Oceanography – Page 3

Ted the “human dolphin”

If you are of an adventurous disposition then you will probably be interested to learn about Ted Ciamillo’s quest to build a human-powered submarine and use it to cross the Atlantic Ocean. Ciamillo is an American inventor who has previously worked on an underwater propulsion vehicle called the Hydrospeeder (like an underwater motobike). Recently, he has been developing a human-powered submarine that uses a propulsion system based on a dolphin’s tail. Apparently this system is much more efficient than a traditional rigid propellor. So, Ciamillo is building small submarine that is driven by such a tail and powered by pushing leg and arm levers back and forth. He intends to sit in this submarine, clothed in a wetsuit and breathing using some kind of scuba or snorkel system. He will pedal a couple of metres below the surface, coming up at night to sleep in a tent rigged up on the top of the submarine. The plan is to complete the route, from Cape Verde off the west coast of Africa to Barbados in the Caribbean, in 50 days – that’s 3700 kilometres, so his average speed would be around about 75 kilometres per day. Apart from the technological and endurance challenges involved, the idea is that he will be able to make unique measurements of marine life from what will be a very quiet and highly manouvreable craft, so , for example, he may be able to make valuable observations of bioluminescent organisms. A New Scientist article about Ciamillo’s submarine and his planned voyage appeared in Issue 2693 (31 January 2009).

Ocean Gliders

Way back when I was a PhD student one of the big fusses in oceanographic circles was an autonomous instrument platform that was under development called Autosub. Autosub is a fairly large autonomous submarine capable of powering its way through the oceans whilst carrying a payload of oceanographic instrumentation. Everyone was excited about the possibilities that Autosub would provide but it was some time before the plans came fully to fruition (the first science missions were carried out in 1998).

Without wishing to do anyone a dis-service, the story that I heard was that the original calculations of the weight of the required battery packs were wrong and so when the first attempts to build Autosub took place it was impossible to get the whole package to float… only when battery technology had advanced several steps was Autosub able to get back on track. I’ve no idea whether this story is true, but if it isn’t it should be because it is a much better excuse than simply saying that these things take time. Anyway, following six science mission campaigns funded by the Natural Environmental Research Council, Autosub moved onto its full-on wow-factor missions, Autosub-Under-Ice although an Autosub did become trapped beneath Antarctica on only its second mission under ice mission. There is a BBC Radio 4 “The Material World” programme on Autosub that was broadcast just before this incident.

More recently, there have been a number of other developments using autonomous underwater vehicles to measure oceanographic parameters. One such involves a trio of robot gliders that are being used to profile the top 1000m of the Atlantic Ocean between the Canary Islands and west Africa. The measurements are being made as part of the Rapid-WATCH programme (Rapid Climate Change – Will the Atlantic Thermohaline Circulation Halt?) and help to fill gaps in data coverage that resulted from traditional moorings being damaged by trawlers. The gliders, which are under 2m long use a pair of floatation bladders within which oil is pumped to vary the buoyancy and thus cause upward or downward movement of the glider. There are also now plans to use the gliders in the waters off Antarctica and also for a new generation of gliders, so it seems as though the early work, and the excitement this generated back in the late 1980s and early 1990s is finally paying off. There is a New Scientist article (Issue 2684, 29 November 2009) on the gliders being used within the Rapid-WATCH programme.

Energy from the depths

When I started my career as a lecturer in Ocean Science way back in 1993 one of the topics that students often wanted to research for their final year project was Ocean Thermal Energy Conversion (OTEC). This is the name give to the potential to utilise the routine difference in temperature between warm surface ocean waters and the colder water found at depth. The basic idea is to use the warm surface water to heat a specially selected low boiling point fluid (such as ammonia) until it boils and then use the resulting high pressure gas to drive a turbine to generate electric power. The gas is then cooled using cold water pumped up from the deep ocean (at least one kilometre down) to turn it back into a liquid before repeating the whole process all over again (and again, and again…). The principal barriers to generating power in this way are the enormous technical difficulties involved in pumping the cold water up to the surface, building a robust and stable platform to complete the whole process at sea and transmitting the power from the point of generation to the point of use. After a few years in my job OTEC seemed to disappear off the radar as oil prices fell and I haven’t encountered it for 15 years or so. It was interesting then, to read a recent article in New Scientist about the latest attempts to use OTEC. These are based around US military bases in Hawaii and Diego Garcia along with several pilot projects in the far east (e.g. India and Indonesia). The technology still has a long way to go before it realises the kind of potential that its proponents claim it has, but the threat of rising oil prices and a drive for energy independence seems likely to sustain recent interest in OTEC over the coming years. The full New Scientist article appeared in Issue 2683 (22 November 2008).

BBC Radio 4 – The Material World

As a child I grew up in a BBC Radio 4 household. People who know me well might say that this explains a lot, certainly it is probably responsible for the way I talk… Nowadays, with a busy life and a home life that seems to generally involve people rushing about here and there, I never seem to find the time to listen to Radio 4 and this is something that I often wish was not the case because Radio 4 is the home of a huge amount of interesting, funny and informative material. One particularly good programme is “The Material World”, a weekly half-hour offering on science. The format is generally the same – there are two items each getting roughly half of the air-time during which the presenter, usually Quentin Cooper, talks to one or more scientists, engineers or similar beings about a topical issue or piece of work.

Fortunately for people like me who never manage to listen to the radio at home, “The Material World” has its own web-page from which it is possible to listen online to past episodes. It is also possible to download episodes as podcasts (e.g. via iTunes). This is great because not only can you listen to past episodes that look interesting, but you can do so whenever you want! Now that I have set this web-site up I will write about episodes that I think are of particular relevance to oceanography and meteorology as and when they occur, but to start things off I thought I would provide a list of some of the past episodes that I might have included in this way if this site was already up and running. I don’ty pretend to have listened to all of these but they are all episodes that judging by the blurb should be of interest to anyone interested in marine and atmsopheric science. Please be aware that each time you click on one of the links the page for that episode will open in a new window. You can then listen to the episode by clicking on the Listen Again link provided. If any of the links are incorrect or broken please let me know so that I can correct or remove them.

From 2005: air pollution – trees and climate change – coastal wind jets

From 2006: ghost ship – Thames barrier – artifical gills – deep sea fish – gas hydrates – mega plumes – forecasting evolving coastlines(1) – Antarctic Science – solar energy – stratospheric broadband – a new look at the sun – sediment analysis and charting the ocean’s organisms – data logging animals

From 2007: the Thames whale – Scapa Flow – international polar year – El Nino – managing uncertainty in complex models – flood warning – seaside bouquet – Sumatran earthquakes – Arctic sea ice – fish stock extinction – algae(2)

From 2008: deep tropical ocean kelvin waves(3) – plate tectonics – Severn barrage – predicting natural disasters – seaweed and iodine – ocean acidification(4) – the secret seeds of clouds – subglacial lakes – seawater greenhouses – lobster hotels – the deep carbon cycle

(1) featuring my PhD supervisor Professor Alan Davies from Bangor University
(2) featuring Professor Peter Liss from the University of East Anglia, former President and current fellow-Council member of the Challenger Society for Marine Science
(3) featuring Professor Karen Heywood from the University of East Anglia, a postdoctoral researcher at Bangor University when I was taking my MSc and PhD there
(4) featuring Dr Jason Hall-Spencer from the University of Plymouth

Google Oceans

Google Earth has been around a few years now and many people are familiar with it as a tool that “lets you fly anywhere on Earth to view satellite imagery, maps, terrain, 3D buildings, from galaxies in outer space to the canyons of the ocean. You can explore rich geographical content, save your toured places, and share with others” (Google Earth website). Now Google Earth has been upgraded to allow users to view large parts of the ocean floor. Given that oceans cover over 70% of the Earth’s surface, the existing Google Earth had to be upgraded at some point but the addition of ocean seafloor has meant a change from the satellite sensors used to provide mapping information for the land surface to the acoustic sensors that are used by marine surveyors to map the seafloor. Much of the seafloor data has come from the US Navy and this means that there are blank regions in sensitive areas. Google Oceans can be obtained by downloading (for free) the latest version of Google Earth. You can read more about this new facility on the BBC website and at New Scientist magazine.