Archive for November, 2011

Flying Penguins

So I have now completed my first proper watch and I just about feel like I know what I am doing. We did two CTD dips,  the first – a deep test dip to 2300 m – took almost 3 hours. I have done as much of the data processing as possible for the test dips and plotted up some of the data from the deep dip, I will post some of the plots I have produced later.

As we were putting the CTD into the water at about 9.30 am a Hercules Fighter Jet flew past, detouring to see what we were up to. It isn’t the only thing we have had flying round us. There is constantly a crowd of birds gliding above our wake, occasionally swooping alongside, almost daring each other to see who can fly closest without losing a wing tip. These birds are not like any I have seen before. Initially they were almost all giant petrols with wingspans well over a metre, they look like big ducks when they sit on the water as we complete the stations. Most of the giant petrols are black, though they fade as they get elderly. Due to lack of predators these birds can live for about 30 years.  They have Dodo-like beaks and look pretty prehistoric. Through the day the species have been changing, or I have started looking better – there isn’t much else outside the boat! My favourites are Cape Petrols, which look like flying penguins with speckled black and white wings. They are one of the smallest around, though they are probably bigger than British seagulls. Storm petrols look like swifts, gliding along dancing on the waves, confusingly the Black Bellied Storm Petrol has a distinctive white underside.

As my watch finished there were lots of Black Browed Albatrosses – the biggest birds I have ever seen, they can have wingspans of over 3 m. Wandering Albatross, Grey Headed Albatross and the occasional Royal Albatross have also been spotted, though I am still unsure of the differences between the Wandering and Royal varieties – something to do with the tail colour, and one sometimes has a pink blush on the sides of its head. We have bird identification books and binoculars in the lab, which has large windows giving brilliant views of the stern of the ship.

Photos on their way….


Read Full Post »

Pudsey’s Adventure

Today we left the Falkland Islands; we are now sitting about 2 km offshore with a buoy monitoring wave motion out on a 100 m tether. We are staying put until midnight.

When we arrived here, our first station, we performed a test ‘dip’. The CTD was lowered through 45 m of the 54 m water column, sampling water properties on the way. At the bottom we ‘fired’ some Niskin bottles to collect samples of the water. We fired a few more on the way back up. Once the CTD was brought back onto the deck we take samples from the Niskin bottles to test the salinity so we can calibrate the readings taken on the way down. Then we start to process the data collected by the CTD, I’ll talk about this in more details once I fully understand what I am doing! This first station took the CTD down to 45 m below the sea surface, at later stations we will be lowering it to around 4000 m depth. The purpose of this first station was to ensure everything was working and we know what we are doing.

One of the scientists has brought a Pudsey bear along for the adventure. Today Pudsey’s adventure was to go diving! He was attached to the CTD and lowered down to 45 m, luckily we paused on the way back up to fire some Niskin Bottles allowing Pudsey decompression time. Pudsey surfaced happily, but has had to spend the rest of the day tied up outside to dry off!
The rest of the day has been used by the WAGES science team to do some short fetch work – see frictionvelocity for what they have been up to. As soon as we arrived they deployed a long thin buoy over the side on a 100 m tether. They have tried to launch a balloon above the buoy to take photos of the sea surface, the photos are used to monitor the white waves. There was also an altimeter (recording height of the balloon) attached to the balloon, but this went for a swim after the second balloon launch. They did get some photos back, including a few underwater shots.

Read Full Post »

We have unloosed the hawsers, drawn in the anchor and set sail across the wine dark sea…

Read Full Post »

I thought I would have to wait until next (British) spring for any open water swimming blogs, I was wrong. Yesterday I got up close and personal with the South Atlantic in the Falkland Islands.

We went on a day trip to Volunteer Point, a 2 to 3 hour drive from Stanley. The main attraction at Volunteer Point is the colonies of three different species of penguins (see previous blog). Penguins live near and in the sea. Unlike some of the Falkland Islands beaches the sea access at Volunteer Point is not fenced off as potential minefields!

There were two areas where we could access the water, Volunteer Lagoon provided calm waters that could (with the removal of the penguins and addition of a few trees) easily be in the Lake District. The second option was Volunteer Beach, with waves like a north Cornwall beach, 4 to 5 foot breakers. Obviously we chose the latter; the clear green colour of the cold Southern Ocean waters was too enticing.

Whilst looking at penguins I was wearing full waterproofs, a ski jacket, hat, gloves and buff. The weather was bleak – foggy and windy. Stripping down to my costume felt ridiculous so we ran across the dunes and down the beach. Amazingly the sea didn’t feel as cold as I was expecting – but there was a strong rip current. It wasn’t just a dip – we played in the surf for a (short) while until I lost feeling in my feet. The sea felt amazing, and the walk back up the beach after was not as cold as expected and provided some good photo opportunities with the penguins! I was very grateful for the radiator in the hut at the top.

So the largest King Penguin colony in the Falklands is not the only reason to visit Volunteer Point!

As well as swimming I have managed to go on some good runs. From Stanley I went on a 14 km run to see my first penguins at Gypsy Cove, then about the same distance along the sea front the other way the following day. My only complaint is the road surfaces – loose gravel does not make my knees happy. We are now on the JCR in Mere Harbour, part of the military base. Bertha Beach, a few kilometres away, provided an amazing run with dolphins playing in the surf alongside.

Read Full Post »

There are about 20 of us with British Antarctic Survey (BAS) going on the James Clark Ross (JCR) to Rothera. From there some fly back to the UK, some stay on the JCR (me included), some are staying in Rothera for weeks or months, a few are overwintering – spending the next 16 months on the frozen continent. After arriving in the Falkland Islands on Monday afternoon we had free time until
Thursday morning, when we join the JCR to prepare to head South, so we went penguin bothering!

Although I just have a cheap compact camera lots of people have proper cameras; I will add some of their photos when I get them but see frictionvelocity for more in the meantime.

Read Full Post »

20 minutes on a train, 50 minutes on a bus, 6 hours in air terminals, 16 hours on an aeroplane, and 2 new passport stamps later I have made it to the Falkland Islands! So far it looks like the Welsh mountains or Scottish highlands with a few sheep and low level vegetation, but with far less evidence of humans. The roads are a mixture of solid and loose stones, no road markings, many cattle grids, occasional signs. The buildings generally have colourful, corrugated roofs; the vehicles are mostly 4×4’s. It’s cold. Ski jacket, gloves and hat cold – I hadn’t expected that so soon.

Whilst flying over the South Atlantic watching the layers of clouds between me and the ocean and trying to do some atmospheric physics revision, I started thinking about the air right outside the window. Television screens updated us on the flight conditions – including speed, height and local time. The air outside the window was a chilly -56°C.

What would happen if a parcel of air was brought inside? This high up (10972 m or 36000 feet according to the television screens) the pressure is much lower than at the Earth’s surface, so presuming the pressure inside the aircraft cabin is the Earth’s surface pressure, the pressure of the air parcel would increase.

When pressure is increased the temperature goes up – think what happens when you use a bike pump, the valve gets hot due to the pressure of the air being forced into the tyre.

So how much warmer would the air get? Potential temperature can be used to calculate this, it is the temperature a parcel would become if brought (at constant entropy, or energy state) to a reference pressure.

Potential temperature = T(Po/P)^(R/Cp)

Where T=temperature (in Kelvin), P0 = reference temperature, P=initial pressure, R= 287 Jkg-1K-1 (specific gas constant) and cp= 1004 Jkg-1K-1 (specific heat at constant pressure).

I knew T=-56 °C or 217 K, the aircraft height was 10972 m, which (from the US standard atmosphere look-up chart) corresponds to ~225 Pascals. The reference pressure inside the aircraft cabin is assumed to be surface pressure, ~1000 Pascals.

Substituting these values into the equation to calculate potential temperature:

Pot. T = 217 x (1000/225)^(R/Cp) = 332K or 59°C

So, rather oddly, the air outside the window would become uncomfortably hot if brought inside. Luckily this can only ever be a theoretical calculation, the cabin is pressurised, and so switching the air is not possible!

The same principles can be applied to the ocean, just in reverse. Water at depth is at a greater pressure than water at the surface due to the mass of water above it. If a water parcel could be brought to the surface at constant entropy it would lose temperature as its pressure would be decreased.

(Quick Disclaimer – these calculations have not been confirmed by a grown-up scientist… I think they are correct!)

Read Full Post »

I’m off…

Last night I was cooked a delicious ‘Greco-Roman’ dinner included stuffed dormouse* and vine leaves to celebrate my departure, then I got pancakes and Bucks Fizz for breakfast – I think I should go away more often! Now to pack…

* No dormice were harmed in the production of this meal.

Read Full Post »

Older Posts »