(MAXIMISER)
llll- The cloud messenger
Clouds, as everyone in the room would already have known, were staging posts in the rise and fall of
water as it made its way on endless compensating journeys between the earth and the fruitful sky. Yet
the nature of the means of their exact construction remained a mystery to most observers who, on the
whole, were still in thrall to the vesicular or 'bubble' theory that had dominated meteorological thinking
for the better part of a century. The earlier speculations, in all their strangeness, had mostly been
forgotten or were treated as historical curiosities to be glanced at, derided and then abandoned. Howard,
however, was adamant that clouds were formed from actual solid drops of water and ice, condensed from
their vaporous forms by the fall in temperature which they encountered as they ascended through the
rapidly cooling lower atmosphere. Balloon pioneers during the 1780s had continued just how cold it could
get up in the realm of the clouds: the temperature fell some 6.S"C for every thousand metres they
ascended. By the time the middle of a major cumulus cloud had been reached, the temperature would
have dropped to below freezing, while the oxygen concentration of the air would be starting to thin quite
dangerously. That was what the balloonists meant by 'dizzy heights'.
Label the diagram below.
Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.
Reaching situation known as the
1
....................... .
----- not much
3 ....................... .
temperature down
4
.........................
per ....................... .
llll- Hurricanes
A hurricane is a tropical cyclone, an area of intense low pressure in the tropics surrounded by a violent
rotating storm. It is called at hurricane in the North Atlantic, the Northeast Pacific east of the dateline,
and the South Pacific Ocean east of 160E; west of the dateline it is called at typhoon, and in the Indian
Ocean, a cyclone. It becomes a hurricane officially if its wind speeds reach 75mph. or force 12 on the
Beaufort scale; below that it is a tropical storm. Every year there are about 100 tropical storms and
about 50 of them reach htlrricalle strength. The name comes from 'Hurican', the Carib god of evil.
Hurricanes need precise meteorological conditions to form: the sea surface temperature needs to be
above 26.5 C. They are formed over the tropical ocean when strong clusters of thunderstorms drift over
warm water. Warm air from the storm and the ocean surface combine and begin to rise, creating an area
of low pressure on the ocean surface. Rising warm air causes pressure to decrease at higher altitudes. Air
rises faster and faster to fill the low pressure, in turn drawing more warm air up off the sea and sucking
cold air downwards. The cluster of thunderstorms merge to become a huge storm, which moves west
with the trade winds. While it remains over warm water the tropical wave begins to grow. Wind speeds
increase as air is sucked into the low pressure centre. If the depression strengthens and its wind speed
climbs above 40 mph it becomes a tropical storm and is named by the US National Hurricane Centre.
Once the sustained winds exceed 74-mph, the storm becomes a hurricane. It can take as long as several
days or only a few hours for a depression to develop into a full-blown hurricane. The fully developed
hurricane is made up of an eye of calm winds surrounded by a spinning vortex of high winds and heavy
rainstorms.
Label the diagrams. Use NO MORE THAN TWO WORDS from the passage.
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