kilograms(“雨凇”、“霜花”、“雾凇”，这些冬日自然气象用英语怎么说？)

“雨凇”、“霜花”、“雾凇”，这些冬日天然景象用英语怎样说？

当冬天到临，我们最渴望的是快点下一场雪！但冬天比你想象的要绚丽多彩。除了皑皑白雪，我们还可以欣赏“雨凇”、“霜花”、“雾凇”……你见过这些天然景象吗？你晓得它们的英文表达吗？

图源：Pexels

HOAR FROST

白霜

One of the first signs of winter is the hoar frost of late autumn. Deriving its name from an Old English word (hoar, meaning “to appear old”), this is the thin, feathery coating of ice that often forms on objects during cool nights with clear skies. The clear skies allow the ground to lose heat more quickly than the surrounding air, and the humidity in the atmosphere condenses and freezes into a solid when it makes contact with surfaces. This frost can occur even when the air a few feet above ground is well above freezing, and usually melts within an hour or two of sunrise.

深秋的白霜（hoar frost）是预示冬天到来的最早预告。它的英文名泉源于一个“新鲜”的英语单词（hoar，意思是“显得新鲜”）。白霜是一层薄薄的羽毛状冰层，通常在明朗的寒夜凝结于物体外表。好天使地表温度比周围氛围的温度下降更快，大气中的湿气在与地表交往时凝结成固体。即使地表上几英尺的氛围远高于冰点，也会构成这种冰霜，并且通常在日出后一两个小时内消融。

FROST FLOWER

霜花

Frost flowers (and the related “ice ribbons” and “ice beards”) are very thin, spindly, unique formations of ice, seen in late autumn or early winter, when plants are first freezing.

霜花（以及干系的“冰带”和“冰须”）是一种薄而细长、十分共同的冰布局，见于深秋或初冬，植物第一次结冰时。

When the water in the plant stem freezes, it expands to the point where the plant splits open along the side, and the frozen water is extruded from the split. More water is then drawn up through the stem from the ground via capillary action, adding more ice crystals to the frost flower.

当植物茎秆中的水凝结时，会涌到茎秆裂开的场合，凝结的水从裂口中溢出。由于毛细作用，植物的茎从地表吸取更多水分，从而结出更多冰晶的霜花。

图源：央视讯息

GLAZE ICE

雨凇

When falling precipitation hits a surface that’s below freezing, it can instantly form what’s known as “glaze ice,” a buildup of smooth, clear, and transparent ice. It can be seen coating tree branches and plants following an ice storm. 当雨点落在温度在冰点以下的外表时，会立刻构成所谓的“雨凇”，即平滑、纯透的冰层。雨雪事后，可见雨凇掩盖在树枝和植物上。

2018年12月12日，游人在吉林省吉林市丰满区吉丰东路松花江畔观看雾凇美景。图源：新华网

HARD RIME

硬雾淞

As the weather cools, freezing fogs can occur, and when that fog is combined with wind, hard rime can form on windward (wind-facing) surfaces. “Rime” literally means “hoar frost,” and while slightly different on a meteorological level, “soft rime” is very similar to a thick hoarfrost. Hard rime, on the other hand, is much thicker and harder, and consists of fairly dense pellets of irregular ice crystals glommed together.

随着天气变冷，约莫会显现冻雾，当冻雾与风结适时，物体迎风面会构成硬雾凇（hard rime）。Rime字面意思是“白霜”，软雾凇与厚厚的白霜十分相似，但在景象层面上略有不同。别的，硬雾凇要更厚更硬，由高密度的不端正冰晶团圆合在一同构成。

THUNDERSNOW

雷雪

The conditions required to create thundersnow are most common around lakes (it occasionally accompanies lake-effect snow) and coastal areas. In these places, the sun is able to heat the ground and cause relatively warm and humid columns of unstable air to rise up and form turbulent clouds.

在湖泊周围（偶尔显现湖泊效应降雪）和沿海地区最常显现满意雷雪天气的天气条件。在这些场合，阳光让地表温度上升，招致相对暖和湿润的不安定氛围柱上升，构成湍流云。

But clouds alone don’t make thundersnow. Only if the layer of air between the clouds and the ground is warmer than the cloud cover, but still cold enough to create snow, and the wind shear is pushing the warmer air slightly upwards, does thundersnow form.

但光有云层并不克不及产生雷雪。仅有当云层和地表之间的氛围层比云层温度高，但仍冷到足以构成降雪，并且风向切变将暖和的氛围略微向上推时，才会构成雷雪。

The snow can often muffle the thunderclap, meaning that many instances of thundersnow probably go unnoticed.

雪通常会遮掩雷声，这意味着很多时分约莫听不到雷声。

图源：Pexels

SNOWPACK

积雪

When a place has an extended cold season, snow rarely melts between each subsequent snowfall. Some of it will sublimate—or transition directly from a solid to a gas—especially in areas with lots of sunlight and dry wind, but the majority of it will stay present on the ground. When fresh snow falls on top of the old snow, the crystals of the old snow get packed down under the weight of the new cover. Depending on the length of time, snowflake types, and weather conditions between snowfalls, each layer of the snowpack may have a different thickness and density.

在严寒季候漫长的地区， 每场雪下完之后都不会消融。此中一些雪会升华（直接从固体变化为气体），特别是在阳光富裕和风干枯的地区，但大局部雪会留在地表上。当新雪落在旧雪外表，旧雪的晶了解被新雪掩盖的分量压下去。依据每次降雪距离的时间长度、雪花典范和天气条件，每层积雪约莫具有不同的厚度和密度。

FIRN

粒雪

When years and years of snowpack accumulate, that buildup is called “firn.” It’s much denser than regular snowpack, because of two factors: the partial melting during warmer seasons packs the snow mass closer together; and the new snow falling on top of the ultra-condensed pack pushes the crystals together without melting during the cold season.

当积雪一年又一年会萃起来，就构成了“粒雪”。粒雪比平凡积雪密度大得多，这是两个要素招致的：在暖和的季候，一局部雪消融使积雪会萃得更严密；在严寒的季候，新雪落在密实的积雪顶部，将晶体推到一同而不消融。

The buildup of firn at high elevations eventually forms glaciers, and replenishes glacial mass to counteract the melting and calving at their lower elevations. The density of firn is between 550830 kilograms per square meter. To put that in perspective, the density of freshly-fallen “powder” snow is around 50 to 70 kilograms per square meter.

高海拔地区的积雪终极构成冰川，并增补冰川物质，以抵消低海拔地区冰川的消融和崩解。粒雪的密度在每平方米550830公斤之间。这是什么看法呢？刚落下的“粉末”雪的密度约为每平方米50至70公斤。

泉源：Mental Floss编纂：董静

泉源：中国日报网