Sunday, April 09, 2017

[jules' pics] The morning after the night before

If you let them keep your contact details then, as well as sending you news on their latest fundraising scheme, your Oxbridge college will invite you back for din dins every decade or so. These days it isn't entirely free, but still a good deal considering the liver damage they try to cause you. Maybe the college is hoping the experience will make us all feel more mortal and rush home and make generous legacies in our wills. Although I matriculated at two Oxbridge colleges, I've managed to miss all these college din dins, due to being in foreign, and so last night's was my first. I only really went because I hadn't been to one before, but it exceeded expectation. Twenty five years on and it was very interesting to find out about the paths people had taken. Everyone I spoke to seems to be making good use of their talents, although ... how can a country need that many corporate lawyers? 

The dinner was dark and drunk so no decent pics, and we start this morning after the night before with breakfast at Corpus. The real sign that quarter of a century has passed is that several of the dead people on the walls are people we knew in life!

Then off for a little walk to try and sober up some more.
On the first corner is Corpus's special toy, Clocky McClock Face
King's Parade is just next door to Corpus.

Here's King's Chapel

Then to the river where the early punter catches the tourists

Later in the day, people were lazing in the warmth 

And the blossom were in full bloom

But back home, James was left holding the baby...

Posted By Blogger to jules' pics at 4/09/2017 09:27:00 PM

Monday, April 03, 2017


Marathon time has come round again. Jules and I decided against a trip to the EGU this year, having just recently gone to the AGU instead. So instead of Vienna Marathon, it was back to Manchester, who had kindly offered an extra discount to make up for the disasters of last year (which didn't actually affect us much as it happened). Due to a clash with some men kicking a pig's bladder around a muddy field, all hotels were getting booked up and expensive quite early on, but I still found a room for a tolerable price, this time at the Horrible Inn Media City, which actually failed to live up to its name by being rather comfortable and coping well with an influx of runners (surely not their usual clientele).

We suddenly realised as the event approached that it didn't really make much sense for jules to waste a weekend and come too, we'd already done The Lowry and it's not that exciting to stand around for 3 hours watching hordes of unknown joggers in Manchester suburbs for the second time. So when I realised that William was also doing it I suggested sharing the room with him, which actually worked out very well as we had a good chat over dinner about the dismal state of climate science while setting up the highly scientific pasta v meat experiment (meat proved to be the winner):

We had a relaxed approach to race day: a decent lie-in, getting up for a leisurely breakfast before strolling the mile down the quayside to the start just in time to hop into the runners' pens. Bumped into Settle Harriers club-mate Fraser who was aiming to cruise round in a comfortable sub-3 (he's much faster than me overall, but wasn't trying too hard for his first road marathon) but otherwise didn't know anyone near the front.

The bag drop (finish area) was actually a fair bit further away, so we just left our stuff at the hotel to return to later. I sacrificed an old unloved t-shirt to the start line gods, don't think WMC even bothered with that as it wasn't cold. As it turned out the organisation was very good this year, with none of the problems of previous events.

I didn't have that much to go on speed-wise: a pitiful 1 sec PB at 10k (39:21) on Boxing Day, a tolerable 1:23:01 half marathon at Blackpool in Feb (though that's not really much better than last year's 1:25:40 at hilly Haweswater). But training seemed to be going ok with no illnesses or setbacks so I thought I should aim a bit higher than last year and plucked 2:50 out of thin air as a possible albeit optimistic target, at least as a starting pace.

Didn't have any arranged running company this time but got chatting to someone on the start line also aiming for 2:50. "Last year I did 2:51, went off far too fast and did the first half in 1:21 then collapsed, won't do that again". Sure enough the second we got over the start line he shot off into the distance. I went past him again at about 18 miles :-) At that point I was still going pretty well and was perfectly on course for my target, but then the 21st mile marker took a long time to arrive and my legs started to hurt and there's still quite a long way to go from there. So I lowered my sights to just getting round the rest as comfortably as possible, and didn't worry too much about the seconds that were slipping away, at first a trickle, but a flood by the end. Can't be too disappointed with the final result of 2:51:46 which is a three minute improvement on last year, though actually a random sampling of strava results suggests that part of this is due to a shorter (but still legal) course. In a way it's a relief that I'm not close enough to 2:45 for this (which would gain entry to the Championship at the London Marathon) to be a serious target, at least for the time being. There are things I could have done a little better for sure (like a few slightly longer runs), but I don't really see where 7 mins improvement could come from.

Food-wise, I had a chunk of home-made Kendal mint cake and a couple of jelly babies every 2nd water station, at least until near the end at which point I couldn't really face any more. Took the water each time, as much to to splash on my hat as to sip. It was a touch warmer than most of my training, but otherwise perfect conditions. Alcohol-free beer at the end was very gratefully received though it took a little while to sip. Hung around in the finish area long enough to pick up a second pint for the stroll/hobble back to hotel. Club-mate came in at 2:56 looking very relaxed. Don't think I'll beat him again!

Saturday, April 01, 2017 Independence day

We all know by now that Brexit means brexit. However, it is not so clear whether independence means independence or perhaps something else entirely. This has been an interesting and important question in climate science for at least 15 years and probably longer. The basic issue is, how do we interpret the fact that all the major climate models, which have been built at various research centres around the world, generally agree on the major issues of climate change? Ie, that the current increase in CO2 will generate warming at around the rate of 0.2C/decade globally, with the warming rate being higher at high latitudes, over land, at night, and in winter. And that this will be associated with increases in rainfall (though not uniformly everywhere – in fact this being focussed on the wettest areas, with many dry areas becoming drier). Etc etc at various levels of precision. Models disagree on the fine details but agree on the broad picture. But are these forecasts robust, or have we instead merely created multiple copies of the same fundamentally wrong model? We know for sure that some models in the IPCC/CMIP collection are basically copies of other models with very minor changes. Others appear to differ more substantially, but many common concepts and methods are widely shared. This has led some to argue that we can’t really read much into the CMIP model-based consensus as these models are all basically near-replicates and their agreement just means they are all making the same mistakes.

While people have been talking about this issue for a number of years, it seems to us that little real progress has been made in addressing it. In fact, there have been few attempts to even define what "independence" in this context should mean, let alone how it could be measured or how some degree of dependence could be accounted for correctly. Many papers present an argument that runs roughly like this:
  • We want models to be independent but aren’t defining independence rigorously
  • (Some analysis of a semi-quantitative nature)
  • Look, our analysis shows that the models are not independent!
Perhaps I’m not being entirely fair, but there really isn’t a lot to get your teeth into.
We’ve been pondering this for some time, and have given a number of presentations of varyng levels of coherence over the last few years. Last August we finally we managed to write something down in a manner that we thought tolerable for publication, as I wrote about at the time. During our trip to the USA, there was a small workshop on this topic which we found very interesting and useful, and that together with reviewer comments helped us to improve the paper in various ways. The final version was accepted recently and has now appeared in ESD. Our basic premise is that independence can and indeed must be defined in a mathematically rigorous manner in order to make any progress on this question. Further, we present one possible definition, show how it can be applied in practice, and what conclusions flow from this.

Our basic idea is to use the standard probabilistic definition of independence: A and B are independent if and only if P(A and B) = P(A) x P(B). In order to make sense of this approach, it has to be applied in a fundamentally Bayesian manner. That is to say, the probabilities (and therefore the independence or otherwise of the models) are not truly properties of the models themselves, but rather properties of a researcher’s knowledge (belief) about the models. So the issue is fundamentally subjective and depends on the background knowledge of the researcher: A and B are conditionally independent given X if and only if P(A and B given X) = P(A given  X) x P(B given X). Depending what one is conditioning on, this approach seems to be flexible and powerful enough to encapsulate in quantitative terms some of the ideas that have been discussed somewhat vaguely. For example, if X is the truth, then we arrive at the truth-centred hypothesis that the errors of an ensemble of models will generally cancel out and the ensemble mean will converge to the truth. It’s not true (or even remotely plausible), but we can see why it was appealing. More realistically, if X is the current distribution of model outputs, and A and B are two additional models, then this corresponds quite closely to the concept of model duplication or near-duplication. If you want more details then have a look at the paper.

Anyway, we don’t expect this to be the last word on the subject, though it may be the last we say about it for some while as we are planning on heading off in a different direction with our climate research for the coming months and perhaps years.

Saturday, February 18, 2017

[jules' pics] Skipton

Blogging while drinking coffee, on another foggy morning in Settle. 

When in Japan we liked to boast about the high humidity. My Dad was unimpressed, pointing out that British humidity is often well over 100% -when it is foggy. Our Japanese friends didn't seem to understand the concept of ground level cloud, and I wondered if this explained the low-level cloud problems in MIROC climate model. After a couple of dodgy experiences recently, I have decided that fog, spectacles, and mountain biking (or fell running) are a dangerous cocktail, but the internets told me that contact lenses now cater to most types of eyesight. So, on Thursday I headed to Skipton, our local megalopolis. As well as hosting about 5 opticians, there are too many charity shops to count, a Poundland(!), and the rest of the town is occupied by coffee shops. Oh, and a canal.

Appointment at 8:30am, the day started at "Bean Loved".

Optician appointment completed and two hours until the train home it was time to count coffee beans, all within about 3 minutes walk... not very exciting pictures, but photographic evidence is required...

TripAdvisor suggests I only found about half of them - perhaps the others are down side-streets - and I didn't even start on the tea shops, as that's a whole other world (although they also sell coffee, of course).

A little further away, but worth the extra 2 minutes walk is the one we call the Upcycled Bean - because it has foolishly upcycled decor... it is actually the cafe attached to Coffee Care, a coffee supplier...

And finally, the Canal!!!

To be fair, there are other shops in Skipton, but you have to seek them out. We have had good fish and chips, bought a good bed, and I even found a fabric shop (although it was mostly selling upholstery fabric). 

Posted By Blogger to jules' pics at 2/18/2017 10:22:00 AM

Saturday, February 11, 2017

[jules' pics] Blackpool

Blackpool, located out on a pointless bump on the west coast of England, remained a little village until the Victorians invented tourism. Later on, tourists discovered that there are beaches in other countries that are warm and sunny, and Blackpool has been in relative decline ever since. However, despite being 50 miles away, it contains the local violin shop so all the violiners in Settle orchestra have to go there some time (my last visit to the shop was in about 1987 when Kevin had recently taken over the shopwork from his Dad.). We were kind of dreading having to spend a day there, but the violin and both bows needed a bit of work, so eventually we went this week. It was nothing like as bad as expected. In fact it was fun. All doors have a lot of locks on in Blackpool, but once we gained entry to the violin shop everything went very well. The violin jobs were done in a few hours, Starbucks was clean and shiny, the Chinese buffet lunch was very relaxing, and we pretty much bought up Poundland. And there were blue skies! It is a bit like San Francisco. Lots of ethnic restaurants, some tourist traps, trams, and a sea front, but the police cars are much prettier (we saw this beauty right away as the only car park that our van could get into was next to the police station - all the others have a 6'3" limit to stop people staying in camper vans instead of the local B&Bs).

Posted By Blogger to jules' pics at 2/11/2017 09:55:00 AM

Monday, January 23, 2017

Pussy Cats

All Americans I've ever met and talked to about my pussies get very embarrassed. I've learned to say "kitties" instead. But, it turns out that these Americans have just been teasing me, and all along Americans have known full well what pussy cats are! I know I said it wasn't going to work, because it didn't work for BREXIT, but it turns out that pusscats are actually going to save the world. 

 So, it seems like a good time to introduce the new ones:

Lola is a little black (so basically impossible to photograph inside in a Yorkshire winter) 7 month old kitten who is bright, loves games, and climbing, and is also very affectionate - curled up on my lap right now. 

Esme is her slight;y larger sister, and is so pretty that she gets 2 pics. I'm not sure, but I suppose she could be a longhaired tortoiseshell and white, possibly dilute (i.e. she seems more cream and grey than ginger and black, but she still has a lot of kitten fur). She is a bit more timid than Lola and took a few days to settle in. She behaves like Lola, but as if she were wearing a pretty frock that she doesn't want to get dirty. She's quite long, and when she lies down she goes very flat and it is easy to mistake her for a scarf draped over the back of the sofa. 

"which one is my tail!?"

And then there is Alphie, although we have been calling him Boris, because he behaves like a Boris and the rescue only called him Alphie due to his alpha-male characteristics. He's the reason we have got this little troupe; he was causing a bit of trouble at the rescue, but I said I wanted more than one cat (we have two laps, after all!). Boris loves banging his head on everything, including people, and  he really puts his weight behind it ("clunk"). He's really fast when he plays, sometimes mowing down the kittens like little Japanese schools boys, but he seems to run out of energy quickly - I think he is a touch overweight. He's not super dominant, however, and seems to quite like the kittens, and since he doesn't push them away from the food bowl, I hope they will eat all the food and help him slim down a bit. 

Oh dear, great minds think alike and I accidentally over-blogged poor James. 

Is the Food Standards Agency fit for purpose?

Fans of Betteridge's Law will already know the answer....

This is about the latest food scare of course. Toast and “overcooked potatoes” which was later revealed to refer to roasted potatoes (and well-fried chips) are the supposed culprits this time. It's not the first time we've been warned about acrylamides, and probably won't be the last. It's all nonsense, sadly. The basic problem with the FSA approach is that it identifies and publicises chemicals as being likely to be a cancer causing agent, without any(*) consideration of the dose required. As David Spiegelhalter's excellent article explains, a typical human diet contains around 100th of the dose that has been observed to lead to a modest increase in the rate of tumours in animals. And despite all the studies that have been done, no-one has found any link between acrylamide and tumours in humans. But that doesn't stop the FSA generating scare stories about how we shouldn't toast bread properly, or roast our potatoes (I heard someone recommend 45 mins in a cool oven which would just produce soft greasy pallid lumps).

Incidentally, that article probably doesn't blow DS's horn sufficiently for people to realise how authoritative an expert he is. He is Winton Professor for the Public Understanding of Risk in the Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge. When he writes about something, he's probably right.

Anyway, I'm going to keep on roasting.

* not strictly true as a careful reading of David Spiegelhalter's article reveals. But the margin of safety has to be astronomical, rather than merely huge, in order for them to discount it.

Wednesday, January 11, 2017 The AGU review 2016

We’d rather enjoyed our last trip to the AGU and had always hoped to go back some time but it’s a long and expensive trip from the UK especially without having access to JAMSTEC’s generous travel budget. Back in February, PEN had decided to propose a session at the AGU this year, and there was at least a strong hint that some financial support might be available to presenters. So we were mulling over the possibility of going back, when a few months later, both jules and I received separate invitations to present our work there in unrelated sessions. We’ve never both been invited to speak there in the same year, so this all seemed too good an opportunity to miss. We cleared our schedules (ha!) and arranged the trip, starting with a couple of months at NCAR.

My invitation was to a new session which covered betting, financial markets and insurance as it relates to climate change. At least, it was new to me, possibly something similar has been tried in the last few years. It didn’t attract enough abstracts for a full session on its own, so was amalgamated with a long-standing session on climate model evaluation and interpretation. Jules was invited to a session on (paleo)-climate sensitivity, which also got folded into a larger session on cloud feedbacks.

We also submitted a poster to the PEN session on combining paleoclimate modelling and data, which focussed on our new attempt at reconstructing the last deglaciation. Interestingly, I found a presentation I gave back in 2009 at a different meeting proposing this idea (and an acronym – 21kaRP), but we had too many other things on our plates at that time and didn’t pursue it further. It is much more timely now that PMIP is pursuing a coordinated experiment aimed at simulating this interval with state of the art GCMs.

from window of Westin

As well as booking our favourite hotel (surprisingly good value through the AGU site, especially with two people to share the room costs) we spent a bit of time surfing tripadvisor for the best places to eat, which threw up a number of old favourites and a handful of new places to try. As a result of our research we didn’t bother with lunch on the flight but instead headed straight to House of Nanking for sesame chicken after landing on Sunday afternoon, before heading off to registration to avoid the Monday morning queues.

We didn’t find the schedule to be completely packed with must-see stuff, but there was enough to keep us interested most of the time. It’s not really sustainable attending lectures non-stop from 8am to 6pm anyway, though the remnants of a bad cold meant we didn’t have much energy for enjoying SF’s sights and shops. We had a few meetings arranged to do outside of the AGU conference itself, which kept us busy in some of the quiet times and made the whole week that much more worthwhile.

Monday was a particularly thin day, so instead of attending lectures we focussed our attention on discussing some joint work with others for most of the afternoon and on to dinner. Tuesday was mostly data assimilation. I find it interesting to see people still pushing the boundaries of what is possible with ensembles and particle methods. One interesting question is how and why the particle filter and even ensemble Kalman filter can work so well, when they should both basically fail for the modest ensemble sizes which are practically achievable. There seems to be some debate as to how these results are best interpreted…

Wednesday was a busy day for me, with a poster first thing and then a talk later. Our poster on the deglaciation is here or perhaps here if the AGU site changes

Unusually, the poster session was particularly well-attended and useful. I think this was a fluke of scheduling, as there wasn’t much of a clash with anything except with Bette’s Emiliani Lecture at 11:20am. So basically everyone who was interested in paleoclimate went to the posters around coffee time and stayed for an hour or so, before heading off to the lecture which was great.

It’s available though the AGU on demand streaming service, which doesn’t seem to have as much as in previous years, or perhaps I’m misremembering that. Anyway, several of the major lectures are available (the Schneider lecture by Battisti was another one that we attended), though not many of the normal short-talk sessions.

My talk (here as pdf) was late in the afternoon. Being shoehorned into someone else’s session gave me some justification, I thought, in going beyond the narrow remit of my submitted abstract to talk a bit more generally about betting and betting markets. So I enjoyed a brief meander through a subset of the betting stories that have popped up in recent years. The AGU has gone widescreen (maybe years ago, but this is the first time we’ve bothered formatting for it) which is all very well but there was at least one room where a bit more attention could have been paid to ensuring that the image didn’t extend beyond the white screen, clipping off figure captions and titles. We made sure our text wasn’t too close to the edges and it wasn’t a problem for us.

A celebratory beer

On Thursday, jules (to whom I had, just in time, successfully passed my cold) gave her talk, which had also been agglomerated into a larger session. This was a repeat of the Pliomip sensitivity paper, nothing that exciting to those of us who knew about this work though a good chance to talk about it with a new audience who mostly knew about cloud feedbacks and modern data and had relatively little exposure to paleoclimate. It actually clashed with a rather similar talk in a different session which I went to instead, so I can’t tell you how great it was🙂 For lunch we penetrated the AGU editors’ lounge which serves much larger lunches than the EGU equivalent. The pretext for this free lunch was to discuss using paleoclimate to estimate climate sensitivity with some colleagues at least one of whom is, we hope, an AGU editor of some sort. We finished off the day with a dinner at Scala’s anyway, where I had a very good ribeye steak.

By Friday we were a bit tired, and there was nothing that great on. We went to learn a bit about renewable energy which was quite fun, but it petered out towards the end. Didn’t have energy to go out for dinner so Pearl’s deluxe burgers had the honour of a second visit in the week. We also had plans for Saturday morning so weren’t really on for a late night.


A few years ago we entered the AGU fun run and were caught in a downpour, which wasn’t actually all that much fun. Plus, the 7am Wednesday start time made it impossible to get back in time for the early session and we were particularly busy on Wednesday this year including the poster presentation first thing. Therefore we decided not to do it this time. I had however spotted that there was now a parkrun on Saturday mornings at Crissy Field (one of only a handful in the USA). So we booked an afternoon flight back to Denver, and planned to take part in this, at least provisionally depending on the weather and how we felt after a week of AGUing. As it turned out, after a fairly wet and drab week for the conference, Saturday morning dawned sunny and perfect, so we greatly enjoyed a quick trot up and down the shore with great views of the Golden Gate Bridge and all the rest of it.


By chance it was the 100th running of the event, so there was perhaps a larger than average turnout and even cake at the finish. So that was quite a treat to end the trip with. The return flight was then heavily delayed due to another snow storm in Denver, and when we finally got to Boulder we had to trudge back home from the bus stop late at night through several inches of snow with temperatures of -20C which was a bit of a shock to the system. I don’t think I would much like to live in Boulder long-term, it’s a struggle to go outside in those conditions though I suppose some must enjoy the skiing.

Next year the AGU will be in New Orleans, then Washington DC the year after, while the Moscone Centre is being renovated in some way. Doubt we’ll be at either of them, but you never know.