1. Halfway Home & Happy Mid‐Winter!
JUNE 2011
Mid‐Winter Weather
Base Power Source And Heating
You've Got to Hand it to Us
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June 2011

2. Half‐way home! And Happy Mid‐Winter!
“In research stations throughout Antarctica, Midwinter is widely celebrated as a way to mark the
fact that the people who winter-over just went through half their turn of duty. [T]he celebrations
… are typically marked by parties, team games, redecoration of the premises and days [sic!] off
work”. (Guillaume Dargaud, 2005 team member on Concordia Base, paraphrased in Wikipedia).
Preparations for the MidWinter Festival begin many days ahead of the event. It is a tradition that
Greetings Cards and Invitations are issued amongst the 40-odd Over-Winter Bases all over the
Continent. We must admit that we would be severely startled if the Germans, say, did actually
pitch up on the day – but still, much effort is put into concocting amusing and cordial welcomes.
We particularly enjoyed the small glimpses these cards afforded us of other Bases.
21 June 2011, MidWinter's Day, and the team slugs out of bed at a gentle hour (all except Paul,
of course. The South African Weather Service doesn't believe in any of this Holiday nonsense
and there he was at 07h45, peering earnestly at the pitch-black sky and intuiting he could see
some cirrus cloud or whatever out there). The plan for the day? - a leisurely start, easing into
the Pull-Up Competition, Dozer-Runs followed by dips into the sauna for those who could handle
it, then cooking a mighty meal, and lastly – the highlight – drinking the mighty meal. And eating
the odd tidbit, as well.
Although the term “Winter Solstice'
suggests a day of freezing darkness
with blustering snow and icy winds,
this was not the case. Our weather
was good (see p.6), and although
there was no direct sunlight, there
were a few hours of bright twilight;
enough for us to get outside prior to
any scheduled activity. A little photo-
shoot on the roof, just to show how
dark it isn't. The perennial Smelly:
work does go on, after all...
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June 2011

3. The Pull-Up competition was the first major event of the
day. Why a pull-up competition goodness only knows.
This is something Renier and Paul cooked up between
them. The entire team assembled in the gym, bets and
counter-bets offered in interested undertones by the
non-contenders as each aspirant stripped his jacket off
and showed his form. Chances were evaluated on the
weight-strength ratio of each individual. Serious money
was on Johan – slender but strong. Serious money got it
wrong. Not that he didn't perform credibly, but S'celo
came in from behind and showed us what real strength
is. 17 pull-ups straight, he acheived. Renier did well with
16, Paul showed what climbers are capable of with 15,
and Johan managed 14½. Those of us who were not
mourning having betted away our entire night's wine and
beer then went for the dozer run. This involves – for
SANAE 50 at least – scampering down BC link stairs,
across the sastrugis, around the dozers, and back
again. Clad in costume, with footwear optional. Then
warming up in the sauna, and repeating at will.
Mid-Winter's day is special not only because of in-base team activities, but also because all
sorts of people phone us to wish us well – anybody from Radio Stations to previous team
members. Paul was unanimously elected as spokesman
when Heart FM phoned us, but the rest of the team took it
in turns to answer the phone and chat to the various well-
wishers.
Our most valued call came from Marten du Preez. Marten
was a member of SANAE 1 in 1960; the very first South
African expedition to Antarctica. Marten was the radio
technician. He returned to Antarctica in 1962 as Team
Leader for SANAE 3, and was a honoured VIP in 1997,
when he was invited to the opening of the SANAE IV Base.
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June 2011

4. He is a keen radio ham with the call sign ZS6ZY, and as such is a friend of Gerard, our
electrical engineer, himself a keen HF man.
Although Mid-Winter is usually thought of as a Christmas
celebration, we had neither turkey nor ham readily
available on Base, so the food was an eclectic mixture of
team specialities: Tiki's garlic bread, Alan's spiced rice,
Paul's stir-fried vegetables, Beat and Kevin's succulent
roast lamb, and a very special hand-crafted (instant)
cheesecake imported by Renier for the occasion – just a
few of the dishes presented.
So we have passed the half-way point. The Sun is returning, the ship is returning, we will soon
be returning Home again. But there's still seven months to go, and we still relish every day of
our life in the icy embrace of Antarctica.
Author: Abi
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June 2011

5. Page 5
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6. Page 6
June 2011

7. Mid Winter Weather at SANAE
‐ by Paul
“Weather outlook for today. Maximum temperature
expected 1 3 degrees below zero dropping to 20 below
through the day. Winds: gale force, 50 kph expected.
Overcast with blowing snow”.... this was my prediction for
the Mid Winter solstice.
The 21 st of June was the Winter solstice and marks the time on the calendar that we start
returning towards direct sunshine and the summer months. But although the Sun should start to
peak along the Northern horizon in late July, the reality is that the Winter is not over and June is
not necessarily the coldest month in the Antarctica. So what significant weather phenomena do
occur in June?
How cold is cold?
The 21 st was not a particularly
eventful day in terms of tem-
perature extremes. The average
for the day was -1 7.2 0C,
fluctuating between a maximum of
-1 3.8 0C and a minimum of
-20.6 0C. However, the mercury
had fallen to –31 .7 0C on the 8th of
the month, marking the coldest
temperature for June. The
average temperature for the
whole month was -20.9 0C.
In the mid latitudes of South Africa
the lowest temperatures of the year tend to occur after the solstice. A well defined Winter
minimum is usually apparent toward August-
September, towards the end of Winter. This is not the
case in the Antarctic, where heat loss occurs early
and rapidly, and Winter temperatures tend to be
euqal throughout the period. Here there is also a
clear asymmetry in the time span of Winter and
Summer. The term “Coreless Winter” depicts a
stable non-fluctuating winter temperature that varies
only a few degrees between the onset and closure of
the winter period, during which polar temperatures do
not continue to fall during the long winter period. The
latter is very short - between December and Johan does a weather station check
February at SANAE. This short duration has earned
the name “ Pointed Summer” as a descriptive title.
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June 2011

8. But there can be a large difference between actual (dry bulb) temperature and apparent
temperature. Our average dry bulb temperature in June was -20.90C. Actual or dry bulb
temperature is the temperature of the air without the effects of relative humidity or wind speed.
However, these parameters are very important when it comes to measuring how quickly we lose
heat. In the Antarctic with its continuous winds, the cooling effect of the wind (“wind chill”) is
significant, and the very low humidity also contributes to a rapid loss of heat by aiding
evaporation. “Apparent temperature” is the term used for that measurement which factors in the
relative humidity (called “heat index” in tropical countries) and the wind chill. Wind chill is the
extra cooling effect felt on the skin due to wind, and is calculated using wind speed and dry bulb
temperature. There are intricate formulae used to derive the apparent temperature (e.g. Wind
chill temp. = 35.7 + 0.6215T - 35.75V0.16 + 0.4275TV0.16). At SANAE, we just take what the
computer says on trust! Apparent temperature is highly significant to us, as this, and not dry bulb
temperature, determines the likelihood of cold injury and frostbite. So on Mid-Winter's Day, the
wind was on average 31 kph and the dry bulb temperature around -17.20C. In these
circumstance the apparent temperature was -300C – very nearly double the dry bulb.
How hard did it blow?
Wind is our most severe environmental hazard at SANAE, in that even relatively low wind
speeds increase the risk of cold injury. Our winds were particularly strong in June. While the
average wind for the month was around 40 kph, which is the norm for SANAE, we reached our
highest wind speed yet on the 24th, three days after Mid Winter. This blizzard produced wind
speeds up to 61 ms-1 - that
is, 21 8 kph. Such speeds
are very much the
exception; in the months
preceding this our maximum
gusts typically peaked at
1 30 kph. So 21 8 kph is
clearly an outlier. The
Meteorological Officer and
several team members
closely scrutinised the data
from the South African
Weather Services station to
ensure that this extra-
ordinary reading
was not just a computer glitch
and concluded it was a
reliable reflection of events.
Our conclusions were aided
by another anomaly occurring
simultaneously - the breaking
of the anemometer propeller.
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9. This piece of equipment is rated for extremes of wind and temperature, and it took something
really out of the norm to cause this failure. Clearly the wind was too high for our anemometer
and it sheared the 5 mm stainless steel prop shaft. As shown on the graph this occurred, not
during the peak at 04h45, but a few hours later at 08h00 the same morning.
Inversion winds
Of course, Antarctica is notorious for its winds. As they say, “when the wind stops blowing, the
penguins fall over”. The question is why is the wind such a feature here. One reason is
topography, causing “inversion winds” – winds that blow in line with the maximum slope of the
terrain in a fixed direction. This is the main cause of wind at SANAE. The cold heavy air from the
polar-plateau shifts down slope from the South Pole in a northerly direction while simultaneously
deflecting leftwards due to the Coriolis force - a
rotationally induced force that deflects a moving
object leftwards in the southern hemisphere.
Because there is s a steady supply of cold air
draining off the polar plateau towards the edges of
the continent these winds tend to blow unabated.
Looking at the wind rose we can see this
reflected in the dominant 1 30 0 direction: the
wind blows mostly from the South-East to the
North-West.
Katabatic Winds
We have also a second and more drastic
wind event, called “katabatic winds” (katabaise in Greek is “going down”). Katabatic winds tend
to exhibit highly variable wind speeds, gusts and weaker winds alternating randomly, with
interspersed periods of complete calm. These occur
at the edge escarpments, on very steep drop-offs.
Because of the steeper slopes, the cold air drains
rapidly and the resultant katabatic wind is more
spasmodic and violent than its inversion counterpart.
Sudden wind speed jumps from calm to 40 knots can
be expected. The wind that broke our anemometer
(our highest wind speed yet) is a good example of
katabatic wind drainage coming off the bulk of the
Ahlmann mountain range to the South, which is
about 1 000 m higher than Vesleskarvet.
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10. Snow, drifting snow and blowing snow and what’s the difference anyway!
Wind is a menace not only in its ability to freeze us, but also in its action on loose
snow. We had clear skies and no surface snow on Mid Winter's Day, despite the stiff breeze of
20 knots (40 kph), so we were lucky. Frequently wind is accompanied by blowing snow as the
loose surface snow lifts and becomes entrained in the air flow. The endless days of wind-borne
snow curtail our outdoor activities, confining us to base and seriously interfering with the
ongoing outdoor work of cargo, transport, melting snow to make water and various other tasks.
The amount of lifted snow varies with wind speed, increasing exponentially, but other factors
also play a role, such as surface roughness, which increases turbulence, or surface freezing,
which restricts lifting. When winds speed attains a moderate 5 ms-1 it will start to lift snow
marginally. If the lift is less than 2 m vertical height the term “drifting snow” is used. Once winds
reach 20 ms-1 the situation is much more severe - even life threatening for anybody trapped
outside. Visibility reduces to less than a few metres at best and the term “blowing snow” is used
to describe snow lifted in excess of 2 m vertical height. Often it blows right over the Base. In
such situations, the sky is obscured and it is not possible to see if there are clouds so it
becomes difficult to differentiate between blowing snow and actual falling snow.
SANAE weather office recorded falling snow on nine
days and drifting/blowing snow on 1 0 days this month.
The question of how much snow falls at SANAE is a
vexing one. We have no means of measuring
precipitation here. The question is by no mean trivial as
it addresses the whole issue of long term ice stability
and accretion and is closely related to global climate
change issues. Certainly we have seen through the
Winter how the snow has built up around Piggen and
other mountain slopes. Yet we cannot know to what
extent this was from blowing snow or falling
precipitation. It is said that the Antarctic plateau is a
vast desert yet it is inarguable that accumulation
balances loss since the ice sheet is not noticeably
changing in the short term. We will await Summer to
see if the accumulations decrease in height again.
We were fortunate on Mid-Winter's Day: the weather
was really mild – by Antarctic standards. Dozer runs
were an option which almost all of us took. At the same
rat an! "
ice Day fo
time, we did not have to feel cheated by our tame Mid-
R enier: "N Winter. Although we could not expect the South African
Weather Service to share our sense of drama, the
breaking of the anemometer prop attested to our rugged Ice Pioneer experience of extreme
conditions. Of course, fixing the wretched thing was another story... .
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June 2011

11. SANAE IV Base Power Source And Heating Systems
‐ by Alan
SANAE IV Base is located in Antarctica with no Eskom around or the electricity hikes affecting
us now; we rely solely on Diesel Engine Generators (Gensets) with electronic systems to keep
all the equipment running and keep us cosy during our over-wintering experience.
Diesel Generators (Gensets)
There are three ADE Diesel Engines.
Each of these is capable of pushing out
an average of 1 50 kW at 1 500 r/min, with
a maximum of 260 kW at 21 00 r/min. As
a comparison: the average motor vehicle
such as a Toyota Tazz (1 .3 litre)
produces 55 kW at 6200 r/min. The S.A.
Agulhas produces 4476 kW.
Our generator engines have an electronic
governor that controls the fuel supply to
either increase or decrease the engines’
power output, depending on the load required. Each engine is coupled to its respective
alternator that will convert this mechanical energy to electrical energy. The output of each
alternator is controlled with an AVR (Automatic Voltage Regulator) that receives information
from the PLC (Programmable Logic Controller). The PLC controls the voltages at 240 V single
phase or 400 V three phase, preventing the voltage from going above or below specification
within the circuits. The engines are fitted with a management system called Gencon Pro II. Its
basic function is to monitor engine temperature, speed, oil pressure and water levels, which
information is sent to the PLC monitoring system.
Now let's have a look at where the Gensets get their fuel from. The Base has six diesel bladders
containing a 100 000 l each. The fuel is called Polar Diesel because of the components that
were added or removed to lower the freezing temperature (cloud point) so that it is still usable in
very cold conditions - minus 500C or even below this. The polar diesel gets pumped from the
diesel bunkers to the Base on a daily basis into the day storage tank, to be available as a
constant supply to the respective gensets.
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June 2011

12. Cooling the engines – and heating the base: one elegant solution
We do not have radiators for
cooling down the engines: we use
heat exchangers instead, which
perform the same function, but just
in a different way. By a multistep
process of heat exchangers we are
able to use all the “waste” engine
heat to warm up our domestic
water: an elegant example of
recycling.
Each engine is equipped with a
water/engine heat exchanger. A
closed loop system of water is
pumped through the engine to cool
it down. This heated water then
circulates through an engine-
water/water heat exchanger, so
that the heated water transfers its
heat to a secondary closed loop
system and returns to the engine
as cool water again. The heat
collected in this secondary water
circuit is still not warm enough for
Base use. It now passes through a
water/exhaust-gas heat exchanger,
drawing off yet more heat.
The exhaust heat recovery process is very
important to the Base and for our survival in
this harsh environment. Instead of just
exhausting the hot gas to the atmosphere, and
losing all the potential heat contained therein,
we first remove the heat from it and this extra
heat is now available to supplement our
heating require-ments. The exhaust-gas heat
exchanger heats the water to about 85 0C.
Finally, this very hot water passes through two
plate heat exchanger systems, one exchanger warming up our domestic water, the other
exchanger warming up water for the Fan Coil units. The Fan Coil Unit systems supply and
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June 2011

13. regulate the air-conditioning in the base
that keeps us cosy in the freezing winter
months.
Although the secondary closed loop
system has now lost heat to the domestic
and fan coil unit water systems, it is still
too warm to be circulated back directly to the heat
exchanger drawing heat off the engine water. Before
it is returned to the engine-water/water heat
exchanger, therefore, it passes through a heat dump
fan in the hangar, where cold air is fanned over the
water and the excess heat dumped in the hangar.
The water in the secondary loop, by giving up its
heat, becomes cool enough to be returned to the
engine-water/water exchanger. The cooling process
is in this way repeated continuously.
Average consumption p/m.
Diesel 24000 l
Electricity Energy 60 000 (kWh)
Water 62 000 l
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June 2011

14. You've got to hand it to us...
‐ by Abi
The view from the Base windows, even at this time of night and twilight, is magnificant. Dark
skies arch vastly overhead, while shadowy ice-plains stretch forever into the wind-blown
distance. Trickles and tendrils of drifting snow curve across the rocks below us. Dusk and cold
are the predominant themes, best appreciated with a cup of coffee snugly in hand, peering out
happily from the comfort of the Base. But occasionally this detached admiration is shattered by
the rude necessities of the job. We have to go outside. The snow smelter needs filling, the
anemometer needs fixing, the dozer needs starting, the vehicle lift needs to be cursed and
glared at... . Outside. Minus 25 and falling. Wind and snow and misery and cold. So, we kit up,
take a deep breath (if we can breathe at all through those balaclavas), and venture forth. Under
working conditions, the hands take the
What do you do with
brunt of the weather, and we have to
plan accordingly.
5 sets of The obvious start to keeping one's
upper extremities warm is gloves. Back
gloves? in Cape Town we were issued with five
different sorts of glove. If any of us, at
that innocent and inexperienced time,
thought that this was a bewildering
overkill, we have since had cause to
learn. Inners, pigskins, mitts... . Each
of them has a different and necessary
function.
The pigskins are thin leather working
gloves. As such they soon
acquire a useful patina of Wabasto-smoke, diesel, various oils, and rusty
varnish from a million spade handles. All this helps cut down the
windchill factor, but even so, more effective measures are needed
when one is not generating a couple
Pig‐
of thousand joules-worth of
finger-warming energy by
hoicking large quantities of snow
skin
from one spot to another with a
hand-held implement. Thus the
s
mitten, which allows one to curl the
Mitt
fingers into a fist and reduce heat-loss
through the palm. Can't work with them, of
course, but at least the fingers don't frost
ens
up. This is very useful when driving skidoos where dextrous
finger-work is not needed but protection against wind-chill is
essential.
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June 2011

15. Then there's something called a “North Polar” which we Southerners find useful as an
alternative to the pigskins. Again an outside leather working glove, with a nice tight ribbed cuff to
stop icy breezes creeping past the wrists. And inners. Inners are self-explanatory: we have a
variety of these for adding that extra layer of warmth while using any of the others, or, in
moments of fine-grip work, by themselves. “Moments” is about all one can manage under usual
conditions here – the fingers start twinging and threaten to fall off if left in only inners for any
length of time.
It becomes evident that there will be occasions when one needs
both warmth and a precision grip. For such occasions, there is
another answer, and that is chemical heating pads or sachets,
made to slip into a glove. Most of us have gone this standard
route and bought commercial sachets, made, we are assured,
with “natural, environmentally-friendly” ingredients. The Grabber
contains iron, water, salt, cellulose, activated carbon and iron; the
Hotties and the HotHands-2 substitutes vermiculite for cellulose. In
a real emergency we could probably shove in some nitrogen and
turn them into tiny bombs, or even flares. They come in nifty little
packets which are easy to carry in one's pocket or back-pack, and
do not self-activate. According to the package blurb, they provide
at least seven hours of heat between 57 and 79 degrees. These
also come in a Toe-warmer form – very useful in those long, still
hours spent driving the dozers about their lawful occasions.
There are a variety of other options. Ruan sourced a heat storage gel-
pack which can be easily activated in the field. These come in engaging
colours, also, so are
especially welcome in the
Tea bags vs Handwarmers long Winter dusk. Paul was
caught warming a stash of
teabags in the microwave
just prior to one outdoor
expedition. The rest of us
are mightily intrigued: does
he have a special tip for us
Easy mistake?...hmm? in the way of tea-leaf hand
warmers? The doctor wants to
do a controlled study to see if
Rooibos or Five Roses teabags are the more effective, but Paul just
doesn't see himself in guinea-pig mode.
But whatever our personal favourites are regarding frostbite prevention
of the extremities, there is an answer which all of us are agreed upon.
The only answer, the one common factor. Nothing, NOTHING, beats a
hot cup of coffee. Freshly ground. At the dining room table.
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16. Page 1 6
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17. Climate Stats: June 2011 SANAE 50 team members
Abigail Paton -Doctor
Pressure Alan Daniels -Diesel Mech (Generators)
Maximum - hPa Beatrice van Eden -Scientist ( Spaceweather)
e
Average Maximum
Average Offl i n - hPa
- hPa Gerard de Jong -Electrical Engineer
Minimum te m - hPa
Average Minimum Sy - hPa Johan Hoffman - Radio Tech ( Dep. Teamleader)
Kevin Van Eden -Scientist ( Spaceeather)
Temperature Paul Lee - Meteorologist (Teamleader)
Renier Fuchs - Scientist ( Particle Physics)
Maximum -1 0.0 ºC
Average Maximum -1 7.7 ºC Ruan Nel - Scientist (HF Radar)
Average -20.9 ºC
Minimum -24.2 ºC S'celo Ndwalane - Diesel Mech ( Vehicles)
Average Minimum -31 .7 ºC
Tiki Jordaan - Mechanical Engineer
Humidity
Maximum 99 %
Average 74 %
Minimum 28 %
Wind
Maximum Gust 60.7 m/s Sunshine Average Day Length 0:00 hrs
(21 9 km/h)
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June 2011