The White Rainbow

July 23rd, just after 7.00 am and the plain was saturated in heavy mist. Two days later would be the hottest day ever recorded in England.

The weathermen were again warning us of high temperatures during the day, so it was another early dog walk up on the plain. As we set off, the valley was still shrouded in heavy mist but I was hoping it would be burning off soon up top.

We arrived at the usual parking space under the trees, and as I opened the door to get out, I was surprised – and a little confused – by the sound of rain. Quite noisy on the canopy above.

I put on my light waterproof and headed towards the open downland. As we got onto the track that led there, I was intrigued to see that the wet part of the track was underneath the tree cover and the other side, open to the elements, was dry. I realised that the heavy mist was drenching the leaves in the canopy and it was dripping off onto the leaves below, causing the sound of rain, and from there down to the ground. It sounded like rain, it was wet like rain, but it was raining inside the woodland and clear outside. A first for me.

As we walked on to the downland, I could see the sun was diffused into a large white disk, low in the sky. This mist would take longer to burn off than I’d originally thought. Our younger, fair-weather whippet was not enjoying the damp. And neither were the butterflies who’d been out there all night. It looked like they were going to take a while to dry out and warm up.

The Marbled White (above left) had dew droplets along the front edge of her wings and bigger drops weighing down her antennae. The Meadow Brown (above right), perched on a saturated Scabius blossom, had a few dew drops on his antennae too. But it looked like he was closer to his first flight of the day.

I saw another dog-walker on a parallel path. He loomed out the fog, then disappeared again. It was all getting a little eerie.

At the turn around point of our walk, we passed through some more woodland, and the sound of rain started again.

The path took us under some tall beech trees, and the sound of a light shower turned into a downpour. Much louder this time. I guessed that the higher canopy was in thick cloud and was getting more saturated, causing more water to drain and drip off the leaves.

But looking up, I could see the sun breaking through to illuminate the higher branches, with blue sky beyond. And still there was the sound of pouring rain. Very odd.

As we came out of the raining woodland, the sun was starting to burn the mist off properly. The wild flower-rich grassland was getting its colour back, and it felt like normal service was being resumed. Then, looking across the downland ahead of me, I realised there was something there even stranger than the raining woodland we’d just left behind. Something I’d never seen or heard of before: a white rainbow.

It stopped me in my tracks.

It was faint. I wasn’t actually sure whether it was really there when I first noticed it. But it was. It was rainbow-shaped and white and it was definitely there. There was a faint hint of yellow at the outer edges near the ground. But I couldn’t make out any other colours.

I’d learnt basic physics at school. I thought I had an understanding of how rainbows worked and how they looked, and this wasn’t it. How could it be white?

I wanted to take a picture but all I had was a narrow field of view telephoto zoom and the rainbow was much wider than it could cover. I thought I’d try taking a number of shots in portrait and then stitch them together later with some panorama software.

Below is the picture the software stitched together.

You may have to stand back a little to see it, and I haven’t managed to get the top of the rainbow, but it’s definitely there. My first, and possible only, white rainbow.

I have since learned they are called “fog bows”, and they occur in fog or mist where the droplets are small and don’t produce the colour split that occurs with the refraction in the larger droplets of rain in a rainbow.

“Fog bow” doesn’t have the same ring to it, for me, so I’m going to stick with “white rainbow”. It was a special morning.


All text and images © David Hoskins

%d bloggers like this: