太空天氣預測專家證實太陽表面出現了新的黑子，並依此徵兆判斷太陽已進入新的活躍週期，可能影響地面的輸電系統及重要的軍事、民用、航空通訊，甚至會干擾手機與銀行交易系統。
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| 太陽日冕噴發影響地球磁場示意圖：太陽若朝地球方向發生日冕噴發現象，帶電物質會於2-4天後到達，使地球磁層發生扭曲，干擾通訊及導航設備，損毀衛星，甚至導致斷電。（示意圖未照實際比例繪製）；圖片來源：美國與歐洲太空總署SOHO太陽觀測站 |
美國海洋與大氣總署（NOAA）的科學家表示，這個黑子3日出現在太陽的北半球。黑子是太陽表面具有強烈磁場活動集結的區域，NOAA太空天氣預測中心的太陽物理學家畢賽克（Douglas Biesecker）說：「就像知更鳥報春一樣，這顆黑子的出現是太陽風暴將在往後數年逐漸增多的早期預兆。」
這個全新的11年週期被定為第24個太陽週期，隨著強度逐漸發展，黑子與太陽風暴的數目預計在2011或2012年達到頂峰，但劇烈的太陽風暴可能會隨時出現。
NOAA從1972年1月開始紀錄太陽黑子，最近出現的這一顆被編為第10981號，NOAA專家表示，此黑子位於太陽北緯27度，緯度高且南磁極位於右方，是全新太陽週期開始的明顯徵兆。
太陽在活躍期間會有更多劇烈噴發的現象。太陽閃燄與巨大的日冕爆發活動，會將高能量的光子與強烈帶電物質射向地球，擾亂電離層與地球磁場。這些磁性物質會干擾衛星、讓太空人員暴露於危險輻射，也會影響地面的配電線路、通訊與GPS定位系統訊號。
太陽週期的強度由黑子極大期的數目決定。黑子是太陽高度磁場活動產生的暗班，黑子越多，越有可能發生強大的太陽風暴。
NOAA署長勞滕巴赫爾（Conrad C. Lautenbacher）指出，「我們對複雜太空科技的依賴日漸加深，太空天氣對我們產生的影響也將因此更勝以往。」
Space weather forecasters have identified a new sunspot on the surface of the Sun as the first sign of a fresh cycle of increased solar activity that could affect power grids, critical military, civilian and airline communications, even cell phones and bank machine transactions on Earth.
The sunspot in the Sun's Northern Hemisphere appeared Thursday, NOAA scientists said. A sunspot is an area of highly organized magnetic activity on the surface of the Sun. "This sunspot is like the first robin of spring," said solar physicist Douglas Biesecker of NOAA's Space Weather Prediction Center in Boulder. "In this case, it's an early omen of solar storms that will gradually increase over the next few years."
The new 11 year cycle, called Solar Cycle 24, is expected to build gradually, with the number of sunspots and solar storms reaching a maximum by 2011 or 2012, though devastating solar storms can occur at any time.
The new sunspot, identified as #10,981, is the latest visible spot to appear since NOAA began numbering them on January 5, 1972. Its high-latitude location at 27 degrees North, and its negative polarity leading to the right in the Northern Hemisphere are clear-cut signs of a new solar cycle, according to NOAA experts.
During an active solar period, violent eruptions occur more often on the Sun. Solar flares and vast explosions, known as coronal mass ejections, shoot energetic photons and highly charged matter toward Earth, jolting the planet's ionosphere and geomagnetic field. This magnetically charged material may disrupt satellites, threaten astronauts with harmful radiation, and interfere with power grids, communications, and Global Positioning System, GPS, signals, on Earth.
Solar cycle intensity is measured in maximum number of sunspots - dark blotches on the sun that mark areas of heightened magnetic activity. The more sunspots there are, the more likely it is that major solar storms will occur.
"Our growing dependence on highly sophisticated, space-based technologies means we are far more vulnerable to space weather today than in the past," said NOAA administrator Conrad C. Lautenbacher, Jr.
參考網站：NOAA太空天氣預測中心網頁
全文及圖片詳見：ENS
