Methods of weather modification

1. The first scientific attempt at coaxing moisture from a cloud was in 1946, when scientist Vincent Schaefer dropped 3 pounds of dry ice from an airplane into a cloud and, to his delight, produced snow. The success of the experiment was modest, but it spawned optimism among farmers and ranchers around the country. It seemed to them that science had finally triumphed over weather.

2. Unfortunately, it didn’t work out that way. Although there were many cloud-seeding operations during the late 1940s and the 1950s, no one could say whether they had any effect on precipitation. Cloud seeding, or weather modification as it came to be called, was clearly more complicated than had been thought. It was not until the early 1970s that enough experiments had been done to understand the processes involved. What these studies indicated was that only certain types of clouds are amenable to seeding. One of the most responsive is the winter orographic cloud, formed when air currents encounter a mountain slope and rise. If the temperature in such a cloud is right, seeding can increase snow yield by 10 to 20 per cent.

3. There are two major methods of weather modification. In one method, silver iodide is burned in propane-fired ground generators. The smoke rises into the clouds where the tiny silver-iodide particles act as nuclei for the formation of ice crystals. The alternate system uses airplanes to deliver dry-ice pellets. Dry ice does not provide ice-forming nuclei. Instead, it lowers the temperature near the water droplets in the clouds so that they freeze instantly – a process called spontaneous nucleation. Seeding from aircraft is more efficient but also more expensive.

4. About 75 per cent of all weather modification in the United States takes place in the Western states. With the population of the West growing rapidly, few regions of the world require more water. About 85 per cent of the waters in the rivers of the West comes from melted snow. As one expert put it, the water problems of the future may make the energy problems of the 70s seem like child’s play to solve. That’s why the U.S. bureau of Reclamation, along with state governments, municipal water districts, and private interests such as ski areas and agricultural cooperatives, is putting increased effort into cloud-seeding efforts. Without consistent and heavy snowfalls in the Rockies and Sierras, the west would literally dry up. The most intensive efforts to produce precipitation were during the West’s disastrous snow drought of 1976-1977. It is impossible to judge the efficiency of weather modification based on one crash program, but most experts think that such hurry-up programs are not very effective.

1. What is the main subject of the text?

a) the scientific contributions of Vincent Schaefer

b) developments in methods of increasing precipitation

c) the process by which snow crystals form

d) the effects of cloud seeding

2. The word spawned (given in the text in Italics) is closest in meaning to

a) intensified

b) reduced

c) preceded

d) created

3. After the cloud-seeding operations of the late 1940s and the 1950s, the farmers and ranchers mentioned in the first paragraph probably felt

a) triumphant

b) modest

c) disappointed

d) optimistic

4. Which of the following can be inferred from the text about the term weather modification?

a) It is not as old as the term cloud seeding.

b) It has been in use since at least 1946.

c) It refers to only one type of cloud seeding.

d) It was first used by Vincent Schaefer.

5. According to the passage, winter orographic clouds are formed

a) on relatively warm winter days

b) over large bodies of water

c) during intense snow storms

d) when air currents rise over mountains

6. To which of the following does the underlined word they (given in the text in Italics) refer?

a) water droplets

b) clouds

c) ice-forming nuclei

d) airplanes

7. When clouds are seeded from the ground, what actually causes ice crystals to form?

a) propane

b) silver-iodide smoke

c) dry-ice pellets

d) nuclear radiation

8. Clouds would most likely be seeded from airplanes when

a) it is important to save money.

b) the process of spontaneous nucleation cannot be employed.

c) the production of precipitation must be efficient.

d) temperatures are lower than usual.

9. About what percentage of the western United States’ water supply comes from run-off from melted snow?

a) 10 percent

b) 20 percent

c) 75 percent

d) 85 percent

10. What does the author imply about the energy problems of the 1970s?

a) They were caused by a lack of water.

b) They took attention away from water problems.

c) They may not be as critical as water problems will be in the future.

d) They were thought to be minor at the time but turned out to be serious.

11. The author mentions agricultural cooperatives as an example of

a) state government agencies

b) private interests

c) organizations that compete with ski areas for water

d) municipal water districts

12. It can be inferred from the passage that the weather-modification project of 1976-77 was

a) put together quickly

b) a complete failure

c) not necessary

d) easy to evaluate

Weather

Ex. 1. Decide which of these words are “hot” words and which are “cold” words.

to boil to pour to brew to drizzle to soak to shiver to freeze to thaw to the skin

warm chilly severe dry haze ice

harsh inclement hail sunshine gale fog patches

frost to melt sleet drought thunderstorm hurricane

gust cloud-burst pea-souper shower blizzard hoarfrost

“Hot” words	“Cold” words

Ex. 2. a) Work in pairs. These words are used to describe weather. Add them to the chart below under the appropriate column.

gusty breezy drizzly cloudy thundery occasional torrential

sultry freezing misty wintry unsettled scattered stifling

violent muggy blustery cloudless heavy slushy dense

gentle foggy windy flurry prolonged thick

strong mild frosty showery frequent dense

damp rainy sunny muddy nasty dull

windy weather	cold weather	wet weather	hot weather

b) Compare your answers. Can some words go under more than one column?

Ex. 3. With a partner, make a list of as many words and phrases as you can that can be used to talk about weather (in summer, in winter, when it rains cats and dogs, when it pours with rain, on a nasty (bright) day). Compare your list with those of the others.

Ex. 4. Complete the sentences with prepositions.

1. Winter sets … … the end … of December … our parts. … a hard frost rivers and ponds are frozen … . When the temperature falls … 25⁰ C … zero it gets very cold.

2. London is famous … its fog. They have fogs especially often … autumn. When a thick fog spreads … the city people can’t see each other at arm’s length.

3. After heavy rains we are … … a spell … good weather again.

4. It looks like rain: the sky is covered … dark clouds, a cold wind is blowing … the sea.

5. It’s a lovely sight when everything is covered … hoarfrost and glistens … the sun.

6. I prefer to stay indoors … rainy weather.

7. Nature looks … its best … early spring.

8. Indian summer is a short period … warm sunny weather … the beginning … autumn.

9. The temperature has fallen … zero and it is freezing.

10. It’s poring … rain. You’d better stay indoors.

11. Many people are fond … winter sports.

Ex. 5. The British love talking about the weather. It’s a neutral topic and there’s always something to say on the topic. Consequently, there are many idioms in the language based on the weather. Read the following expressions and decide which ones could replace the underlined sections of the sentences below. Make up situations with new expressions.

· a storm in a teacup

· under a cloud

· make heavy weather of

· the calm before the storm

· under the weather

· get wind of

· bright and breezy

· it’s an ill wind that blows nobody any good

***

1. You’re very cheerful for a dismal Monday morning.

2. Things are quiet at the moment but it’s an uneasy truce.

3. It seems like a tragedy now, but someone will derive some benefit from it.

4. He finds doing his homework very difficult indeed.

5. She is not very well at the moment.

6. We tried to keep the party a secret but, they’ve managed to find out about it somehow.

7. He is in disgrace because of the way he behaved at the party last night.

8. The whole affair is a lot of fuss about nothing.

Ex. 6. Some people have strong reactions to the weather. What about you? Find out how other members of the group often feel:

– on a cold winter’s morning

– on a warm summer’s evening with a gentle see breeze

– on a wet and windy day

– towards the end of a long spell of very hot humid weather

– just before a violent thunderstorm

Ex. 7. Give profound answers to the following questions.

thunderstorm drought hurricane flood

blizzard typhoon tornado

snow shower

hail storms

· Which of these events occur where you live?

· Which have you (never) experienced?

· Which one is the most frightening?

· Which does the most damage?

· Which one is the most mysterious?

Ex. 8. Think of a specific day in the past week, and describe the weather in detail. Can your classmates guess which day you’re describing?

Ex. 9. Read the dialogue and reproduce it: a) abridged; b) in the form of a monologue.

Weather

Simon:	Isn’t it marvellous to take a walk in Hyde Park on such a beautiful day, Mr. Winter?
Winter:	It is. These parks are really the lungs of London. – By the way, I’m a bit tired. There’s a nice bench.
S.:	You mean the bench where the girl is sitting?
W.:	Yes. I’d like to talk to her. She looks a nice girl.
S.:	It’s best to start with the weather. That’s always a safe subject.
W.:	Let’s try.
W.:	Lovely day today, isn’t it?
Girl:	It is.
W.:	It seems a glorious day.
G.:	I think we are in for a fine spell.
S.:	I hope it will last long. There’s hardly a cloud in the sky.
G.:	We’ll have a heat wave, I fear.
W.:	The thermometer is rising, but the barometer is falling. It must be 25 degrees in the shade.
S.:	25 degrees centigrade correspond with – wait a minute – 77 degrees Fahrenheit.
G.:	Goodness me, an electronic computer seems to be necessary to compare centigrade and Fahrenheit thermometers,
W.:	It is very close and sultry today.
S.:	You are right. It is muggy and oppressive.
W.:	Not a leaf is stirring.
S.:	There’s hardly a breath of air.
G.:	I am hot. And the sun dazzles my eyes.
W.:	It would be better to wear sun-glasses.
G.:	By the way, I’ve just read the weather forecast in my newspaper here.
S.:	Let me see.
G.:	Pressure will remain high to the south-west of the British Isles.
S.:	There will be occasional rain drizzle.
G.:	But bright weather with a few scattered showers will spread to England and Wales.
W.:	And here is the weather-chart.
S.:	On the Continent we’ve had so much of English weather, and we’ve always wanted to experience a real London fog.
G.:	A pea-souper, you mean. But not in late spring or summer; it is in autumn and winter that you get the real pea-soupers. Then the whole traffic is put out of order, and the bobbies have to carry torches.
W.:	I fear a thunderstorm is brewing. Do you see the sheet lightning there?
G.:	Yes, I do. The sky is overcast, and the sun is going in. It looks like rain.
S.:	What a gust of wind!
W.:	Thunder and lightning!
G.:	It’s beginning to rain.
S.:	And we’ve forgotten our umbrellas and macs!
W.:	It never rains, but it pours!
G.:	Fortunately enough, I’ve brought my folding umbrella. Let me put it up …
W.:	What a tremendous clap of thunder!
S.:	And what a flash of lightning!
G.:	Chain-lightning. I hope it didn’t strike a building.
W.:	I don’t think so, because all the buildings have lightning conductors.
S.:	The rain is torrential. It’s absolutely pouring down now.
G.:	It’s raining cats and dogs.
S.:	A real cloud-burst.
G.:	The ground is becoming soft and muddy.
S.:	It’s clearing up.
W.:	The clouds are lifting.
G.:	Yes, it has left off raining. Look at this wonderful rainbow!
S.:	Bright sunshine again.
W.:	Now we know why English weather is something worth talking about.