them the route. They may have ‘arrived’ but they will be ‘lost’.
  • Travelling by tube to a location teaches them nothing about where they are!

Similarly, by sophistry, or by entertaining imagery, it is possible to give people the illusion that they understand something. But unless they can link this new state of insight to their previous understanding, they will still be ‘lost’.

I thought I would illustrate the general idea with a picture of a route on a Google map. But when I tried to generate a route from Teddington to nearby Richmond (upon Thames), Google assumed that the word ‘Richmond’ referred to the much more populous Richmond, Virginia!

And the impossibility of explanations is clear in this video of Dave Allen ‘explaining’ how to tell the time. It features the classic lines:

“There are three hands on a clock. The first hand is the hour hand, the second hand is the minute hand, and the third hand is the second hand.”

Enjoy.

Theories and Facts about Santa Claus

December 21, 2014

My friend Alom Shaha recently scripted the video above to try to explain the concept of ‘a scientific theory’.

I like the video, but I feel one point gets lost. And that is that  ‘theories’ are like ‘plot lines’ in a TV detective programme – they link together ‘the facts’ to tell ‘a story’.

Example#1: Café Mimmo

  • I am observed at 10:15 a.m. leaving my house on Church Road
  • I am observed at 10:21 a.m. at the junction of Church Road and Walpole St.
  • I am observed at 10:27 a.m. near to Café Mimmo on Broad Street.
  • I am observed at 10:28 a.m. in Café Mimmo on Broad Street.
  • I am observed at 10:58 a.m. walking North on Church Road.

These are ‘the facts’. But what is really going on? Is there a ‘story’ that links all these facts together? Let me propose a theory:

  • Theory: Michael goes for coffee every day at Café Mimmo

This theory links all these facts i.e. it explains how they relate to each other.

If this is a good theory, it ought to be able to predict new facts – and these predictions could then be checked.

Notice that the theory doesn’t specify the route I take to the Café. So even though the theory explains why I was seen on Church Road, it doesn’t predict that I always will be.

But the theory does predict that I will go to Café Mimmo every day. This could be easily tested. And if I didn’t visit every day, the theory could either be invalidated, or it might need to be revised to state Michael goes for coffee most days at Café Mimmo

I am sure you get the idea. But notice how the theory is simpler and more meaningful than a large number of facts. Facts tells us ‘what happened’, but theories tell us ‘what’s going on’.

Example#2: Santa Claus

  • On Christmas Day (usually, but sometimes on Christmas Eve) children all around the world receive presents.
  • On Christmas Eve parents leave out gifts – typically whisky (please) and a carrot – and these gifts are at least partly consumed by the morning.

These are ‘the facts’. But is there a theory that links these facts together? In fact there are two theories.

The traditional theory is that a mysterious being known as ‘Santa Claus’ delivers the presents on a sleigh pulled by flying reindeer and filled with an improbably large bag of toys.

Alternatively, some people contend that there is a vast conspiracy in operation in which otherwise honest and rational parents consistently lie to their children, year after year. According to this theory, it is in fact parents that buy all the presents, and fabricate forensic evidence of a visit by the fictional being ‘Santa Claus’.

The traditional theory has been heavily criticised, largely due to the unknown identity and quasi-magical abilities of the ‘Santa Claus’ figure.

However, I have never been a fan of conspiracy theories – they always seem rather unlikely to me. In particular I am sceptical that millions upon millions of parents would systematically lie to their children. I would never do such a thing.

So I will leave it up to you to imagine experiments that you could perform that would help to decide which theory is in fact correct.

One obvious experiment is to stay up late on Christmas Eve and watch for the arrival of ‘Santa Claus’.

But can I please ask you to be careful: Santa Claus is known never to bring gifts to boys and girls that don’t go to sleep at night. So use a webcam.

But whatever you believe: I hope you have a Happy Christmas 🙂

Protons for Breakfast

December 14, 2014
The last few moments of the 20th presentation of Protons for BReakfast. (Picture by Lindsay Chapman)

The last few moments of the 20th presentation of Protons for Breakfast. (Picture by Lindsay Chapman)

Last Thursday I finished the twentieth and final presentation of Protons for Breakfast and this weekend I am busy trying to do nothing. Mainly sleeping, but in turn feeling sad, happy, proud and relieved.

I am lost for words. However, despite being lost for words, I want to say three things.

Thing one: Thank you

I have loved putting on the course and learned so much in so many ways in doing so. So the first words are simple:

  • Thank You.

To whom?

  • To ‘the helpers’ without whom the course would not be possible: it is rare to have such great colleagues and friends.
  • To the expert helpers – especially those who travelled to take part.
  • To my wife and children who have put up with 12 weeks of psychological absence each year for the last 10 years.
  • To NPL management, especially Fiona Auty, who has supported this kind of thoroughly non-corporate outreach.
  • To everyone who attended, because fundamentally the course was for, and about, you rather than me.

And finally to Jorge Ramirez who – just when I thought I had been given the ultimate gift (a framed triple-point of water cell!) topped that with the Protons for Breakfast Song!

Thing two: So why am I stopping?

Protons for Breakfast is a very personal course: and it needs to be presented by me.

That is part of what has made it successful – that I am genuinely present and not reading from any kind of script – but ultimately that makes it unsustainable.

This wasn’t what I thought originally. I had hoped that members of the team of helpers would take over parts of the course and that gradually it would become more of ‘a production’.

However, making that shift would have involved much more work – and since I wasn’t able to make that change, it seemed better to just keep on doing what we had been doing.

The immediate reason for stopping now doesn’t really matter. But the more profound reason is that this kind of activity – relatively free-form and focussed on a particular individual – does not sit easily in any kind of modern corporate structure.

So despite the good will and support from many individuals, ending the course while it was popular and successful was probably best for all concerned.

And hopefully NPL or someone else will ‘pick the bones’ of the course and create a replacement that is sustainable.

Thing three: What Next?

I don’t know. And at this point, I don’t want to think about it.

But I do have a few ideas! And if I ever catch my breath and get my energy back, perhaps I will actually make them real. Because:

Protons for Breakfast… is what you need…
Protons for Breakfast… will get you thinking…

 

I love data

November 24, 2014
Lake Windemere on a misty morning - or at least that what Wikipedia claims this is.

Lake Windemere on a misty morning – or at least that’s what Wikipedia claims this is.

Lake Windemere in the UK’s Lake District is beautiful.

Standing alone, as from a rampart’s edge,
I overlooked the bed of Windermere,
Like a vast river, stretching in the sun.
With exultation, at my feet I saw
Lake, islands, promontories, gleaming bays,
A universe of Nature’s fairest forms
Proudly revealed with instantaneous burst,
Magnificent, and beautiful, and gay.

Thus Wordsworth described what he saw..

The UK’s Lake Ecological Observatory Network (UKLEON) also ‘looks’ at Lake Windemere and eight other lakes. Its observations are recorded less poetically than Wordsworth’s. But its data tells a story that Wordsworth missed: the story of how the lake interacts with its environment.

For example, the graph below shows the temperature of Lake Windemere at different depths below its surface. The data tell us that below 20 metres, the lake undergoes only a small seasonal temperature change. Nearer the surface the seasonal temperature changes are more dramatic, with the upper few metres showing changes of 18 °C from winter to summer.

Temperature verus depth profiles in Lake Windemere for the last year. The data show that below 20 metres, the lake undergoes a small seasonal temperature change. Nearer the surface the seasonal temperature changes are more dramatic with the upper few metres showing changes of 18 °C.

Temperature versus depth profiles in Lake Windemere for the last year.

Looking at the corresponding data for Blelham Tarn, a smaller lake which feeds into Windemere, we see strikingly similar changes but with differences that reflect the ecology of that particular lake.

LEON Blelham Tarn

Temperature versus depth profiles in Blelham Tarn for the last year.

UKLEON makes lots of data available to allow a wide range of studies of lake ecology. Specifically data is available on:

Air Temperature;  Barometric Pressure; Wind speed; Wind Direction (from vector addition of unit length vectors); Solar radiation; Surface photosynthetically available radiation; Surface water temperature; Temperature Profiles; Underwater photosynthetically available radiation (1m);  Conductivity normalised to 25 degrees C; pH; Dissolved oxygen (% saturation); Dissolved oxygen (mg per litre); Dissolved carbon dioxide; Chlorophyll a concentration (relative units); Phycocyanin concentration (relative units).

And UKLEON is just a small part of the UK Environmental Change Network, UKECN. Through this portal you can gain access to a wider range of data in a wider range of environments.

For example the figure below shows the earliest recorded spawning date for frogs over a period of 13 years to 2010. Who knew that data was available? Or maybe you are interested in butterfly counts? UK ECN has the data for you.

Graph showing the day of year on which frogs were first observed to spawn at 9 different sites around the UK.

The day of year on which frogs were first observed to spawn at 9 different sites around the UK.

I am not an ecologist, and so I don’t understand the significance of many of these measured quantities.

But I love the fact that the data is available for anyone to look at and perhaps make their own discoveries.

 


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