The Flying Saucer At Sunset

Lenticular clouds (Altocumulus lenticularis) are stationary lens-shaped clouds with a smooth layered appearance that form in the troposphere, usually above mountain ranges. One was spotted in Singapore recently...

Eyes Of 30,000 Honeycombs

With 30,000 individual facets, dragonflies have the most number of facets among insects. Each facet, or ommatidia, creates its own image, and the dragonfly brain has eight pairs of descending visual neurons to compile those thousands of images into one picture...

A Kaleidoscope Of Colours, Shapes And Patterns

Spectacular and innovative in design, the Flower Dome replicates the cool-dry climate of Mediterranean regions like South Africa, California and parts of Spain and Italy. Home to a collection of plants from deserts all over the world, it showcases the adaptations of plants to arid environments...

Lightning Strikes, Not Once, But Many Times

Unlike light, lightning does not travel in a straight line. Instead, it has many branches. These other branches flashed at the same time as the main strike. The branches are actually the step leaders that were connected to the leader that made it to its target...

Are You My Dinner Tonight?

A T-Rex has 24-26 teeth on its upper jaw and 24 more on its lower jaw. Juveniles have small, sharp blade-shaped teeth to cut flesh, whereas adults have huge, blunt, rounded teeth for crushing bones. Is the T-Rex a bone-crushing scavenger?

Hello Moon Halos!

Singapore
August 2013

There were two rainbow-tinted rings around the moon last night. - TWO!


The rings that encircled the moon arose from light passing through six-sided ice crystals high in the atmosphere. These ice crystals refract, or bend, light in the same manner that a camera lens bends light. The crystals have to be oriented and positioned just so with respect to your eye, in order for the halo to appear. The ring has a diameter of 22° , and sometimes, a second ring, 44° diameter, forms. 

Thin high cirrus clouds lofting at 20,000 feet or more contain tiny ice crystals that originate from the freezing of super cooled water droplets. These crystals behave like jewels refracting and reflecting in different directions. Cloud crystals are varieties of hexagonal prisms, (6 sides) and range in shapes from long columns to thin plate-like shapes that have different face sizes.

(Source : Keith's Moon Page)

That’s why, like rainbows, halos around the sun - or moon - are personal. Everyone sees their own particular halo, made by their own particular ice crystals, which are different from the ice crystals making the halo of the person standing a short distance away. 

Hmmm that explains why, despite Singapore's small size, 
a moon halo in Changi may not be visible by someone staying in Jurong...
(Source : NEA)

Folklore has it that a ring around the moon signifies bad weather is coming. It is believed that the number of stars within a moon halo indicate the number days before bad weather will arrive. 

Ok, there were zero stars around the two halos.

A while later, the sky completed cleared up and the craters on the moon can be seen clearly.


So how can rings around the moon be a predictor of weather to come? The ice crystals that cover the halo signify high altitude, thin cirrus clouds that normally precede a warm front by one or two days. Typically, a warm front will be associated with a low pressure system which is commonly referred to as a storm.

True enough, this was the sky this morning...


With this weather forecast for the next 12 hours...

(Source : NEA)


More photos are available on Merlion Wayfarer Goes Green's Picasa at :
Natural Phenomena - Clouds and Natural Phenomena - The Moon



Sources



Orange Fire In The Sky

Singapore 
17 August 2013

This morning, the sunlight was golden. The walls of the buildings nearby were awash with slanted yellow rays. In the horizon loomed a strip of cumulonimbus clouds. True enough, by mid-afternoon, a fiery thunderstorm swept across Singapore.

In the evening, the sky was still awash with Stratus and Altocumulus clouds...

In places, thins wisps were being blown away by the strong wind...

At around 1900h, a golden spectrum started spreading across the western sky...

This was sunset yesterday...




More photos are available on Merlion Wayfarer Goes Green's Picasa at :
Natural Phenomena - Clouds


Sources