冬日雨水加快格陵兰冰盖融化

一项新的研究发现，格陵兰岛上的降雨越来越频繁，同时雨水加快了冰层的融化。科学家们说他们很 “惊讶” 地发现，即使在漫长的极地冬日期间也会有降雨。

Rain falls on the tent of scientist Jason Box. He's camped on the Greenland ice sheet. The usual pattern is that ice melts in the summer and is restored by fresh snow in the winter. But temperatures in the Arctic are rising twice as fast as the rest of the planet and Professor Box believes there’ll be more rain in future.

雨水落在了科学家杰森·博克斯的帐篷上。他在格陵兰冰盖上扎了营。这里正常的气候模式是：夏季冰川融化，冬季新雪结冰，恢复原状。但北极地区的气温上升速度是地球其它地区的两倍，博克斯教授认为未来还会有更多的降雨。

A big surprise in this latest study is that rain can fall not only in summer but also in winter, when the polar night would normally mean temperatures are well below zero. The reason is that warm, moist air occasionally flows up from the Atlantic bringing rain, and this is happening more often.

在这项最新研究中，一个令人非常意外的发现是，不仅夏季有雨，冬季也下雨，而且冬季的极地夜晚意味着气温通常远低于零度。因为温暖、湿润的空气会偶尔从大西洋刮来，带来雨水，而且这种现象愈加频繁。

Although rain falling in winter will quickly refreeze, it’ll change the surface, making it darker and smoother, which means that in the following summer the ice will be likelier to melt.

虽然冬天的雨水会迅速再次结冰，但降雨会改变冰面，使其颜色更黑、质地更滑，这意味着在接下来的夏天里，冰川将更易融化。

This matters because the Greenland ice sheet is so large that if all of it melted the global sea level would rise by seven metres - around 20 feet. No one is suggesting that could happen soon. But the fear is that even a slight increase in melting could threaten coastal cities around the world.

这很重要，因为格陵兰冰盖十分巨大，如果它全部融化，那么全球海平面将上升七米，约 20 英尺。没有人认为这种情况将很快到来。但令人担忧的是，即使融化的速度稍有增加，也可能会给世界各地的沿海城市带来威胁。