Climate and Weather in Great Britain (Климат и погода в Великобритании)
Climate and Weather in Great Britain (Климат и погода в Великобритании)
Climate and
Weather in Great Britain
Weather
is not the same as climate. The weather at a place is the state of the
atmosphere there at a given time or over a short period. The weather of the
British Isles is greatly variable.
The climate of a place or
region, on the other hand, represents the average weather conditions over a
long period of time.
The climate of any place
results from the interaction of a number of determining factors, of which the
most important are latitude, distance from the sea, relief and the direction of
the prevailing winds.
The geographical position
of the British Isles within latitudes 50o to 60o N is a basic factor in determining the main
characteristics of the climate. Temperature, the most important climatic
element, depends not only on the angle at which the sun’s rays strike the
earth’s surface, but also on the duration of daylight. The length of day at
London ranges from 16 hours 35 minutes on June to 7 hours 50 minutes on 21
December. British latitudes form the temperate nature of the British climate,
for the sun is never directly overhead as in the tropical areas.
Britain’s climate is
dominated by the influence of the sea. It is much milder than that in any other
country in the same latitudes. This is due partly to the presence of the North
Atlantic Drift, or the Gulf Stream, and partly to the fact that north-west
Europe lies in a predominantly westerly wind-belt. This means that marine
influences warm the land in winter and cool in summer. This moderating effect
of the sea is in fact, the cause of the relatively small seasonal contrasts
experienced in Britain.
The moderating effect of
the ocean on air temperature is also stronger in winter than in summer. When
the surface water is cooler than the air above it – as frequently happens
during the summer months – the air tends to lose its heat to the water. The
lowest layers of air are chilled and become denser by contradiction, and the
chilled air tends to remain at low levels. The surface water expands because it
is warmed, and remains on the surface of the ocean. Unless the air is
turbulent, little of it can be cooled, for little heat is exchanged.
Opposite conditions apply
in winter. The air in winter is likely to be cooler than the surface water, so
that the heat passes from water to air. Air at low levels is warmed and expands
and rises, carrying oceanic heat with it, while the chilled surface water
contracts and sinks, to be replaced by unchilled water from below. This
convectional overturning both of water and of air leads to a vigorous exchange
of heat.
The prevailing winds in
the British Isles are westerlies. They are extremely moist, as a result of
their long passage over warm waters of the North Atlantic. On their arrival to
Britain, the winds are forced upwards, and as a result large-scale condensation
takes place, clouds form and precipitation follows, especially over the
mountainous areas.
North and north-west winds
often bring heavy falls of snow to north Britain during late October and November,
but they are usually short-lived. Continental winds from the east sometimes
reach the British Isles in summer as a warm, dry air-stream, but they are more
frequently experienced in winter when they cross the north sea and bring cold,
continental-type weather to eastern and inland districts of Great Britain.
Relief is the most
important factor controlling the distribution of temperature and precipitation
within Britain. The actual temperatures experienced in the hilly and
mountainous parts are considerably lower than those in the lowlands. The effect
of relief on precipitation is even more striking. Average annual rainfall in
Britain is about 1,100 mm. But the geographical distribution of rainfall is
largely determined by topography. The mountainous areas of the west and north
have more rainfall than the lowlands of the south and east. The western
Scottish Highlands, the Lake District (the Cumbrian mountains), Welsh uplands
and parts of Devon and Cornwall in the south-west receive more than 2,000 mm of
rainfall each year.
In contrast, the eastern
lowlands, lying in a rain-shadow area, are much drier and usually receive
little precipitation. Much of eastern and south-eastern England (including
London) receive less than 700 mm each year, and snow falls on only 15 to 18
days on the average.
Rainfall is fairly well
distributed throughout the year, although March to June are the driest months
and October to January are the wettest.
Ireland is in the rather
a different category, for here the rain-bearing winds have not been deprived of
their moisture, and much of the Irish plain receives up to 1,200 mm of rainfall
per year, usually in the form of steady and prolonged drizzle. Snow, on the
other hand, is rare, owing to the warming effects of the Gulf Stream. The
combined influences of the sea and prevailing winds are equally evident in the
general pattern of rainfall over the country.
Because of the North
Atlantic Drift and predominantly maritime air masses that reach the British
Isles from the west, the range in temperature throughout the year is never very
great. The annual mean temperature in England and Wales is about 10oC
, in Scotland and Northern Ireland about 9oC. July and August
are the warmest months of the year, and January and February the coldest.
The mean winter
temperature in the north is 3OC,the mean summer temperature 12oC. The
corresponding figures for the south are 5oC and 16oC. The
mean January temperature for London is 4oC, and the mean July
temperature 17oC.
During a normal summer the
temperature may occasionally rise above 30oC in the south. Minimum
temperatures of –10oC may occur on a still clear winter’s night in
inland areas.
The distribution of
sunshine shows a general decrease from south to north – the south has much
longer periods of sunshine than the north.
It is frequently said that
Great Britain does not experience climate, but only weather. This statement
suggests that there is such a day-to-day variation in temperature, rainfall,
wind direction, wind speed and sunshine that the “average weather conditions”,
there is usually no very great variation from year to year or between
corresponding seasons of different years.
No place in Britain is
more than 120 km from the sea. But although the British are crowded very
closely in a very small country, there is one respect in which they are very
fortunate. This is their climate. Perhaps, this is a surprising statement
because almost everyone has heard how annoying the weather usually is in
England. Because of the frequent clouds and the moisture that hangs in the air
even on fairly clear days, England has less sunshine than most countries, and
the sunlight is weaker then in other places where the air is dry and clear.
What is worse, sunshine rarely lasts long enough for a person to have time to
enjoy it. The weather changes constantly. No ordinary person can guess from one
day to another which season he will find himself in when he wakes in the
morning. Moreover, a day in January may be as warm as a warm day in July and a
day in July may be as cold as the coldest in January.
But although the English
weather is more unreliable than any weather in the world, the English climate –
average weather – is a good one. English winters are seldom very cold and the
summers are seldom hot. Men ride to work on bicycles all through the year.
Along the south coast English gardens even contain occasional palm trees.
The most remarkable
feature of English weather, the London fog, has as exaggerated reputation. What
makes fog thick in big industrial areas is not so much the moisture in the air
as the soot from millions of coal fires. Such smogs (smoke + fog) are not
frequent today. Since 1965 as a result of changes in fuel usage and the
introduction of clean air legislation, they have become less severe. It is quite
natural that in fine, still weather there is occasionally haze in summer and
mist and fog in winter.
The amount of rainfall in
Britain is exaggerated, too. Britain seems to have a great deal of rain because
there are so many showers. But usually very little rain falls at a time. Often
the rain is hardly more than floating mist in which you can hardly get wet.
Although a period of as long as three weeks without rain is exceptional in
Britain.
It is no wonder that,
living in such an unbearable climate with so many rules and with still more
exceptions, the Englishmen talk about their weather, whatever it may be, and
their climate, too.
Literature
1.Baranovski L.S., Kozikis
D.D.. How Do You Do, Britain? – Moscow ,1997.
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