kilograms(“雨凇”、“霜花”、“霧凇”，這些冬日自然氣象用英語怎么說？)

“雨凇”、“霜花”、“霧凇”，這些冬日天然景象用英語怎樣說？

當冬天到臨，我們最渴望的是快點下一場雪！但冬天比你想象的要絢麗多彩。除了皚皚白雪，我們還可以欣賞“雨凇”、“霜花”、“霧凇”……你見過這些天然景象嗎？你曉得它們的英文表達嗎？

圖源：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）是預示冬天到來的最早預告。它的英文名泉源于一個“新鮮”的英語單詞（hoar，意思是“顯得新鮮”）。白霜是一層薄薄的羽毛狀冰層，通常在明朗的寒夜凝結于物體外表。好天使地表溫度比周圍氛圍的溫度下降更快，大氣中的濕氣在與地表交往時凝結成固體。即使地表上幾英尺的氛圍遠高于冰點，也會構成這種冰霜，并且通常在日出后一兩個小時內消融。

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“冰帶”和“冰須”）是一種薄而細長、十分共同的冰布局，見于深秋或初冬，植物第一次結冰時。

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.

當植物莖稈中的水凝結時，會涌到莖稈裂開的場合，凝結的水從裂口中溢出。由于毛細作用，植物的莖從地表吸取更多水分，從而結出更多冰晶的霜花。

圖源：央視訊息

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. 當雨點落在溫度在冰點以下的外表時，會立刻構成所謂的“雨凇”，即平滑、純透的冰層。雨雪事后，可見雨凇掩蓋在樹枝和植物上。

2018年12月12日，游人在吉林省吉林市豐滿區吉豐東路松花江畔觀看霧凇美景。圖源：新華網

HARD RIME

硬霧淞

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.

隨著天氣變冷，約莫會顯現凍霧，當凍霧與風結適時，物體迎風面會構成硬霧?。╤ard rime）。Rime字面意思是“白霜”，軟霧凇與厚厚的白霜十分相似，但在景象層面上略有不同。別的，硬霧凇要更厚更硬，由高密度的不端正冰晶團圓合在一同構成。

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.

在湖泊周圍（偶爾顯現湖泊效應降雪）和沿海地區最常顯現滿意雷雪天氣的天氣條件。在這些場合，陽光讓地表溫度上升，招致相對暖和濕潤的不安定氛圍柱上升，構成湍流云。

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.

但光有云層并不克不及產生雷雪。僅有當云層和地表之間的氛圍層比云層溫度高，但仍冷到足以構成降雪，并且風向切變將暖和的氛圍略微向上推時，才會構成雷雪。

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

雪通常會遮掩雷聲，這意味著很多時分約莫聽不到雷聲。

圖源：Pexels

SNOWPACK

積雪

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.

在嚴寒季候漫長的地區， 每場雪下完之后都不會消融。此中一些雪會升華（直接從固體變化為氣體），特別是在陽光富裕和風干枯的地區，但大局部雪會留在地表上。當新雪落在舊雪外表，舊雪的晶了解被新雪掩蓋的分量壓下去。依據每次降雪距離的時間長度、雪花典范和天氣條件，每層積雪約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.

當積雪一年又一年會萃起來，就構成了“粒雪”。粒雪比平凡積雪密度大得多，這是兩個要素招致的：在暖和的季候，一局部雪消融使積雪會萃得更嚴密；在嚴寒的季候，新雪落在密實的積雪頂部，將晶體推到一同而不消融。

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.

高海拔地區的積雪終極構成冰川，并增補冰川物質，以抵消低海拔地區冰川的消融和崩解。粒雪的密度在每平方米550830公斤之間。這是什么看法呢？剛落下的“粉末”雪的密度約為每平方米50至70公斤。

泉源：Mental Floss編纂：董靜

泉源：中國日報網