Since the 1850s researchers have tried to show that variations in seasonal weather are connected in some way with sunspots, the outward sign of an increase in the Sun's activity. However, scientists lacked evidence supporting such a link until the mid-1980s, when van Loon and Labitzke compiled statistical evidence suggesting that a link exists and that it involves winds in the upper atmosphere above the equator which reverse their direction, from east to west or west to east, every twelve to fifteen months. This phenomenon is called the quasi-biennial oscillation (QBO), and although meteorologists have known about the QBO since the 1950s, until the 1980s no one recognized a subtle but statistically significant link between the QBO and certain patterns of weather. When the west to east direction of winds in the upper atmosphere coincides with periods of high solar activity that occur approximately every eleven years, winters in the eastern and central United States are very cold.

On this basis, some meteorologists predicted that the winter of 1988-1989 in the United States would be severe. However, the winter was a mild one overall, and the meteorologists' attempt to make the connection between the Sun and weather on the Earth appeared unsuccessful, until Barnston and Livezey proposed a hypothesis explaining why the prediction had failed. They argued that the prediction had not taken into account another important element in the climate: the more or less regular pattern of fluctuations in the temperature of the surface waters of the tropical Pacific Ocean.

Barnston and Livezey noted that when the water temperature is abnormally high-the phenomenon called EI Niño- the chances of cold winter weather over North America increase. The opposite situation, when surface temperatures are well below normal-La Nina-is far less common. In fact, until late 1988 no one had seen the combination of La Nina, westerly winds in the upper atmosphere, and high solar activity. Thus, according to Barnston and Livezey, La Nina canceled out the effect of the other two climatic factors and caused the mild winter of 1988-1989. Although this hypothesis is plausible, much research remains to be done before meteorologists can establish and explain the effects of increased solar activity on seasonal weather changes.

The author of the passage would most likely agree with which of the following statements about the link between increased solar activity and certain seasonal weather changes on the Earth?

Since the 1850s researchers have tried to show that variations in seasonal weather are connected in some way with sunspots, the outward sign of an increase in the Sun's activity. However, scientists lacked evidence supporting such a link until the mid-1980s, when van Loon and Labitzke compiled statistical evidence suggesting that a link exists and that it involves winds in the upper atmosphere above the equator which reverse their direction, from east to west or west to east, every twelve to fifteen months. This phenomenon is called the quasi-biennial oscillation (QBO), and although meteorologists have known about the QBO since the 1950s, until the 1980s no one recognized a subtle but statistically significant link between the QBO and certain patterns of weather. When the west to east direction of winds in the upper atmosphere coincides with periods of high solar activity that occur approximately every eleven years, winters in the eastern and central United States are very cold.

On this basis, some meteorologists predicted that the winter of 1988-1989 in the United States would be severe. However, the winter was a mild one overall, and the meteorologists' attempt to make the connection between the Sun and weather on the Earth appeared unsuccessful, until Barnston and Livezey proposed a hypothesis explaining why the prediction had failed. They argued that the prediction had not taken into account another important element in the climate: the more or less regular pattern of fluctuations in the temperature of the surface waters of the tropical Pacific Ocean.

Barnston and Livezey noted that when the water temperature is abnormally high-the phenomenon called EI Niño- the chances of cold winter weather over North America increase. The opposite situation, when surface temperatures are well below normal-La Nina-is far less common. In fact, until late 1988 no one had seen the combination of La Nina, westerly winds in the upper atmosphere, and high solar activity. Thus, according to Barnston and Livezey, La Nina canceled out the effect of the other two climatic factors and caused the mild winter of 1988-1989. Although this hypothesis is plausible, much research remains to be done before meteorologists can establish and explain the effects of increased solar activity on seasonal weather changes.

The passage provides information to support which of the following statements about La Nina?

Since the 1850s researchers have tried to show that variations in seasonal weather are connected in some way with sunspots, the outward sign of an increase in the Sun's activity. However, scientists lacked evidence supporting such a link until the mid-1980s, when van Loon and Labitzke compiled statistical evidence suggesting that a link exists and that it involves winds in the upper atmosphere above the equator which reverse their direction, from east to west or west to east, every twelve to fifteen months. This phenomenon is called the quasi-biennial oscillation (QBO), and although meteorologists have known about the QBO since the 1950s, until the 1980s no one recognized a subtle but statistically significant link between the QBO and certain patterns of weather. When the west to east direction of winds in the upper atmosphere coincides with periods of high solar activity that occur approximately every eleven years, winters in the eastern and central United States are very cold.

On this basis, some meteorologists predicted that the winter of 1988-1989 in the United States would be severe. However, the winter was a mild one overall, and the meteorologists' attempt to make the connection between the Sun and weather on the Earth appeared unsuccessful, until Barnston and Livezey proposed a hypothesis explaining why the prediction had failed. They argued that the prediction had not taken into account another important element in the climate: the more or less regular pattern of fluctuations in the temperature of the surface waters of the tropical Pacific Ocean.

Barnston and Livezey noted that when the water temperature is abnormally high-the phenomenon called EI Niño- the chances of cold winter weather over North America increase. The opposite situation, when surface temperatures are well below normal-La Nina-is far less common. In fact, until late 1988 no one had seen the combination of La Nina, westerly winds in the upper atmosphere, and high solar activity. Thus, according to Barnston and Livezey, La Nina canceled out the effect of the other two climatic factors and caused the mild winter of 1988-1989. Although this hypothesis is plausible, much research remains to be done before meteorologists can establish and explain the effects of increased solar activity on seasonal weather changes.

Which of the following most accurately describes the organization of the passage?

Since the 1850s researchers have tried to show that variations in seasonal weather are connected in some way with sunspots, the outward sign of an increase in the Sun's activity. However, scientists lacked evidence supporting such a link until the mid-1980s, when van Loon and Labitzke compiled statistical evidence suggesting that a link exists and that it involves winds in the upper atmosphere above the equator which reverse their direction, from east to west or west to east, every twelve to fifteen months. This phenomenon is called the quasi-biennial oscillation (QBO), and although meteorologists have known about the QBO since the 1950s, until the 1980s no one recognized a subtle but statistically significant link between the QBO and certain patterns of weather. When the west to east direction of winds in the upper atmosphere coincides with periods of high solar activity that occur approximately every eleven years, winters in the eastern and central United States are very cold.

On this basis, some meteorologists predicted that the winter of 1988-1989 in the United States would be severe. However, the winter was a mild one overall, and the meteorologists' attempt to make the connection between the Sun and weather on the Earth appeared unsuccessful, until Barnston and Livezey proposed a hypothesis explaining why the prediction had failed. They argued that the prediction had not taken into account another important element in the climate: the more or less regular pattern of fluctuations in the temperature of the surface waters of the tropical Pacific Ocean.

Barnston and Livezey noted that when the water temperature is abnormally high-the phenomenon called EI Niño- the chances of cold winter weather over North America increase. The opposite situation, when surface temperatures are well below normal-La Nina-is far less common. In fact, until late 1988 no one had seen the combination of La Nina, westerly winds in the upper atmosphere, and high solar activity. Thus, according to Barnston and Livezey, La Nina canceled out the effect of the other two climatic factors and caused the mild winter of 1988-1989. Although this hypothesis is plausible, much research remains to be done before meteorologists can establish and explain the effects of increased solar activity on seasonal weather changes.

The passage provides information to support which of the following statements about the occurrence of very cold winters in the eastern and central United States?

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells.Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share

It can be inferred from the passage that the mortality caused by agents such as predatory birds or parasites was measured in an attempt t

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells.Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share

The primary purpose of the passage is to

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells.Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share.

According to the passage, before the discovery of new techniques for detecting viral DNA, population ecologists believed that viral diseases _______________

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells.Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share.

According to the passage, nuclear polyhedrosis viruses can remain virulent in the environment only when

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells.Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share.

It can be inferred from the passage that while inside its polyhedrin protein crystals, the nuclear polyhedrosis virus

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars Line during most of their life cycle) exhibit regularly recurring patterns of population growth and decline— such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists’ attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

Recent work suggests that this agent may be a virus. For many years, viral disease had been reported in declining populations of caterpillars, but population ecologists had usually considered viral disease to have contributed to the decline once it was underway rather than to have initiated it. The recent work has been made possible by new techniques of molecular biology that allow viral DNA to be detected at low concentrations in the environment. Nuclear polyhedrosis viruses are hypothesized to be the driving force behind population cycles in lepidoptera in part because the viruses themselves follow an infectious cycle in which, if protected from direct sun light, they may remain virulent for many years in the environment, embedded in durable crystals of polyhedrin protein. Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect’s cells. Late in the course of the infection, millions of new virus particles are formed and enclosed in polyhedrin crystals. These crystals reenter the environment after the insect dies and decomposes, thus becoming available to infect other caterpillars.

One of the attractions of this hypothesis is its broad applicability. Remarkably, despite significant differences in habitat and behavior, many species of lepidoptera have population cycles of similar length, between eight and eleven years. Nuclear polyhedrosis viral infection is one factor these disparate species share.

Which of the following, if true, would most weaken the author’s conclusion in lines 18- 22?

Researchers bet their bottom dollar on a combination of polar ice cores, tree-rings, geochemistry, and a medieval chronicle little-known in the West to solve one of vulcanology’s most enduring mysteries: which peak blew its top in the mid-13th century, causing a catastrophic eruption that ranks as one of the biggest in the recorded history? As with any investigation, the team had to rule out other suspects as it followed a trail of clues - and even read palms, or at least palm leaves, ultimately finding the culprit of the massive 1257 AD eruption, which the researchers say is Samalas volcano on Lombok Island in Indonesia.

For decades, scientists have been searching for the volcano responsible for the largest spike in sulfate deposits in the last 7,000 years, which were revealed in the ice cores from Greenland and Antarctica. The spike indicated a massive eruption around 1257 that may have sent up to eight times more sulfate into the stratosphere than the 1883 eruption of Karaktau, often held up as an archetype of volcanoes behaving badly. Researchers say the 1257 mystery spew is comparable in scope to a second-century AD eruption in the Taupo Volcanic Zone of New Zealand, known as the most intense historic volcanic event. Multitude of futile attempts for a few decades compelled the researchers to write the project off as “unsolved”. Some thirty years later, one of the researchers’ tips came from Babad Lombok, a 13th century historical record in Old Javanese, written on palm leaves, the chronicle referencing a massive eruption of Samalas that created an enormous caldera. The current research zeroed in on Samalas, part of the Mount Rinjani volcanic complex. The team was able to accumulate a sizable amount of incriminating evidence, including pyroclastic deposits from the eruption more than 100 feet thick found more than 15 miles from the ruins of the volcano. The range of deposits and the volume suggest that the Samalas eruption exceeded that of the Tambora event in 1815.

The team sampled carbonized tree trunks and branches in the Samalas deposit zone and used radiocarbon dating to confirm a mid 13th-century eruption. Reviewing wind patterns, researchers were even able to narrow the timeframe for the eruption. The distribution, to the west, of volcanic ash and other ejecta from Samalas suggest that the dry season’s easterly trade winds were prevalent, putting the eruption window between May and October of 1257.

The author is primarily concerned with:

Researchers bet their bottom dollar on a combination of polar ice cores, tree-rings, geochemistry, and a medieval chronicle little-known in the West to solve one of vulcanology’s most enduring mysteries: which peak blew its top in the mid-13th century, causing a catastrophic eruption that ranks as one of the biggest in the recorded history? As with any investigation, the team had to rule out other suspects as it followed a trail of clues - and even read palms, or at least palm leaves, ultimately finding the culprit of the massive 1257 AD eruption, which the researchers say is Samalas volcano on Lombok Island in Indonesia.

For decades, scientists have been searching for the volcano responsible for the largest spike in sulfate deposits in the last 7,000 years, which were revealed in the ice cores from Greenland and Antarctica. The spike indicated a massive eruption around 1257 that may have sent up to eight times more sulfate into the stratosphere than the 1883 eruption of Karaktau, often held up as an archetype of volcanoes behaving badly. Researchers say the 1257 mystery spew is comparable in scope to a second-century AD eruption in the Taupo Volcanic Zone of New Zealand, known as the most intense historic volcanic event. Multitude of futile attempts for a few decades compelled the researchers to write the project off as “unsolved”. Some thirty years later, one of the researchers’ tips came from Babad Lombok, a 13th century historical record in Old Javanese, written on palm leaves, the chronicle referencing a massive eruption of Samalas that created an enormous caldera. The current research zeroed in on Samalas, part of the Mount Rinjani volcanic complex. The team was able to accumulate a sizable amount of incriminating evidence, including pyroclastic deposits from the eruption more than 100 feet thick found more than 15 miles from the ruins of the volcano. The range of deposits and the volume suggest that the Samalas eruption exceeded that of the Tambora event in 1815.

The team sampled carbonized tree trunks and branches in the Samalas deposit zone and used radiocarbon dating to confirm a mid 13th-century eruption. Reviewing wind patterns, researchers were even able to narrow the timeframe for the eruption. The distribution, to the west, of volcanic ash and other ejecta from Samalas suggest that the dry season’s easterly trade winds were prevalent, putting the eruption window between May and October of 1257.

The author of the passage alludes to the discovery made in Greenland and Antarctica in order to

Researchers bet their bottom dollar on a combination of polar ice cores, tree-rings, geochemistry, and a medieval chronicle little-known in the West to solve one of vulcanology’s most enduring mysteries: which peak blew its top in the mid-13th century, causing a catastrophic eruption that ranks as one of the biggest in the recorded history? As with any investigation, the team had to rule out other suspects as it followed a trail of clues - and even read palms, or at least palm leaves, ultimately finding the culprit of the massive 1257 AD eruption, which the researchers say is Samalas volcano on Lombok Island in Indonesia.

For decades, scientists have been searching for the volcano responsible for the largest spike in sulfate deposits in the last 7,000 years, which were revealed in the ice cores from Greenland and Antarctica. The spike indicated a massive eruption around 1257 that may have sent up to eight times more sulfate into the stratosphere than the 1883 eruption of Karaktau, often held up as an archetype of volcanoes behaving badly. Researchers say the 1257 mystery spew is comparable in scope to a second-century AD eruption in the Taupo Volcanic Zone of New Zealand, known as the most intense historic volcanic event. Multitude of futile attempts for a few decades compelled the researchers to write the project off as “unsolved”. Some thirty years later, one of the researchers’ tips came from Babad Lombok, a 13th century historical record in Old Javanese, written on palm leaves, the chronicle referencing a massive eruption of Samalas that created an enormous caldera. The current research zeroed in on Samalas, part of the Mount Rinjani volcanic complex. The team was able to accumulate a sizable amount of incriminating evidence, including pyroclastic deposits from the eruption more than 100 feet thick found more than 15 miles from the ruins of the volcano. The range of deposits and the volume suggest that the Samalas eruption exceeded that of the Tambora event in 1815.

The team sampled carbonized tree trunks and branches in the Samalas deposit zone and used radiocarbon dating to confirm a mid 13th-century eruption. Reviewing wind patterns, researchers were even able to narrow the timeframe for the eruption. The distribution, to the west, of volcanic ash and other ejecta from Samalas suggest that the dry season’s easterly trade winds were prevalent, putting the eruption window between May and October of 1257.

Which of the following statements about “the most intense historic volcanic event” is supported by information in the passage?