Sunset

We were so lucky this year to be able to see a long and beautiful sunset at the South Pole!  The official sunset occurred at 2:54 PM on March 23 local time.  If the earth did not have an atmosphere, sunset would have occurred about a day earlier, but because of the refraction of light when it hits the atmosphere, we enjoyed one extra day of sunlight, and we will get another extra day of sunlight at sunrise in about six months.  In the days preceding the sunset a thick ice fog shrouded the area, visibility dropped to less than 1/4 mile, and our hopes of seeing the sunset appeared doomed, but then, miraculously, the fog dissolved and cleared the air for a view of a spectacular sunset, my first one since I left New Zealand on Oct 19, and likely my longest ever, lasting a good couple of days.
We set up a 12" telescope in the galley and took turns at the eyepiece to try and see the very elusive green flash.  The green flash is produced by the refraction of light against the atmosphere.  Just like the color of the sun changes to red at sunset, in a phenomenon of reverse mirage, a green band of light can become visible at the top of the setting sun, when the atmospheric conditions are right.  It occurs at all latitudes.  Sailors on the ocean are the most likely to see one.  It is called a flash because it lasts a fraction of a second at mid-latitudes.  Here at the pole, with a sunset lasting days, under the right conditions, the flash lasts several seconds, and it comes and goes for hours at a time.  The right conditions at the South Pole this year occurred in the evening of March 22, and then again in the morning on March 23.  I was lucky to be in the galley for a late dinner around 9 PM on March 22, after spending the afternoon skiing, right at the time when the sun decided to display the green.  I could not see it with my naked eye, but could clearly see it through the telescope.

Christy was able to record the green flash with her camera in the morning of March 23.

In the days preceding the sunset, as the sun revolves lower and lower on the horizon, the shadows get longer and longer, and the plateau changes its appearance hour by hour.  On March 17, it looked like an ocean, with just the top of the sastrugi lightening up like the crest of the waves on rough seas.  As a reference, the tower in the picture is 100 ft (30 mt) tall.

This is the last photo of the sun before a dense ice fog came down and reduced the visibility to less than 1/4 mile threatening to deprive us of the only sunset we were entitled to in more than one year.  I took this photo on March 19 at the end of the skiway, 2.5 miles from the station, where I went on skis.

A steady wind during the following two days blew the ice fog against anything that would stand up against it on the plateau.  This is what the station looked like when the fog started to disappear on March 22.  It looks very wintry, even though, astronomically, this is still summer down here.

There has been a lot of activity in the station around sunset, as we are trying to catch the last few days of daylight and twilight to complete outdoor work, before darkness sets in and makes things much more difficult.  Six of us have been going out to the wasteyard all week long to sort a large amount of construction materials left behind at the end of the summer.  Everything needs to be sorted into what can be re-used, what is recyclable (and we have 22 categories of recycling materials) and what is not recyclable.  In the end everything needs to be taken off the continent, in full respect of the Antarctic Treaty.  We have been working two hours every day in -60 C (-76 F) temperatures before the cold has been forcing us back inside for hot drinks.  We should be able to finish today.  In this photo, taken on March 22, the sun appears as a shade of orange behind the dissolving fog.

As the sun reappeared out of the fog in the evening of March 22, I put on my skis,turned on my MP3 player, and to the tune of Bach's Brandenburg Concert I went back to the end of the skiway for a shot at the sun disappearing beneath the sastrugi.  The orange circle in this photo is sunlight diffused by the remaining fog.  The actual sun is the very brightest last sliver of light right up against the snow.  I will not be able to listen to the Brandenburg concert again without thinking back to this fabulous ski trip.

On March 23, to the tune of Spyro Gyra, a CD that had accompanied me all the way to the AGO site when the sun was the brightest, I went on my last run of the summer to wave good-bye to the sun for the next six months, but at -61 C (-78 F), and with a windchill of -84 C (-120 F), it was a short one: only 2 miles.  A little later, at 1 PM, and just two hours before the official sunset, I went on the roof of the station to take the last photo of the sunset.  Here again, the actual sun is the thin line of bright light closest to the horizon.  The cloud of smoke seen in this photo is from our nearby power plant.

As tradition obliges, we celebrated the sunset with a sumptuous dinner on March 19, the Saturday before sunset.  The menu included Crostini and Baked Shrimp Wrapped in Bacon and Cream Cheese as appetizers, Duck Breast with Mixed Green, Lobster Tail and Beef Tenderloin with a Jack Daniels Demi-Glaze as the entree, three different desserts, and Australian wines.  We set up a long table for the 49 of us, we played some old Billie Holiday songs, and watched the fireplace on large LCD screens while the sun shone its last rays into the room (photo courtesy of Susan).

My contribution to the sunset dinner was the ironing of all the table cloths.  Susan took this photo as I was hard at work in the laundry room.

Now that the sun is down, the science work will take on a new pace.  We have to shut down the solar observations and, in a couple of weeks, at the end of the period of civil twilight, which will occur when the sun reaches 6 degrees below the horizon, we will start turning on the instruments that look at the night sky.  For me this includes two all-sky cameras that record auroras and two high resolution interferometers that measure wind speeds in the mesosphere (that is 100 km above the earth) by Doppler shift of oxygen molecule emissions.  The pyranometer in this photo on the roof of the Atmospheric Research Observatory has been measuring the bightness of the sky all summer long.  The arm on the right of the instrument roates to shadow the sun and remove its contribution from the measurement.  Seen in this picture is also the full moon, which occurred at the same time as the sun was setting.  Yesterday, March 24, we saw Venus for the first time, and we expect the sky to start turning on its stars one at a time over the next few weeks.  The moon and the stars will be the only lights to guide us for the next six months, as we will continue to venture outside for work and for recreation.

Extreme Cold Weather Running

The South Pole is one of the most special places where I have had the pleasure to run and, much to my surprise, extreme cold temperature are easily overcome with not-so-extreme gear.

My friend Nick was outside for work on March 2nd, when he saw me running in the distance.  He was quick with his camera to take a photo of my silhouette against the setting sun.  The temperature was -52 C (-62F), the wind about 10 mph, and the sun 8 degrees above the horizon.

When I first arrived at the South Pole on November 2nd, with temperatures around -44 C (-48 F), it felt very cold and inhospitable.  Within a few days a fierce storm broke wind speed records for the month of November at close to 50 mph.  I thought that I had made a big mistake committing to spending one whole year here at the South Pole, imagining that I would never be able to go out and exercise.  The reality has been quite different.  I have never run as much since my years in college.  In the last month I have averaged 32 miles/wk, going out an average of 6 days a week, not to mention the marathon that a bunch of us ran in January.  A couple of days ago, on March 14, the temperature dropped down to -64.6 C (-84.3 F), and I still enjoyed a nice 5-mile run on the skiway in light winds.  All it takes is a little bit of warm gear, or maybe a lot of it, depending on how you look at it: 12 lbs (5.4 kg), as I weighed mine.  Here is what I wear:

I start with a basic layer of cotton socks, spandex legwear, a long sleeve shirt, and a cotton shirt.  This is what I would wear in the coldest mornings at home, in California, when temperatures approach the freezing point.  Running shorts are probably not necessary here, but I like them because they have a small internal pocket to hold my MP3 player.  It is important to choose the music before starting the run, because taking off the gloves to tweak the volume or change the songs during the run would cause the hands to become dangerously cold.  I have tried it at -45 C (-49 F), and I do not recommend it, both for the fingers and for the MP3 player itself.  I run the wires inside my cotton shirt because, if exposed to cold temperature, they become as rigid as steel.

The next layer of clothing is a pair of heavy wool socks and a 100% Polyester thermal top.  I only started using the thermal top at temperatures below -55 C (-67 F).

Then I wear a 100% polypropylene thermal bottom. I started using this layer below -50C (-58 F).

Next is a 300-weight fleece bottom, this one made by The North Face.  I have owned these pants for more than 10 years and they have kept me warm in so many different circumstances that would be too long to list.  I never thought they would prove useful all the way down to the South Pole.

Next the UHF radio.  This is a very important piece of safety equipment, as it would allow me to call for help if for any reason I ran into some difficulty.  Before I leave I make sure that the battery has been freshly charged, that the radio is set on the proper channel, so that I can make an emergency call by pressing a single button, and that the radio is somewhat close to the body so that it does not get too cold and inoperable.  In the summer, when temperatures were above -40C (-40 F), I would hold the radio in my hands, but as temperatures got colder, holding the radio would make my hands cold even through two pairs of gloves, so our radio Engineer, Mike, gave me a shoulder strap, which works very well.

For shoes I use an old pair of Adidas Boston.  I would not use them on asphalt any longer, as they have probably lost most of their cushioning, but here at the South Pole, the cushioning is provided by the soft ice and snow on the ground more than by the engineered layers of materials in the shoes -running at the South Pole is a little bit like running on partially wet sand.  In any case, the soles of the shoes become very rigid in cold temperatures, particularly below -50 C (-58 F), which defeats the purpose of any cushioning built into the shoes.  I bought a new pair of running shoes (Adidas Glide) through Zappos -which delivered free of charge all the way to the South Pole before station closing- but I would not want to use them in such cold temperatures for fear of causing long term damage to the rubber in the soles.  In any case, my old Adidas Boston have done great so far down to -64.6 C.

Next is the balaclava, a piece of equipment that covers the entire head, leaving just an opening for the eyes.  Breathing is through a mesh woven in correspondence of where the mouth is, and there is a small opening to breathe through the nose.  The one I use is made by Outdoor Research.

The balaclava leaves dangerously exposed a spot on the temple, close to the eyes.  I found that out when one day, with temperatures around -48 C (-54 F) I caught some wind on the way back to the station and it caused a little windburn.    I secure it by tying a double knot under my chin, so that it stays nice and tight.

Next I wear a fleece top.  This is part of the gear that we are issued for the South Pole, and is equivalent to any good quality 300-weight fleece on the market.

The last piece of head protection is the neck gaiter.  I only use it when temperatures fall below -40 C (-40 F), mostly as an emergency piece of clothing, in case the wind picked up unexpectedly, and found its way into my nose or mouth through the mesh in the balaclava.  I have not had to lift the neck gaiter over my face so far, but I like to know that I have at least a little bit of extra gear along with me.  Another technique that I found very effective against headwind, which was taught to me by my friend Healy, who was here in the summer, is to run backwards.  That is because the face is typically more exposed than the back of the head so sometimes, if it gets a little windy, I alternate running forward and backwards.  This is fun, too.  Of course, this works well here at the South Pole where the terrain is flat with absolutely no obstacles in any directions for miles and miles.  At home I would not want to do this, unless I were maybe on a track.

All is left to wear is gloves.  The first layer is a pair of wool glove liners, just like the ones we would wear in cold weather at home.

The second layer is a pair of leather mittens lined with insulation inside.  These work very well for temperatures down to -45 C (-49 F) and for exposures up to a couple of hours.

Below -45 C (-49 F), I use gauntlets on top of the mittens.  They consist of two pairs of gloves one inside the other: an inner layer of synthetic insulation, and an outer layer of leather, further covered with synthetic fur on the outside of the hand.  The gauntlets also protect the arm almost to the elbow.  It is difficult to use the hands for any type of work with all these gloves on but, just for running, this combination is excellent.  Before putting on the gauntlets I lower my Smith goggles onto my eyes, making sure I seal any possible gaps that could leave an entryway for the wind.  The objective here is to have enough layers to provide an air pocket around the body, and to make sure that no skin is exposed.

Wonderful South Pole!  The last layer of insulation is provided by nature itself!  While the ice mask that forms after running for 1 hr outside may look a little macabre, it actually conceals warmth inside.  The ice is the result of breathing, which condenses and freezes immediately upon contact with the air.  In turn, the layer of ice provides excellent thermal insulation and extra protection against the wind.  It is remarkable how warm one can be inside, after the ice has formed, which only takes a few minutes.  As I said in a previous blog, it is a little bit like being inside an igloo.  This photo was taken on March 17, only 5 days before sunset, with a temperature of -52 C (-62 F) and an average wind of 12 mph.  High clouds in the sky made the sun invisible, so I lifted the goggles over my forehead about halfway through my run.  On the left on this picture in the far background is the South Pole Telescope.

Now, you may think that all this gear would make running cumbersome, but I found instead that it still allows plenty of freedom for movement.  What limits my speed is not the amount of clothing that I wear, but the soft surface of the snow and ice on which I run on.  While at home I typically run an 8-minute/mile pace, here I run more of a 10~11 minute/mile pace, regardless of how cold it is and how many layers of insulation I wear.  Finally, I should make a point that here at the South Pole we live at an average barometric pressure of 681 mbar, which is equivalent to a physiological altitude of 10,591 ft (3,228 mt).  That is one third less air than at sea level.  Therefore, with less air and humidity to conduct the heat away from the body, temperatures here at the South Pole may not feel as cold as they would at sea level.  This is one of the few rational explanations that I can give on how it is possible to have fun and feel comfortable running at these extreme temperatures.

It actually does not get much colder than this here at the South Pole.  Although the coldest temperature ever recorded here is -82.8 C (-117.0 F) on June 23, 1982, the average temperature in July, which is the coldest month is -59.8 C (-75.6 F), which is warmer than the coldest temperature that I have run in.  Nevertheless, I am afraid that my happy days of outdoor running at the South Pole are counted for two reasons: first, it is soon going to be dark for six months; and second, snowdrift is starting to accumulate on the skiway, making it more and more difficult to find firm ground to run on.  I hope I can still run a few more days until sunset.  We'll see.

The South Pole Greenhouse

Last night I enjoyed a delicious and abundant plate of fresh mixed greens, dressed in olive oil, and accompanied with freshly baked bread - one of my favorite dishes.  All summer long we have had loads of fresh fruits and vegetables brought to us on a regular schedule by airplanes, but since station closing three weeks ago, with no more flights coming our way for the next eight months, we are eating produce from our own hydroponic greenhouse: a marvel of technology that allows us to grow fresh vegetables in a location where there is no soil, no sunlight for 6 months, and where the temperature never rises above freezing.

My dinner salad on March 9 at the South Pole!

The Antarctic Treaty prohibits us from bringing soil to the Continent, so the National Science Foundation turned its attention to the University of Arizona: the same institution that is developing greenhouses for a possible human settlement on the moon.  With no settlement on the moon, yet, the South Pole greenhouse is probably the most extreme environment where plants have been grown. 

The hydroponic chamber is a closed and controlled environment where all the inputs (water, minerals, carbon dioxide, and light) are precisely administered to the plants; all the critical parameters (temperature, humidity, PH) are controlled, and all the outputs (liquid and gaseous efflluents, and weight and type of the produce) are accurately measured.  Seeds are planted in a sponge-like material, germinated, pollinated, and transferred into larger trays where they can grow to their normal size.

The rate at which the plants grow is phenomenal.  Intuitively I would have thought it difficult for plants to grow outside of their natural environment, but, as Lane, the researcher from the University of Arizona who visited us in the summer, explained to me, it is just the opposite.  In the greenhouse we can give the plants exactly what they want: the right amount of light, the right temperature, the right amount of nutrients, the right air composition.  In fact, we could make plants grow even better if we only could optimize the parameters for a single crop, but because we have a great variety of vegetables that we grow, we have to make compromises.  For example, strawberries like 15 hrs of sunlight every day, but that would not be good for other plants, so our strawberries do not grow as fast and as large as they could.  Another reason why plants grow so well here is because there are no bugs, no birds, or other extraneous living organisms trying to go at them.  Therefore, we do not use any pesticides, which makes all of our vegetables organic.  We do have to be careful about mold, which has developed occasionally.  So a big part of the job of the greenhouse caretaker is to thoroughly clean the trays with bleach before planting a new crop, and constantly inspecting the roots of the plants.  If there is mold, the plant must be removed, the mold must be observed under a microscope for identification, the information is shared with the experts at the University of Arizona, and an appropriate course of action is taken.

Although we are nowhere close to space, the cost of producing these vegetables is astronomical.  We have estimates, which include the cost of melting ice to produce water, the cost of transporting fuel by airplane to produce electricity, the cost of transporting all the nutrients, including the cylinders of carbon dioxide, etc., and I do not even want to venture publishing that figure in a public blog.  I just try to savor and appreciate my delicious fresh greens every day knowing how much study, research, and care has gone into bringing them to the table, and knowing that through all this work we are advancing science.

It doesn't take a Ph. D. to run the South Pole Greenhouse, but it doesn’t hurt.  Susan, our greenhouse caretaker, holds one in Chemistry and has spent most of her life as an Analytical Chemist before coming to spend the winter with us at the South Pole.  Besides her job in Colorado, she left her lovely dog George.  The Antarctic Treaty prohibited George from following her this time.  Susan’s dream job is to run an analytical chemistry lab on board a sailing ship on an around-the-world sampling cruise. 

 

Plants grow in plastic trays.  The root system develops in a sponge, which is fed with water and nutrients through a complex computer-controlled hydraulic system of pumps, mixers, tubes, valves, and measurement sensors, hidden under the plastic trays.  The trays are built on rails and can be moved in and out to expose different plants to different amounts of light.

Green lettuce is my favorite vegetable.  We harvest the larger leaves and let the plant continue to grow until the following harvest.

We also grow excellent red leaf lettuce.

Our basil does very well …

… as do our tomatoes.  Too bad we have not yet figured out how to make fresh mozzarella, because I do miss Caprese salad every now and then.

This is Bok Choi, a green that I did not know about until I came here at the South Pole.  It is of Asian origin, and grows very well in our greenhouse.  It is also very good.

Beets and Swiss chard.

My favorite vegetable to eat steamed is kale.  Luckily, we have lots of it here at the South Pole.

Leeks

Besides vegetables, we also grow flowers, not for eating them, but for reminding us of the world we left behind.  In addition to sunflowers, we also grow chamomile flowers, which we use to make soothing evening drinks as a fresh complement to the variety of teas that we already have on station.

On February 23 we had the first harvest party of this winter season.  Here is Shannon holding a large bag of fresh lettuce, Rico, enjoying his work, and John and Joselyn hard at work in the back.  On that day we harvested more than 100 lbs (more than 45 kg) of fresh vegetables.  Working in the greenhouse brings back the memory of smells that we do not get to experience here at the South Pole.  The humid air feels thick, when compared to the 3% of relative humidity in which we live inside the station (Photo courtesy SP).

My winter room

Now that the station population has gone down to 49 people, we have been able to enjoy some more elbow room.  At the beginning of February I moved into a new, larger room.  Not only is the room larger, but I have an unobstructed view over the plateau from the window. 
It is now March 8, less than two weeks away from the only sunset that we will get to see this year.  The shadows are getting longer and longer, as seen in these photos.  The weather has been very stable for the last couple of weeks, meaning blue skies with very little wind.  The temperature has been dropping steadily a few degrees every day.  Today we have reached -57 C (-71 F), but when there is no wind it is still very nice out.  In fact, last week I logged the most distance ever covered since I got here at the Pole: 63 miles equally split between running and skiing.  I am trying to get the most out of these last few days of summer before the next storm will likely cover the skiway with snowdrift and put an end to my running.  This morning, after I finished my usual 5-mile run on the skiway, I felt so nice and warm under my layers of fleece, my two hats, and my three pairs of gloves, that I kept going 3 more miles.  On Saturday I did my last field work for the season, so, unless some of the instruments break, I should not have to work outside until at least the next sunrise.

My new room, circled in red, is situated in the outermost wing of the station.  At the far right, denoted by flags, is the ceremonial south Pole.  At the right, but still attached to the building is what we call the beer can: a metal structure connecting the elevated station to the service and utilities tunnels under the ice.

A look inside my room shows an architecture very similar to my summer room, but the additional 10 square feet of space make room for a 6-ft desk.

The view from my window is spectacular.  Nothing but ice for 1,400 miles in this direction, until we get to the ocean, except for the Russian station of Vostok half way in between.  At the far left and in the background are the Atmospheric Research Observatory, then the Cosmic Ray Detector platform.  Closer up are vent pipes from the utilities tunnels under the ice.