A Rainbow Primer

Incomplete

Incomplete, photo by Jamie MacDonald

I’ve never found a better website for information about rainbows and other optical phenomena than Atmospheric Optics. They have information about all flavors of rainbows including the primary rainbow, and explain that rainbows are disks of light rather than sets of coloured rings:

Early morning and late afternoon are the best times to see them because the sun must not be too high. Rainbows are always opposite the sun and their centres are below the horizon at the the antisolar point. The lower the sun the higher is the bow.

Red is always outermost in the primary bow with orange, yellow, green and blue within. Occasionally, when the raindrops are small, fainter supernumerary arcs of electric greens, pinks and purples lie just inside the main bow.

A rainbow is not just a set of coloured rings. The sky inside is bright because raindrops direct light there too. The primary bow is a shining disk brightening very strongly towards its rim.

About this particular rainbow, Jamie writes:

This is the first time I have ever seen part of a rainbow in open skies. Look to the sky above the barn and you can just make out the missing portion of the rainbow.

View his photo bigger and see more in his Landscapes slideshow.

More rainbows on Michigan in Pictures!

Follow the Rainbow

Follow the Rainbow

Follow the Rainbow, photo by Matt

View Matt’s photo background bigtacular and see more in his slideshow.

Contrails in a winter sky

Contrail Sunset by Mark Swanson

Contrails in a winter sky, photo by Mark Swanson

Whole lot going on in that sunset – definitely not like the ones I grew up with.

Mark writes:

I could not avoid contrails in the sky tonight (pretty sure much of this is Chicago), so I decided to focus on them.

I think that’s a good choice.

View his photo bigger on Flickr and see lots more Lake Michigan wintry goodness in Mark’s slideshow.

PS: Speaking of Lake Michigan goodness

Halo, Sundog & Circumzenithal Arc over Marquette

Solar Halo over Marquette Lighthouse

Welcome to the Smile High Club, photo by Lake Superior Photo

Today’s photo is one of the most incredible pictures I’ve seen. In addition to the Marquette Harbor Light and the frozen Superior shore, there’s a cornucopia of solar optics that fairly defies imagination.

Atmospheric Optics is a wonderful website, certainly the best I’ve found for describing solar phenomena in a clear and inspiring manner. Here’s a bit of decoding of what’s happening in the skies of Marquette yesterday, but definitely follow the links to explore. There’s so much information and some great photos too!

First, above the lighthouse, there’s a 22º radius halo:

…visible all over the world and throughout the year. Look out for them (eye care!) whenever the sky is wisped or hazed with thin cirrus clouds. These clouds are cold and contain ice crystals in even the hottest climes.

The halo is large. Stretch out the fingers of your hand at arms length. The tips of the thumb and little finger then subtend roughly 20°. Place your thumb over the the sun and the halo will be near the little finger tip.

The halo is always the same diameter regardless of its position in the sky. Sometimes only parts of the complete circle are visible.

There’s also a sundog, known also as parhelia or mock sun. These appear in the 22º halo, even when you can’t see the halo. You can see one at the visible base of the halo on the right:

They are most easily seen when the sun is low. Look about 22° (outstretched hand at arm’s length) to its left and right and at the same height. When the sun is higher they are further away. Each ‘dog’ is red coloured towards the sun and sometimes has greens and blues beyond. Sundogs can be blindingly bright, at other times they are a mere coloured smudge on the sky.

They advise you’ll see one or two a week if you look and if you click over you can learn about how they form & moon dogs.

Finally, we come to the circumzenithal arc (CZA), the upside down rainbow at the top:

…the most beautiful of all the halos. The first sighting is always a surprise, an ethereal rainbow fled from its watery origins and wrapped improbably about the zenith. It is often described as an “upside down rainbow” by first timers. Someone also charmingly likened it to “a grin in the sky”.

Look straight up near to the zenith when the sun if fairly low and especially if sundogs are visible. The centre of the bow always sunwards and red is on the outside.

The CZA is never a complete circle around the zenith, that is the exceptionally rare and only recently photographed Kern arc.

Read on for more, and definitely be sure to check atoptics.co.uk when you see solar & lunar phenonmena you’d like to know more about.

View Shawn’s photo bigger and join thousands of others in following Lake Superior Photo on Facebook … and on the Twitters. You can purchase this photo on the Lake Superior Photo website.

PS: Check out Dominic B. Davis’s photo of the solar halo in the morning too!

and then I saw this cloud…

Untitled

Untitled, photo by Scottie Williford

Hoping you see some cool sights and enjoy a great weekend!

View Scottie’s photo bigger and see more in his slideshow.

More clouds on Michigan in Pictures.

The Lunar Express

Something Special in the Air

Something Special in the Air, photo by Shane Wyatt

A reminder that The Lunar Express boards early tomorrow morning for a total eclipse of the October full moon. The partial umbral eclipse begins at 5:15 AM EDT on October 8, with the total eclipse starting at 6:25 AM, peaking at 6:55 and ending at 7:24.

Get all the details on the Super Hunter’s Blood Moon in eclipse from Michigan in Pictures!

View Shane’s photo bigger and see more of Shane’s moon photos right here.

 

Bye Bye Summer

Summer ... bye bye

Summer … bye bye, photo by Ken Scott

Probably the best thing I’ve heard about “Summer 2014” being over is that it really wasn’t much of one anyway.

I hope everyone enjoys their last weekend of summer, and that we have a warm & long fall!

View Ken’s photo bigger, see more in his massive Sleeping Bear Dunes slideshow and definitely follow him on Facebook.