Yukimarimo are balls of fine
frost
Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) ...
formed at low temperatures on the
Antarctic plateau
The Antarctic Plateau, Polar Plateau or King Haakon VII Plateau is a large area of East Antarctica which extends over a diameter of about , and includes the region of the geographic South Pole and the Amundsen–Scott South Pole Station. This h ...
during weak wind conditions. Yukimarimo were discovered in 1995 at
Dome F
Dome Fuji (ドームふじ ''Dōmu Fuji''), also called Dome F or Valkyrie Dome, is an Antarctic base located in the eastern part of Queen Maud Land at . With an altitude of above sea level, it is the second-highest summit or ''ice dome'' of ...
by the 36th Japanese Antarctic Research Expedition (JARE-36) at temperatures of –59 to –72 °C.
Electrostatic attraction
Coulomb's inverse-square law, or simply Coulomb's law, is an experimental law of physics that quantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is convention ...
between ice crystals explains the formation of yukimarimo at these low temperatures.
Name
Yukimarimo were named by T. Kameda on JARE-36 in 1995. "Yuki" means
snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
in Japanese, and "
marimo
Marimo (also known as Cladophora ball, moss ball, or lake ball) is a rare growth form of ''Aegagropila linnaei'' (a species of filamentous green algae) in which the algae grow into large green balls with a velvety appearance.
The species can be ...
" is a ball-like growth of water
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
which the yukimarimo resemble.
Formation
During a storm on the Antarctic plateau, humidity rises above normal levels. After a storm, the temperature drops rapidly and, due to the excess humidity,
hoarfrost
Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a ga ...
forms on the surface of the snow. At these low temperatures,
electrostatic attraction
Coulomb's inverse-square law, or simply Coulomb's law, is an experimental law of physics that quantifies the amount of force between two stationary, electrically charged particles. The electric force between charged bodies at rest is convention ...
between the rapidly formed ice crystals is high, due to growth charging during formation. When a light wind blows after the formation of this hoarfrost, the hoarfrost breaks apart and the frost crystals clump together and stick due to the high electrostatic attraction and subsequent fusing of the ice crystals. They then tumble across the snow in a manner similar to
tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...
.
The sizes of the yukimarimo range from a few millimeters to several centimeters in diameter.
South Pole Station
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþaz ...
, Antarctica, in 2008
File:Yukimarimo at Concordia Station (closeup).jpg, Yukimarimo at Concordia Station
Concordia Research Station, which opened in 2005, is a French–Italian research facility that was built above sea level at a location called Dome C on the Antarctic Plateau, Antarctica. It is located inland from the French research station a ...
, Antarctica, in 2014
Commercial products
To celebrate the discovery of the yukimarimo, a line of cookies were manufactured in Japan. They are available at a few stores in Japan and onlin
See also
*
References
{{reflist, group="Ref", refs=
[
{{Cite journal, last1=Kameda, first1=T., last2=Yoshimi, first2=H., last3=Azuma, first3=N., last4=Motoyama, first4=H., date=1999, title=Observation of "yukimarimo" on the snow surface of the inland plateau, Antarctic ice sheet, journal=Journal of Glaciology, language=en, volume=45, issue=150, pages=394–396, doi=10.1017/S0022143000001891, bibcode=1999JGlac..45..394K, issn=0022-1430, doi-access=free]
[
{{Cite journal
, author = T. Kameda
, title = Discovery and reunion with yukimarimo
, journal = Seppyo (Journal of Japanese Society of Snow and Ice)
, year = 2007
, volume = 69
, number = 3
, pages = 403–407
, url = http://homepage3.nifty.com/takaokameda/en/Kameda2007-AboutYukimarimo-inSeppyo.pdf
]
[
{{Cite journal, last1=Nelson, first1=J., last2=Baker, first2=M., date=2003-01-06, title=Charging of ice-vapor interfaces, journal=Atmospheric Chemistry and Physics Discussions, volume=3, issue=1, pages=41–73, doi=10.5194/acpd-3-41-2003, issn=1680-7375, url=https://hal.archives-ouvertes.fr/hal-00300838/file/acpd-3-41-2003.pdf, doi-access=free]
External links
Yukimarimo homepageYukimarimo cookies
Frost and rime