I was born and brought up in North Wales until the age of eight, when my family moved to the Sultanate of Oman. I spent four and a half years at school there at the British School Muscat, before going to Malvern College in Worcestershire for five years. During that time my family left Oman and moved to Santiago in Chile. After Malvern I went to St John's College, Cambridge to read Natural Sciences, obtaining a 2.1 in Astrophysics in 2005. I then moved to Linacre College, Oxford to do a DPhil in Physics based at AOPP, which I completed in December 2009. This was followed by a short stint at the Centre for the Analysis of Time Series at the London School of Economics, before moving back to Oxford to start a post-doc position in the Geophysical and Planetary Fluid Dynamics group in AOPP. I married Julia Angell in August 2009, who is a Speech and Language Therapist, and we lived in Wolvercote until 2017, and then in Évry near Paris until 2019. My family is based near Conwy in North Wales, so I spend time there as well. I have a sister, Lucy.

I am a Fellow of the Royal Astronomical Society, an Associate Fellow of the Royal Meteorological Society, and a Member of the Institute of Physics.

In my time at Malvern and Cambridge I spent a lot of time involved with rifle shooting, which took up much of my time outside of school/university. When I moved to Oxford I turning my attention to fencing and cricket instead. In days gone by I have also been known to play the trombone and piano. These days I spend what spare time I have involved in tabletop wargaming and painting, and I also enjoy having two pet dogs, Django and Scout.

A miscellany of useful technical / computing things and links I have found useful

Not updated for some time!

Commenting: some LaTeX classes don't have a selective comment (i.e. ignore text) command. This can be rectified by putting \newcommand{\ct}[1]{} at the top of your document; any subsequent text placed within \ct{} will be ignored by the compiler.

Derivatives can be contracted by using the following custom commands:
Full, first derivative: \newcommand{\fd}[2]{\frac{d #1}{d #2}}
Full, second derivative: \newcommand{\ffd}[2]{\frac{d^2 #1}{d #2^2}}
Partial, first derivative: \newcommand{\pd}[2]{\frac{\partial #1}{\partial #2}}
Partial, second derivative: \newcommand{\ppd}[2]{\frac{\partial^2 #1}{\partial #2^2}}

The Comprehensive LaTeX Symbol List: A list of all the symbols you could ever think of with their LaTeX commands, and then some more.

A shorter list of symbols

Various LaTeX guides are here and here.

The Comprehensive TeX Archive Network - first place to look for packages to download.

BibTeX document types

JabRef reference manager for BibTeX. Much more user-friendly than typing in all the syntax yourself, and easy to manipulate large sets of references at once. Works under both Windows and Linux.

KBibTeX is also a good GUI for BibTeX documents.

TeXnicCenter (Windows) and Kile (Linux). Two good GUI frontends for LaTeX editing.

Conditional compilation: this is useful for example when you need to include different versions of the same figure for online and print versions of a paper (usually one in colour, one not). Insert the following before the \begin{document} command:

Then in the main part of the document, wherever you need only one option to be compiled, use

\ifthenelse{\boolean{onlineversion}}{ONLINE version content}{PRINT version content}

Only the online content will appear. To get the print content to appear, set the boolean onlineversion to false.

A presentation class to use with LaTeX (pdflatex, to be precise). It can be found here. I think the presentations made with this package look a lot more professional than PowerPoint (I can't comment on Apple's Keynote, as I have never used it). Particularly neat is the ability to place bars along the top and bottom of the slides which allow the audience to see at a glance where you are in the presentation. As with all things LaTeX, it is somewhat fiddly to start with, but I feel it is worth the effort.

I have found that when IDL figures are used in presentations they usually look grey and are hard to see. This is because the lines are too thin when printed to the .ps format. To get around this, add the following line to the plotting code:


The result looks weird when displayed within IDL, but much better than the default when used to output as postscript.

There is a useful list of IDL colour tables here.

TeXtoIDL: routines to include LaTeX syntax in plots, etc.
IDL colour bars
A Library of IDL Programs by Daithi Stone.
Functional list of IDL routines

Special Characters in bash

One-liners in csh, awk, and sed.

Alan Iwi has a page with a lot of useful UM information here. In particular, the file utilities and parallel installation guide are very useful.
xconv / convsh - software for file manipulation and conversion

Panoply - netCDF viewer created by NASA for geo-gridded data.
VAPOR: Visualization and Analysis Platform for Ocean, Atmosphere, and Solar Researchers.

Some comments on presentation technique

27 April 2007
Updated 2 September 2011

Having attended 97 talks over five days at the 2007 European Geosciences Union General Assembly, I now feel suitably qualified to identify some things that make a good talk, and some things that make a bad one. The most surprising thing I learned at the conference was that speakers don't necessarily bring their 'A-game' to international conferences, in terms of presentation technique and preparation. More experience ⇒ better presentation is definitely not a general statement; many poor talks were given by speakers whose experience would lead you to expect otherwise. True, many were presenting in a foreign language, but you will see below that most (but not all!) of the points relate to slide and talk structure, rather than oratorical style. Every example of 'poor' technique noted below was made at least once.

Presentation preparation depends primarily on (1) the target audience and (2) what the speaker wants to get across. These notes were compiled from attending talks at a conference covering many different fields. The typical audience member could therefore be assumed to be interested and intelligent, but not necessarily an expert (similar to the audience at a departmental seminar, for example). The notes below apply primarily with this audience in mind; the approach will differ when the audience is one's research group, for example.

Beamer is a presentation class for LaTeX. In my opinion, it looks more professional than PowerPoint; an example presentation can be found here. It is a bit fiddly (like everything in LaTeX), but I think the results are well worth the effort.

Oh, and I'm sure I am guilty of some of these things too - please tell me if I am, otherwise I will never improve!

Some 'schoolboy' errors...

  • Face the audience! If you must face the screen, at least point your feet towards the audience and turn your head towards the screen.
  • If a microphone is available and you have a sore throat, use it!
  • If something can be said simply, say it simply. Leave out as many unnecessary technical details as possible (e.g. names of model variables).
  • Try to avoid using the words 'obviously' or 'clearly', or words to that effect, as you can be guaranteed that at least one person in the audience will think it is neither.
  • Use a large font size on axes. The plot and axes labels should be as large as the main text in order to be seen from the back of the room.

General points:

  • Spend at least one minute on each slide - it takes that long to read and take in most slides, and some people may be taking notes.
  • If you are going faster than your normal speaking speed, there is too much material.
  • Put the most important parts of the slide in the top half - the audience seating may not be stepped and the screen may not be raised.
  • Speak loudly, smile and be generally enthusiastic. If you look bored, or come across as confused, arrogant or unconfident, your material will appear so too.
  • A colourful title page gives the audience confidence that the rest of the talk will be interesting.
  • Not every slide needs a title.
  • If a movie doesn't work when running through the presentation beforehand, make sure you have an image or two to replace it. Going to a new slide mid-presentation and finding that your movie doesn't work looks rather amateurish. To avoid this, use your own laptop if possible - try to avoid using the provided hardware as inevitably something won't work.
  • If you have many slides you know you won't use, remove them (for example, if the presentation is a shorter version of an earlier one).
  • A conclusion / summary slide at the end is essential.
  • Humour can work, but only in context...

Some things I saw which worked well:

  • Leaving up a page of references as the final slide, while questions are asked.
  • Linking to subplots relevant to only part of a diagram by clicking on that part of the diagram.
  • Comparisons with familiar concepts, e.g. comparing the size of Antarctica with the relative positions of European cities.
  • If the main focus of the talk can be posed as a single question, pose and answer that question as part of the introduction, before expanding on it. This is instead of building up to the answer, as people will eventually forget what the question was, and any impact will be lost.
  • If your presentation style is a bit 'off the wall', the audience will stay interested for longer, and will be more likely to remember your talk afterwards...
  • Flow charts work well, as long as they are built up sequentially and not displayed all at once.
  • If displaying a large matrix (particularly a matrix of data), use a contour representation of the numbers instead of a table, unless the matrix is very sparse.
  • Lists are usually OK and can be used effectively (e.g. the ExoMars payload list by priority for a number of different funding scenarios).

Things to avoid:

  • Complete paragraphs / covering the slide with text (probably 40-50% of speakers were guilty here). However, lots of text sometimes works if you know that your spoken English isn't very clear.
  • Equations. Only include equations if absolutely essential or very simple - replace them with images or words if at all possible. Usually equations serve to confuse rather than clarify, and anyone sufficiently clued up with the subject to understand the equations in the time spent on the slide will know them already.
  • Abbreviations, unless you are sure they are part of that particular audience's common knowledge (e.g. NASA, EGU), as people will forget them (maybe put the full version in small text at the bottom of the slide).
  • Overrunning - people moving between rooms at a multi-session conference are relying on talks finishing on time, in order to get to the next talk before it starts. If you have something groundbreaking to say then this can be relaxed, but if so it should have been put earlier in the talk! Most of the audience won't remember the details, and will resent you for overrunning and for cutting into the time available for questions.
  • Tables, unless they are 2x2 - even 3x2 tables are difficult to follow with other things on the slide. If nothing else is on the slide, however, then slightly larger tables can work.
  • Slides with multiple but very similar plots, without explicitly stating the difference between them. You need to say how the parameters change between plots (i.e. why there are multiple plots at all) and what the difference is between the plots themselves.
  • Assuming the audience is completely familiar with the plotting techniques you are using - at least put labels on plots to explain them (e.g. Talagrand or Hovmöller diagrams).
  • Splitting words over lines - choose a different word or use an abbreviation.
  • In a short talk, avoid a summary slide at the beginning, unless your talk structure is non-standard (i.e. different from motivation, aims, method, results, and future work).
  • Significant areas of the slide taken up by titles/toolbars/logos/template structure etc., leaving little space for actual content (which is then displayed too small).
  • Displaying an extended technical scheme (e.g. all the components of a satellite instrument and their interactions) - just include the important bits. Otherwise, people not familiar with the diagram will wonder why you didn't talk about the bits you missed out.

Some colour combinations which don't work:

  • Green and light blue
  • Grey and blue
  • Red and black
  • Blue (text) on red (background)
  • Light green on white
  • Black on blue
  • Black on white is just boring, if it is the only thing on the slide.

A few comments on posters:

I found it easier to spot faults in orals than on posters. Having said that, I spent 85% of my time in talks and only about 15% of the time looking at posters. A few points:

  • Make A4 copies for people to take, and leave them by the poster board after taking down the poster.
  • Make the title big enough and contrasted enough with the background to be seen on the other side of a lecture-hall sized room.


In one talk I attended, the speaker inflected the end of every sentence of a 15 minute talk, except the very last sentence of the talk. It was quite hypnotic, eventually hilarious, and quickly distracted the audience from the material. Not to be recommended. If anyone you know does this, please tell them, as they probably don't realise it.

About the sport of rifle shooting in the UK

The basic idea is to shoot at targets between distances of 25 and 1200 yards away, and to try to get as many shots as close to the centre as possible! At Cambridge I shot in nine Varsity matches against Oxford in various disciplines of the sport, winning four Half Blues, and I was Captain of the University first team in my final year.


  • At short range (25 yards, small-bore) we use the .22 rifle. This fires small lead bullets about 2cm in length (including the casing) and 0.22 inches in diameter at card targets (the area within the box is about A4, giving an indication of the size of each target).
  • At longer ranges (300-1000 yards, full-bore) we use high-powered target rifles with "iron" sights (two iron circles mounted on either end of the rifle), firing a 7.62mm calibre (diameter) bullet.
  • At the longest range, 1000-1200 yards (also referred to as full-bore), we use match rifles, which are very similar to target rifles but have a telescopic sight mounted on the top. The bullets they fire are the same calibre as the target rifle, but have about 30% more gunpowder in them.

The accuracy of these rifles means that it is possible for a good shot to hit the bull's-eye from 1200 yards away with 6 out of 10 shots, with the remaining three falling within a foot or so of the 'bull'. At 1200 yards the bull is about the same size as a bathroom sink. As the standard of equipment has improved, it has become necessary to introduce a smaller 'V-bull' inside the bull to separate the top competitors. This is worth 5.1 points instead of 5 for a bull (however, ten V-bulls are worth 50.10 in total, not 51). At 1200 yards the 'V' is about the size of a large dinner plate. It was not until 2001 that the maximum score of 100.20 was made in top-level competition.

The bullet takes just over a second to reach the target from 1200 yards away, leaving the barrel at about 900 m/s (supersonic). In the right light and humidity conditions, it is possible to see the bullet travelling down the range if you position yourself directly behind a firer and look through a telescope at the target; the shape formed is approximately a left-handed helix of pitch 2π.

The practice of competing with a particular weapon is called a discipline. I was most involved with the latter two full-bore disciplines, so the text below refers primarily to those.


Most competitions (or 'shoots') in full-bore consist of a string of ten shots fired from the prone position (lying on your front), with up to two non-scoring shots beforehand to 'sight' the rifle and to test the wind conditions. Some shoots are 7 or 15 shots long, and in match rifle a handful of competitions are 20 shots long - this is very hard on the shoulder and upper back in particular as the 'kick' from these rifles is harder than that from a shotgun or a military rifle such as the AK-47 or SA80. To counter this, a thick padded shooting jacket is worn, in addition to the obvious safety kit such as ear protection. Some match rifle shots choose to shoot while lying on their backs; this is called the supine position.

The strength and direction of the wind is very important and an individual's performance in a particular shoot depends greatly on an ability to 'read' the wind. While this can be done systematically, after a time it becomes more of an intuition. At long range, a change in the angle of the wind by 30 degrees may mean the bullet lands on the target over a metre away from where it was aimed!

International competition

The two full-bore disciplines are most common in the UK, the Commonwealth and in former British colonies, along with a few other countries such as Germany and the USA (although it is very much a minority discipline in the USA compared with other types of shooting!). As of ~2005, the UK, Canada and Germany were the strongest national teams.

International team and open individual championships take place each year at the national ranges of each of the major nations who compete: the UK, South African, Australian and Canadian meetings are the main events in the calendar. The nature of the sport (i.e. being minimally dependent on fitness and strength) means that it is one of the few in the world where every person competes on equal terms; there are no ability divisions by age or between men and women.

The most prestigious of these open competitions is the Imperial Meeting, which is held over three weeks each July at Bisley Camp near Guildford in Surrey. The two full-bore disciplines form the bulk of the Meeting, with about 1500 competitors from all over the world. There are a number of other disciplines competed in such as Service Rifle, Historic Arms, and the Schools Meeting, which is a week of competition for CCF units in UK independent schools.

Bisley is the 'home' of the sport and the individual competitions which make up the Imperial Meeting are regarded as being the de facto target shooting world championships. Bisley is a very strange place. It contains two main ranges: Century has 108 targets and is 600 yards long (almost exactly a square), and Stickledown has 50 targets and is 1200 yards long (very much not a square). Surrounding these are 40 to 50 clubhouses, about ten smaller ranges, several camping sites and caravan parks, and a lot of green space. Many of the clubhouses are over 100 years old; as a result of this, and of the rather conservative attitudes associated with a sport of this type, it is occasionally said that Bisley is the last true remnant of the British Empire, and that entering Bisley is like stepping back into the 19th century.

The National Rifle Association of the UK has its HQ at Bisley, and is the UK governing body for rifle shooting. The UK NRA should not be confused with the NRA in the USA - the UK NRA is almost exclusively a sporting organisation and not a political one like its American counterpart.

As with all sports, some competitions are more prestigious than others. There are five competitions held at the Imperial Meeting which are the most important competitions in the UK rifle shooting calendar:

  • The Grand Aggregate (individual, target rifle) - An aggregate of all the individual target rifle shoots; the winner usually gets no less than about 695/705.
  • The Kolapore (team, target rifle) - The main international target rifle match, for teams of 8. In recent years the Great Britain team has been very strong, setting a record score of 1199/1200 in 2012. Other important international matches are the Palma Match, held every four years, and the Australia Match (called the Empire Match until 1988), which is usually held every year. Both of these matches are held in a different country each time, but the Kolapore is always held at the UK Imperial Meeting.
  • The Hopton (individual, match rifle) - An aggregate of all the individual match rifle shoots; the record score is currently 1004/1025, set in 2004.
  • The Elcho (team, match rifle) - The home nations (England, Scotland, Wales, Ireland) team match, for teams of 8. It is held each year.
  • HM The Queen's Prize (individual, target rifle) - This is the most prestigious prize in the sport of target shooting. It is a three-stage competition, held each year. The first and second stages are at short range (300, 500 and 600 yards), and the third stage is at long range (900 and 1000) yards. Only 100 people compete in the third stage. Queen's III is the last event of the Imperial Meeting and attracts a crowd of several thousand spectators; the spectator-unfriendly nature of the sport is helped in this event by each firer having a continually-updated scoreboard behind their firing point, and there is a leaderboard at the side of the range which is updated shot-by-shot. After the competition is complete the winner is chaired from the range by friends, and spends the rest of the day (and night!) being chaired round all the clubhouses on Bisley Camp, usually accepting a drink from each one... The winner of The Queen's is immortalised in the sport; such is the significance of the competition that winners may subsequently use the letters GM after their names in shooting circles. When the Queen's prize was first held the prize itself was £250, enough to buy a house; however, the prize has remained at £250 ever since! Most other national meetings have an equivalent competition (for example the Governor General's Prize in Canada), but the status of Bisley as the home of target shooting has meant that the Queen's Prize remains the premier competition in the sport.


At Cambridge I was part of the Cambridge University Rifle Association (CURA) and the Cambridge University Small Bore Club (CUSBC), which are the full-bore and small-bore clubs respectively.

CURA has a long history stretching back over 100 years, and is one of the oldest sports clubs in the University. The Club competes as a team and as individuals at the Imperial Meeting described above, at which the Varsity Matches against Oxford take place.

There are three Varsity matches each year: the Chancellors (target rifle, teams of 8, and the most important of the three), the Humphry (match rifle, teams of 4) and the Heslop (small bore, teams of 8, which takes place in February in London). Between 1981 and 2004 CURA won an unprecedented 24 straight Chancellors Varsity match victories, a record not even approached by any other sport at either University. The run was stopped in 2005, one short of a quarter-century of victories, in a match won convincingly by Oxford 1155.112v-1142.115v (out of 1200). This followed two very close results; the 2004 match was won by Cambridge by one point, and the 2003 match produced record scores from both teams, 1170.126v-1164.132v.

The sport has Discretionary Full Blue status: all participants in the two full-bore Varsity matches and some of the participants in the small-bore Varsity match are awarded Half Blues, and if a set of very stringent individual-score-based criteria are met, a Full Blue may be won. The Chancellors is shot at the same time as the Kolapore (see above), and the criteria for a Full Blue are based on the Great Britain score in that match. Therefore a Full Blue is won for being of approximately international standard; only 19 have been won since the sport was granted this status in 1985.

In my time with CURA I held positions as Secretary and Vice-Captain, and was Captain of the club in my final year. Unfortunately my legacy as Captain was the first Varsity Match loss in 25 years! I competed in the Chancellors four times, the Humphry twice and the Heslop three times.