Prepared - The Scout Association€¦ · Prepared The Scout Meteorologist Badge Your guide to...

PreparedThe Scout Meteorologist BadgeYour guide to meeting the requirements www.scouts.org.uk www.metoffice.gov.uk

The weather is a fascinating subject, not least because we are affected by such changeable weather in the British Isles. It’s a great idea for Scouts to learn more about this vast subject — so many Scout activities are outdoors and prone to disruption due to adverse weather conditions.

01 The Scout Meteorologist Badge

Gaining the Meteorologist Badge will also help the Scouts with their schoolwork, by using practical experience to reinforce the meteorological elements of the National Curriculum syllabus.

By learning more about the weather, Scouts will be able to recognise which clouds could produce rain, guess how cold it is likely to be at night, learn where best to pitch tents so they are sheltered from the wind, etc. These skills will not only put the Scouts in touch with nature, but may also be used to avoid potentially life-threatening situations.

To gain the Meteorologist Badge, Scouts should satisfy the six requirements detailed to the right. With each requirement are suggested activities which will enable the Scout to understand and complete that task. These are only suggested activities (described in full later in this booklet), you may think of others which will fit in with other troop activities you are planning.

The Scout Meteorologist Badge 02

The Meteorologist Badge, in conjunction with the Met Office TASK 1

Explain and demonstrate how the following are measured: • Temperature • Wind force and direction • Pressure • Rainfall

TASK 2

Keep a daily record of these weather conditions from your own observations for at least two weeks: • Wind force and direction • Weather type • Temperature • Rainfall TASK 3

Understand three different ways in which clouds are formed. TASK 4

Know the typical weather produced in your own area by ‘warm’ and ‘cold’ air masses in summer and winter, noting the effects of land and sea. Understand the weather associated with a change of air mass at a ‘front’.

TASK 5

Understand a simple weather map, with fronts and isobars, similar to those shown on television and printed in some newspapers. Relate the observations you made in task 2 to the corresponding weather maps.

TASK 6

Understand the effects of temperature, wind and water on the human body in cases of hypothermia and exhaustion.

Everybody at Met Office wishes all Scouts the best of luck in trying to gain the Meteorologist Badge.

We are the UK’s national weather service with a worldwide reputation in the fields of forecasting, climate research, and other meteorological subjects. As part of our commitment to educating young people about the weather, we are working closely with the Department for Education to provide teachers and students with weather and climate related learning resources.

Through working with the Scouts on the Meteorology badge we aim to inspire more young people to learn about weather and climate.

For more information, please contact Customer Centre, Met Office, FitzRoy Road, Exeter EXP1 3PB. Tel: 0870 900 0100or visit our website at www.metoffice.gov.uk


TASK 1

Be able to explain and demonstrate how the following are measured: • Temperature • Wind force and direction • Pressure • Rainfall

WIND FORCE AND DIRECTION

Anemometer

Wind speeds can be estimated with the aid of the Beaufort wind scale. Some amateur observers make cup anemometers using four ice cream or margarine cartons mounted on a metal, plastic or wooden cross, which rotates horizontally about a vertical spindle at the top of a mast. One of the cups should be a different colour from the rest. By rotating the anemometer at a known speed and counting the number of revolutions per minute for various speeds, the equipment can be calibrated. Simple hand-held anemometers can also be purchased. Meteorologists measure the wind speed using an anemometer located 10 m above the ground.

TEMPERATURE

Thermometer

The basic type of thermometer is the liquid-in-glass thermometer. It depends upon the fact that a liquid expands by an amount depending upon the temperature. Consequently, as the temperature increases the liquid (usually alcohol) in the bulb of the thermometer expands and pushes a column of liquid up a tube. Thermometers should be placed in the shade; ideally, they should be in a slatted box (thermometer screen) facing north. They should not be placed on the side of a house, as walls retain heat which spoils the readings. The temperature is given by the length of the liquid on the scale by the side of the tube.

Force

0

1-3

4

5

6-7

8-9

10-11

12

Description

Calm

Light

Moderate

Fresh

Strong

Gale

Storm

Hurricane

Wind speed (knots)

Less than 1

1-10

11-16

17-21

22-33

34-47

48-63

More than 63

Typical effect over land

Smoke rises vertically

Smoke drifts or leaves rustle

Small branches move

Small trees in leaf begin to sway

Large branches or whole trees in motion

Chimney pots and tiles removed

Trees uprooted, widespread damage

Devastation


PRESSURE

Barometer

Many barometers allow pressure to be measured in terms of millibars, hectopascals, or inches of mercury. The easiest way to measure the pressure is to use an aneroid barometer – this is the type of instrument found in many homes. Inside the barometer there are corrugated capsules which have no air inside. As the pressure changes the capsule changes shape and the resulting very small movement is magnified so that a pointer shows the pressure on a circular scale.

Pressure is dependent upon height above mean sea level (msl) and the weather situation, so a barometer needs to be set so that it shows the pressure at msl. The actual msl pressure can be obtained by telephoning the Weathercall service for your area. See www.weathercall.co.uk. However, if a correction for msl cannot be obtained an indication of whether the pressure is rising or falling is a very useful thing to note.

A barometer does not have to be located in the open air or in a thermometer screen. It can be located in a house or building nearby.

RAINFALL

Rain-gauge

A simple rain-gauge consists of a tin can with the depth of water in the can giving the amount of rain. A more accurate rain-gauge can be made with a plastic funnel placed in a collecting bottle, and some form of measuring cylinder. The rain-gauge should be firmly fixed so that it remains upright with the funnel about 300 mm above the ground.


RAIN-GAUGE

What you will need

• An empty plastic bottle (2 litre fizzy drink bottle would be ideal) • Scissors • Sticky tape • Ruler • Paper • Pencil

What to do

1. Cut around the plastic bottle about two thirds of the way up.

2. Turn the top part of the bottle upside down and place it inside the bottom part – fix it in place using the tape.

3. Make a scale in centimetres on a piece of tape, using a ruler, and fix it to the side of your bottle.

4. Find a place outside to put your rain gauge. It must be open and away from trees.

5. Dig a hole and bury your rain gauge so that the top is sticking out about 5 cm out of the ground. This will stop the wind gauge from blowing down on windy days.

6. Check the rain gauge every day at the same time, measure the amount of rain collected, and empty the bottle.

ACTIVITY

Construct a simple version of a weather instrument that will help with some of the daily observations required in task 2. • Rain gauge • Wind vane • Anemometer

WIND VANE

What you will need

• Ruler • A pen top • A plastic fizzy drink bottle • Card • A knitting needle • Matchsticks • A cork • Sand • Blu-Tack (or similar)

What to do

1. Draw an arrow 25 cm long on the card and cut it out.

2. Make another arrow by drawing around the first arrow and cutting it out.

3. Place the pen top between the arrows, in the centre, and glue together.

4. Push four matchsticks into the long edge of the cork at right angles to each other.

5. Cut out four small squares of card and label with the four main points of the compass; N, E, S, W. Attach these to the end of each matchstick with Blu-Tack.

6. Fill the bottle with sand.

7. Push the knitting needle into the cork and push the cork in the top of the bottle. Now balance the wind vane on top of the needle.

8. Choose an open area, perhaps near your rain gauge, to place your wind vane. Ask an adult or use a compass to point the N label on the bottle towards North.

The arrow always shows the direction the wind is blowing from.


ANEMOMETER

What you will need

• A table tennis ball • Fishing line or similar • A protractor

What to do

1. Thread the ball onto the fishing line.

2. Suspend this from the centre of the protractor so it can swing freely.

3. The fishing line should hang down the 90 degree line on the protractor.

An indication of the wind speed will be given by the angle shown on the protractor when the instrument is held in the air.

Gaining the Meteorologist Badge will also help the Scouts with their schoolwork, by using practical experience to reinforce the meteorological elements of the National Curriculum syllabus.


TASK 2

Keep a daily record of these weather conditions from your own observations for at least two weeks:

• Wind force and direction • Weather type • Temperature • Rainfall

Encourage the Scouts to make their daily observations at the same time each day. They should stand in the same spot to record the wind and weather type so the observations can be compared. Use the table on page 15. The log has enough fields to cover two weeks of observations.

To measure wind force, use the Beaufort scale as a guide. To measure the wind direction use a compass to determine which way is north and then estimate which direction the wind is blowing from.

Weather should be described in words. Suggested descriptions are listed below:

• Sunny • Bright • Rain • Drizzle • Snow • Hail • Thunderstorm • Fog • Fine • Cloudy • Partly cloudy

Temperature can be measured using a thermometer as described in task 1. If the Scout can’t access any of this equipment then a figure may be taken from the local paper or TV news programmes.

Rainfall can easily be measured using the rain gauge as described in task 1.


TASK 3

Understand three different ways in which clouds are formed.A classification of clouds was introduced by Luke Howard (1772-1864) who used Latin words to describe their characteristics:

• Cirrus – a tuft or filament (e.g. of hair) • Cumulus – a heap or pile • Stratus – a layer • Nimbus – rain bearing

There are now ten basic cloud types with names derived from combinations of these words (the word ‘alto’ meaning high is now also used to denote medium-level cloud).

Clouds form when moist air is cooled to such an extent that it becomes saturated. The main mechanism for cooling air is to force it to rise. As air rises it expands, because the pressure decreases through the atmosphere, and therefore cools. Eventually it may become saturated and the water vapour then condenses into tiny water droplets, similar in size to those found in fog, to form cloud. If the temperature reaches below about –20 °C many of the cloud droplets will have frozen so the cloud is mainly composed of ice crystals.

There are three main ways in which air rises to form cloud:

1. Rapid local ascent when heated air at the earth’s surface rises in the form of thermal currents (convection)

• This tends to produce cumulus type clouds

2. Slow widespread mass ascent where warm moist air is undercut by cold air (the barrier between the warm and cold air is called a ‘front’)

• This usually produces layered clouds

3. Air forced to rise over a barrier of mountains or hills

• This can produce layered or cumulus-type cloud depending on the state of the atmosphere

The range of ways in which clouds can be formed and the variable nature of the atmosphere give rise to the enormous variety of shapes, sizes and textures of clouds.

ACTIVITY

To demonstrate convection, simply boil a kettle and watch the steam plume out of the lip. Right at the entrance the steam will be invisible but as the steam rises the water vapour condenses in to visible steam. Also note that as the steam rises, it cools and begins to sink down to the ground allowing the water to evaporate and the steam to disappear.

To make the Scout more aware of cloud formation due to forced ascent, get a local Ordnance Survey map and ask the Scout to highlight areas of high ground, hills and mountains. These are the local areas where ‘upslope’ cloud is most likely to form. Try to watch for cloud formation on these features.

1.

2.

3.

1000

m

hot earth

warm, moist air

cool, dry air

8000

m50

0 m


TASK 4

Know the typical weather produced in your own area by ‘warm’ and ‘cold’ air masses in summer and winter, noting the effects of land and sea. Understand the weather associated with a change of air mass at a ‘front’.

AIR MASSES

An air mass is a large body of air and has the same temperature and humidity throughout. It is separated from differing air masses by fronts. The notion that northerly winds (i.e. winds from the north) are cold and southerly winds (those from the south) are warm (at least in the northern hemisphere) is quite common. Similarly, air that has travelled over the sea picks up moisture, while air travelling over the land is relatively dry. These simple concepts help in the understanding of air masses.

In polar and subtropical regions there are large semi-permanent anticyclones (high pressure areas). The air resides in these systems for a long time and is gradually influenced by the underlying surface — air at the poles is cooled and air in the tropics is warmed. The result is a large body of air with little horizontal variation in temperature and moisture content.

Sometimes there is a large outflow of air from the anticyclones, and these air masses may approach the British Isles. However, on their journey they may be modified by contact with the underlying surface. Air which travels over the sea (maritime air) is moistened, whereas there is little change in moisture content of air which travels over the land (continental air). The boundary between two different types of air mass is called a front. It is common for the British Isles to be affected by sequences of fronts, which usually separate polar maritime and tropical maritime air.

polar co

ntin

enta

l air

tropical continental air

polar m

aritime air

returning polarmaritime air

tropica

l mar

itim

e ai

r

Air masses


TROPICAL CONTINENTAL

Tropical continental air masses originate in North Africa and often travel over the Mediterranean, Spain and France before reaching the British Isles. The air picks up some moisture over the Mediterranean (and perhaps the Bay of Biscay), but overall the air tends to be quite dry and the skies are typically cloudless.

The majority of tropical continental airstreams give a marvellous heatwave (in summer). However where the air has picked up moisture which then has made its way to medium levels in the atmosphere, tremendous thunderstorms develop. Another noticeable feature of this air mass is haze, and poor air quality.

POLAR CONTINENTAL

Polar continental air masses originate in Scandinavia or Russia and mainly affect the British Isles during winter.

Temperatures in polar continental air masses are below average in winter, except perhaps downwind of the mountains. In summer, however, the temperatures tend to be above average.

The moisture content is low in these air masses, especially when they take the short sea track in the Calais/Dover region. This leads to clouds being generally well broken, and so the weather is fine and sunny. Air that has crossed the North Sea between Denmark and Scotland is said to have taken a long sea track. It therefore collects more moisture, and clouds tend to form during its journey over the sea. Consequently, it is mainly cloudy in eastern districts (with perhaps drizzle or snow flurries.)

TROPICAL MARITIME

Tropical maritime air usually approaches the British Isles from the south-west. During its passage across the Atlantic, the air is cooled from below as it passes over a progressively cooler ocean, and so it becomes more stable. While it cools down, little of its moisture is lost. It therefore reaches south-west England or western Ireland almost saturated, giving dull, warm, overcast weather.

On the coasts, sea fog is common in these tropical maritime south-westerlies. However, if the cloud base is several hundred feet, sea-level sites may be saved from the fog.

In a tropical maritime air mass the nights are mild and damp, especially in mid-winter. In December and January the overcast skies result in there being little variation in temperature between day and night. However, if there are light winds and clear skies, fog may form inland overnight.

tropical continental air

polar co

ntin

enta

l air

tropica

l mar

itim

e ai

r


TASK 4

POLAR MARITIME

Polar maritime air is the most common type of air mass affecting the British Isles. The air has its source in the Canadian Arctic or the Greenland area. As the cold air travels over the relatively warm sea it is warmed from below and becomes unstable. Unstable airstreams tend to produce convection, and so cumulus clouds, cumulonimbus clouds and showers are likely. Other characteristics of the air are that it is cool (especially in summer), fairly moist and associated with good visibility.

In winter most of the convection is initiated over the Atlantic and showers hit the coasts, spreading inland if the winds are strong. In spring and summer, convection clouds tend to be set-off to rain inland by daytime heating.

RETURNING POLAR MARITIME

Returning polar maritime air, like polar maritime air, originates in Polar Regions, but travels southwards before turning north towards the British Isles.

The air is originally cold, but as it takes a long sea track southwards across the Atlantic the lower layers become warmer, more moist and more unstable. However, as it returns northwards the lower layers are cooled and become more stable. This mixture of a stable layer near the surface and an unstable layer aloft can lead to a wide variety of weather.

On exposed coasts and hills the combination of high moisture content and low-level stability can lead to stratus clouds and hill fog. Sometimes, however, the unstable layer leads to the formation of cumulonimbus clouds and showers (and occasionally thunderstorms). Further inland a mixture of weather can occur — stratus lifts and disperses and then suddenly gives way to a heavy shower.

ACTIVITY

Ask the Scouts to draw and present a weather forecast map of one type of front, where two distinct air masses meet. They should explain how features of the land and sea will affect the weather and also show the different cloud types and weather that could be expected at the front.

returning polarmaritime air

polar m

aritime air


TASK 5

Understand a simple weather map, with fronts and isobars, similar to those shown on television and printed in some newspapers. Relate the observations you made in task 2 to the corresponding weather maps.

ACTIVITY

Ask the Scout to collect a week’s worth of daily weather charts that are available in newspapers or on the Met Office website.

Ask them to label the maps using the information in the diagram below.

Some of them might want to pretend to be a TV weather presenter and do a ‘live’ weather forecast!

cold front warm front occluded front

front moving front moving

brig

hter

wea

ther

b

ehin

d

fair

ly n

arro

w r

ain

bel

t on

the

fron

t

occa

sion

al r

ain

beh

ind

wid

e ra

in b

elt

beh

ind


The human body is very vulnerable to extremes of weather. When the outside temperature falls below a certain point our body temperature can drop to a dangerously low level. Our body temperature falls most rapidly when we are immersed in cold water, as the water conducts heat out from our body. A cold wind has a similar effect, taking heat away from the body and thus reducing body temperature. This effect is known as wind-chill, and it can make the air ‘feel’ much colder than it actually is. If it is also raining, this can reduce the body temperature further.

• A low body temperature can cause us lasting physical damage. Hypothermia develops when body temperature falls below about 35 °C. Although moderate hypothermia can normally be reversed, hypothermia can lead to death if the body temperature falls below 26 °C. To reduce the risk of hypothermia, expeditions and outdoor activities must be planned very carefully. No one suffering from minor illness should take part.

• Wear several layers of loose clothing and an outer wind-proof layer

• Take a waterproof layer (cagoule and over trousers)

• Take a woolly hat or balaclava

• Carry spare, dry socks

• Ensure boots are suitable for the terrain you are travelling in

• The kit in your back pack should include:

- Spare clothes

- First aid kit

- Survival bag

- Means of providing a hot drink

- Emergency, high-energy food

- Map and compass

All members of the party should be aware of the dangers of hypothermia and take preventative steps to avoid the situation. It is also useful to understand what affects the night temperature and what precautions should be taken when sleeping outdoors.

TASK 6

Understand the effects of temperature, wind and water on the human body in cases of hypothermia and exhaustion.


ACTIVITY

Using the wind outdoors, ask the Scout to dip a hand or bare foot in a bucket of water. The Scout should then hold that limb exposed to the moving air and observe the cooling of the soaked limb compared with the dry one. Is it cooler? Ensure they understand the reasons why it is cooler.

Also, ask them to make a list of things they think they need to take to ‘Be Prepared’ on an outdoors expedition. Ask them to mark their list against the one on the left and see how many they think of.

At the opposite end of the scale, overheating can also be very dangerous. Heat exhaustion is caused by a loss of salt and water from the body, usually due to strenuous exercise or a hot, humid environment. It can cause headaches, sickness or fainting, but the effects can be reversed by moving the casualty to a cooler location and replacing lost fluids and minerals.

Again, prevention is better than cure, so keep fluid intake high, and wear light clothing and a sun hat.

Heatstroke can occur during exposure to extreme heat or high humidity when there is no air current to cool the body down. The body temperature may rise as high as 43 °C, causing unconsciousness in some cases. Anyone suffering from heatstroke should always receive urgent medical attention.

Date and time Wind direction Wind forceTemperatureWeather Rainfall

RESOURCES: TASK 2

Weekly observations log

Record your daily observations at the same time each day. Stand in the same spot to record the wind and weather type so the observations can be compared. Use the table below to record the data. This table has enough fields to cover a two week period.


Met OfficeFitzRoy Road, ExeterDevon, EX1 3PBUnited Kingdom

Produced by the Met Office© Crown copyright 2010 10/0262Met Office and the Met Office logo are registered trademarks

Tel: 0870 900 0100Fax: 0870 900 [email protected]

The Met Office is committed to helping people of all ages make the most of the great outdoors.

If you are interested in other environmental activities designed to help you explore and enjoy nature, take a look at the OPAL website.

www.opalexplorenature.orgThe Open Air Laboratories (OPAL) network is an exciting new initiative that is open to anyone with an interest in nature. They aim to create and inspire a new generation of nature-lovers by getting people to explore, study, enjoy and protect their local environment.

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