单选题 It seems to happen with depressing frequency-surely skies turn to rain just as the weekend arrives. Now Spanish researchers say they have evidence that in some parts of Europe the weather really does follow a weekly cycle, although not in the straightforward way that the anecdote might suggest.
Evidence has been mounting over the years that the weather in certain parts of the world, including the US, Japan and China, can be driven by the weekly cycle of human activity. This is because we tend to produce more air pollution during the week and less at the weekend. Evidence that such an effect occurs in Europe is controversial and has been harder to come by. Arturo Sanchez-Lorenzo of the University of Barcelona, Spain, and his colleagues examined data gathered between 1961 and 2004 from weather stations across Spain to see whether such a pattern existed. They claim to have found it in Spain, as well as hints of weekly changes in air circulation more broadly over Western Europe.
The result is puzzling, but it is known that airborne pollutants produced by human activity can affect the weather in a variety of ways. For example, particles can be heated by absorbing sunlight, which in turn heats the air and changes air circulation patterns. Pollutant particles can also provide seeds for cloud formation. Exactly which effect has the greatest influence seems to depend on conditions that vary season by season. They also found signs that air pressure in Western Europe tends to be lower midweek than at the weekend in data from a global database. This suggests that the human influence on weather goes beyond known local effects, says team member Josep Calbó of the University of Girona in Spain.
However, it is not clear whether the team's findings are statistically significant, says Thomas Bell of NASA's Goddard Space Flight Center in Greenbelt, Maryland, who was part of a team that found a stronger weekly cycle in the US. "This whole enterprise of looking for weekly cycles is rife with possibilities for misleading oneself."
Why a weekly cycle would be less noticeable in Europe than in the US and Asia is still unknown. No weekly cycle has ever been found in the UK, probably because the weather is dominated by large systems blowing in from the Atlantic Ocean. These larger systems may be harder for weekly pollution cycles to influence, points out Douglas Maraun of the University of East Anglia in Norwich, who studies UK precipitation. "I doubt that there is a weekly influence of human activity on such a large weather system," he says.
单选题 In the opening paragraph, Spanish researchers suggest that
  • A. the weather system of Europe follows a strict weekly cycle.
  • B. there is a great possibility of rain in Spain on weekends.
  • C. rain cycles have resulted from the excessive human activities.
  • D. weather interacts with human activities in a straightforward way.
【正确答案】 B
【答案解析】
单选题 The reason why weather changes are possibly due to human factors is that
  • A. the weather usually follows a weekly cycle.
  • B. when people stay at home, they are careful with pollutants production.
  • C. air circulation acts in different manners because of deliberate human interference.
  • D. different activities on weekdays and weekends have imposed effect on the air.
【正确答案】 D
【答案解析】
单选题 Airborne pollutants can affect
  • A. sunlight absorption.
  • B. air circulation.
  • C. cloud movement.
  • D. human activities.
【正确答案】 B
【答案解析】
单选题 What's Thomas Bell's attitude toward the study of weekly change in weather?
  • A. He supports the findings through his own research statistics.
  • B. He agrees that the findings are possibly true.
  • C. He points out that the findings lack in abundant data.
  • D. He is certain that the purpose of study is misleading.
【正确答案】 C
【答案解析】
单选题 The climate in UK is probably
  • A. under the influence of large weather systems.
  • B. the same to that of the other regions of Europe.
  • C. drawing the attention of global research world.
  • D. less changeable due to weak human activities.
【正确答案】 A
【答案解析】