〈石鎚神社中宮成就社境内より霧氷咲く石鎚山頂を望む〉 The ice rime-covered summit of Mt. Ishizuchi, viewed from the precincts of Chugu Jojusha of Ishizuchi Shrine
〈有名な蔵王の樹氷/スノーモンスターなどとも呼ばれる〉 Famous Tree frost "Jyuhyo" in Zao; often labelled as "Snow Monsters"
〈成就地区で観る霧氷〉Rime ice "Muhyo" found in Joju area
石鎚神社 祢宜 曽我部英司／NPO法人石鎚森の学校事務局長 リチャード
Richard's Column "It doesn't bother you even if you don't know it, but..." vol. 4
"Ice, ice, ice, and ice...?"
It's January, 2022, we welcomed New Year here in Joju area (located at an elevation of 1,450 meters) , which is at the seventh station of Mt. Ishizuchi, the highest peak in western Japan (at an elevation of 1,982 meters). In Japanese, we often use the word "Early Spring" (Hatsu-haru, or Shin-shun) to celebrate the coming of New Year, but we are still in the midst of winter. In recent years, the amount of snowfalls is getting smaller and smaller, which I think reflects another influence of the climate change. Thirty to forty years ago, it was not at all unusual that the precincts of Jojusha Shrine was covered in more than one metre of snow in mid-January, but today (13, January 2022), we have only 20 centimeters of snow. These days, even in mid-February, when we should have the largest snowfalls, we have only 5-6 centimeters of snow.
When it comes to temperature, however, we still have a very cold winter and it comes to sub-zero temperature; it comes down to minus 15 degrees celsius on a cold day. Very rarely we have a warm day and it's 2 or 3 degrees or warmer, but the average temperature of Joju area in winter falls below the freezing point; we usually find our thermometer showing minus 5 degrees.
Thus, our great Nature shows the visitors so impressive a sight like the picture above; the ice rime-covered summit shining against the clear blue sky is so dignified and breath-takingly beautiful. Shikoku island, whose highest peak is Mt. Ishizuchi, is located to the southwest of the main island, so people call Shikoku a warm Southland, but once you come up to the seventh station of the mountain, you can see diamond dust composed of tiny ice crystals, often called "Ice Flowers" shining brightly in the sun...
Today, let me talk about such a beautiful "Rime ice" called Muhyo (literally meaning "Fog-ice") in Japanese of Mt. Ishizuchi. Rime ice is formed when small supercooled water droplets freeze onto surfaces. The fog freezes usually to the windward side of tree branches, and gets clear and solid. The phenomenon called "Tree frost" called Juhyo (literally meaning "Tree-ice") in Japanese looks similar, but to be strict, Rime ice and Tree frost should be distinguished; Tree frost looks whiter and fragile, and it often covers not only branches but the whole trees; fully-covered trees look like white monsters and that is why the well-known frost covered trees in Zao are called "Snow Monsters".
Well, let me move on to the phenomenon called "Glaze ice" called Uhyo (literally meaning "Rain-ice") in Japanese. Many of you have never heard of this name before. Please have a look at the pictures below. These pictures were taken in the precincts of Jojusha Shrine a couple of years ago, and I should say they are very, very rare pictures.
...how do you like them? "Glaze ice" phenomenon occurs when the supercooled rain drops, which have not frozen yet even at the temperature below zero, freeze upon impact with cold surfaces of grounds or trees and are coated by ice.
Then, let me give you one more phenomenon; it's "Air Hoar" called Jyuso (literally meaning "Tree-hoar"). Again, the term sounds quite strange to many of you, so let me show you the pictures of Shimenawa rope, a sacred rice straw festoon, of Jojusha Shirine. Again, they are very rare pictures...
"Air Hoar" is deposit of hoar frost on objects above the surface, such as tree branches and, as you see in these pictures, it grows in any directions, both vertically and horizontally.
Besides, we have another phenomenon called "Hard rime" called Sohyo (literally meaning "Coarse ice"), which is somehow similar to "Glaze ice" above and again "Hard rime" appears in the form of ice coating branches and other objects. While "Glaze ice" is frozen rain, thus it often appears in the form of drops like icicles, "Hard rime" is formed by water droplets in fog freezing to the outer surfaces of objects, thus does not appear in the form of icicles.
...well, I hope it does not upset you, but all the phenomena that I have explained so far, I mean "Muhyo", "Juhyo", "Uhyo" and "Sohyo"...I know they look somehow similar and my explanation must have sounded quite complicating, I know.........To be very honest, however, they all belong to the same phenomenon....well, I mean they are all "Rime ice"! Ha-ha-ha...and again...ahem!...it does not bother you even if you don't know it, but it might make your life a bit happier, as I always say at the opening and ending of my columns, you know ;-D
Oh, talking about icicles, let me show you the picture of the huge icicles taken at somewhere in the precincts of Joju shrine. One of the largest one was more than 2 meters long! Amazing, isn't it?
...At present, Mt. Ishizuchi is surrounded with tranquility of winter. Nevertheless, please remember that the Great Nature is quietly but surely preparing for coming of spring. Seasons come and go, that has been unchangeable Nature's work for more than 1300 years since when Mt. Ishizuchi, our sacred peak was opened.
-- Hideshi Sogabe, Senior Priest of Ishizuchi Shrine, a.k.a Richard; Director and Secretary General of NPO Ishizuchi Mori-no-Gakko “School of the Woods” (13, January 2022)