The next solar cycle - the 11-year pattern when dark spots appear on the sun's surface - may be delayed or even go into "hibernation" for a while, according to US scientists.
Astronomer Frank Hill of the US National Solar Observatory and other scientists cited a missing jet stream, fading spots and slower activity near the sun's poles as signs that the sun is heading into a rest period.
"This is highly unusual and unexpected," he said. "But the fact that three completely different views of the sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation."
But this does not mean a new ice age is coming, Hill said.
They also wondered whether this cessation of sunspot activity indicates an upcoming return of the Maunder Minimum, a 70-year sunspot drought seen from 1645-1715.
The potentially cooling influence of the sunspot activity could not cancel out the warming caused by human activities that generate climate-warming greenhouse gases.


据英国《卫报》16日报道：美国科学家预测，下一个太阳活动周期，即每十一年太阳黑子在太阳表面出现的这个时间可能推迟，太阳或暂时进入"冬眠期"。

美国国家太阳观测台的天文学家弗兰克•希尔和其他科学家把太阳喷流消失、太阳黑子减弱、太阳两级活动变缓作为太阳正趋于休眠的标志。


"这很不寻常，出人意料" ，希尔说，"三项截然不同的太阳观测项目都发现了相同的迹象，这一事实有力地的证明，太阳黑子活动周期也许正在进入冬眠期。"

但是希尔说这并不意味着冰河时代会再度到来。
专家正在研究这段非活动期会不会预示着 "蒙德极小期"重新来临--从1645年至1715年的70年间，人类几乎观测不到任何太阳黑子活动。

太阳黑子活动可能带来的降温还不足以抵消人类活动所产生的温室效应气体对全球暖化的影响。

• missing [´misiŋ] a.缺掉的；失踪的 (初中英语单词)
• stream [stri:m] n.河 vi.流出；飘扬 (初中英语单词)
• unusual [ʌn´ju:ʒuəl] a.不平常的；异常的 (初中英语单词)
• cancel [´kænsəl] vt.删去；勾销；放弃 (初中英语单词)
• minimum [´miniməm] n.最小量 a.最小的 (高中英语单词)
• drought [draut] n.旱灾；干旱 (英语四级单词)
• warming [´wɔ:miŋ] n.暖和；加温 (英语四级单词)
• generate [´dʒenəreit] vt.创造；发生；引起 (英语四级单词)
• observatory [əb´zə:vətəri] n.天文台；气象台 (英语六级单词)
• greenhouse [´gri:nhaus] n.温室，玻璃暖房 (英语六级单词)