Rain rain go away…

My 2 kids were singing the rain rain go away rhyme during last weekend’s epic rainfall in Copenhagen and it reminded me that I have not yet put up a post about a paper I was a co-author on this summer related to late summer/autumn rainfall and the effects on the Greenland ice sheet, so here goes….

Mostly when we think of precipitation in Greenland we think of snow in the winter, but it does rain quite a lot, as I know from personal experience (see photo taken as the clouds started to clear one September field season in Eastern Greenland…). This paper in Nature Geoscience by Sam Doyle and co-authors including myself shows that when rain falls on the ice sheet at the “wrong” time of year it can have a very far-reaching effect, causing the speed up of a large area across the ice sheet.

Rain clouds over the Stauning Alps of Eastern Greenland after the third day of rain... Exploratory mining camp tents in the foreground.
Rain clouds over the Stauning Alps of Eastern Greenland after the third day of rain…
Exploratory mining camp tents in the foreground.

The important caveat is that rainfall during the main part of the melt season is more or less evacuated away quickly. Glaciers – and the Greenland ice sheet is basically a very big glacier – develop a drainage system more or less analogous to large underground sewers during the melt season. These tend to close down during the colder accumulation season and reopen by the sheer pressure of water running through them when the melt season starts. Rainfall during that crucial late summer/early autumn period when the drainage is closing down and therefore less efficient at evacuating surplus liquid water is therefore not able to move away from the glacier very easily and forces its way through any way it can find.

During this period, most of the snow will have melted off the surface, leaving vast areas of bare ice. By contrast, rain on snow in the early part of the melt season when there is a thick snow pack is more likely to refreeze inside the snow. In late summer however, there will be a relatively short period between rain falling and accumulating in the glacier drainage system.

In practice this means the water makes its way to the bed of the glacier through moulins and englacial channels, where it more or less hydraulically jacks up the glacier over a large region, allowing the ice to flow to the margins faster. There may then also be a knock-on effect with increased calving of icebergs at outlet glaciers. in 2011, the field team were able to measure both the rain fall and the following cascade of processes in a range of different datasets as shown below:

Rainfall (a,b) over the ice sheet runs off the bare ice quickly as shown by discharge stations on a number of rivers in western Greenland (c). This triggers acceleration  across a wide area, shown by GPS stations on the ice sheet at 10 different locations (d). Figure taken from the paper
Rainfall (a,b) over the ice sheet runs off the bare ice quickly as shown by discharge stations on a number of rivers in western Greenland (c). This triggers acceleration across a wide area, shown by GPS stations on the ice sheet at 10 different locations (d). Figure taken from the paper

My contribution to the paper was in the form of some HIRHAM5 model runs for Greenland which show the last decade has seen a significant increase in rainfall events in the summertime compared with the previous decade. We chose as a study region the K-transect of weather stations in western Greenland. These are operated by Utrecht University and have a long time-series of data which previous work has shown our model can replicate quite nicely. The model is forced by the ERA-Interim reanalysis, a data set based on weather forecast models with real observations included in it run for the whole world so we are pretty confident the rainfall patterns are realistic. There are actually two interesting points illustrated in the picture below taken from the paper. Firstly that there is more rain falling and secondly that this rain is falling at higher elevations on the ice sheet, potentially causing a much wider area of the ice sheet to be affected by late-summer rainfall events.

The decadal change in rainfall events is partly due to a persistent North Atlantic Oscillation anomaly which has funnelled storms over the western edge of the ice sheet. There is also some evidence that the stratospheric Rossby waves have become more “wavy” over the same period, due to the increasing warming and vanishing sea ice in the Arctic. This hypothesis was articulated in a very nice paper by Francis and Vavrus but it remains a very open area of research as we just don’t have a lot of evidence right now.

We do know that the Arctic is one of the fastest warming regions on the planet and this will certainly have a knock-on effect on the Greenland ice sheet both in terms of melting and, perhaps, in the frequency of storms bringing rain over the ice sheet in the future. I am now preparing a new study to see if we see a signal along these lines in our future simulations of the Greenland domain.

Rainfall events at a weekly timestep over the K-transect in western Greenland  for two different decades and the difference between the two. The second decade has many more rainfall events that reach to a much higher elevation than the first decade.
Rainfall events at a weekly timestep over the K-transect in western Greenland for two different decades and the difference between the two. The second decade has many more rainfall events that reach to a much higher elevation than the first decade.

Conversion Factors

The official end of the hydrological year in Greenland (1st September to 31st August) means I am rather busy writing reports to give an overview of where the ice sheet is this year and what happened. I will try to write a quick blogpost about this in the next week or so (in case you’re curious here’s a quick plot to show the entire annual SMB, see also: http://polarportal.dk/en/groenlands-indlandsis/nbsp/isens-overflade/)

Daily and accumulated surface mass budget of the Greenland ice sheet, 31st August, 2015, last day of the hydrological year
Daily and accumulated surface mass budget of the Greenland ice sheet, 31st August, 2015
Anyway, as I find I am constantly switching between Gigatonnes (or indeed Gigatons), cubic kilometres and sea level equivalent, here is a quick and handy guide to converting different units of mass, for my own use as much as anyone else.

1 gigatonne is 1 billion metric tonnes  (or 1 milliard if you like the old British style, that is one thousand million).

However, on the Polar Portal we usually reckon everything in water equivalent. This is to save having to distinguish between snow (with a density between ~100 kg/m3 when freshly fallen and ~350 kg/m3 m when settled after a few days), firn (snow that has survived a full annual cycle with a density up to ~800 kg/m3) and glacier ice (anything from ~850 kg/m3 to 900+). Water has a density (at 4C) of 1000 kg/m3

1 gigatonne of ice will still weigh 1 gigatonne when it is melted but the volume will be lower since ice expands when it freezes.

1 metric tonne of water is 1 cubic metre and 1 billion metric tonnes is 1 km3 (a cubic kilometre of water)

A cubic kilometre of ice does not however weight 1 gigatonne but about 10% less because of the density difference.

100 gigatonnes of water is roughly 0.28mm of sea level rise (on average, note there are big regional differences in how sea level smooths itself out).

Finally, 1 mm sea level rise is 360 Gt of ice (roughly the number of days in a year) 

EDIT: – thanks to ice sheet modeler Frank Pattyn and ice core specialist Tas van Ommen on Twitter for pointing out I’d missed this last handy conversion. Interestingly and probably entirely coincidentally this is very close to the amount of mass lost by the Greenland ice sheet reported by Helm et al., 2014 for the the period January 2011 – January 2014 (pdf here) of 375 +/-24 km3 per year.

Over the last 10 years or so, Greenland has lost on average around 250 Gigatonnes of ice a year (Shepherd et al., 2012), contributing a bit less than a millimetre to global sea level every year with some big interannual variability. This year looks like it will be a comparable number but we will have to wait for the GRACE satellite results in a couple of months to fill in the dynamic component of the mass budget and come up with our final number.

Of course, gigatonnes and cubic kilometres are rather hard to visualise so we have skeptical science to thank for this post that tries. And as aside, Chris Mooney wrote a nice piece in the Washington Post on the difficulties of visualising how much ice is being lost which contains the immortal  line “Antarctica is clearly losing billions of African elephants worth of ice each year”.

A brief introduction to crevasses

As an impressionable seven year old I learnt what a crevasse was; namely a large split in a glacier of great hazard to glacier travellers. This knowledge was imparted by a venture scout in my parents group who, on a climbing trip to the Alps, managed to end up in one, breaking several bones in the process. Years later this did not discourage me from my own forays into alpine mountaineering, so it was probably inevitable that I would have my own brush with mortality in a crevasse while researching them as part of my PhD work (see photo).

Some injuries, 3 days after falling into a crevasse (thankfully to be rescued by quick-thinking field assistants).  Not recommended
Some injuries, 3 days after falling into a crevasse (thankfully to be rescued by quick-thinking field assistants).
Not a recommended “experience”.

The research was interesting and made more so by being carried out in such a spectacular environment. Breiðamerkurjökull is a southern outlet glacier of the Vatnajökull ice cap in Iceland. It’s actually one of the more popular tourist destinations in Iceland thanks to the boats that run on the lagoon in front of the glacier, getting people up close and personal with icebergs. The icebergs are one of the reasons we chose to work there, as the rationale of my Phd project was can a crevasse depth relation be used as a parameterisation for calving in ice sheet models?

I was moved to revisit this work recently when a friend (and ace glacier/climate blogger) Liam Colgan posted about crevasse factoids.

Crevasses on Breidamerkurjokull, note figure for scale
Crevasses on Breidamerkurjokull, note figure for scale

Crevasses are extremely beautiful features to observe and they are interesting scientifically since they indicate all sorts of information about what is going on in a glacier. As they are aligned more or less with the principal stresses in a particular location we can see where a glacier is accelerating or decelerating, that is stretching or compressing respectively, based on the shape and alignment. They can also be used as a feature to track glacier velocity between two successive images taken from aircraft or satellites. Crevasses are also significant in other ways, since they are a plane of weakness that can be exploited by meltwater, channelling it away from the surface of the glacier to the bed changing the velocity of the glacier. And as proved in the case of my Phd work, when they extend deep enough in the right place, they cause large chunks of ice, namely icebergs, to fall off the front of glaciers.

Given all these interesting habits it is probably surprising to learn that the large computer models of ice sheets and glaciers don’t usually include crevasses in them, though there are some more recent honourable exceptions, mostly working with single outlets or small glaciers such as Sue Cook’s work with the Elmer model. This is because an individual crevasse is not only too small for the resolution of a model, it’s also a discontinuity, and the approximations of the physics of ice sheets do not easily allow discontinuities. To put it another way, when we model glaciers we usually assume they are really large and thick fluid bodies, and as everyone knows, fluids don’t crack. This is just another bizarre property of water, and if I get chance I’ll discuss that again in further detail in another entry. But back to crevasses.

Now I mostly work with a climate model, HIRHAM5, using it to calculate surface mass balance, that is accumulation of snow and the melt and run-off from the surface of glaciers and ice sheet. However, I am finally (loosely) involved in a project that sets out to finish in some way the work I started as a young PhD student.

At DMI we run the PISM ice sheet model, fully coupled with a global climate model EC-Earth as I wrote about in this post. We will also soon be running HIRHAM5 coupled to PISM in order to study feedbacks between ice sheet dynamics and surface climate forcing (mainly in terms of how topography and elevation of the ice sheet affects the surface mass balance). We also intend to participate in the ISMIP6 model comparison project which will compare the results of several different global climate models that also include ice sheets in a realistic fashion.

 

One of the key challenges in getting these running is how to deal with the ocean interface with the ice sheet, both in terms of submarine melt of outlet glaciers (likely a far more important process than earlier recognised) and in terms of calving icebergs. One of our main (and in my opinion most interesting) projects right now, ice2ice has allowed us to employ a PhD student to work on this specific issue. She will be using a similar idea to Faezeh Nick’s model of outlet glacier calving, which in turn was based on a long ago work (pdf) I was part of as a lowly PhD student.

By comparing the measured crevasse depths with numerical models I was able to show that simple models can be used as approximations of crevasse depth. That study is still one of the very very few where actual empirical measurements of crevasse depth, strain rate, spacing and other variables were made and compared with model output.

In my current incarnation as modeller I will be keeping very carefully away from all sharp fractures in the ice and concentrating instead on the model part. Expect updates here…

 

Mining for (data) gold

UPDATE: I don’t really touch on the issue of availability of data in this post but a post by Victor Venema has just come to my attention urging the WMO to agree a free data convention to free up climate data archives for science purposes. I urge you to read it and support. In Greenland at least we are lucky most of the data is open access, but we also rely on other data sources that are not…

One of the problems all modellers face, but particularly in remote regions of the earth like Greenland, is the lack of available independent observational data which can be used to compare with model output to see how well the model simulates reality.

Compariosn between modelled and observed monthly mean temperatures for Danmarkshavn using DMI automatic weather station data and HIRHAM5 model output
Comparison between modelled and observed monthly mean temperatures for Danmarkshavn using DMI automatic weather station data and HIRHAM5 model output
Comparison with Promice KPC_U station observations and HIRHAM5 modelled monthly mean temperatures
Comparison with Promice KPC_U station observations and HIRHAM5 modelled monthly mean temperatures

I actually spend much more time trying to model the recent past (say the last 35 years or so, almost my whole lifetime), rather than the future. We can compare the model output with specific metrics to assess if the model is representing any particular processes well or poorly. If the latter then clearly we need to do a bit of work to improve it, or alternatively we can gain an insight into how a particular process or system works. This is a gigantic topic to explore and I recommend the blogs Variable Variability from Victor Venema and the Climate Lab Book from Ed Hawkins and Doug McNeall if you really want to get into it.

(As an aside and related to my previous post, I generate model output faster than I can look at it, so any students who are interested in a project looking at observations and model output for any/all of various locations in the Arctic do get in touch. I have some particularly interesting results from Devon Island I don’t really have time to get into right now…)

Image of Devon Island from the Canadian Encyclopedia
Image of Devon Island from the Canadian Encyclopedia

At a recent meeting in Sheffield we had much discussion on using data from Greenland to evaluate how well the different climate models are performing over Greenland. This is complicated by the generally short records and limited geographical coverage of meteorological observations. Often those observations are made in easy to get to places rather than the places we really need them such as the South East of Greenland where most of the precipitation falls. So here is a quick run down of the met observations I do have access to.

The gold standard of met observations, following guidelines set by the WMO, are the DMI weather stations (pdf ) which are largely confined to the coast of Greenland, plus Summit station at the top of the ice sheet, but have records going back, in some cases, to the 18th century. This data is all publically available and can be downloaded in a zip file from DMI.

Henrik Krøyer Holm weather station in Northern Greenland. It's very expensive to maintain so it is visited only once every 3 years or so. Like most instruments in Greenland, it is built to be tough. Picture from DMI archive
Henrik Krøyer Holm weather station in Northern Greenland. It’s very expensive to maintain so it is visited only once every 3 years or so. Like most instruments in Greenland, it is built to be tough. Picture from DMI archive

On the ice sheet itself the GC-Net project has set up automatic weather stations on the ice sheet. This data is also pretty freely available, but it does have some quality problems as with any dataset from instruments operating in incredibly tough environments. These instruments are high up on the ice sheet in the accumulation zone, more recently the Danish funded PROMICE project, with whom I work quite closely, have been putting automatic instruments out in the ablation zone. Although these instruments are lower the conditions are also quite tough as the snow and ice under the stations melts out each summer and in some locations the piteraq is also very challenging with 150km/h wind speeds measured during one storm in 2013.

Weather station in Tasiilaq, one of the longest records in Greenland and in one of the most data sparse regions. Image from DMI archive
Weather station in Tasiilaq, one of the longest records in Greenland and in one of the most data sparse regions. Image from DMI archive

The data from Promice goes back only to 2008 but has been quality checked and homogenised so it is much easier for modellers like me to work with and it comes from a zone that is particularly important to understand. As the climate changes we expect the ablation zone to get bigger and melt to increase with some important but difficult to model processes such as retention and refreezing and albedo changes playing a big role in how quickly the Greenland ice sheet will contribute mass to the oceans.

There are of course also a number of other automatic weather stations operated by other projects and agencies, including the K-transect instruments, operated by University of Utrecht IMAU which are also associated with a long time series of mass balance measurements based on stakes drilled into the ice sheet.

For precipitation measurements, which are notoriously difficult to make especially with blowing snow, we tend to rely on shallow cores and snow pits, though again these are only available in the accumulation zone. This open access paper by our friends at the University of Copenhagen‘s Niels Bohr Institute is a very nice summary of all the measurements available. Unfortunately there are very few shallow cores taken after 2000 and even fewer taken where we need them in the south east.

Promice scientist measuring snow density in a snow pit in southern Greenland
Promice scientist measuring snow density in a snow pit in southern Greenland taken from this piece on fieldwork on the polarportal

I will end with a plea: all of these measurements are made possible only with budgets that have a continuous downward pressure on them. We rely on them for the weather forecast and for climate research, if you use any of this data do remember to acknowledge it. A lot of time effort and money has gone in to making those measurements, once a station is removed it’s pretty hard to get it back again. When the DMI stations were set up no-one was really thinking of climate change, they were more concerned with shipping and later on aviation and yet we now find them some of the most valuable datasets we have making measurements in a very data-poor region, the Arctic. That is true data gold.

Calling all students…

I’m off to the UK next week for a workshop at Sheffield University where we will discuss the Surface Mass Balance of the Greenland Ice Sheet. The ISMASS workshop includes all the main modelling groups and observation groups who are involved in assessing surface mass balance in Greenland. I will be representing DMI’s Greenland SMB work there (not an easy task condensing it down to a 20 minute talk!).

In the course of preparing my presentation I have been making plots and figures and really investigating some exciting results. Sadly, I very rarely get the chance to spend time on this these days and I am keen to recruit students to assist in this work. Should any potentially interested students want to discuss this at Sheffield do let me know.

At the risk of spoilers in my presentation, here for example is one showing how different ways of characterising the surface snow pack affects our estimates for surface mass balance, and how the effects of the specific changes can be very different in different years.

Surface mass balance map plots of Greenland
Surface mass balance for the hydrological year (Sep -Aug) ending in 2012 and 2013 calculated using HIRHAM5 with 2 different surface schemes. The maps on the right show the difference between the 2.

As I mentioned I rarely get enough time to analyse the output from our runs and I would be very happy to hear from any students who are interested in doing a project on our simulations. We have lots of MSc and Bachelors projects already listed on our website at DMI but we are always happy to hear new ideas from students on related topics. I have terabytes of data from simulations I would like to be properly analysed and this could be very interesting given we are talking about Greenland and the Arctic in the present day and in the future. It’s a really nice opportunity to work with some cutting edge research. I am also happy to hear from students who would like to do a summer project and for the right candidate I would be able to look into a paid “studentmedarbejderhjælper” position for a few months, especially if you are already a trained computer science candidate….

If you are an undergraduate looking into an MSc, I urge you to consider Denmark. EU citizens usually qualify for generous support grants (rare these days!) as we have a shortage of candidates wanting to study in the sciences in Copenhagen. The research and teaching are world class and done in English at MSc level. The possibilities for projects in Greenland are literally endless.

If you want any more details or to talk about any of the possibilities, do get in touch!

Space for cycling

Golden bike sculpture on tower in Rådhusplads, Copenhagen
Copenhagen: A city that loves bikes so much it puts golden ones on the top of some buildings…

Warning! This post is positively evangelical about cycling…

I bike everywhere. I take the Sterna chicks cycling everywhere and it has got to the point I almost don’t know how to get around the city without my bike. This is not unusual in Copenhagen. Cycling culture is one of the things I love most about living here. The wider benefits of being in a biking city are far-reaching and far too many mention here (but check out Copenhagenize for an inspiring run-down).

I have always cycled everywhere, and in fact have never owned my own car, though I can drive and even enjoy it – albeit on congestion free roads such as you might find in the North of Scotland.  However, the vulnerability of cyclists in the UK has come to disturb me ever more. Especially since the very tragic death of Dr. Kat Giles, a polar scientist I had met a couple of times, under the wheels of an HGV in London on a route she had cycled for ten years or so back in 2013.

I am so accustomed to the safety of cycling in Copenhagen that I think I would find it hard to go back to cycling in the UK or anywhere else without good bike infrastructure (including separated bike lanes). I would certainly not let my 4 year old bike to the nursery as I do at present (and for which a poor child was threatened with having their bike confiscated recently in the UK, but I digress). Even my mother (hi Mum!) has been witnessed riding a bike in Copenhagen. I have video evidence.

Be that as it may, such are the benefits of biking that I feel the UK and in particular the mega-city that is London should really be doing A LOT more to facilitate normal people cycling everyday . So I was rather disappointed, but entirely unsurprised to see this pop up on twitter:

https://twitter.com/Hackneycyclist/status/592387246063538176

Hackneytwitter

Now, on my regular commuting route, the University of Copenhagen is building a brand new and very large building spanning both sides of a large dual carriageway that is one of the main routes into Copenhagen. Bear in mind that around 40% of commuters travel by bike in this city and this is a major route, so clearly the bike path cannot just be closed. Here are a few photos I took yesterday on the spur of the moment (with my fairphone in case you’re interested in cool ethical consumer electronics) showing what the builders have done:

2015-04-27 15.31.44 2015-04-27 15.31.47 2015-04-27 15.31.49 2015-04-27 15.31.53 2015-04-27 15.31.56 2015-04-27 15.32.01 2015-04-27 15.32.05 2015-04-27 15.32.10

The pavement and separated bike lane have been taken over by the construction, shielded by the link fence on the right; the near side lane on the road is now a shared bike/pedestrian route and the whole thing is smoothly transitioned in and out with the assistance of some blue paint and traffic bollards on the road and of course temporary tarmac ramps to help cyclists get over the kerb at both ends of the building works. The same is true on the other side, so the road has temporarily narrowed to a normal road before widening again to a dual carriageway.

You see, it really isn’t hard to do major building works and keep the bike traffic flowing.

The thing is, this isn’t a unique situation, even small building works where the bike lane and/or pavement is likely to be blocked is treated like this in Copenhagen. It’s about treating all people on the move with respect and it’s something a lot of cities, and countries could learn from when thinking about road safety, sustainable transport and above all quality of life for everyone.

This is what #spaceforcycling really looks like.

Climate and ice sheet modelling at DMI

I was very honoured to be asked to give a short talk last week to some students at the Danish Technical University. The subject was ice sheet modelling and climate at DMI where I work in the Research department, climate and Arctic section.
I thought this could be interesting for others to look at too, so I have uploaded the powerpoint presentation on my academia.edu page.

In the presentation I try to explain why we are interested in climate and ice sheets and then give a brief overview of our model systems and the projects we are currently working on. We are mainly interested in the Greenland ice sheet from the perspective of sea level rise. If we are to climate change we need to know how fast and how much of Greenland will melt and how this will change local and regional sea level. There are also studies showing that increased run-off from the ice sheet may change ocean circulation patterns and sea ice. There is lots more stuff to look at so feel free to download it.

I end up with a very brief overview of our biggest project at the moment, ice2ice. This is a large ERC funded project with the Niels Bohr Institute and partners in Bergen at the Bjerknes Climate Research Centre. I may write a brief post on ice2ice soon if I get chance. It’s a really interesting piece of work being focused on past glacial-interglacial climate change rather than present day or the future and I think we have potential to do some great science with it.

At the risk of seeming like I’m blowing the DMI trumpet (something rarely done or even really seen as socially acceptable in Denmark!), I think we at DMI have a lot to be proud of. We are a small group from a small country with limited resources but my colleagues have pioneered high resolution regional climate modelling of the Greenland ice sheet and the development of coupled climate and ice sheet models at both regional and global scales. I was brought in as a glaciologist to work on the interface between ice sheet and atmosphere, needless to say I have learnt a hell of lot here. It’s been an exhilarating few years.

If you have any questions, I will enable comments for this thread (but with moderation so it may take  a while for you to see it).

Finally, here is a little movie of calving icebergs

shot by Jason Amundson, University of Alaska Fairbanks at Jakobshavn Isbrae in West Greenland.

 

 

 

Planet Carbon

There are some really powerful visualisations in this short 4 minute video from Carbon Visuals about the sheer amount of energy, mostly from fossil fuels, that we have come to rely on. I think it really shows what a huge challenge we face in terms of both energy policy (we’re burning through it as if it will never run out) and climate change.

I am not really convinced by CCS (Carbon capture and storage) though, it seems to require a very large amount of energy just to make the CCS process work (around 30% of powerplant output if I recall correctly) burning through our fossil fuel supplies even faster. Several programmes I have seen recently (for example, the excellent Planet Oil from the BBC, now probably available on youtube, made by Professor Iain Stewart, head of the RSGS) make the point that our civilisation is basically burning through the easy energy.

If we don’t invest in developing other sources now, it will be so much harder in the future. Those other sources, realistically speaking, have to include nuclear. As Brian Cox points out in his beautifully filmed epic Human Universe, this will also have to include nuclear fusion.

I think the best resource I have found to think about some of these issues is Without Hot Air, an excellent book by David MacKay and available here for free download or you can buy a paper copy in the usual places.

 

 

 

 

Up Goer 5

I’m a bit late jumping on this bandwagon, but here is my first attempt to explain my research simply. The explanation behind this was a cartoon from the well-known web comic xkcddescribing the Saturn V moon rocket using only the ten hundred most commonly used words. It has since become something of a web phenomenon, especially amongst scientists (for example look up the #upgoer5 hashtag on twitter). To give due credit, I put this together using the text editor handily made available by Theo Sanderson.
 
 

I study the way ice and water are changing at the top of the world. My work uses a very big computer which makes lots of attempts to tell us what the world will be like in one or two hundred years at the top of the world. We want to know how much ice there will be, how much ice will turn into water and how warm the air will get and how quickly this will all happen so that we can be ready for changes in the water around the land.

One of the other things I have been working on is a picture of the ice in the place called green land, which is a piece of land near the top of the world. Every day this picture is changed to show how much ice has fallen from the sky and how much ice has changed into water.

You can see this picture here.

http://www.dmi.dk/dmi/index/gronland/indlandsisens_massebalance.htm

accumulatedmap

Dunning-Kruger

The idea of this blog is to describe some of the things I have been working on to a non-technical audience (I’m envisioning my grandmother here – though I suspect my parents are actually the only people who read this blog). Some of the things I work on are (I hope) potentially important and useful data products for business, planners and public alike, other things are pure research.
In any case much of what I do is funded directly or indirectly by people who pay taxes so I feel it is equally important that the people who pay for it also understand it. This is not always as straightforward as I hope it is and in this post I explore one of the difficulties I have in communicating my science.

Some years ago, I was having a hair cut and chatting to the hairdresser (as you do), when she asked me what I did for a living. I explained I was studying for a PhD in glaciology. Bearing in mind I hadn’t the least idea what  PhD actually was until I became a student myself, I then said that I basically studied how glaciers moved (close enough). Her next question completely stumped me.

‘What’s a glacier?’

I had taken for granted that she would know what a glacier is but as I later realised, there is no reason that she would or should. She had never visited the alps or gone skiing or hiking in the mountains (the most obvious way to come into contact with glaciers) and she was certainly not a budding geography student.

Glaciers never featured in my school curriculum, so why would they have done in hers? I had immediately fallen over one aspect of the Dunning-Kruger Effect, where you assume others have an equivalent understanding of the same things you do. The other, more well known aspect of the Dunning-Kruger Effect is illusory superiority, where individuals commonly rate their intelligence, skills etc as above average.

I still find it difficult to know what kind of level to aim for when discussing my work. I truly believe everyone should be able to understand the principles and the concepts behind what I do and if it sounds too complex to understand then I am not communicating it well enough. At the same time I have to recognise that a 4 year degree, a 1 year masters and a 3 and a half year PhD plus 4 years of post-doc work have inevitably shaped my thinking and the ‘stuff what I know’; my (non-technical) audience does not have that advantage.

My greatest fear is that I am patronising or boring the people I am talking to and repeating tired or obvious metaphors. The interest with which people usually react when I explain what I do for a living suggests that there is a great latent interest in climate and glaciers but I often then feel hamstrung about going further than a few superficial comments.

Navigating the Scylla and Charybdis of science communication is a major reason I started this blog, so I am posting this shortish piece now by way of an explanation and an apology in advance for when I get it wrong.

Following the dictum that the world needs a new blog like I need a chocolate biscuit I would like to discuss some things that are not commonly discussed elsewhere on the web, and in particular my own work in glaciology.

Flying over Brediamerkurjokull and Vatnajokull
Flying over Breidamerkurjokull, an outlet of the Vatnajojull icecap, a glacier in Iceland

As for the answer I finally gave to the inquisitive hairdresser? Well a glacier is like a very slow moving frozen river. Snow falls at the top is pressed down by more snow falling on top and becomes ice, this very very slowly starts to flow downhill like very slow moving water until it gets to the end of the glacier where it melts.

These days of course, with web browsers on most phones, the answer is obvious, wikipedia it…