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Author: Stefan

Date: August 8th  2012

Temperature: -37.5 deg C

Wind Speed: 5 knots

Temp with wind chill: -45 deg C

Sunrise: n/a

Sunset n/a

 

It was extremely difficult for me to get my head around just exactly how the transition of the seasons work down in Antarctica, but I guess the best way you could describe it is:

 

• 24hr constant sunlight

• 3-4 weeks of ambient light (without seeing the sun) getting shorter everyday

• 24hr constant darkness, with some illumination from the moon, when clear

• 3-4 weeks of ambient light (without seeing the sun) getting longer every day, and with a great deal of illumination from the moon.

 

.Sunrise.jpg

First sun of the season on the Hut, 26th August, 1911

 

Now, learn’d folk reading this, will be saying “yeah! obvious…derrrr”, but until you experience that mixture of tiredness, confusion, and firsts, trust me, the events of everyday, come as a bit of a shock. Just the other day, four of us watched a huge fiery golden globe rising over the horizon, although we knew it was the moon, it didn’t stop us asking each other over and over “it’s definitely not the sun, right?”

 

N-Cloud1.jpg

Nacreous Clouds forming over Mt Erebus

 

Equal to the aurora’s, nacreous clouds unfurl in the sky like smudges of diesel, making you feel like you’re inside a huge opalescent mussel shell, (indeed the word is derived from ‘nacre’ or mother of pearl).

 

I’ve never really had any time for solstice events but the joy of seeing the light on the snow here does place you in tune with all of your thoughts, and a real sense of time passing, life changing. Looking over Mt Erebus and seeing the light emission of the swirling pinks and violets, there is a desperation to be naive to all you’ve learned of science and to see it as a cauldron of magic, that will soon spill over and bring only good.

 

It’s nice to think that the explorers would have begun their long hauling seasons with this fever of positivity in their veins.

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Author: Julie
Date: 18/8/11
Temperature: -33 C
Wind Speed: 12
Temp with wind chill: -48 C
Sunrise: 11:52
Sunset: 14:10

small nacreousclouds 10 am_Julie1 small.jpg

Nacreous clouds at 10 am. Julie/AHT

 

Yesterday was the day of spectacular nacreous clouds.  Nacreous clouds are wispy clouds that form under certain specific conditions (very cold temperatures at very high altitudes) and that can appear iridescent when the angle of the sun is very low, as it is now at Scott Base.  If you do a web search for images of nacreous clouds, many of the images you will see were taken from locations near Scott Base on Ross Island.

 

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Nacreous clouds at 2 pm: not photoshopped, I swear. Julie/AHT

 

For the last week or so, as the sun has come closer to rising, we have been in prime nacreous cloud viewing conditions.  Nearly every day Sarah or Jane says, “go look out the window at the clouds,” and I run over to a window to see what we’re getting.  However, yesterday topped everything we have seen so far, and in fact topped everything most people at Scott Base have ever seen.  Pretty much as soon as a strip of light appeared at the horizon (at a respectable 9:13 a.m.), the Scott Base staff started making cloud announcements over the base-wide p.a. system.  I remember Jana saying at about 10 a.m., “Scott Base, Scott Base, look at the clouds above,” and Steve, at about noon, saying, “Scott Base, Scott Base, if you’re not looking at Erebus right now, you probably should be.”  At around 2 p.m., Sarah, who was supposedly in a meeting at that point, made the announcement: “Scott Base, Scott Base, the clouds are green.”  Before darkness hit at 4:39 p.m., I personally had taken 93 photographs of clouds.

 

small nacreousclouds 3 pm_Sarah3 small.jpg
Nacreous clouds at 3 pm. Sarah/AHT

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Posted by Cricket

 

Date: 1 Sept 2010
Sunrise: 9:36am
Sunset: 16:15pm
Temperature: -34C
Wind Speed: 10 knots
Temp with wind chill: -53C

 

The word “nacreous” stems from the Latin “nacre,” meaning mother of pearl.  Nacreous clouds are thin and transparent with a wave-like form, and were so named for their dazzling iridescent colors.  They appear most prominently at dawn and dusk, and have been an almost daily feature during the last couple weeks.

 

Nacreous clouds - Williams resized.jpg

Nacreous clouds during sunrise © Antarctica New Zealand/Steven

 

 

In the late mornings they can be mixtures of rainbow colors, and by late afternoon, can change to waves of greens, blues and grays. 
Steven, our Scott Base science technician, explained that nacreous clouds are polar stratospheric clouds that only form in very cold polar regions and below –80C.  They exist well above our atmosphere at heights of 15-25km in the stratosphere, and being so high up, they appear stationary.  They gain their colors by reflecting sunlight coming from below the horizon, and so, are a skyline feature unique to this time of year.  They are a reminder of larger forces at play, and are associated with the chemical reactions that cause ozone depletion.

 

Nacreous clouds-Harbeck resized.jpg

Nacreous clouds during the afternoon © AHT/Cricket

To those wintering over in Antarctica, nacreous clouds must seem like fireworks after a 4-month-long term of darkness.  Seeing them does feel like a celebration, and their presence fosters joy and conversation.  Summer is coming quickly here and every day we have longer periods of daylight – a stark contrast to the almost constant darkness that we encountered upon our arrival several weeks ago.  As the sun reaches higher in the sky, our time for sighting nacreous clouds draws to a close.  Their appearance has been the best welcome to this fantastic landscape.