18 May - Heading North
RRS James Clark Ross Diary
Noon Position: 40° 10.7 S, 40° 57.7 W)
Distance Travelled since Grimsby: 36379.5 Nautical Miles
Air temperature @ Noon today: 13.8°C
Sea temperature @ Noon today : 16.8°C
Weather: Good, WSW, 5, 1018.8
The long road home
With a fresh crew, fresh scientists, fresh strawberries and full of fuel, we slipped gently away from FIPASS on Monday. The JCR passed through the Narrows for the last time this season and leaving Port William, turned north for the first time this year. The Falklands disappeared behind us, under a gorgeous sunset that brought down the curtain on our southern activities and saw us heading north to start AMT 12, a science cruise that will take us all the way home to sunny Grimsby in around 5 weeks time (Hooray! - Doc).
Above: Leaving the Falkland Islands and heading north. Click the images to enlarge them.
Alongside FIPASS when the JCR left was the fisheries protection vessel, Sigma, that had just returned from the fishing boat debacle that had occurred at South Georgia. It was carrying a large number of Korean fishermen back to Stanley so they could fly home. Being painted a similar red and white colour scheme as the JCR it looked like a baby brother of the JCR.
Above: Left: Sigma. Right: RRS James Clark Ross. Click the images to enlarge them.
Heading straight out into the South Atlantic, the JCR headed ENE and found a large swell coming in from the west. This meant a rocky few days for all our new scientists who had still to find their sea legs. There were a few people who had a distinctly green tinge to them for a few days and kept a low profile. Our biggest roll was about 30° each way, which tested how well all the new gear was lashed down!! The sharps bin in the surgery flew across the room and scattered sharps all over the floor and it resembled a Falkland Islands minefield until it was carefully cleared up. Fortunately by Friday things had settled down and everyones smiles had returned as the sun came out. Spirits rose as the weather improved and the scientists were getting into the swing of their proper science after a few test runs.
Paul Clarke got very excited around Saturday lunch time as he eagerly listened to the FA Cup Final on BBC World Service. An avid Saints fan, Paul was showing his support for the team by flying the flag off the bridge. Deluded by a previous night's dream in which Southampton won, he was full of confidence prior to the match. Willing the south coasters on, his psychic encouragement was not enough as Pires netted Arsenal's winner in the first half. Southampton then hung on for a creditable defeat and Paul disappeared for the rest of the day.......
Despite the bad weather we have had a chance to celebrate lots of birthdays this week. Colin the bosun, Tom the 4th engineer, Elena the zooplankton expert, Malcolm the top nutrient analyst and Mark the ETS engineer all had birthdays this week resulting in a social start to the cruise. Below are from L to R, Elena, Tom, Malcolm and Colin. Click the images to enlarge them.
We have a few more coming up in the next few weeks so it should prove to be a very sociable cruise!!
On Thursday night the JCR was lucky to see some interesting celestial activity. A large crowd had dragged themselves onto the bridge wing to see, at approximately 2230 local time on a clear cloudless night, a blurred shadow covering one side of the full moon. This was followed at 2303 by a much darker and semicircular shadow passing slowly across the face of the moon. The darkness had reached halfway by approximately 2335 and the moon was completely enveloped in shadow by 0014 on the 16th May. At this stage the moon was noted to be still visible but with its brightness much reduced allowing many more of the surrounding stars to be visualized (which appeared to have greater luminescence than the eclipsed moon). The surface markings of the moon could still be observed with binoculars but the surface was noted to be a dull copper colour. The eclipse was visible for several hours and the moon was noted to be fully visible by 0217. During the entire eclipse the James Clark Ross was on course 038° at 12 knots and midnight was at position 44 56 03S. 40 15 02 W. Below is a representation of what it actually looked like.
Atlantic Meridional Transect No 12. (AMT 12)
As many of you are aware the good ship James Clark Ross has been making the annual pilgrimage (down to Antarctica in the Autumn and back to the UK in early Summer) every year for the past 12. So to make good use of this time the Atlantic Meridional Transect was organized.......
AMT - the history
In the mid 1990's, satellites were launched to study the oceans from space, producing some of the images seen below. They measure variables such as sea temperature and colour, that have important effects on the life of the ocean. However, the satellites needed to be calibrated across a wide range of sea conditions so that scientists could make sense on the images that were sent back from space. The JCR travels each year between the Falklands and the UK, from cold sub polar regions through the tropics to Northern Europe and so provided the ideal platform to take measurements over a wide range of sea conditions. Also a significant fact is that because the ship had to do the cruise anyway, it was cheap for the scientists to come onboard and hitch a ride. So during the 1990's a total of 11 AMT cruises were completed with a wide range of oceanographic scientists onboard sampling the sea water as they went. Most cruises were between the Falklands and UK but one lucky cruise went via Cape Town. Funding ceased and the AMT cruises stopped for a few years..........
AMT - the present
A multidisciplinary team from 7 oceanographic centres, mainly based in the UK, have collaborated to restart the AMT programme. Funded through NERC (National Environmental Research Council) the team will be conducting studies over the next 5 weeks over a wide range of areas. A total of 28 scientists and support staff are onboard, including 12 graduate students, who have crammed the with ship with more technology and sampling equipment than anyone thought possible. Every lab is crammed with gear ready to go.
AMT - the future
AMT is funded for 6 cruises over 3 years and so will be conitinuing to conduct science each time the JCR finishes or starts an Antarctic season. The PhD students will be researching for their degrees over the next few cruises.
AMT - the advantage
The wide variety of oceanographic expertise available on the cruise and the contrasting backgrounds and experience of the team in such a small space will allow 'cross-fertilization' of ideas between the different individuals, different research areas and different institutes. It will also allow a new generation of oceanographers experience at sea and allow them to make measurements of the widest possible range of parameters. The long AMT transect also passes through such a vast spectrum of ocean conditions and areas that it will give an insight into a huge ocean space and allow analysis on a macro scale.
The image below reveals the cruise track that we will be taking back to the UK and the amount of phytoplankton in the water. This satellite image demonstrates the low levels of phytoplankton in the water in the tropical regions (dark blue) compared to those around Europe, Eastern North America and Brazil (yellow/green). It is really meant to illustrate the variation in levels of primary production throughout our journey back the UK. Click the image to enlarge it.
AMT - the aim
The aim is simple - Measure the quantity, variation and interactions of phytoplankton in the ocean.
AMT - WHY?
- Phytoplankton are the main driver of the food web and they supply the energy for all the other animals and bacteria in the sea and so it has a major effect on all organisms in the sea.
- There is such a huge amount (biomass) of phytoplankton that it has a major effect on both light and gases above and within the ocean.
- The oceans remove roughly half the carbon dioxide from the atmosphere. Understanding the behaviour of this important green house gas is crucial in climate models that tell us about global warming. Since the ocean plays an important role we need to understand its dynamics to make accurate predictions.
- Many of the gases diffuse in and out of the ocean, to and from the atmosphere. These again play a role in global warming and climate control and are affected by phytoplankton.
The central theme to the AMT cruises is improving oceanographic knowledge to allow accurate global climate modelling. NB: This is also a key theme in most of the research the JCR has performed this year!
AMT - the basics
Each day we will be taking two sets of samples at 4 am and 11 am, sampling the ocean from the surface down to about 1000 m. This is so that one station is taken in daylight and the other at night. The nightime station will be investigating growth of phytoplankton in various experiments whilst the daylight samples will correlate with the time orbiting satellites are overhead and allow their calibration to take place. The rest of the day is spent analysing the water onboard for various nutrients, minerals and phytoplankton. Experiments will be performed investigating nutrients in the water, the optical properties of the water and looking at dissolved and atmospheric gases. Hopefully in the next few weeks I'll write a little bit more about each one.......
I'll leave you with a satellite image of the ocean temperature. You can see that we are sailing into warmer waters and it will soon be time for sundowners in shorts again (not a moment to soon - Ed). Click the image to enlarge it.
The Zapiola Ridge and all that....
In March 2002 a couple of US/German satellites called GRACE were launched into space. They orbit the earth 220km apart from one other and 500km above the surface of the earth. They can very accurately measure the distance between themselves using a microwave link to 10 micrometers (thinner than a human hair!). The point of this was to record the minute changes in gravitational field on earth. With clever calculations the bottom pressure of an ocean can then be calculated. Bottom pressure (no coloproctology jokes please - Ed), can tell you all sorts of things about oceanic water movements.
So where does the JCR get involved? The problem is that the satellites only pass over each part of the ocean every 30 days. However there are changes in water pressures (barotropic changes) that occur more frequently. So what, you may say, but it means that the measurement of these short term effects is very difficult to measure. It is all very complicated but is something to do with sampling error and so calibration is needed.
Last year Proudman Oceanographic Laboratory Technicians dropped 3 small buoys over the side, which sank to the seabed and recorded the bottom pressure there. The three bottom pressure recorders were placed in a triangle around a prominent seabed feature.......the Zapiola Ridge.
This prominent sea mount is in the Argentine Basin where a short term, approximately 25 day, cycle of barotropic changes is present that the satellites have difficulty in being able to recognize. The JCR track is seen as the red line on the above chart with each of the 3 buoys marked as POL1-3. Two of the three buoys were recovered by acoustically releasing them from the seabed and collecting them once they had floated to the surface. The two buoys successfully recovered were moored at a depth of 5100m and so take several hours to float to the surface. The deepest buoy was at 5500m but no contact could be made with it and so recovery proved impossible.
What is the point? The whole aim of these buoys is to provide data on the short cycles of barotropic changes that are seen around the Zapiola Ridge. This information can then be integrated into the GRACE modelling system to allow the satellites to 'see' these short term effects that it cannot currently observe elsewhere in the world.
What does it all mean? It means that Geoff Hargreaves, who has been sent down to pick them up, had the biggest smile ever seen onboard when he had recovered his little babies!
Thankyou this week: to all the birthday babies
Coming up next week: warmer weather and a few miles closer to home!!