Sunlight

After 2 and a half months of darkness the sun has returned to Summit Station. Over the past few weeks we have watched as the mid-day skies grew lighter each day. Any light, however diffuse, is welcome and we have had some beautiful dawn and dusk colors.
Sunrise was officially on January 28, 2018, however due to poor weather and low visibility it was obscured almost the entire week, until Saturday…

Almost sunrise on Jan 27

The sun on Feb 3

Unobstructed sunrise

Looking out the window I could see the clouds were breaking up, and around 10am I saw the sun’s orb partly shielded by haze. Molten gold, it lit up the clouds and soon stretched its rays to the surface. As I did my station rounds I saw my shadow for the first time since November. I stared in awe as the buildings were bathed in brilliant light, windows and exhaust vents glinting, and the blue surface of the snow turned a pale gold. I blinked away the ice on my lashes and stared into the sun until it was burned into my eyes. Just feeling the light on my face was more than enough. I love the night sky and the darkness, but it must be balanced with the light.

HDR image of the sunset behind TAWO, the 10m met tower, and the GISP2 borehole

Despite the sun’s return it’s still very cold: -60F today with a windchill of -90F and the sun is above the horizon for just 4 hours. Not quite out of winter. We were also hoping to see the full lunar eclipse on Jan 31, but unfortunately just as it was becoming visible the moon slipped behind a layer of hazy clouds.

Start of the lunar eclipse on Jan 31

Back in 2015 however, I was here for another lunar eclipse that did not fail to amaze:

Hot and Cold Science

There’s an old saying that to make ice cubes freeze faster use boiling water in the tray rather than cold water as one might guess. Perhaps surprisingly, there might be some scientific truth to that…it’s called the Mpemba Effect.
The exact science behind this phenomenon is still being worked out and debated, however it raises some interesting questions. Last year Nature published a paper arguing that the Mpemba Effect doesn’t actually exist while another paper published earlier this year in the Journal of Modern Physics suggested that it does indeed exist, perhaps having to do with the structure of water collapsing when heated leading to more random collisions between molecules and thus faster cooling.

{If you’ve heard the old adage about the reverse phenomenon, that cold water will boil faster than hot water and are wondering if that’s true now, I’m sorry…that one has been proven false. Cold water does however bypass the hot water tank in your home and may taste better even if it takes longer to boil.}

But going back to the process of hot water freezing…
Another interesting phenomenon occurs when very hot water meets very cold air. Hot water contains more energy and has less structure (as explained by the above article in the Journal of Modern Physics). It’s actually closer to steam than cold water. So when it’s thrown into the air it breaks apart into tiny droplets each with a large surface area, facilitating the evaporation and freezing processes. Hot water thrown into cold air freezes almost instantly creating an impressive cloud of ice particles and fog. Try again with cold water and you’ll just end up with a puddle of ice on the ground.
Huffington Post published an article back in 2014 explaining this effect with some cool videos (www.huffingtonpost.com/boiling-water-extreme-cold-water-gun-ice). With the recent cold weather across the US I imagine there are lots of posts about this too.

This works best at temperatures below -40F and makes for some pretty cool photos. Unfortunately, we don’t have the bandwidth to upload videos here, so these pictures will have to do.

-90F at the South Pole on March 25, 2013:

South Pole March 2013

-50F at Summit Station on December 5, 2017:

 

-55F at Summit Station on December 1, 2016:

 

 

 

We also experimented with freezing bubbles. However, with no trees or mountains to break the wind it’s generally too windy for bubbles to last very long. It’s also been pretty cold lately at -75F last week so they freeze very quickly, often bursting.

 

If you’re looking for more fun science projects to do at home this winter check out this awesome post by NPR: www.npr.org/dont-just-shiver-here-are-3-cold-weather-experiments-to-try

And if you’re still interested in the science and history of cold check out the aptly titled, fascinating, and well written book: Cold by Bill Streever.

Rave Ice

Last winter I was in the midst of my monthly building checks when I went out to visit the Mobile Science Facility (MSF). It was a dark day and snowing lightly. I noticed a flickering light on the snow out of the corner of my eye and proceeded to the back of the building where there are no outside lights. In the shadow of the building and under the angled LiDAR beam the ground was alive with bright green flashes of light.

A starstax image

The LiDAR glows green atop the MSF

The MSF on 11/28

Taking IcePICs

The LiDAR laser is mounted to the roof of the Mobile Science Facility (MSF) and is part of the ICECAPS project which is looking at atmosphere, precipitation, radiation, and cloud properties over the Greenland ice sheet.
The science techs had noticed these reflected lights earlier, but I had not seen it before. It was truly magical! The lights danced and flickered around lasting only a fraction of a second. Some streaked across in lines, others just flashed a tiny spot, still others revealed intricate interference patterns on the snow. Later that evening the techs and I returned with our cameras. Like auroras, it’s difficult to capture the movement, but still beautiful and interesting none the less!

It was reminiscent of disco ball lights, but faster and brighter. At first we called it “Disco Ice,” but that wasn’t quite right…lasers, neon green, a high frequency pulse… “Rave Ice” was a better fit.

Intrigued, we decided to do some research to find out what exactly was happening. Was this a normal LiDAR by-product? How was it related to the falling or blowing snow? What did it tell us about current atmospheric conditions? Surprisingly we found almost nothing on the topic. One paper described a similar phenomenon, however the authors said it had only ever been observed in controlled optics research labs and computer programs, never outside. They speculated that snow or ice crystal size, shape, and orientation could be inferred from the light patterns displayed. One of the science techs wanted more information and reached out to the authors sharing some photos we had taken. They were amazed.
This phenomenon has most certainly been occurring since the LiDAR was first installed in 2010. However, it is rare, can only be seen in the dark, and had never been documented until last winter (2016-17). Over the next few months the ICECAPS Primary Investigators, the science tech here, and the optical researchers collaborated to write an article explaining the unique phenomenon. It was published in the July 2017 edition of Applied Optics!

They were able to link the patterns we photographed, the ice crystals we collected, and the shapes and patterns they had modeled in their labs. For example, a bullseye pattern is created by a smooth sided disc, while a bright spot surrounded by six broken dashed lines is a distinct hexagonal plate. We saw both of these patterns and also collected these types of crystals during the event.

It appears that this phenomenon occurs relatively often. When seen from afar the LiDAR beam glints and sparkles reflecting off the crystals. But conditions must be just right to get well defined patterns. There can’t be too much freezing fog, it can’t be blowing tons of snow, it needs to be dark, and there needs to be some precipitation. While any crystals will reflect the laser the most intricate patterns are a result of proper snowflakes and other more complex crystal shapes; something that requires relatively high humidity (so not too cold) and not too much turbulence (otherwise they’ll break apart). Up here it tends to be either very cold, calm, and clear with no precipitation, or warm, humid, and windy with far too much turbulence for complex crystals to form.
Earlier last week however there was an abnormally warm period with very low winds. Temperatures in some areas of Greenland were as much as 50˚F above average. While temperatures here have been around -50˚F the week prior and again this week, during the warm event Summit temps reached +7˚F! This warm spell affected much of Greenland and was so unusual it made the news:
https://thinkprogress.org/omg-heat-wave-scorches-greenland
https://weather.com/news

It also proved to be absolutely perfect conditions for Rave Ice. I had noticed the sparkling LiDAR beam on Tuesday afternoon and knew it would be worth hauling my tripod and camera out there. As I was walking out one of the techs called out on the radio that I should come out to see…and it was some of the best yet. I set up my tripod and started taking pictures while the tech collected snow samples, photographing the ice crystals, and recording meteorological data.

The science tech in the unheated shelter used to photograph ice crystals

Observing the Rave Ice

These are some of the crystals she photographed:

And these are some stacked images of the reflections:

November Afternoons

Station lights on a misty afternoon

Aurora Borealis over the MSF

The Long Arctic Winter

It has been a month since we arrived on station and we have settled into our roles. Every week seems to bring some form of excitement to keep things interesting, and we’ve had a few good wind storms, but thankfully nothing too dramatic. We are doing well and the station is running fine.

Long shadows beneath the Big House

The MSF at dawn

Last glimpses of the sun

When we arrived it was full on autumn, the sun rose at 8:30am and set at 4:34pm. It was blustery with lots of blowing and drifting snow. Temperatures were erratic; cool, but not terribly cold. Over the past month we have shifted into winter. The sun began rising later and setting later…each day losing 10 minutes, then 15 minutes, then 20 minutes of daylight. Finally, earlier this week on November 13, the sun rose and set for the last time. A mere 1 hour of daylight: 10:46am-11:48am. Unfortunately, that day was cloudy and cold and we did not get a proper view of the sun. But the days since have had beautiful periods of dusk and dawn, the sun stopping just short of breaking the line of the horizon. It’s a magical time with vibrant colors, long shadows, and the potential for auroras though we haven’t seen much yet.

Blowing snow at 40 knots

Working outside at -55F

The lowest temperature we’ve seen so far was -67.5°F on Nov. 12. Not the coldest I’ve been in, that was -107.9°F at the South Pole in 2013, but it’s pretty chilly. There seems to be a shift at -40°F where materials become a bit more brittle, the cold just a bit more sharp. Around -60°F there is another step; the solid steel of the loader tracks creaks and crackles, bamboo shatters, leather becomes solid, and your exhalations whoosh loudly past your ears as the moisture freezes instantly.

As the temperatures have dropped it has grown darker. Below is a solar chart showing hours of daylight in light blue, twilight in greys, and night in black throughout the year at our latitude. The x-axis is months of the year and the y-axis is hours in the day. The break in the graph is daylight savings time here in Greenland. The white double-line on the right is the showing today – which is also broken down at the bottom. You can see that between late May and August the sun never sets while between mid-November and late-January it never rises. Here is my post from sunset last year: Antarcticarctic.wordpress.com/2016/11/23/sunset.

This just a fascinating affirmation of grade school physics and astronomy – proof that our earth is tilted 23.5degress off the elliptic and spherical. For comparison, here is a graph of today at the South Pole – the sun rises and sets just once a year at the poles (which I wrote about here) so you can see they go from 24hrs of daylight on the equinoxes to 24hrs of twilight and night.

And this is a graph of Nairobi which is very close to the equator, you can see there is very little change in daylight throughout the year.

Regardless of the cold and the dark there is work to be done inside and out. We try to wait for good days (warmer temps and lower winds) to do the more involved outside tasking, but we still need to add snow to the melter to make water, fuel the generators, move between buildings, and check on scientific instruments.

Daytime….

Nighttime!!

 

 

February Drifting

The sun has returned and it’s glorious…sun dogs, halos, soft pastel light, and crisp shadows! It’s powerful and beautiful and I catch myself staring at the blinding light. We’re gaining almost 15 min of daylight every day now and it makes our jobs so much easier.

We are down to the last few weeks here – the spring crew is due to arrive at the end of this week! Things were looking good until we got slammed by a few big wind storms this week. We’re nearing springtime and the worst weather of the year. On Thursday we had sustained 35 knot winds and on Saturday they rose to 40-50kn sustained winds with gusts close to 60 knots…it’s hard to walk in that kind of weather and so much snow gets lifted into the air that it’s impossible to see more than a few feet. Temperatures also rise with the wind speed. Yesterday when it was 50 knots out it was -5F. Nice not to have as much frostbite concerns, but it’s sticky and relatively wet. I would take clear, calm, and -80F any day.

The shop surrouned by it’s moat

A drift that formed after just a few hours of 30+kn winds

 

With so much snow being blown around monster snow drifts form. We had just cleaned up after the last good blow when we were hit again. There’s a giant moat around the shop and the Green House is buried to the roof on all but the south side. There’s still a bit of a moat there. The snow grains are tumbled by the wind, breaking into tiny shards and ground down to rounded grains. The wind pushes it through the tiniest hole – around door frames and through invisible cracks in window caulking and gaps around the walls. The building entrances and exits often comprise of two sets of doors – vestibules help to retain heat and also offer some protection against the persistent snow. Caulking and weather seals help, but in the extreme dry and cold they invariably crack and fail. With a little moisture they freeze to the door and rip off the frame. Constant chipping of ice and shoveling of snow wears down the material too – no matter what you do it’s a losing battle.

The vestibule ufll of snow blown in around the main door.

A snow drift inside from a tiny gap in the wall/floor…below an auxiliary heater.

Thankfully the cold means there is very low water content in the snow and the super dry air evaporates any snow that gets into the buildings quite quickly. We don’t need to worry about mildew or mold here.

Even with the storms, this is my favorite time of the year; gorgeous sunrises and sunsets, a few hours of daylight, but still enough darkness at night to see the stars and auroras. We’ve had a few spectacular nights since sunrise…

A half moon and Venus below aurora

Spring time on the ice cap:

Looking North. Photo: Sam via kite

Sunrise!

On January 28^th the sun returned at last! We’ve had periods of twilight each day, but the sun has not breached the horizon since November 13^th. Unfortunately, it was cloudy on Saturday…but it is getting noticeably brighter each day and we will have plenty more sunrises and sunsets before we leave at the end of February! Today is cloudy again, but technically the sun rose at 10:52am and set at 12:44pm. Unlike the South Pole, where there is only one sunset each year (see my post on that here), Summit Station gets many sunrises until May 6 when it will rise and remain above the horizon until setting again briefly on August 7^th.
On the 27^th the sun was very close to the horizon; a brilliant golden glow and colorful clouds hinting at its presence. On clear days this past week we have been admiring the defined earth shadow (another nice explanation of the phenomenon can be found here from Sky and Telescope) and beautiful pastel skies.

The Earth’s shadow defined to the North as we walk back to the Green House

The pink layer above the darker earth shadow is called the “belt of Venus”

The new moon on the 27^th meant it was a very dark night and we had a stunning view of the stars and Milky Way as well as a few curtains of aurora. Standing beneath this spread of stars with the infinite depth of the universe spread out around us is awe-inspiring.

The Big House under the northern sky – Orion is just to the right of the dome

Standing beneath the Milky Way!

Inside our buildings we maintain our routine. We have all but finished our fresh food and rely now on frozen, dried, or canned provisions. Everyone is growing tired and looking forward to returning to the ‘real world’ soon. Part of the issue is that we are at 10,550ft above sea level here at Summit and the physiological altitude is often much higher (we’ve seen atmospheric pressure equivalent to 12,500ft this winter). Even after initial acclimatization to the altitude it’s physically exhausting. People generally don’t sleep well up here – whether due to lack of oxygen or too much/too little day light, and after a few months it’s hard to ever feel well-rested. There’s also the mind numbing routine and isolation: We’ve been cooped up in a handful of buildings with no where else to go for months now. We all knew what we were signing up for and everyone is doing quite well, but the last 2 or 3 weeks are the hardest of any season and we’re all showing signs of Toast. There is some debate as to whether this is a “real” phenomenon – whether there is actually a medical cause (lack of T3 or vitamin D or something), but regardless it affects almost everyone in winter-over crews. Some of it is comical: short term memory degrades and you walk into a room forgetting what you were doing, then do it again 2 more times. People start a sentence or a story and forget what they’re talking about half-way through. Words become hard to remember: “Do we have any more of…umm, that thing that water goes through to make coffee?” or “Have you seen my book?…and by that I mean, my hat?” And simple math becomes especially difficult. On the flip side, frustration levels run high, tempers shorten, sleep becomes difficult, and physical energy runs low. It’s a time to remember to think before you speak, and to have extra patience for everyone who is likely feeling just as burnt out as you.

It’s also a time to be aware that we are not running on “all cylinders,” and to add to that folks are excited about post-ice plans and may not be fully present and focused on the tasks at hand. We will talk about staying present and being aware of our surroundings a lot, but we have made it through the darkest times and are down to the last month of our season now!

TAWO looking very small against a clear horizon

Plastic Balloons

The ozone layer is a vital part of our atmosphere, filtering out harmful solar radiation. One of the projects we support here at Summit is measuring the atmospheric ozone over the Greenland ice cap. For most of the year the techs use simple rubber balloons that reach heights of 20-30km. During very cold periods in the winter the rubber becomes brittle resulting in a burst at lower altitudes. These times however, are often when the ozone is the thinnest and most interesting. So the techs use much larger plastic balloons which can reach heights of 30-40km even in the coldest temperatures. These plastic balloons are not elastic like the rubber ones so they appear quite empty at launch. As the balloon rises through the atmosphere the helium expands filling it out completely.

A normal rubber balloon

Plastic balloon launches generally only happen once or twice a year so it’s kind of exciting. They are huge and fragile and require all hands. First we laid out canvas tarps to protect the balloon from the potentially sharp ice and snow on the ground. Then we placed the balloon on the tarps ensuring it was free of kinks and tight folds. A carefully calculated weight was hung from the balloon to ensure we added the proper amount of helium. Too much helium and it would rise too fast for the calibrated instruments to measure properly. Too little and it might not rise fast enough or get high enough. Helium bottles were moved closer to the door and a long hose run out to the filling tube on the balloon. Filling took quite a while.

Once the balloon was filled with a sufficient amount of helium we connected the instrument box and carefully walked the whole thing to an open area away from the building and major drifts. One person held the inflated part of the balloon, careful not to let it pull too strongly or touch anything in the wind, two more held the middle section of the balloon off the ground, and a fourth held the instrument box. At a count of three everyone let go in sequence allowing the balloon to lift smoothly away from our arms and rise into the sky…

Laying the balloon out and getting the hose set up

Filling the balloon with helium!

Back in the Green House we listened to the data being received; a Morse code like series of beeps and boops. When the signal grew weak or distorted one of the techs climbed onto the roof to adjust the antenna. The latest ozone data from Summit can be found here: www.esrl.noaa.gov/gmd/graph.php

Ozone levels above the Arctic

Last week we hit a low of -73F according to the Green House thermometers. This week however,  has been dark and stormy with temps around -30F and winds around 30kn. Lots of shoveling to be done!

{Also, some of my halo photos from this fall have their own page at Atmospheric Optics check it out!}

The horizon is growing brighter every day!

A full moon shines over the Big House

Nacreous Clouds!

The sun is on its way back and while we still have 3 weeks until the first sunrise each day is a little brighter than the last. New Year’s Eve dawned bright and clear with crisp stars and a few very special clouds on the horizon. At first they were startling neon pink, orange, and red. The first real sign of the sun in weeks and a beautiful contrast to the greens and blues of the night sky and aurora. As the day progressed the clouds grew in size, becoming clearly iridescent. With no insulating clouds overhead it was a chilly -60F ambient. The cold temperature, otherwise clear sky, low sun, and wavy iridescent features all pointed towards these clouds being Polar Stratospheric Clouds (aka PSCs or Nacreous Clouds).

These rare clouds are both terrible and beautiful. Forming in the stratosphere at 49,000-82,000ft and at temperatures below -100F they are composed of water, nitric acid and/or sulfuric acid. While beautiful, they are implicated in the depletion of stratospheric ozone – an important protective layer against harmful UV rays. According to TheOzoneHole.com:
“PSCs were long regarded as curiosities and of no real consequence. However, Type I clouds are now known as sites of harmful destruction of stratospheric ozone over the Antarctic and Arctic. Their surfaces act as catalysts which convert more benign forms of man-made chlorine into active free radicals (for example ClO, chlorine monoxide). During the return of Spring sunlight these radicals destroy many ozone molecules in a series of chain reactions. Cloud formation is doubly harmful because it also removes gaseous nitric acid from the stratosphere which would otherwise combine with ClO to form less reactive forms of chlorine.”

Bright neon clouds

Polar Stratospheric Clouds – note their brightness, iridescence, and feathery/wavy structure

Measuring the ozone layer above us and the seasonal Arctic ozone hole is one of the many projects we support here at Summit. Every week the science techs launch a large balloon with a carefully calibrated instrument to measure ozone concentrations, as well as normal meteorological data (wind speed and direction, pressure, temperature, and humidity). The data is sent back via radio signal to the computer here at Summit.

Flat White Christmas

Merry Christmas and Happy New Year from Summit Station!

We celebrated the holidays with a rare 2-day weekend and a nice dinner. The Big House smelled of baking and the atmosphere was festive with our decorated plywood tree. Everyone enjoyed a little down time to rest and catch up with family back home.

We also all got showers which was a nice treat! We had been on water restrictions for the past week or so while we completed some routine maintenance on the primary generator. We rely on our generators to produce light, heat, and water. There are two diesel generators and a back-up emergency generator on station. During the maintenance we ran on our secondary generator, which is perfectly fine except that it’s a little smaller and thus a little less efficient at melting snow for water. We are always mindful of our water usage and limit showers to 2 minutes twice a week and one load of laundry per week.

After Christmas the winds picked up to a proper storm. 55kn sustained! We hunkered down and focused on projects indoors. Thankful for our flag and rope lines! There was lots of blowing/drifting snow and visibility was very low. High winds usually bring higher temperatures as well. So while it’s difficult to see and physically travel outside it’s rarely the cold that is the limiting factor. The storm has passed now and it’s starting to get just slightly lighter each day. There are some new and larger drifts around station, but nothing we can’t handle. The blowing snow gets everywhere though and despite the door to the shop being fully closed we still had to shovel out a nice drift that had formed overnight.