11 Magnetic Tempests
地球物理學：介紹當前關于地球磁場風暴和磁場移動的研究

導讀

磁暴是當太陽表面活動旺盛，特別是在太陽黑子極大期時，太陽表面的閃焰爆發次數也會增加，閃焰爆發時會輻射出X射線、紫外線、可見光及高能量的質子和電子束。其中的帶電粒子（質子、電子）形成的電流沖擊地球磁場，引發短波通信稱磁暴。磁暴時會增強大氣中電離層的游離化，也會使極區的極光特別絢麗，另外還會產生雜音掩蓋通信時的正常信號，甚至使通信中斷，也可能使高壓電線產生瞬間超高壓，造成電力中斷，也會對航空器造成傷害。

 

The Earth's magnetic field is generated as the molten iron of the Earth's outer core revolves around its solid inner core. When surges in the molten iron occur, magnetic tempests are created. At the Earth's surface, these tempests can be detected by changes in the strength of the Earth's magnetic field. For reasons not fully understood, the field itself reverses periodically every million years or so. During the past million years, for instance, the magnetic north pole has migrated between the Antarctic and the Arctic.

Clearly, geophysicists who seek to explain and forecast changes in the field must understand what happens in the outer core. Unlike meteorologists, however, they cannot rely on observations made in their own lifetimes. Whereas atmospheric storms arise in a matter of hours and last for days, magnetic tempests develop over decades and persist for centuries. Fortunately scientists have been recording changes in the Earth's magnetic field for more than 300 years.

Sentence Translation

句子翻譯

1. When surges in the molten iron occur, magnetic tempests are created. At the Earth's surface, these tempests can be detected by changes in the strength of the Earth's magnetic field.

2. Whereas atmospheric storms arise in a matter of hours and last for days, magnetic tempests develop over decades and persist for centuries.

Key

1．當熔融的鐵發生浪涌時，就引起磁場風暴。在地球表面，磁場風暴可以根據地球磁場強度的變化來加以測定。

2．大氣風暴的發生是幾小時之內的事情，其持續時間也不過幾天；而地球磁場風暴的發生要經過幾十年，其持續時間要達數世紀之久。