I believe that I've been threatening to start writing a blog for around half a decade now. Given my recent career change I thought that this would be as good a time as any, communicating the work being done at the Met Office and within my previous career in astronomy. After all, as the joke among other 'extronomers' at the Met Office goes, British astronomers all end up studying the weather because they spend most of their time looking at clouds anyway...
Since starting my new job at the Met Office in November I've been keeping my eye out for reasonably interesting topics for posts, fortunately I didn't have to wait very long. Over coffee with some of my new colleagues I got invited to a seminar on assimilating seals into the Met Office oceanography models. At this point comes one of my first realisations of the differences between Met Office scientists and astronomers. Out of the astronomers I've known, few could have resisted the opportunity here to make a 'Borg' joke and fewer still wouldn't have gotten the joke (mostly based around the key word 'assimilating' but the Borg connection is almost unavoidable once you see the picture above). Around the coffee table with meteorologists of various stripes, I was met with blank stares following my (ok, not very funny) attempt. I guess Star Trek-awareness within the scientific community is particularly high amongst astronomers, who'd a thunk it?
After the somewhat mandatory back and forth (to be repeated by everyone I told about the talk) along the lines of 'seals? You mean like sea lions? - yeah', 'trained ones? - no', 'wild ones - yeah', etc. I decided that this seminar was something I wanted to see. I wasn't disappointed as, of all the talks/lectures/seminars I've attended over the years this was definitely among the best in terms of cool, interesting science and of generally fresh thinking.
The starting premise is that temperature and salinity profiles of the ocean are an important thing for oceanographers, climatologists and the like to know in order to feed and confirm models of ocean currents and the climate generally. This is important for all sorts of reasons, such as how ocean circulation warms or cools parts of the world (like the UK for example) or determining the level of melt-ice in polar regions, important for climate-change and impact studies.
This information has historically been hard to collect and generally has come in the form of 'opportunistic' measurements, such as bathytherm(ograph)s which are dropped from commercial ships or research vessels. There have been large strides in this area in recent years with the Argo network of autonomous floats that spend their lives at sea, surfacing periodically to report their collected data via satellite.
While the Argo floats have substantially increased the amount of data available on the temperature and salinity profiles of the upper 2000m or so of global oceans, there are still many locations where these data are hard or impossible to collect. For example, areas which have large amounts of sea ice are particularly difficult to analyse in an automated way. Particularly in recent years, data on the state and variation of sea ice and the associated ocean water are vital for climatalogical studies. Enter the use of seals - opening up a new measurement system which, although is pretty limited geographically, yields information that would be uncollectable in any other way. While hydrographic profiles from seals aren't going to be available where seals aren't, the places where seals are tend to be inaccessible and so other types of data which might be used instead are pretty much non-existent.
What I found particularly cool was that the data coming from the seals isn't necessarily even intended to be used in meteorological studies. For example, the Sea Mammal Research Unit at the University of St. Andrews started collecting these data in order to study the foraging ecology of elephant seals. This allows them to study the seals behaviour in relation to the ocean conditions as well as differences in population trends. This paper might be a starting point if you wanted to find out more about this connection.
Finally, the use of seals in this way might be objectionable to some people. The seals are tranquilised before the data loggers/transmitters are attached and I'm told that the glue that is used is non-toxic to them and dissolves after six months to a year. It's true that shooting a dart at a seal and gluing a circuit board to their head can't really be described as 'zero impact' but, on a scale from 'none' to 'Loreal' I think that the level of harm to the seals is minimal. The fact that the collected data aid in the study of the seals behaviour and their protection further supports the use of this method.
