By:Tushar Garg
ECE
(21105094)
Strange Natural
Phenomena
Mammatus clouds
Clouds with bag or pouches like
formation
Shape can vary widely, from classic
shape to more elongated tubes
Average diameter (of 1 lobe) = 1-3 km
Average length (of a lobe) = 0.5 km
A lobe can last an average of 10 min
Mammatus clouds in Nepal Himalayas
Source: Wikipedia
Mechanisms
of formation
Aren't inherently dangerous
But commonly found in the vicinty of
thunderstorms
Many different types of mammatus clouds have
given rise to multiple hypothesized formation
mechanisms. But in general view,
Formed the same way cumulus clouds are formed
but in reverse
Sinking cold air form pouch-like figures as they
are carried into a warmer layer of air
Contrary to the puffs of clouds rising through
the convection of warm air
Mammatus clouds forming in
Minnesota in 2005
Cloud
Iridescence
A colorful otical phenomenon
Iridescence: A lustrous rainbow
like play of color that tends to
change with angle of view
Colors resemble those seen in soap
bubbles and oil on a water
surface
Appears generally in the
proximity of the Sun or Moon
Image captured in 2012 in New Albany, Indiana
Mechanism
Caused by diffraction of light by
uniform small water droplets or
small ice crystals
Large ice crystals cause halos, a
different phenomenon
Cloud must be optically thin
Thus mostly seen at cloud edges or
in semi-transparent clouds
Corona (bright circular disk
Captured on July 31, 2012 looking West from
Boynton Beach, Florida USA
around the Sun or Moon)
Hair Ice
Hair ice on a branch
Also known as 'ice wool' or 'frost
beard'.
Forms on dead wood in the shape of
fine, silky hair.
Somewhat uncommon phenomenon.
Reported mostly at latitudes
between 45 and 55 degree North.
Alfred Wegener described it in 1918
(assuming some fungi as catalyst).
Formation
Forms on moist, rotting wood from
broadleaf trees.
Temperature are slightly under 0
degree celsius and air is humid.
Appear to root at the mouth of wood
rays(cellular structures found in some
species of wood).
Diameter of a hair ice: about 0.02 mm.
Length of a hair ice strand: upto 20cm
The fungus Exidiopus effusa help in
its formation.
Hair ice growing on wood on the forest floor
Snow Rollers
Rare meteorological phenomenon.
Cylindrical snowballs are formed.
Formed from chunks of snow that roll
down hill or are blown along the
ground by wind.
Can be as small as a tennis ball and as
large as a car (though most are not).
Look like a doughnut or Swiss roll.
Snow rollers in hilly area
Conditions
Relatively thin surface layer of wet,
loose snow.
Temperature near melting point of ice.
A layer of ice or powder snow beneath
the layer of wet snow.
Winds of proper magnitude.
Inner layers are the first layers
to form, are weak and thin, and
get easily blown away forming
A hole in the cylinder.
Snow roller in a farm
Blue Holes
The Great Blue Hole, near Belize City, Belize.
A large marine cavern or sinkhole
open to the surface.
Developed in a bank or island
composed of a Carbonate bedrock.
Discovered in the late 20th century
by fishermen and recreational
divers.
Typically contain tidally influenced
water of fresh, marine, or mixed
chemistry.
The Great Blue Hole is 125 meters
deep and 300 meters wide
FORMATION
Low sea levels existed during the Ice
Age.
Glacial runoff began dissolving the
limestone ground, forming sinkholes with
caverns below.
Ceilings of the caverns collapsed making
holes in ground.
Water got filled in the holes due to ice
melting at the end of Ice Age.
Guillaume Nery base jumping at Dean’s Blue Hole
~ Dark blue appearance due
to greater absorption of light
with increasing depth.
Red Rainbow
Red rainbow in Wiltshire market town,
Malmesbury
Also known as 'Monochrome rainbow'.
Optical and meteorological
phenomenon.
A rare variation of multicolored
rainbow.
Mostly forms at sunset or sunrise
(low light environment).
Zoomed in image of a red rainbow
Formation
Formation process is identical to
that of normal rainbow.
Reflection/Refraction of light in
water droplets.
Sun is close to the horizon.
Light has to travel longer distance in
the atmosphere.
Shorter wavelengths get scattered,
leaving primarily red.
Red rainbow on Jul 10,2017 at sunset
Moonbows
Also known as 'Moon Rainbow' or 'Lunar
Rainbow'.
Much rarer than normal daytime rainbows.
Produced by moonlight rather than direct
sunlight.
Seen near waterfalls like Niagara Falls,
Cumberland Falls, Victoria Falls etc.
Much fainter than solar rainbows and
appears white to human eye (faint light).
Moonbow at the bottom of
Yosemite National park's
waterfall
Formation and View
Other than difference in source of light,
formation is the same as for solar rainbows.
Reflection/Refraction of light from water
droplets, such as rain shower or waterfall.
Positioned opposite to the Moon relative
to the observer.
Most easily viewed during the brightest
phase of full moon.
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H a w a ii a n V o l c a n
Observatory.
Observed in dark, cloudless night sky, 2-3
hours before sunrise and after sunset.
Hidden Beach
Plants
Sailing Stones
Volcanic lightning
Pink Lake
Bioluminescent sea
Roll clouds
Thank
You