A regular drop in the sun’s radiation(辐射) can cause unusually cold winters in pa

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A regular drop in the sun’s radiation(辐射) can cause unusually cold winters in parts of North America and Europe, scientists say, a finding that could improve long-range forecasts and help countries prepare for snowstorms.
Scientists have known for a long time that the sun has an 11-year cycle during which radiation measured by sunspots on the surface reaches a peak then falls. But explaining a clear connection to weather is harder.
“Our research confirms the observed connection between solar change and regional winter climate,” lead author Sarah Ineson of the UK Met Office told the reporters in an email. The study was published in the magazine Nature Geoscience on Monday.
The researchers found that the reducing of ultraviolet(UV，紫外线) radiation from the sun can affect high-altitude wind patterns in the Northern Hemisphere(半球), causing cold winters.
“While UV levels won’t tell us what the day-to-day weather will do, they show us the bright future of improved forecasts for winter conditions for months and even years ahead. These forecasts play an important role in long-term possibility planning,” Ineson, a climate scientist, said.
Ineson and colleagues from Imperial College London and the University of Oxford used satellite data that more accurately(精确的) measures UV radiation from the sun and found a much greater change than previously thought.
They found that in years of low activity, unusually cold air forms high in the atmosphere over the tropics. This causes a redistribution(重新分配) of heat in the atmosphere, making easterly winds that bring freezing weather and snowstorms to northern Europe and the United States and milder weather to Canada and the Mediterranean.
When solar UV radiation is stronger, the opposite occurs.
More study was needed, though. A key uncertainty in the experiment lay in the satellite data used, because it covers only a few years. “So questions remain concerning both accuracy(精确) and also applicability to other solar cycles,” she said.
小题1:The new finding claims cold winters in the North Hemisphere can be caused by ______.

A．a sharp rise in the amount of sunspots

B．a drop in the sun’s UV radiation

C．a complex computer model simulation

D．a clear link between the sun and the earth

小题2: It has long been known by scientists that ______.

A．UV radiation can affect high-altitude wind patterns

B．there’s a clear connection between the sun’s activity and weather

C．the sun’s radiation reaches a peak every eleven years

D．they can predict day-to-day weather conditions from UV levels

小题3:What will happen if the sun turns into years of high activity according to the finding?

A．Canada and the Mediterranean will have milder weather.

B．The whole Northern Hemisphere will suffer from extreme winter days.

C．Freezing cold weather will appear in northern Europe.

D．Burning hot weather will appear in the United States.

小题4: It can be inferred from the passage that ______.

A．researchers have analyzed the data collected in eleven years

B．long-term weather conditions can be accurately predicted depending on UV levels

C．the research doesn’t seem correct and true enough due to limited satellite data used

D．climate scientists have just begun their research in severe weather forecast

答案

小题1:B
小题2:C
小题3:D
小题4:C

解析

试题分析：科学家们发现太阳紫外线的降低会使北半球的冬天更为寒冷，这一研究发现有可能会有助于发展长期准确的天气预报，从而能够提醒人们提前防备暴风雪的来临。但是科学家们同时也指出这项研究还有待于更多的科学数据支持。
小题1:B细节理解题。根据文章第四段 the reducing of ultraviolet(UV，紫外线) radiation from the sun can affect high-altitude wind patterns in the Northern Hemisphere(半球), causing cold winters.可知太阳紫外线辐射的降低有可能造成北半球冬天气温的下降，所以B选项正确。
小题2:C细节理解题。根据文章第二段Scientists have known for a long time that the sun has an 11-year cycle during which radiation measured by sunspots on the surface reaches a peak then falls.可知太阳辐射每十一年到达一个顶峰,所以C选项正确。
小题3:D推理判断题。根据文章倒数第二段内容可知当太阳黑子活动减少的时候，会造成北美等地的寒冷气候，而文章倒数第三段又进一步提到When solar UV radiation is stronger, the opposite occurs.由此判断当太阳紫外线强的时候，北美等地就会炎热，故答案选D。
小题4:C推理判断题。根据文章末段More study was needed, though. A key uncertainty in the experiment lay in the satellite data used, because it covers only a few years.可知实验的不确定性在于可以依赖的数据较少，目前参考的仅仅是几年的数据，所以判断C为正确选项。