有撒哈拉“沙漠之门”之称的艾因塞夫拉小镇近日迎来一场降雪。厚度近半米的白雪覆盖在延绵不尽的红色沙丘上，景色格外壮观。

This coincides with just as extreme weather in other parts of the world.
这场降雪恰逢世界其他地区也出现极端天气。

The east coast of the United States continues to face the brutally cold winter storm Grayson and Sydney, Australia swelters in the hottest temperatures seen in nearly 80 years at 116.6 degrees Farenheight.
美国东海岸持续受到冬季超强风暴格雷森的影响，而澳大利亚悉尼经历了近80年来最炎热的天气，气温高达47摄氏度。

High pressures over Europe caused cold air to be pulled down into northern Africa and into the Sahara Desert. This mass of cold air rose 3,280 feet to the elevation of Ain Sefra, a town surrounded by the Atlas Mountains, and began to snow early Sunday morning.
欧洲上空的高压将冷空气推进到北非和撒哈拉沙漠。艾因塞夫拉海拔近1000米，处于阿特拉斯山脉的环绕之中。这团冷空气上升到这一高度，并在8日清晨带来降雪。

Ain Sefra, known as "the gateway to the desert" has an average high of 99.7°F during the month of July, making locals much more accustomed to managing extreme heat rather than snow. Unequipped to manage snow on roads, cars and buses were stranded on roads as they became icy.
艾因塞夫拉有“沙漠之门”之称，7月份平均气温在37.6摄氏度，相比于大雪，当地人更习惯应对酷热天气。由于道路上的积雪无法清除，小汽车和巴士都被困在结冰的路面上。

The snow didn't last long as temperatures rose to 42°F by the late afternoon. This was enough time for children to make snowmen and sled on the sand dunes, creating memories that may not be reenacted for many years to come.
积雪并没有持续很久，因为下午晚些时候气温就回升到5.5摄氏度。但对于孩子们来说，这些时间足够他们堆雪人、在沙丘上滑雪，创造可能未来多年都无法重演的回忆了。

The Sahara Desert town of Ain Sefra has experienced just three snow events in the past 37 years with the last two years having snow (1979, 2016, and 2017).
撒哈拉沙漠的艾因塞夫拉小镇在过去37年里仅出现过三次降雪（1979，2016和2017），在前两年这里都下过雪。

In the coming decades and centuries, we may find the Sahara Desert becoming the fertile grassland it once was. Research shows that northern Africa where the Sahara currently is was once dotted with large lakes, vegetation, animals, and human settlements. This period, known as the African Humid Period was far from northern Africa we know today.
在未来几十年、几百年里，我们可能会发现，撒哈拉沙漠回到曾经的样子，变成了一片肥沃的草原。研究表明，目前撒哈拉沙漠所处的北非地区曾经遍布湖泊、植被、动物和人类居住区。这一时期被称为非洲湿润期，离我们现在所熟悉的北非十分久远。

It appears that approximately 5,500 years ago, however, northern Africa moisture was suddenly cut off, ending the humid period. Research is ongoing as to why and how fertile northern Africa suddenly became the Sahara Desert. One thing is clear though, the switch between humid and arid can be abrupt. Are we on the verge of another African humid period? No one knows for sure, but it will likely be the focus of continued research studies and the hopes for many northern Africa countries.
然而，大约在5500年前，北非地区的湿气突然中断，湿润期终结。有关肥沃的北非为何突变为撒哈拉沙漠的研究正在进行中。但有一点可以肯定的是，从湿润到干旱的转换可以是突然的。我们现在是处于另一个“非洲湿润期”的边缘吗？没有人可以肯定，但这可能将是持续研究下去的重点，也是北非国家的希望所在。

原文链接：http://bbs.acadsoc.com.cn/thread-11890-1-1.html