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  • General

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  • 热浪和干旱

    A landscape covered in dust, featuring abandoned farm equipment and a dilapidated building.
     

    Is the current drought like the Dust Bowl?
    ::目前的干旱像尘土碗吗?

    The worst   wave in U.S. history came in 1936. The already struggling Midwest was hit hard by extreme temperatures and  drought .  Soil  lost moisture so it blew away. Crops were destroyed, and more than 5,000 people died. The Western US is currently suffering with drought with different, but severe, consequences.
    ::美国历史上最严重的浪潮发生在1936年。 已经陷入困境的中西部地区受到极端气温和干旱的沉重打击。 土壤水分流失,因此被吹走。 农作物被摧毁,5 000多人死亡。 西部美国目前遭受干旱,其后果各不相同,但却是严重的。

    Heat Waves
    ::热热波

    A  heat wave  is different depending on its  . A region has a heat wave if it has more than five consecutive days of temperatures that are more than 9 o F (5 o C) above average. A heat wave in Portland, Oregon might be just an average warm week in Phoenix, Arizona.
    ::热浪随热浪的不同而不同。如果一个区域连续5天的温度超过平均温度9°F(5°C)以上,那么它就会有一个热浪。 俄勒冈州波特兰的热浪可能只是亚利桑那州凤凰城的一周平均暖热浪。

    Heat  waves have increased in frequency and duration in recent years. The summer 2011 North American heat wave brought record temperatures across the Midwestern and Eastern United States. Many states and localities broke records for   and for the most days above 100 o F.
    ::近几年来,热浪的频率和持续时间都在增加。 2011年夏季北美热浪给中西部和东美国带来了创纪录的温度。 许多州和地区打破了100摄氏度以上的记录。

    Causes
    ::原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因原因

    A high pressure cell sitting over a region with no movement is the likely cause of a heat wave.
    ::高压电池在无动静的区域上坐着,可能是热浪的原因。

    What do you think caused the heat wave in the image below ( Figure   )? A  high pressure zone  kept the  jet stream  farther north than normal for August.
    ::高压区让喷气流在8月比正常更北。

    Heat radiation map of the U.S. on August 8, 2007, showing temperature variations.
     
    A heat wave over the United States as indicated by heat radiated from the ground. The bright yellow areas are the hottest, and the blue and white are coolest.

    Droughts
    ::干旱

    Map indicating drought intensity levels across the western United States as of September 2018.
     
    Drought has many consequences. Recent droughts in the western US have weakened trees, making them vulnerable to the spread of beetles, which kill them. Entire forests are now brown with dead trees. When trees and brush are dry, wildfires spread more easily. California and other western states have experienced devastating wildfires in recent years.

    Droughts  also depend on what is normal for a region. A region that gets significantly less   than normal for an extended period of time is in drought. The Southern United States is experiencing an ongoing and prolonged drought.
    ::干旱还取决于一个区域的正常状况。 长期明显低于正常状态的地区是干旱地区。 美国南部正在经历持续和长期干旱。 干旱地区是干旱地区,而美国南部是干旱地区。

    Drought has many consequences. When soil loses moisture it may blow away. This happened during the  Dust Bowl  in the United States in the 1930s. Forests may be lost, dust  storms  may become common, and wildlife are disturbed. Wildfires become much more common during times of drought.
    ::干旱带来许多后果。当土壤失去水分时,它可能会被吹走。 这发生在1930年代的美国尘土碗期间。 森林可能丧失,沙尘暴可能变得司空见惯,野生动物可能受到干扰。 在干旱时期,野火会变得更加常见。

    Summary
    ::摘要

    • A heat wave or a drought is defined as conditions different from normal in a region.
      ::热浪或干旱的定义是不同于某一区域正常的情况。
    • A heat wave is caused when a warm high-pressure cell sits over a region.
      ::当一个温暖的高压细胞坐在一个区域之上时,就会产生热浪。
    • Drought may have extremely severe consequences. The severity depends on its duration and intensity.
      ::干旱可能带来极其严重的后果,其严重程度取决于干旱的持续时间和强度。

    Review
    ::回顾

    1. How is a heat wave defined?
      ::热浪是如何定义的?
    1. How is a drought defined?
      ::干旱是如何界定的?
    1. How does the position of the jet stream cause a heat wave?
      ::喷气流的位置如何引起热浪?

    Explore More
    ::探索更多

    Use the resources below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What will happen if the world's average temperature increases by 3 degrees?
      ::如果世界平均气温上升3度会怎样?
    1. What will become the norm in Europe and the Mediterranean?
      ::欧洲和地中海的规范是什么?
    1. What happened in the summer of 2003?
      ::2003年夏天发生了什么?
    1. How many people died in Europe that summer?
      ::那年夏天欧洲有多少人死亡?
    1. Why was this catastrophe, caused or exacerbated by global warming, unique?
      ::为什么这场由全球变暖造成或加剧的灾难是独一无二的?