Archive for January, 2014

Book review: Brunel by LTC Rolt

January 30, 2014

LTC_ROLTShort review
Excellent read on 2 levels: the actual biography is really enjoyable and authoritative because of Rolt’s access to Brunel’s papers; and the introduction describing how Rolt’s hatchet job of John Scott Russell (the “other” engineer on the failed SS Great Eastern project) is probably unfair is fascinating from a historical/interpretation point of view. Overall, I came from a position of relative ignorance about Brunel’s life and work and was surprised at how unsuccessful Brunel was a commercial engineer (though his innovation is almost unrivalled).

Long review
Somehow, I have now been a lecturer at Brunel University for 3.5 years. It seems like only yesterday that I was starting this blog as a postdoc at the University of Manchester. In those 3.5 years my responsibilities have expanded (at home and at work) so, as I said in my last post, blogging has taken a backseat, which is a shame as I quite enjoy it.

The point of a brief autobiographical introduction is that my knowledge of Isambard Kingdom Brunel’s life and work was relatively low when I took the job here at Brunel University. I knew he was an official, BBC advocated “Great Briton” but that was about it.

I did have a little go at addressing the conflict of being a climate scientist at a university named after one of the fathers of the Industrial Revolution on my work blog recently (and in a talk for the London Science Festival) but I still felt that I really needed to find out more.

So I picked up a relatively old biography – LTC Rolt’s Isambard Knigdon Brunel, first publsihed in 1957 – which is still considered authoritative as Rolt had unprecedented access to the Brunel archive.

I’m glad I did. It’s really well written and has a nice mix of quotes from contemporary documents and descriptions of the engineering projects alongside important personal events. It flows really well too, which is surprising given the temporal overlap of much of Brunel’s work: I’ve tried to summarise this overlap in a little timeline that you can see below.

A timeline of Brunel’s major projects. Bridges and tunnels are shown in blue; railways in black; ships in red; and other projects in green. Start and end dates are not definitive. I’ve washed out the shading where a project continued without Brunel’s intense contribution. Brunel died in 1859.

A timeline of Brunel’s major projects. Bridges and tunnels are shown in blue; railways in black; ships in red; and other projects in green. Start and end dates are not definitive. I’ve washed out the shading where a project continued without Brunel’s intense contribution. Brunel died in 1859.

The timeline also demonstrates how Brunel’s work was very intense (in a relatively short life – 1806-1859) and covered a wide range of areas: tunnels, bridges, railways, ships and other projects.

As an academic, I was quite interested in Brunel’s “impact”. What surprised me was that relative few of his projects were successful commercially. His ships were all failures commercially. The Thames Tunnel was a death trap that was never used for its intended purpose. The Great Western Railway’s legacy is somewhat tarnished by the “Gauge Wars”.

Perhaps this is a harsh summary of his work but it made me feel a bit closer to him: he wasn’t a great businessman but he was a successful innovator and researcher. His ideas were ahead of their time and were difficult to monetise in that period. His longer term legacy was much more important and changed the way that engineering was done globally.

Perhaps the most interesting passages in the book are those relating to John Scott Russell, who worked on one of Brunel’s biggest failures: the SS Great Eastern. Rolt tries to argue that Scott Russell was the villain in that piece and deliberately tried to undermine Brunel’s ship. However, the excellent introduction (by RA Buchanan) highlights some of the flaws in Rolt’s argument and supposes that Rolt’s position was driven by his desire to absolve Brunel of the SS Great Eastern’s failure and was biased by the contents of the Brunel archives.

Overall, highly recommended reading.

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Thunderstorms in the IPCC AR5

January 28, 2014

It’s been a while since I blogged; I hope you didn’t think I’d forgotten you! My workload has “shifted” recently and I’m doing a bit more teaching/supervision/management these days. Blogging has taken a bit of a backseat. So I’m a bit late on this one but thought that it was still interesting. Anyway, enough of the excuses…

I’ve often thought it was odd that the potential changes in frequency and/or intensity of small scale severe storms/thunderstorms – one of my areas of research – was absent from the IPCC TAR, AR4 and SREX.

This has been put right in the IPCC AR5, which was published in late 2013 but, if anything, it highlights some of the problems with the slow and rigidly structured IPCC process.

So here’re a few sentences from IPCC AR5 that deal with severe thunderstorms:

The large-scale environments in which [severe thunderstorms] occur are characterized by large Convective Available Potential Energy (CAPE) and deep tropospheric wind shear (Brooks et al., 2003; Brooks, 2009). Del Genio et al. (2007), Trapp et al. (2007; 2009), and Van Klooster and Roebber (2009) found a general increase in the energy and decrease in the shear terms from the late 20th century to the late 21st century over the United States using a variety of regional model simulations embedded in global-model SRES scenario simulations. The relative change between these two competing factors would tend to favour more environments that would support severe thunderstorms, providing storms are initiated.

Overall, for all parts of the world studied, the results are suggestive of a trend toward environments favouring more severe thunderstorms, but the small number of analyses precludes any likelihood estimate of this change.

It’s a pretty good, concise summary of work in this area up to 2012/13. (I’ve not included some of the text on examples and the few studies outside of the US, you can find the full text here towards the end of section 12.4.5.5 Extreme Events in the Water Cycle. There’s another bit in 2.6.2.4 Severe Local Weather Events as well.)

However, whilst the IPCC report was being published, this paper came out:

Diffenbaugh, N. S., Scherer, M. and Trapp, R. J. (in press) “Robust increases in severe thunderstorm environments in response to greenhouse forcing” PNAS, doi: 10.1073/pnas.1307758110

They say:

We use an ensemble of global climate model experiments to probe the severe thunderstorm response. We find that this ensemble exhibits robust increases in the occurrence of severe thunderstorm environments over the eastern United States. In addition, the simulated changes in the atmospheric environment indicate an increase in the number of days supportive of the spectrum of convective hazards, with the suggestion of a possible increase in the number of days supportive of tornadic storms.

It’s a much more up-to-date and robust analysis of the problem and even uses the CMIP5 climate projections that form the backbone of the IPCC AR5. (I’ve been working on something similar for the Northern Hemisphere but not quite finished it yet!) I guess that this paper must have been accepted for publication after the deadline for the IPCC process so it isn’t mentioned. It’s a shame as a citation to this paper would have added something to the argument.

And this seems to be a problem with the IPCC. Climate science research is a much bigger area now than when the IPCC process started in the late 1980s/early 1990s. So a whole area of research (e.g. severe thunderstorms in a changing climate) becomes a couple of sentences with the most up-to-date paper missing.

As good as the IPCC has been over the years, perhaps it’s time to move on. The SREX example seems to be a good one: a multi-disciplinary, timely analysis of an important area. I think that a series of special reports like SREX would be a better use of valuable time than an AR6.