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17 September 2000 - A New Season Begins

RRS James Clark Ross Diary

RRS James Clark Ross: Diary entry, 17 September 2000

Noon Position : 38° 50.7' N 17° 46.5'W
Distance travelled since Grimbsy: 1343 Nautical Miles
Air temperature @ noon: 21.7 degrees Celsius
Sea temperature @ noon: 21.5 degrees Celsius

The JCR heading south

Welcome to the 2000-2001 webpages of RRS James Clark Ross and the change in crew and other personnel. It appears that Hamish is off the hook, but I (Pippa) seem to have quadrupled my workload (if not more, for those who know about the arduous duties of the ship's doctor). Many thanks to Dave Gooberman and Simon Wright for all the advice that they left me, and for the great job they have done over the last four months, I'll try to keep up the excellent standard and I apologise now for any errors. The saying "a steep learning curve" doesn't quite describe the enormity of how much I've got to learn. I'll be calling on Andy Barker (BAS Information Technology Engineer) for tons of advice, so thanks in advance Andy, and thanks to the scientists who have kindly agreed to produce the "technical" section each week.

SOUTHWARD BOUND: We left Grimbsy in the early hours of Tuesday 12 September heading for Portsmouth, where we picked up the AVCAT (Aviation fuel for the BAS aeroplanes) to take down south. (Whilst talking about fuel, for those still in crisis, Duncan, (Chief Engineer) advises us that he may have a spare several thousand  litres or so, at a price, so anyone who wishes to avail themselves of this offer just needs to get to us, at our above location!!). RRS James Clark Ross was in good company in Portsmouth, with HMS Victory and HMS Warrior in full view. We set off out through the Solent with a stunning sunset, heading for our next port of call, Montevideo. Since then the weather has remained fair, even some sunshine, so those without sea legs have managed to find them, and those with no suntan are working on it.

Heading out of Portsmouth into the sunset

Everyone seems to have slipped into the normal routine of ship life; watch rotas, maintenance, safety drills etc., and the scientists are already busy, seeming to be up at all hours. Apparently science doesn't stop for anyone or anything. If you're wondering what science an Antarctic-bound vessel can possibly be doing between Grimbsy and Montevideo, Malcolm Woodward (Principal Scientist for the cruise) will explain. Enough for me to say that no opportunity for research is ever missed. The passage to Montevideo involves an international team of scientists for the Atlantic Meridional Transect (AMT) cruise, and I have yet to work out what the common language is (Spanglish).

SCIENCE: (from AMT core scientists) The Atlantic Meridional Transect is an on-going oceanographic research programme to measure physical, chemical, biological and optical properties of the upper 250 metres of the water column along the transect of the north and south Atlantic oceans between the UK and Montevideo. This programme should further our understanding of marine ecosystems over broad spatial scales and demonstrate the role of the world's oceans in carbon cycling.

Vas deploying the CTD The core AMT science is scheduled to use up to 48 hours of science time during the duration of the cruise track from the UK to Montevideo / Falkland Islands. There will be two daily casts of the CTD (Conductivity Temperature Depth profiler) with fluorometer, transmissometer and light sensors. Firstly, a pre-dawn CTD  cast for primary production studies and for oxygen production and respiration. There is then the ‘standard’ AMT CTD at approximately 1100 GMT.

Claudia and Graham deploying optics rig FRRF Sampling will be from up to twelve depths with ten-litre Niskin bottles to a maximum depth of 250 m. An example of the depths of the bottles is:  six depths sampled above the 1% light irradiance depth, including the sub-surface chlorophyll maximum, then three across the thermocline and three in the sub-euphotic zone.

Scientific rationale (for the scientifically minded): AMT-11 will combine the now standard suite of measurements (chlorophyll, POC/PON, nutrients etc.) carried out previously, but with new measurements to enhance this data set.The nutrient autoanalyser on board will be used to analyse for micromolar concentrations of nitrate, nitrite, silicate, phosphate and ammonia. A fluorimetric analyser for the analysis of nanomolar ammonia concentrations will also be used during the transect. New analytical systems for nanomolar phosphate, nitrate and nitrite will be field trialled. Urea will be added to the suite of nutrients measured.Experiments involving on-deck incubation of surface seawater samples will determine the breakdown of Dissolved Organic Matter (DOM) with specific interest in the nanomolar ammonium and nitrite concentration changes.

There will be 2 FRRF (Fast Repetition Rate Fluorometers) deployed and these link with the light field and ocean colour studies carried out on previous AMT cruises, together with the ocean ground truthing studies for ocean colour and the SeaWiFs satellite. Fine scale investigations will take place around the nutricline and the relationship of the nitrate and the fluorimetric signals will be studied. Plankton production and respiration will be determined in close collaboration with the Spanish scientists. We will be studying the percentage of photosynthetically fixed carbon available for export and that available for return to the atmosphere as carbon dioxide. There are relatively few measurements of respiration and the data that are available tend to have been collected during blooms of larger celled algae. This paucity of representative data may be the cause of the recent contentious suggestion that respiration exceeds production in unproductive aquatic systems.

We will be hearing from the other scientists aboard over the next few weeks.

Russell protecting himself from Claudia's high pressure hose
Russell protecting himself from Claudia's high pressure hose.

Weekly diary entries