据说，北京今天上班的人是这样的……

昨天晚上，北京的朋友应该感受了春风“狂飙”的烈度。

有网友表示，大家在集体参演《银翼杀手2049》……不少人还在朋友圈晒图，称北京的沙子里掺了点空气。

根据预报，本次沙尘天气过程将于4月11日左右逐步结束，但紧随其后在13日至14日，还会再有一次沙尘天气过程现身，西北、华北和东北地区一带将再遭风沙侵扰。

A sandstorm from Mongolia swept through parts of China on Monday, spreading from far north Heilongjiang province to as far south as Shanghai. According to the National Meteorological Center, the sandstorm will weaken starting from Tuesday. It is forecast that another sandstorm may occur around April 14.

今春沙尘天气缘何如此频繁？沙子都是哪里来的？沙尘来袭时如何防护？双语君今天为大家一一解答：

▌这次沙尘主要来源是哪里？

图源：北京环境监测官网

北京地区此次沙尘的主要来源是蒙古国沙漠和戈壁，在蒙古气旋及其后部冷空气东移过程中，强烈的大风卷起沙尘，通过高空输送，南下东移，在北京等下游地区沉降形成沙尘天气。

The sandstorm originated in the Gobi Desert areas of Mongolia. During the eastward movement of a Mongolian cyclone and its subsequent cold air mass, strong winds picked up the sand and dust, which were then transported southward and eastward at high altitudes and eventually settled in downstream areas such as Beijing, resulting in the sandstorm.

▌今年北方沙尘为何如此频繁？

目前的这次沙尘天气过程是今年以来第8次，常年同期的沙尘过程次数大约是5至6次左右，今年沙尘出现的次数略偏多。

The current dusty weather is the eighth round in this year, while the average number of sandstorms during the same period in previous years is about 5 to 6 times. There are multiple reasons for the frequent sandstorms in the north of China this year.

为何北方今年以来沙尘天气会如此频繁？

“从气候条件上来说，前期沙源地的气温偏高、降水偏少，加之植被尚未返青，裸露的沙源地地表条件就容易触发沙尘天气。”中国天气网气象分析师王伟跃介绍，从天气条件上来说，进入3至4月份以来，我国冷空气活动仍处在活跃期，在冷空气影响期间，蒙古气旋和地面冷锋成为有利的推手，将沙尘从沙源地带到下游地区，甚至一路输送到更南、更远的地方。

According to meteorologist Wang Weiyue, the cold air activity in the country has remained active in March and April. During the influence of cold air, Mongolian cyclones and cold fronts on the ground have become favorable catalysts, transporting sand and dust from the sand source areas downstream to even more southern and farther areas.

▌天空泛黄就是沙尘暴吗？

图源：视觉中国

并不是所有的沙尘天气都是沙尘暴。只有沙尘天气达到一定强度时，才能称为沙尘暴。在气象学上，按照影响由轻到重，沙尘天气可分为浮尘、扬沙、沙尘暴、强沙尘暴和特强沙尘暴。

Is a yellowish sky always an indicator of a sandstorm? Not exactly. Only when the sandy and dusty weather reaches a certain intensity can it be called a sandstorm. In meteorology, according to the severity of the impact, the dusty weather can be divided into floating dust, blowing sand, sandstorm, strong sandstorm, and severe sandstorm.

▌沙尘天气如何防范？

室内关好门窗，开启空气净化器，采用洒水、开启加湿器、用湿墩布拖地等方式除尘。外出佩戴好口罩、纱巾等防尘用品，回家清洗面部、鼻腔。开车减速慢行，打开车灯等。

Stay indoors as much as possible, and keep windows and doors closed. Use air purifiers, sprinkle water, use humidifiers, and mop the floor with wet cloth to remove dust; Wear masks, gauze or other dust-proof items when going outdoors, and clean your face and nose when returning home; When driving, reduce speed, turn on headlights, and drive with caution.

编辑：焦洁

来源：中国天气网 中国日报网