On the Dark Side of the Planet:
A letter from South Pole Station,
by Stephen G. Warren
Antarctica had been on my mind for a long time,
but it wasn't until February 1960 that the idea
of wintering captured my imagination, when my father
took me to an evening slideshow at Purdue by Paul
Siple: "Man's First Winter at the South Pole."
Then I took a glaciology course in 1968, changed
careers in 1978, and joined three spring-and-summer
Antarctic expeditions. After all that preparation
I was ready for the winter of 1992, with experiments
on climate processes involving snow, clouds, sunlight
and atmospheric radiation. My students Rich, Von,
and Susan designed and built their equipment and
came for the summer to install it and instruct me
on how to operate it; then left me for the winter
to gather the data for their thesis projects.
There are 22 of us here for the eight-month winter
season: ten carrying out science projects and twelve
support staff. The winter research projects involve
weather and climate, clouds and snow, atmospheric
chemistry, stratospheric ozone, physics of the ionosphere
and magnetosphere, aurorae, solar and infrared radiation,
seismology, gamma-ray astronomy and neutrino astronomy.
The environment on the interior plateau is surprisingly
friendly to scientific experiments: instruments
here are not subjected to soaking by rain, corrosion
by seawater, or breaking by strong winds. They are
safer here than in the tropical jungle, where trees
would drip on them and toads would sit on them.
Of course the winter here is colder than anything
we're used to, with an average temperature of -60
C, but we've learned to adapt to it; we're even
able to conduct an experiment that involves walking
out periodically to a remote clean site and working
for three hours to collect snow samples.
It is beautiful here, even though we have only
the snow and the sky. Low ice-clouds occur throughout
the year, but in summer there are also clouds of
supercooled liquid droplets. Snow grains fall from
these clouds, and tiny sparkling ice crystals called
diamond-dust fall from the clear sky, causing beautiful
colored halos and arcs around the Sun and Moon.
After sunset in March the twilight fades slowly
and is still faintly visible until early May. Toward
the end of twilight we once saw a "noctilucent"
cloud: although the Sun had sunk far below our horizon
it could still illuminate this high cloud 80 kilometers
In winter we see aurorae on most clear days: usually
just broad white streaks but sometimes swirling
colors, and just once we witnessed an aurora of
dancing needles. The Moon circles above the horizon
for two weeks; then it sets for two weeks to allow
the constellations to dominate the sky: the Scorpion,
the Centaur, the Southern Cross, and the Magellanic
Clouds, with Orion chopped in half by the horizon.
The bright stars Sirius, Canopus, Achernar, Fomalhaut,
Alpha and Beta Centauri, and Spica compose a familiar
pattern unchanging throughout the winter, while
Saturn wanders slowly through Capricorn.
Here are some stories from the winter....
Monday morning 23 March 1992
by Stephen G. Warren
In March the Sun moves one degree to the north
every two-and-a-half days. The Sun's width is half
a degree, so at the South Pole it takes thirty hours
for the Sun to set: thirty hours from the time the
bottom of the Sun touches the horizon until the
upper rim finally disappears. This is the most leisurely
sunset anyone on Earth will ever experience. The
Sun entered the Northern Hemisphere on Friday evening,
but we can still see its upper arc even today refracting
through our temperature-inversion, dimmed and distorted
by a dusty haze of blowing snow.
I'm writing this letter by the big picture windows
up in the Skylab lounge. The Sun no longer looks
round; it's now a stack of three orange pancakes.
The tops and bottoms of these cakes ripple with
the wind. The left and right edges flash alternately
yellow and green. Behind me, on the night side of
the sky, the past-full Moon shines high and bright.
A great-circle boundary line separates the day
half of the Earth from the night half. Today the
South Pole is on that boundary. Look over to the
Sun; just now that's the direction of Hawaii; in
that time zone it's noon now. Look in the opposite
direction to the dark sky, toward Botswana and Finland;
in that time zone it's midnight.
We were treated to a fine show on Saturday evening.
The entire Sun was still above the horizon, but
it was giving us a farewell display that isn't supposed
to happen until the upper rim sets. Green flashes
came and went for an hour or so. From the green-fringed
shimmering upper arc, green flakes would cleave
off, rise, then vanish; sometimes two or three flakes
would be following one another as if on a conveyor
belt: as the top one disappeared another would rise
from below. Then came the most amazing shocker that
stunned us all: a triangular green cap perched on
top of the orange disk; this little green pyramid
was visible to everybody, not just through the binoculars.
What a treat; there were some wide grins on those
orange-glowing faces at the Skylab window!
Tuesday 16 June 1992
by Stephen G. Warren
The winter airdrop was scheduled for Saturday the
thirteenth of June, the only delivery of mail and
"freshies" [fresh food] between February
and October. Gary, our Station Manager, called a
planning meeting for Wednesday evening, at which
I parceled out my remaining supply of chemical hand-warmers
and toe-heaters to everybody for use during the
airdrop recovery; I was expecting a big shipment
to replace them. After the meeting we brought in
the Christmas tree and put up decorations.
A blizzard began on Thursday, continued through
the airdrop, and still continues today. On Saturday
afternoon at 1:45 the airplane came, an Air Force
C-141. It had flown all the way from New Zealand
(3300 miles), and would return without landing anywhere,
so it had to be refueled in the air by a tanker-plane
over the Antarctic Ocean.
In order to see our smudge-pots marking the drop-zone
on the runway, the plane had to descend below the
clouds; yet it had to remain above 1500 feet to
allow the parachutes sufficient time to open. Kitt
and Bob were reporting clouds at 1000 feet all morning,
so we doubted that the airdrop would occur. It's
a one-shot event; if it fails we don't get our mail
The plane was able to see the drop-zone. Eighteen
bundles drifted down from the dark sky, each hanging
from its own parachute. Three teams, each carrying
a radio and followed by a tractor with a forklift,
were sent out to find them. After watching the drop,
Bob and I were on our way inside to help with unpacking,
but we decided briefly to be tourists and walked
out with Team 3 toward the smudge pots. We wanted
to see how the parachutes were attached and how
deeply the bundles had dented the snow. It turned
out that Team 3 consisted of just Dave and Joe,
followed by Martha driving the tractor. They asked
for our help, so we ended up working with them for
We trudged out into the blizzard. For a short while
we could still see Team 2 in the distance to our
left (Bill, Mike and John), silhouetted by Darrell's
blinding headlights as he lumbered along behind
them, bouncing over the sastrugi (snow dunes).
Away from the headlights it was pretty dark; the
Moon was obscured by blowing snow and thin clouds.
In three hours our team located seven of the bundles.
Each bundle, a big cardboard container, weighed
about 500 pounds. And by the time we reached the
last one, its parachute also weighed about 500 pounds,
because of the snow that had drifted onto it!
We walked far out along the runway, beyond the
new telescope building, to find the most remote
bundle. It had split open on impact, but nothing
had fallen out. We righted the bundle so the forklift
could get under it; then Bob walked out north into
the darkness to search for even more distant bundles.
Dave and Joe were sheltering behind the box out
of the wind, waiting for Martha to return with her
forklift after delivering our first three bundles
to the dome. I peeked through an opening in the
broken cardboard. By the moonlight I could see that
it was full of small parcels. Curious as to whether
the mail for McMurdo Station had been dropped here
by mistake, as had happened last year, I pulled
out one package, borrowed Dave's flashlight to illuminate
it, then asked Joe to look at the address. Through
his ice-encrusted eyelashes, his frosted glasses,
and a swirl of blowing snow, he was still able to
make out his own name on the package: Joseph P.
By 4:30 pm all eighteen bundles were inside the
dome. Drew had discovered how to use a butter knife
to remove the cargo straps. Dan and Jim helped Paul
hang the parachutes to dry over the volleybag court.
They shook the loose snow off them, then Roger swept
it out the door.
By 6 pm Betty and Jarvis had sorted all the mail
in the galley. Peter turned on the Christmas-carol
music, and the package-opening began. I opened only
what was unexpected; the eleven boxes of cargo I
had requested from Von and Susan at the University
(four of them full of handwarmers and toe-heaters)
could wait. The very first package I saw was from
a long-lost friend: what a surprise; how did she
even get my address?
Saturday evening I briefly left the cheerful chaos
of the mail-opening party to check on Susan's experiments
out at the Clean Air Facility. Before returning,
I stood on the balcony and leaned against the railing
for a while in the brisk warm wind (twenty-five
knots and forty-below). Besides the nearly full
Moon, the bright stars Alpha and Beta Centauri also
shone dimly through the blowing snow. Two days later
the full Moon, as far above the horizon now as the
Sun is below it, would be eclipsed for three hours
by the Earth's shadow.
Kitchen cleanup duty comes every 22 days; Sunday
was my day. It involved more work than usual because
of all the packaging trash, and because Jerilyn
prepared a special Christmas dinner with turkeys,
wine, candles, and tablecloths, so I got a lot of
help from volunteers. Jeff and Dale were also there
all afternoon unpacking fresh pineapples, watermelons,
onions, and eggs that had fallen from the night
I'm reluctant to admit this to my friends and relatives
who took the trouble to send me those (now much-appreciated)
letters and packages, but I guess it has to be part
of the complete story: I was not eager for the airdrop.
I still hadn't yet read all my February mail, and
I still had enough work and reading material to
keep me busy for another year at least. I had settled
contentedly into the pleasant life of a remote station,
able to restrict news from the outside world. The
airdrop threatened to disrupt my routine, bringing
in tempting distractions before I'd completed my
work on what's already here. The airdrop cracked
open the South Pole cocoon, and forced the world
upon us at least briefly, which I'm sure was a good
thing for everyone.
Sunday 26 July 1992
by Stephen G. Warren
When I brought up the idea of a July campout in
Antarctica, Martha was the one to show the most
interest. She had previously lived in a tent for
several long summers as a backcountry ranger in
the Pacific Northwest's North Cascades, but this
would be a new experience, even for her.
The purple tent I had bought in Tasmania four years
ago was going to be put to a severe test. Would
it shatter into a million pieces when exposed to
the cold air? We didn't know. Saturday evening we
erected it in the computer room. Drew, the computer
manager, promptly posted a sign "Camping $5;
free use of the Vax [90s computer] included."
We cut sections of two-inch-thick styrofoam "blueboard"
to cover the floor of the tent. On top of them went
a layer of closed-cell ensolite pads, then four
wool blankets, then two lightweight sleeping bags.
Finally we added three very heavy green down-filled
bags, each lofting to about eight inches: one for
Martha to crawl into, and one for me; the third
spread out over the top. All this fluff filled the
tent more than halfway to its roof, and puffed the
walls out so that tent-pegs were unnecessary.
The tent had to be partly dismantled to carry through
the door, so we reassembled our masterpiece outside
the building, then perched the whole thing on a
pair of sleds, "a mobile home." The tent
fabric became stiff in the cold air and crackled
at the touch, but it didn't break. Drew and Peter
pulled the sleds out of the dome and up toward the
runway, while Martha steadied the tent and I searched
with a powerful flashlight to find the Geological
Survey marker indicating the South Pole.
The sky was clearing, the wind weakening and shifting
to the east, the temperature dropping. The stars
brightened and broad wavy auroras streaked across
the sky. After setting the tent on a patch of flat
snow at the Pole, we went back to the station to
change into bedclothes that could also be worn for
the walk out to the tent. I wore two "balaclava"
facemasks, puffy down mittens, a down parka, down
pants, socks, and the foam liners of my moon-boots.
Even with all this bulk in my sleeping bag, I was
still quite comfortable, even able to roll over.
For seven hours Martha and I were the southernmost
people on Earth, and actually quite warm. I had
expected my wool balaclavas to become caked with
ice, stiff and unbreathable, as they do on three-hour
walks to the snowpit. However, the tent interior
became warm enough that our breath froze not on
the balaclavas but instead on the sleeping bags
and tent walls. At 7:30 this morning we emerged
from the frost-coated bags to a clearer, colder
scene. We quickly aborted our fumbling attempts
to pull on our boots, and decided instead just to
walk back to the station in the liners.
The only painful part of this whole excursion was
closing the tent door this morning as we left, because
the zippers couldn't be pulled with big clumsy mittens.
My hands, wearing thin gloves, had to dash back
into the puffy mittens several times before the
task was completed. Back at the station, I went
to the weather office to read the air temperature.
It was about average for wintertime here: 62°C
(-80°F). Just a July weekend campout in our
Tuesday 22 September 1992
by Stephen G. Warren
On August 28th Betty was finally ready to learn
the Southern stars and asked me to point them out
to her. By then twilight was already encroaching
on the night sky and the constellations no longer
looked so dramatic, so she lamented: "I can't
wait till it gets dark!" But most of the crew
were quite ready to welcome the Sun.
The South Pole sunrise began two weeks early with
the Sun still at five degrees North latitude. On
September 8th, a calm day with an extreme temperature
inversion causing bizarre distortions of the horizon,
Dan, Kitt and Paul saw the Sun rise in an amazing
mirage, then set again after just five minutes:
a mirage that was last reported at such a large
angle 400 years ago when Barents saw it at the island
of Novaya Zemlya in the Arctic Ocean in 1597.
The rest of us had to wait almost till Equinox
to see the Sun. On Sunday the 20th I gave myself
a birthday treat, taking a day off to write letters
by the window as a blizzard raged outside. By evening
the winds had weakened and we were allowed a brief
break in the storm. The blowing snow began to settle,
revealing the horizon, but there was still no sign
of the Sun when I went to bed. At 2:30 am Jarvis
knocked on my door to wake me: "The Sun is
rising!" He prodded several of us up to the
picture windows in the Skylab lounge; others stumbled
outside to have a look. And it was beautiful. I
had been learning the Beatles' song "Here Comes
The Sun;" now I played it on my recorder over
the loudspeaker to alert the whole station.
The upper limb of the orange disk threw off green
flashes occasionally for two hours, just like at
sunset six months ago. Then the clouds closed in,
but we all knew the Sun had now returned for good.
All longitude lines meet at the Pole, so we're
free to choose any of the Earth's 24 time-zones.
Normally we use New Zealand Standard Time, and it
was already early on the morning of the 21st when
I first saw the Sun. But birthdays are reckoned
in the time-zone of one's birthplace, and in Wisconsin
it was still the 20th. So the Sun had indeed returned
as my birthday present!
What does sunrise mean to an Antarctic winterer?
Our most memorable image is of Mike standing alone
down on the snow at 4 am, looking out across the
vast cold ice-sheet, just standing out there in
the wind, forlorn, long after everyone else had
gone back inside, still standing there motionless
and staring silently at the Sun, entranced, eyes
fixed on the Sun as it slowly moved around west
toward Longitude 92, where his wife Edie and two
young daughters, at the end of a hot Missouri summer,
could be looking up at that same noonday Sun.
Tuesday 20 October 1992
by Stephen G. Warren
In a few days the station will open for the summer,
and our little group will never again be alone together.
What did we miss the most, in our isolation from
the world? I never would have guessed it: what many
of the winterers miss is snow! After a year of continual
faint dustings of microscopic ice crystals, we're
happy to return to the humid North with its heavy
storms of big wet snowflakes.