COP29 will take place in Azerbaijan in November 2024.
Adapt these ideas to support your teaching in the weeks leading up to and during the conference to engage your students with the negotiations and where they are taking place:
Priorities for COP29 include:
Climate finance to developing countries to support climate change mitigation and adaptation.
Encouraging countries to commit to more ambitious greenhouse gas emission reduction targets by 2035
Developing a global carbon market
Greening education
Azerbaijan in context
Using google maps, explore where Azerbaijan is, who its neighbours are, how big it is (how many times the size of Wales), it’s in Eurovision, but is it in Europe?
Contour drawing practice – the sketch map below has selected November temperatures for Azerbaijan. Draw the 10°C contour. (Click on image for an easy to print pdf)
What are Azerbaijan’s total emissions/ emissions per person/ emissions per GDP like compared to other countries? (use the graphs to ask specific questions such as how much more greenhouse gasses did the UK emit per person from fossil fuels in 2022 than Azerbaijan?)
How have Azerbaijan’s emissions changed over time?
How vulnerable is Azerbaijan to climate change? What impact of climate change (sea level change, river flooding, drought, disease or conflict) poses the greatest risk to Azerbaijan?
Climate justice recognises the fact that the people and countries most vulnerable to climate change are often not the ones who have done the most to cause it. Thinking about Azerbaijan’s greenhouse gas emissions, GDP and vulnerability to climate change, write a paragraph to justify this definition of climate justice.
Possible extension – Azerbaijan’s climate mitigation action is rated ‘critically insufficient’ by the Climate Action Tracker. How does this relate to the concept of climate justice?
We have two fieldwork based resources which allow students to investigate the microclimate of their schools – inside and out – during a heatwave and then evaluate potential adaptation options.
All schools in England have to produce a Climate Action Plan, and part of that action plan involves assessing the schools’ vulnerability to extreme weather, such as heatwaves, and taking actions to reduce the risk of extreme heat.
These fieldwork options are designed to allow secondary geography students in our schools to explore how vulnerable their school is and what can be done to adapt to that risk.
This resource has been developed by Rob Gamesby (Cool Geography) with the Royal Meteorological Society and the Field Studies Council for the National Festival of Fieldwork.
All schools in England have to produce a Climate Action Plan, and part of that action plan involves assessing the schools’ vulnerability to extreme weather, such as heatwaves, and taking actions to reduce the risk of extreme heat.
These fieldwork options are designed to allow secondary geography students in our schools to explore how vulnerable their school is and what can be done to adapt to that risk.
Why you need one; what to buy; where to put it; what to do with the data.
Geoff Jenkins 2014
Why does our school need a weather station?
There are lots of reasons why a weather station will be welcomed as a valuable new resource to the school. Some of those given below are more suited to primary schools, others to secondary ones.
The National Curriculum requires weather to be measured. Weather and climate feature several times in the new (2014) English National Curriculum for geography. In science, the Year 1 PoS requires that “pupils should be taught to observe changes across the four seasons, and observe and describe weather associated with the seasons”. Guidance suggests that “Pupils should observe and talk about changes in the weather, and work scientifically by making tables and charts about the weather.” And in Years 3 and 4 they should “make systematic observations using … thermometers and data loggers”.
Weather also links naturally into many other subjects such as History (weather affecting the outcome of battles, eg D-day), ICT (make your own instruments, weather blog/website, linking to the internet), Maths (analysing and plotting real-world data), English (write stories about unusual weather – maybe even get the local paper interested in printing a routine report), Art (Turner, Constable, etc) and even Sport (performance in different conditions).
Having a display of current weather, perhaps in the school’s main foyer, is a great general resource and talking point, especially at times of unusual weather – hot days, cold mornings, torrential rain and so on. In primary schools this can get pupils used to thinking scientifically, using units (ºC, mm of rain, etc.) and decimals. They will also learn to associate measurements of weather with their personal comfort, for example outside at break time. It can also help with practical decisions, eg has there been too much rain today to allow the playing field to be used?
Even a cheap weather station can be linked to a computer, so that readings from the weather station can be shown on the school’s website; this will impress parents and prospective parents. If the school is in a village or small town that is unlikely to have any other weather station, then this information can be useful for others in the community and help build links.
You can add many other features to the website weather display, such as satellite photographs, weather maps and even your own webcam looking at the sky. You could add pupils’ own photographs of weather events, such as frost or snow.
With the right (free) software, your weather readings can be sent automatically to the Met Office, where they are shown hour-by-hour on a website (called WOW) alongside thousands of others from all over the world – a great resource when teaching about UK and world climate.
A weather station can be used as an integral part of a school Weather Club, Environment Club or Science Club.
Extreme weather seems to make the TV news headlines very frequently. So what was the weather like at our school yesterday when there was heavy flooding in Somerset or damaging winds in Wales?
What type of weather station should we buy?
The first choice you need to make is between a traditional manual weather station and a wireless automatic station. These are described below together with some discussion of pros and cons in each case. If you have already decided you want an automatic type then skip the next section.
A traditional manual weather station
This type uses instruments to measure temperature, including maximum and minimum, and humidity, kept in a white louvred screen (“Stevenson screen”) to keep sunshine from warming up the instruments. Alongside this will be a rain gauge on the ground. The photos below show such an arrangement using glass thermometers, but mechanical (dial-type) ones can be used just as well. Wind measurements can be made with a hand-held anemometer, and pressure using a barometer on the classroom wall. More about setting up this type of weather station, and the instruments that could be used, can be found at:
Typically, a couple of pupils will be assigned to go outside in the morning and at lunch time, and jot down readings, and display them in the classroom or foyer. If you want to keep long term records then they can be entered into a log book or (more commonly these days) a spreadsheet. One big advantage of using manual instruments is that they have to be read, which gives lots of practice with scales and units
(Left) A traditional manual weather station, with thermometers for measuring humidity (left) and maximum and minimum temperature (right), in a small louvered screen. (Right) A simple plastic rain gauge with, alongside, a cylinder to measure the rainfall collected.
How much does it all cost? The collection of instruments illustrated above can be bought separately for a total of about £100 (including a self-assembly screen). Anemometers will be around £60, and a barometer about £20. Although the Royal Meteorological Society does not recommend specific instruments, suppliers such as MetCheck and Brannan carry a wide range and can be found easily online.
What about using instruments we make ourselves? There are plenty of examples shown at: https://www.metlink.org/experiments/ and while these are great for teaching principles, they are generally not accurate or robust enough to be used outside for long periods.
A wireless automatic weather station
Wireless automatic weather stations (AWS) send all the information you need right into your classroom. They have two separate parts, outdoor and indoor, as illustrated below. A number of sensors are mounted outside on a mast attached to a building, with electronics that transmits data to a receiver console inside the school. Most AWS will measure temperature, humidity, rainfall, wind speed and wind direction. The indoor console will display these measurements (plus pressure), and in many cases also store them for a few weeks; they can then be downloaded into a PC using a USB cable. The weather station can be taken out of the box and set up by someone without a detailed technical knowledge of either weather or computing, using the instruction book provided.
A typical wireless automatic weather station costing around £60, with the sensor array outdoors (left) and the console which displays and records the data (right). But don’t put too much faith in the forecast shown.
A wireless automatic weather station and indoor console at the other end of the price range, costing around £900.
The price of such a weather station can be anywhere from £60 up to £900. In general, you get what you pay for, and pricier stations will generally be more accurate and reliable, and measure more things (solar radiation, for example). In many cases, the main problem with budget weather stations is that the temperature and humidity sensors aren’t very well screened from sunshine, so they can often read a few degrees too high. But even if you cannot afford to spend a few hundred pounds, quite a lot can be got from stations at the lower end of the market, so lack of massive funds should not stop you buying something.
Although the Royal Meteorological Society does not recommend specific instruments, suppliers such as Maplin, Oregon, ProData and Weathershop carry a wide range of products and can be found easily online.
Where should we put it?
The good news is: you are not trying to be an official Met Office station! Many schools and enthusiasts are deterred from setting up a weather station because they think that observations can only be made if you have a large expanse of open area away from buildings. This just isn’t true – perfectly good readings can be taken in pretty much any situation – many schools and amateurs attach their stations to the top of a building wall. It all comes down to what the readings represent – most Met Office stations are needed to represent weather that occurs in open, unsheltered, conditions, so there are strict rules about proximity to buildings and trees. In addition, measurements of different weather elements have to be at set heights above the ground: temperature and humidity at 1.2m, rainfall at 0.3m and wind speed and direction at 10m. But your weather station doesn’t have to do all this, it just has to represent what the weather is like around your school – which may be similar to that around many other schools and back gardens, but will probably be nothing like that at a Met Office station. So do not let a lack of perfect exposure to weather put you off setting up a station.
Having said that, if you are lucky enough to have an area at ground level which is as open to the weather, and can provide a pole for the anemometer and some fencing to protect the station, then your data will look more like that at official stations.
As noted above, one common method for mounting a wireless automatic weather station is on the side of a wall, poking above a roof, perhaps on an outbuilding (see photos below). If possible, put the anemometer and wind vane up higher than the other instruments so that the speed and direction of the wind is less affected by buildings. You could even attach it to an existing lamppost or tall fence.
The transmitter part of the weather station has to be reasonably close to the receiver console, somewhere between 50m and 300m depending on the type, or even closer if the radio signal has to penetrate walls. Always check that you have good reception before you finally decide on a spot.
Vandalism can be a problem, so mount it out of reach, or use fencing (which can be expensive). On the other hand, someone in charge will need to access it from time to time (see next section), so think about the safety issues too.
Two videos (Location Part 1 and Location Part 2) from the London Grid for Learning (LGfL) discuss some of the issues:
You can also Google “school weather station” images, to see examples of what other schools have decided to do – these show both automatic weather stations and traditional manual ones.
The final decision is always going to be a trade-off between several factors: as open to the weather as possible, accessibility for maintenance, security from damage and distance from the receiver. Quite often, you can get a position which isn’t too bad for temperature and humidity, is just about OK for rainfall, but isn’t very good at all for wind speed and direction. Remember, do the best you can, but a less-than-perfect exposure is better than nothing. But bear in mind the deficiencies of location when comparing with other schools etc.
(Left) A well exposed station at Sutton, part of the LGfL network, although quite difficult to access. (Centre)The weather station at Maiden Erlegh school. (Right)A typical home weather station on the side of a garage.
What maintenance is needed?
Like most things, a weather station will perform better if it is looked after, but this doesn’t need to be very onerous.
Batteries. Even if the weather station has solar panels, batteries are needed to help the station run at night and during the depths of winter, so need changing periodically. The indoor receiver and console will also need batteries replacing, unless it has a mains adaptor.
Make a visual check from time to time to make sure the mounting pole is still vertical and hasn’t been bent over by high winds – this could affect wind and rainfall observations.
Rain gauges are prone to a couple of common problems that can be easily cured. Firstly, remove any leaves that may have gathered in the collecting funnel as eventually these can block any rain from getting to the measuring mechanism below. Secondly, lift off the funnel and check that there aren’t any spiders’ webs stopping the bucket from tipping – this is more common than you might think.
Keep an eye on your data, and in particular compare it with the nearest station (this is easy to do using the WOW network – see below). There are sometimes tell-tale signs of problems, for example lack of rainfall over a few days compared to a neighbour indicating a blocked gauge, or straight line traces invariably indicating a battery problem. Usually the pressure sensor is inside the receiver console, so if this is still working and the other readings aren’t, this may indicate a problem with the wireless link.
How do we store or disseminate the data?
Of course you don’t have to store any data, you can simply read the console (or the instruments) when you want to and leave it at that, or just note down the weather conditions, for example every morning.
The consoles of many automatic weather stations (even cheap ones) can be plugged into a PC with a USB lead and readings can be displayed on the screen using a programme supplied with the station. The console also usually acts as a logger, to store weather data, typically at 10 min intervals. The same programme also allows you to download the data (maybe every two or three weeks) and keep it as an Excel spreadsheet on the PC. This means you can plot the data on a graph later, or use it for investigations (see later paragraph). An alternative to the manufacturer supplied software is a programme called Cumulus, which is available as donation-ware from www.sandaysoft.com
Cumulus also makes it very straightforward to put your observations on the web, using the Weather Observations Website (WOW) developed by the Met Office and the Royal Meteorological Society. This network shows observations from all over the world and has the following advantages for schools:
Forecasters at the Met Office HQ at Exeter use WOW maps to help them see if their forecast is evolving accurately, so contributing your school’s data will be helping to improve the forecast.
If you zoom in on your own area on the map, you can see how your school’s weather compares with other nearby stations. You can also select the nearest Met Office station to compare with – but remember, that will generally have a perfect open exposure so any differences will be partly due to this.
By clicking on your station, you can show graphs of weather over the past day or month or even longer – and, again, compare your station with a nearby one .
You can see your data as a table, and cut and paste it into an Excel spreadsheet. As this is always available from WOW, you may decide you don’t need to download and save your data yourself.
You can look back at maps of observations hour by hour, even months or years ago. So you can look at a special weather event such as thick fog, a baking hot day or some heavy rainfall. Or perhaps a special event such as Sports Day or a town carnival.
If you zoom out, you can see how your weather compares with that being collected at the same time by schools in Australia or Alaska – an instant geography lesson!
If there is an exciting weather event in some other country, such as a hurricane in Florida or a heatwave in Australia, you might be able to find evidence of it on WOW
WOW can display your weather station data over any time period in the past, in this case a week with warm and dry days and cool and humid nights.
(Left) Using WOW it is easy to compare your readings with other schools or amateurs in the same area. This shows relative humidity in the Reading – Farnham area reported by 17 stations. (Right) Temperatures across the UK at the time of the 2014 London Marathon; cool areas are green, warm areas are orange.
Using WOW for an instant view of world weather (January 2014); on this day the temperature ranged from -20ºC in Alaska to +38ºC in Australia.
How can we use the weather station for teaching activities?
Plot on a graph (using a spreadsheet or manually) pairs of weather elements, to see if there is any correlation between them. These could include rainfall and temperature, rainfall and pressure, temperature and wind speed, or wind speed and time of day. If there does appear to be a correlation, why should this be?
How does weather vary each season? Each month? What has the weather been like over the past week?
Produce a weather report for the day and present it as if you were a TV weather presenter.
Compare your readings with those from a nearby school or schools (you could use WOW for this) and explain the differences. You could forge links with the other school(s) to make this a joint project.
Host visits from other local schools that don’t have a weather station, to tell them what they are missing and help them set up their own.
Invite the Maths department to make full use of your data to teach statistics and graphs or as the basis of projects. This could include the correlations idea, above. Once you have a few years’ data, you can ask questions such as “What is the probability of getting frost at our school”, “How likely am I to get wet if I am playing football outside for an hour” or “Does it rain more at weekends than during the week?”
Once the school has collected, say, 5 years of data, this can be used to look at average conditions, and published (eg on the website) as “The climate of Meldrew School”.
Keep a log (either online or on the PC or even in a book) of “Weather extremes for Meldrew School”. Add the date and time of new extremes of temperature, wind speed etc. New extremes get more exciting as time goes on.
Add in visual observations of clouds (amount and type) and visibility, thunder and lightning, snow, sleet, hail, etc.
Use your school weather station to lead into the topic of climate change by pointing out that it is an affordable version of the sort of weather stations which are deployed in their tens of thousands all over the world. A careful examination of the data from those that have been operating for several decades allows us to say if climate is changing.
The weather station is a natural way to introduce many concepts in science – water vapour as a gas, evaporation and condensation, atmospheric pressure, solar radiation, etc
Compare the weather station data with measurements in different parts of the school using handheld instruments such as anemometers, simple rain gauges and thermometers, to build up a picture of the school’s microclimate
Use the microclimate data collected in the project above to make practical decisions about where would be the best place to put a wind generator, a rainwater collector or a solar panel.
(See in addition some of the points made in the opening page of this note).
Further information
Try Googling “running a school weather station” to see what others have done, and what they get out of it.
There is a wealth of forums on the web, run by both education and weather enthusiasts, where answers to many questions can be found.
Some of the ideas in this paper have come from online articles by Martin Sutton, who runs a weather station at Maiden Erlegh School near Reading. You can read more of his excellent advice at: http://www.weatherstations.co.uk/maiden-erlegh.htm
Collect data and analyse mode, mean and median, range, interquartile range and standard deviation
Introduction: There are many words and many descriptions for different types of rain: fine rain, heavy rain, pelting down, mizzling. In fact the BBC news magazine has an article entitled “Fifty words for rain”. But how big is a rain drop? Does the size vary depending upon the time of year or the type of rain?
Aim: To collect data, manipulate data and analyse data to calculate and compare the size of raindrops.
Equipment Required
A platform of area of about 0.5m2 with edges.
Enough flour to cover the platform to a depth of about 3cm
An accurate measuring device, e.g. electronic sliding callipers.
Collecting the data
Cover the platform with the flour.
Place the platform in the rain for about 90 seconds, long enough for about 200 raindrops to hit the platform.
Use your measuring device to measure the diameter of the raindrops and record the data.
Manipulating, analysing, displaying and interpreting the data
There follows a number of suggestions of how the data can be used depending upon the ability of the students.
1. Calculate the mode, mean and median diameter of raindrop. Which is the most appropriate measure to use? Compare results from different groups.
2. Group the data into appropriate groups. Represent the data using histograms. Discuss whether it is appropriate to have all the groups the same size of vary the size of the groups. Compare the results from different groups. Compare data collected at different times of year if possible.
3. Calculate the spread of the data using range, interquartile range and standard deviation.
4. Discuss different methods of displaying the data. Is the data discrete or continuous? Should a bar chart or a histogram be used? This activity is ideal for discussing when a histogram should be used and the reasons for using a histogram.
5. Draw box plots to show the distribution of the data. Compare the spread of different data sets. What does this information tell us?
6. Write a report comparing the size of raindrops.
Find out about how to borrow weather instruments in order to be able to carry out a microclimate investigation with your school here, or more about urban heat islands here.
A microclimate is the distinctive climate of a small-scale area, such as a garden, park, valley or part of a city. The weather variables in a microclimate, such as temperature, rainfall, wind or humidity, may be subtly different from the conditions prevailing over the area as a whole and from those that might be reasonably expected under certain types of pressure or cloud cover. Indeed, it is the amalgam of many, slightly different local microclimates that actually makes up the microclimate for a town, city or wood.
It is these subtle differences and exceptions to the rule that make microclimates so fascinating to study, and these notes help to identify and explain the key differences which can be noticed by ground-level observations.
What are the different types of microclimates?
In truth, there is a distinctive microclimate for every type of environment on the Earth’s surface, and as far as the UK is concerned they include the following:
Upland regions
Upland areas have a specific type of climate that is notably different from the surrounding lower levels. Temperature usually falls with height at a rate of between 5 and 10 °C per 1000 m, depending on the humidity of the air. This means that even quite modest upland regions, such as The Cotswolds, can be significantly colder on average than somewhere like the nearby Severn Valley in Gloucestershire.
Occasionally, a temperature inversion can make it warmer above, but such conditions rarely last for long. With higher hills and mountains, the average temperatures can be so much lower that winters are longer and summers much shorter. Higher ground also tends to be windier, which makes for harsher winter weather. The effect of this is that plants and animals are often different from those at low levels.
Hills often cause cloud to form over them by forcing air to rise, either when winds have to go over them or they become heated by the sun. When winds blow against a hill-side and the air is moist, the base of the cloud that forms may be low enough to cover the summit. As the air descends on the other (lee) side, it dries and warms, sometimes enough to create a föhn effect. Consequently, the leeward side of hills and mountain ranges is much drier than the windward side. The clouds that form due to the sun’s heating sometimes grow large enough to produce showers, or even thunderstorms. This rising air can also create an anabatic wind on the sunny side of the hill. Sunshine-facing slopes (south-facing in the Northern Hemisphere, north-facing in the Southern Hemisphere) are warmer than the opposite slopes.
Apart from temperature inversions, another occasion when hills can be warmer than valleys is during clear nights with little wind, particularly in winter. As air cools, it begins to flow downhill and gathers on the valley floor or in pockets where there are dips in the ground. This can sometimes lead to fog and/or frost forming lower down. The flow of cold air can also create what is known as a katabatic wind.
Coastal regions
The coastal climate is influenced by both the land and sea between which the coast forms a boundary. The thermal properties of water are such that the sea maintains a relatively constant day to day temperature compared with the land. The sea also takes a long time to heat up during the summer months and, conversely, a long time to cool down during the winter. In the tropics, sea temperatures change little and the coastal climate depends on the effects caused by the daytime heating and night-time cooling of the land. This involves the development of a breeze from off the sea (sea breeze) from late morning and from off the land (land breeze) during the night. The tropical climate is dominated by convective showers and thunderstorms that continue to form over the sea but only develop over land during the day. As a consequence, showers are less likely to fall on coasts than either the sea or the land.
Around the Poles, sea temperatures remain low due to the presence of ice, and the position of the coast itself can change as ice thaws and the sea re-freezes. One characteristic feature is the development of powerful katabatic winds that can sweep down off the ice caps and out to sea.
In temperate latitudes, the coastal climate owes more to the influence of the sea than of the land and coasts are usually milder than inland during the winter and cooler in the summer. However, short-term variations in temperature and weather can be considerable. The temperature near a windward shore is similar to that over the sea whereas near a leeward shore, it varies much more. During autumn and winter, a windward shore is prone to showers while during spring and summer, showers tend to develop inland. On the other hand, a sea fog can be brought ashore and may persist for some time, while daytime heating causes fog to clear inland. A lee shore is almost always drier, since it is often not affected by showers or sea mist and even frontal rain can be significantly reduced. When there is little wind during the summer, land and sea breezes predominate, keeping showers away from the coast but maintaining any mist or fog from off the sea.
Forests
Tropical rainforests cover only about 6% of the earth’s land surface, but it is believed they have a significant effect on the transfer of water vapour to the atmosphere. This is due to a process known as evapotranspiration from the leaves of the forest trees. Woodland areas in more temperate latitudes can be cooler and less windy than surrounding grassland areas, with the trees acting as a windbreak and the incoming solar radiation being ‘filtered’ by the leaves and branches. However, these differences vary depending on the season, i.e. whether the trees are in leaf, and the type of vegetation, i.e. deciduous or evergreen. Certain types of tree are particularly suitable for use as windbreaks and are planted as barriers around fields or houses.
Urban regions
These are perhaps the most complex of all microclimates. With over 75% of the British population being classed as urban, it is no surprise that they are also the most heavily studied by students of geography and meteorology. Therefore, the rest of these notes focus on the various elements that constitute an urban microclimate.
What is an urban microclimate?
The table below summarises some of the differences in various weather elements in urban areas compared with rural locations.
Sunshine duration
5 to 15% less
Annual mean temperature
0.5-1.0 °C higher
Winter maximum temperatures
1 to 2 °C higher
Occurrence of frosts
2 to 3 weeks fewer
Relative humidity in winter
2% lower
Relative humidity in summer
8 to 10% lower
Total precipitation
5 to 10% more
Number of rain days
10% more
Number of days with snow
14% fewer
Cloud cover
5 to 10% more
Occurrence of fog in winter
100% more
Amount of condensation nuclei
10 times more
Urban heat islands
Marked differences in air temperature are some of the most important contrasts between urban and rural areas shown in the table above. For instance, Chandler (1965) found that, under clear skies and light winds, temperatures in central London during the spring reached a minimum of 11 °C, whereas in the suburbs they dropped to 5 °C.
Indeed, the term urban heat island is used to describe the dome of warm air that frequently builds up over towns and cities.
The formation of a heat island is the result of the interaction of the following factors:
the release (and reflection) of heat from industrial and domestic buildings;
the absorption by concrete, brick and tarmac of heat during the day, and its release into the lower atmosphere at night;
the reflection of solar radiation by glass buildings and windows. The central business districts of some urban areas can therefore have quite high albedo rates (proportion of light reflected);
the emission of hygroscopic pollutants from cars and heavy industry act as condensation nuclei, leading to the formation of cloud and smog, which can trap radiation. In some cases, a pollution dome can also build up;
recent research on London’s heat island has shown that the pollution domes can also filter incoming solar radiation, thereby reducing the build up of heat during the day. At night, the dome may trap some of the heat from the day, so these domes might be reducing the sharp differences between urban and rural areas;
the relative absence of water in urban areas means that less energy is used for evapotranspiration and more is available to heat the lower atmosphere;
the absence of strong winds to both disperse the heat and bring in cooler air from rural and suburban areas. Indeed, urban heat islands are often most clearly defined on calm summer evenings, often under blocking anticyclones.
Urban pollution dome and plume
The precise nature of the heat island varies from urban area to urban area, and it depends on the presence of large areas of open space, rivers, the distribution of industries and the density and height of buildings. In general, the temperatures are highest in the central areas and gradually decline towards the suburbs. In some cities, a temperature cliff occurs on the edge of town. This can be clearly seen on the heat profile below for Chester.
Urban heat island in Chester
Urban precipitation
As noted previously, the greater presence of condensation nuclei over urban areas can lead to cities being wetter and having more rain days than surrounding rural areas. Indeed, it was often said that Rochdale, the famous mill town, had significantly smaller amounts of rain on Sundays when the town’s factories were closed.
However, other factors play a major role, especially the heat islands. These can enhance convectional uplift, and the strong thermals that are generated during the summer months may serve to generate or intensify thunderstorms over or downwind of urban areas. Storms cells passing over cities can be ‘refuelled’ by contact with the warm surfaces and the addition of hygroscopic particles. Both can lead to enhanced rainfall, but this usually occurs downwind of the urban area.
Smog
Smogs were common in many British cities in the late 19th and early 20th centuries, when domestic fires, industrial furnaces and steam trains were all emitting smoke and other hygroscopic pollutants by burning fossil fuels. The smogs were particularly bad during the winter months and when temperature inversions built up under high pressure, causing the pollutants to become trapped in the lower atmosphere and for water vapour to condense around these particles.
One of the worst of these ‘pea-soup fogs’ was the London smog of the winter of 1952/53. Approximately 4,000 people died during the smog itself, but it is estimated that 12,000 people may have died due to its effects. As a result, the Clean Air Act of 1956 was introduced to reduce these emissions into the lower atmosphere. Taller chimney stacks and the banning of heavy industry from urban areas were just two of the measures introduced and, consequently, fewer smogs were recorded in the UK during the 1960s and 1970s.
Research in the 1990s has shown, however, that another type of smog – photochemical – is now occurring in some urban areas as a result of fumes from car exhausts and the build up of other pollutants in the lower atmosphere which react with incoming solar radiation. The presence of a brown-coloured haze over urban areas is an indication of photochemical smog, and among its side effects are people experiencing breathing difficulties and asthma attacks.
Urban winds
Tall buildings can significantly disturb airflows over urban areas, and even a building 100 metres or so high can deflect and slow down the faster upper-atmosphere winds. The net result is that urban areas, in general, are less windy than surrounding rural areas.
However, the ‘office quarter’ of larger conurbations can be windier, with quite marked gusts. This is the result of the increased surface roughness that the urban skyline creates, leading to strong vortices and eddies. In some cases, these faster, turbulent winds are funnelled in between buildings, producing a venturi effect, swirling up litter and making walking along the pavements quite difficult.
Web page reproduced with the kind permission of the Met Office
We have made a cloud wheel that can be cut out and used to identify clouds. Simply download the pdf, cut out the two circles, fasten together with a split pin and use to identify clouds.
How to measure wind speed and direction using bubbles
Equipment
Bubble blowing kit
Stopwatch or phone
Compass or compass app
Bubble Chase to Measure Wind Direction
Place a marker at your start location. Choose an area of open ground which is safe and away from roads.
Blow some bubbles then pick one to follow.
Chase your chosen bubble, without getting in its way, until it pops or floats somewhere you cannot follow.
Blow another bubble from where you end up and follow that one.
Wherever you end up, look back at where you have come from. Now use your compass to work out the direction back to the starting point. This will give you the wind direction, because wind direction refers to where the wind is blowing from. Repeat a few times if possible.
Remember: wind direction is the direction wind is blowing from. Turbulence: If you are in an area where there is a lot of turbulence the bubbles may not move very far from the release point, or may go all over the place!
Bubble Race to Measure Wind Speed
Two people are needed for this: a ‘blower’ to blow bubbles and a ‘timer’ to time them using a stopwatch or watch.
Place a marker at your start location and another marker 10 metres away (about 10 adult paces) in the general direction the wind will carry the bubbles. This is your finishing line. If the wind is very light you can use a shorter distance.
The blower blows some bubbles and the timer picks one to follow.
The timer uses the stopwatch or watch to measure how long it takes the bubble to reach the finishing line.
Calculate the wind speed by dividing 10 metres by the time the bubble takes to cover that distance. So if the time it takes is 5 seconds, then the windspeed is 10 ÷ 5 = 2 metres per second.
There are two ways to measure temperature and humidity in your garden; either using individual instruments or using a weather station.
Temperature can be measured with a simple glass thermometer (below left, £3-5) filled with alcohol, which expands up a thin tube when the temperature increases. (Older thermometers may use mercury). Use the Celsius (C) scale, and estimate temperature to the nearest degree, or half degree if it is in between.
Digital thermometers (above right, £5) use electronics to measure temperature and are easier to read. The probe at the end of the cable that senses the temperature could be put outside in the shade with the readout in a garage, for example. They usually show temperature to a tenth of a degree, for example 28.9ºC, so enter this number in your report. (NB: When using digital thermometers (or indeed digital instruments of any type) remember that, although the display may have a precision of 0.1°C, its accuracy is likely to be much poorer than that – maybe a degree or two).
Instruments for measuring humidity are known as hygrometers. We will be measuring relative humidity in percent (%). A dial hygrometer (above left, around £10) uses hair, which expands when the atmosphere is moist. An electronic hygrometer uses electronics and has a clear display – devices which read both temperature and humidity are popular. Some of them (above right, £16-20) transmit data from outside sensors to a display indoors.
Humidity can also be measured with a wet and dry bulb hygrometer. This gives a more accurate reading, but involves the use of tables, so is a lot more complicated. Instructions will come with the hygrometer.
All types of thermometer and hygrometer must be kept out of direct sunlight at the time of reading (15:00-16:00) and for half an hour beforehand, either using some form of white louvered screen (below, £90), or by placing it in a position where sunlight doesn’t reach when you are observing, for example sheltered north facing location. As a last resort the thermometer can be hung on a north-facing wall or fence, but stood off as far away from the wall as possible to allow air to circulate all around it.
An Automatic Weather Station (AWS) measures temperature and humidity (and other quantities) with outdoor instruments which radio the data to an indoor display console. They can be bought for as little as £100 (below left), but for better accuracy you will have to pay £300 or more (below, right). They are generally mounted on top of fences or garages, to put them out in the open as much as possible. AWS can be mounted in direct sunlight, but in light winds and strong sunlight the budget versions can be up to 4 degrees in error. Temperature and humidity can be read direct from the indoor display and entered in your report.
