Take this Quiz: Reading 2 — the urban heat island | Zestly

Question 1

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— Which heading best fits Paragraph D?

Accepted Answer

When the difference is at its biggest

Answer

The trouble with choosing a place to compare

Answer

Reversing the causes, one at a time

Answer

What a narrow street does to escaping heat

Question 2

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— Which heading best fits Paragraph E?

Accepted Answer

Comparing two places is not as simple as it looks

Answer

Three properties of the surface

Answer

The first recorded observation

Answer

Why nights matter more than days

Question 3

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— Why does a paved surface stay warmer than a field after rain?

Accepted Answer

Because the water runs into a drain before it can evaporate

Answer

Because paving is darker than soil in every case

Answer

Because less rain falls over cities than over open country

Answer

Because concrete absorbs water and then releases it slowly

Question 4

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— What is the sky view factor?

Answer

The proportion of sunlight a surface reflects

Answer

The fraction of the sky visible from a point on the ground

Answer

The number of hours of clear sky a city gets in a year

Answer

The height of the buildings divided by the width of the street

Question 5

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— When is an urban heat island usually strongest?

Answer

In the middle of a summer afternoon

Answer

During windy weather in winter

Answer

Whenever cloud cover is heaviest

Answer

A few hours after sunset on a clear, calm night

Question 6

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— Which ONE of these statements does the writer never make?

Answer

Luke Howard published paired readings from inside and outside London from 1818

Answer

Howard's measurements were later shown to be inaccurate

Answer

Satellites measure the temperature of surfaces rather than of the air

Answer

Street trees return water to the air through their leaves

Question 7

Reading Passage — Why a city does not cool down at night

A  Anyone who has walked out of a city on a summer evening has felt it: the air cools as the buildings thin out. The difference is measurable and it has a name. An urban heat island is the warmth of a built-up area relative to the countryside around it, and the first person to document one was a London chemist, Luke Howard, who from 1818 published years of paired readings taken inside the city and beyond it. London, he found, was consistently the warmer of the two — by something under a degree on average, and by considerably more on some nights.

B  Three properties of a city account for most of the effect, and none of them is heat from machines. The first is the surface itself: asphalt and dark roofing absorb a large share of the sunlight that falls on them, where a field or a pale wall would reflect more of it away. The second is the mass of the material. Brick, concrete and stone store what they absorb and give it back slowly, so a city is still releasing the previous afternoon long after sunset. The third is the absence of water. In the countryside a great deal of the sun's energy goes into evaporating moisture from soil and leaves, a process that cools the surface as surely as sweat cools skin; a paved catchment sheds rain into a drain within minutes and has nothing left to evaporate.

C  A fourth factor is geometry rather than material. A narrow street between tall buildings is a poor radiator: heat leaving one wall is intercepted by the wall opposite instead of escaping to the sky. The measure climatologists use for this is the sky view factor — the fraction of the sky visible from a point on the ground — and it falls as streets grow narrower and buildings taller. Waste heat from vehicles, industry and cooling equipment adds to the total, and in a dense business district on a hot afternoon it is not trivial, but across a whole city it is the smaller contribution.

D  The effect is not constant, and the moments when it is largest are not the ones most people expect. A heat island is usually weakest in the middle of a summer afternoon, when the sun is heating city and country alike, and strongest a few hours after sunset, when open ground has cooled quickly and the city has not. It is also strongest on clear, calm nights: cloud slows the escape of heat from the countryside as well, and wind mixes urban and rural air, so both flatten the difference. That is why the phenomenon is described in terms of the night-time minimum rather than the daytime maximum.

E  Comparing a city with its surroundings is harder than it sounds. A thermometer in a car park reads differently from one on grass fifty metres away, and the standard rural reference site may be an airport, which is itself a large expanse of asphalt. Satellites measure the temperature of surfaces rather than of the air a person breathes, and on a sunny day the two can differ by many degrees. Careful studies therefore use fixed networks of identical instruments, or a vehicle driven along the same route at the same hour — a modern version of what Howard did on foot.

F  What follows from a few degrees is mostly a matter of health. Heat kills through the cumulative strain of days and, above all, of nights that do not cool; a body that cannot recover overnight starts the next day already depleted, and the people least able to leave are usually the ones living in the warmest streets. Cooling equipment is the obvious individual response and the worst collective one, since it moves heat from inside buildings into the street and consumes the electricity that cities are least able to supply on exactly the days it is wanted.

G  Most of the remedies reverse one of the causes rather than adding anything new. Pale roofs and paving reflect the sunlight that dark ones absorb. Street trees shade the surfaces beneath them and return water to the air through their leaves, doing the work of the first and third mechanisms at once. Permeable surfaces and planted roofs restore some of the moisture that drainage takes away. None of it is quick — a street tree is an investment in a decade's time — and none of it alters the fact that a city is built of the materials a city is built of.

— Which ONE of these statements does the writer contradict?

Answer

Waste heat from machines is the main cause of the urban heat island

Answer

Cloud and wind both reduce the measured difference between city and country

Answer

Dark roofing absorbs a large share of the sunlight falling on it

Answer

A heat island is usually weakest in the middle of a summer afternoon