Page 1June 2011

JUNE2011 Halfway Home & Happy Mid‐Winter!

Mid‐Winter Weather

Base Power Source And Heating

You've Got to Hand it to Us

Page 2June 2011

“In research stations throughout Antarctica, Midwinter is widely celebrated as a way to mark thefact 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!] offwork”. (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 thatGreetings Cards and Invitations are issued amongst the 40-odd Over-Winter Bases all over theContinent. We must admit that we would be severely startled if the Germans, say, did actuallypitch 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 nonsenseand there he was at 07h45, peering earnestly at the pitch-black sky and intuiting he could seesome cirrus cloud or whatever out there). The plan for the day? - a leisurely start, easing intothe Pull-Up Competition, Dozer-Runs followed by dips into the sauna for those who could handleit, then cooking a mighty meal, and lastly – the highlight – drinking the mighty meal. And eatingthe odd tidbit, as well.

Although the term “Winter Solstice'suggests a day of freezing darknesswith blustering snow and icy winds,this was not the case. Our weatherwas good (see p.6), and althoughthere was no direct sunlight, therewere a few hours of bright twilight;enough for us to get outside prior toany scheduled activity. A little photo-shoot on the roof, just to show howdark it isn't. The perennial Smelly:work does go on, after all...

Half‐way home! And Happy Mid‐Winter!

Page 3June 2011

The Pull-Up competition was the first major event of theday. Why a pull-up competition goodness only knows.This is something Renier and Paul cooked up betweenthem. The entire team assembled in the gym, bets andcounter-bets offered in interested undertones by thenon-contenders as each aspirant stripped his jacket offand showed his form. Chances were evaluated on theweight-strength ratio of each individual. Serious moneywas on Johan – slender but strong. Serious money got itwrong. Not that he didn't perform credibly, but S'celocame in from behind and showed us what real strengthis. 17 pull-ups straight, he acheived. Renier did well with16, Paul showed what climbers are capable of with 15,and Johan managed 14½. Those of us who were notmourning having betted away our entire night's wine andbeer then went for the dozer run. This involves – forSANAE 50 at least – scampering down BC link stairs,across the sastrugis, around the dozers, and backagain. Clad in costume, with footwear optional. Thenwarming 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 allsorts of people phone us to wish us well – anybody from Radio Stations to previous team

members. Paul was unanimously elected as spokesmanwhen Heart FM phoned us, but the rest of the team took itin turns to answer the phone and chat to the various well-wishers.Our most valued call came from Marten du Preez. Martenwas a member of SANAE 1 in 1960; the very first SouthAfrican expedition to Antarctica. Marten was the radiotechnician. He returned to Antarctica in 1962 as TeamLeader for SANAE 3, and was a honoured VIP in 1997,when he was invited to the opening of the SANAE IV Base.

Page 4June 2011

He is a keen radio ham with the call sign ZS6ZY, and as such is a friend of Gerard, ourelectrical engineer, himself a keen HF man.Although Mid-Winter is usually thought of as a Christmascelebration, we had neither turkey nor ham readilyavailable on Base, so the food was an eclectic mixture ofteam specialities: Tiki's garlic bread, Alan's spiced rice,Paul's stir-fried vegetables, Beat and Kevin's succulentroast lamb, and a very special hand-crafted (instant)cheesecake imported by Renier for the occasion – just afew of the dishes presented.

So we have passed the half-way point. The Sun is returning, the ship is returning, we will soonbe returning Home again. But there's still seven months to go, and we still relish every day ofour life in the icy embrace of Antarctica.

Author: Abi

Page 5June 2011

Page 6June 2011

Page 7June 2011

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 necessari ly 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 7.20C,

fluctuating between a maximum of

-1 3.80C and a minimum of

-20.60C. However, the mercury

had fal len to –31 .70C on the 8th of

the month, marking the coldest

temperature for June. The

average temperature for the

whole month was -20.90C.

In the mid latitudes of South Africathe lowest temperatures of the year tend to occur after the solstice. A well defined Winterminimum is usually apparent toward August-September, towards the end of Winter. This is not thecase in the Antarctic, where heat loss occurs earlyand rapidly, and Winter temperatures tend to beeuqal throughout the period. Here there is also aclear asymmetry in the time span of Winter andSummer. The term “Coreless Winter” depicts astable non-fluctuating winter temperature that variesonly a few degrees between the onset and closure ofthe winter period, during which polar temperatures donot continue to fall during the long winter period. Thelatter is very short - between December andFebruary at SANAE. This short duration has earnedthe name “ Pointed Summer” as a descriptive title.

Johan does a weather station check

Page 8June 2011

But there can be a large difference between actual (dry bulb) temperature and apparenttemperature. Our average dry bulb temperature in June was -20.90C. Actual or dry bulbtemperature 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 loseheat. In the Antarctic with its continuous winds, the cooling effect of the wind (“wind chill”) issignificant, and the very low humidity also contributes to a rapid loss of heat by aidingevaporation. “Apparent temperature” is the term used for that measurement which factors in therelative humidity (called “heat index” in tropical countries) and the wind chill. Wind chill is theextra cooling effect felt on the skin due to wind, and is calculated using wind speed and dry bulbtemperature. There are intricate formulae used to derive the apparent temperature (e.g. Windchill temp. = 35.7 + 0.6215T - 35.75V0.16 + 0.4275TV0.16). At SANAE, we just take what thecomputer says on trust! Apparent temperature is highly significant to us, as this, and not dry bulbtemperature, determines the likelihood of cold injury and frostbite. So on Mid-Winter's Day, thewind was on average 31 kph and the dry bulb temperature around -17.20C. In thesecircumstance 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 bl izzard 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 typical ly peaked at

1 30 kph. So 21 8 kph is

clearly an outl ier. 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 gl itch

and concluded it was a

rel iable reflection of events.

Our conclusions were aided

by another anomaly occurring

simultaneously - the breaking

of the anemometer propeller.

This piece of equipment is rated for extremes of wind and temperature, and it took something

really out of the norm to cause this fai lure. 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 windsOf course, Antarctica is notorious for its winds. As they say, “when the wind stops blowing, the

penguins fal l over”. The question is why is the wind such a feature here. One reason is

topography, causing “inversion winds” – winds that blow in l ine 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 Coriol is force - a

rotational ly 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 1 300 direction: the

wind blows mostly from the South-East to the

North-West.

Katabatic WindsWe have also a second and more drastic

wind event, cal led “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.

Page 9June 2011

Snow, drifting snow and blowing snow and what’s the difference anyway!Wind is a menace not only in its abil ity 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 curtai l 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 l ifted snow varies with wind speed, increasing exponential ly, but other factors

also play a role, such as surface roughness, which increases turbulence, or surface freezing,

which restricts l ifting. When winds speed attains a moderate 5 ms-1 it wil l start to l ift snow

marginal ly. I f the l ift 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. Visibi l ity 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 fal l ing snow.

SANAE weather office recorded fal l ing 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 stabil ity

and accretion and is closely related to global cl imate

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 fal l ing

precipitation. I t 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 wil l 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 al l of us took. At the same

time, we did not have to feel cheated by our tame Mid-

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. . . .

Page 1 0June 2011

Renier: "Nice Day for a tan! "

Page 11June 2011

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 l itre)

produces 55 kW at 6200 r/min. The S.A.

Agulhas produces 4476 kW.

Our generator engines have an electronicgovernor that controls the fuel supply toeither increase or decrease the engines’

power output, depending on the load required. Each engine is coupled to its respectivealternator that will convert this mechanical energy to electrical energy. The output of eachalternator is controlled with an AVR (Automatic Voltage Regulator) that receives informationfrom the PLC (Programmable Logic Controller). The PLC controls the voltages at 240 V singlephase or 400 V three phase, preventing the voltage from going above or below specificationwithin the circuits. The engines are fitted with a management system called Gencon Pro II. Itsbasic function is to monitor engine temperature, speed, oil pressure and water levels, whichinformation 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 bladderscontaining a 100 000 l each. The fuel is called Polar Diesel because of the components thatwere added or removed to lower the freezing temperature (cloud point) so that it is still usable invery cold conditions - minus 500C or even below this. The polar diesel gets pumped from thediesel bunkers to the Base on a daily basis into the day storage tank, to be available as aconstant supply to the respective gensets.

Page 1 2June 2011

Cooling the engines – and heating the base: one elegant solutionWe 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 sti l l not warm enough for

Base use. I t 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 al l 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 850C.

Final ly, 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

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 sti l l

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 lElectricity Energy 60 000 (kWh)Water 62 000 l

Page 1 3June 2011

You've got to hand it to us...‐ by Abi

The view from the Base windows, even at this time of night and twil ight, is magnificant. Dark

skies arch vastly overhead, while shadowy ice-plains stretch forever into the wind-blown

distance. Trickles and tendri ls 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 fi l l ing, the

anemometer needs fixing, the dozer needs starting, the vehicle l ift needs to be cursed and

glared at. . . . Outside. Minus 25 and fal l ing. Wind and snow and misery and cold. So, we kit up,

take a deep breath (if we can breathe at al l through those balaclavas), and venture forth. Under

working conditions, the hands take the

brunt of the weather, and we have to

plan accordingly.

The obvious start to keeping one's

upper extremities warm is gloves. Back

in Cape Town we were issued with five

different sorts of glove. I f any of us, at

that innocent and inexperienced time,

thought that this was a bewildering

overkil l , 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 mil l ion spade handles. All this helps cut down the

windchil l factor, but even so, more effective measures are needed

when one is not generating a couple

of thousand joules-worth of

finger-warming energy by

hoicking large quantities of snow

from one spot to another with a

hand-held implement. Thus the

mitten, which allows one to curl the

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

up. This is very useful when driving skidoos where dextrous

finger-work is not needed but protection against wind-chil l is

essential .

Page 1 4June 2011

Mittens

What do you do with5 sets ofgloves?

Pig‐skins

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 al l one can manage under usual

conditions here – the fingers start twinging and threaten to fal l off if left in only inners for any

length of time.

I t becomes evident that there wil l 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 sl ip into a glove. Most of us have gone this standard

route and bought commercial sachets, made, we are assured,

with “natural, environmental ly-friendly” ingredients. The Grabber

contains iron, water, salt, cel lulose, activated carbon and iron; the

Hotties and the HotHands-2 substitutes vermicul ite for cel lulose. In

a real emergency we could probably shove in some nitrogen and

turn them into tiny bombs, or even flares. They come in nifty l ittle

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, sti l l

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

especial ly welcome in the

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 mighti ly intrigued: does

he have a special tip for us

in the way of tea-leaf hand

warmers? The doctor wants to

do a control led 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.

Page 1 5June 2011

Tea bags vs Handwarmers

Easy mistake?...hmm?

Page 1 6June 2011

Maximum

Average Maximum

Average

Minimum

Average Minimum

Climate Stats: June 2011

Maximum

Average Maximum

Average

Minimum

Average Minimum

Maximum

Average

Minimum

Maximum Gust Average Day Length

- hPa

- hPa

- hPa

- hPa

- hPa

-1 0.0 ºC

-1 7.7 ºC

-20.9 ºC

-24.2 ºC

-31 .7 ºC

99 %

74 %

28 %

60.7 m/s

(21 9 km/h)0:00 hrs

Abigail Paton -Doctor

Alan Daniels -Diesel Mech (Generators)

Beatrice van Eden -Scientist ( Spaceweather)

Gerard de Jong -Electrical Engineer

Johan Hoffman - Radio Tech ( Dep. Teamleader)

Kevin Van Eden -Scientist ( Spaceeather)

Paul Lee - Meteorologist (Teamleader)

Renier Fuchs - Scientist ( Particle Physics)

Ruan Nel - Scientist (HF Radar)

S'celo Ndwalane - Diesel Mech ( Vehicles)

Tiki Jordaan - Mechanical Engineer

SANAE 50 team members

Pressure

Temperature

Humidity

Wind

Sunshine

SytemOffline

Page 1 7June 2011