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 question of observation?

It’s been a while since I lasted posted anything, not for want of ideas but mainly lack of time. I shall try to catch up over the next few weeks. For now I was inspired to write an ultra-quick post about a very trivial question that came up at work today. I think it really captures how observational meteorology works (or should work).

Today, a colleague, John Cappelen, (also known as Mr. Greenland observational data), happened to mention in passing that on the 15th July this year, the weather station at Summit on the Greenland ice sheet had transmitted back to us in Copenhagen, a temperature observation of 2.5°C. This was during one of the highest melt periods this summer.

Automatic weather station operating at Summit, June 2015
The automatic weather station doing it’s thing at Summit, June 2015. Photo: DMI

Bearing in mind that Summit Camp is at roughly 3,216m, this is a pretty high measured temperature. In fact it would be rather noteworthy, especially as it occurred on one of the highest melt days of the summer. Temperatures above 0°C at Summit are not unknown and the record, during the famous summer of 2012 when around 95% of the ice sheet surface experienced melt, the water sweeping away a bridge on the Watson River near Kangerlussuaq, was 3.6°C.

Now, my colleague is a very experienced and careful scientist. He had checked the observations and the temperatures before and after this measurement were well below zero, so, my colleague asked, was there any reason to believe this measurement or can we assume an instrument failure of some kind?

My office mate in the Arctic and Climate Research section and I obligingly had a quick look at our Polar Portal Greenland ice sheet surface plots (see below) and at the melt extent plots that are updated daily on the DMI website. We had to conclude there was no evidence of melt that high on the ice sheet and there was also no reason to believe that a sudden sharp warming had occurred at Summit on this day based on DMI’s own weather forecast. We then turned to check the weather plots, also on the polar portal and based on data from the European Centre for Medium Range Weather Forecasting (the ECMWF – probably the best weather forecast modellers in the world).

Again, the anomaly plots showed rather cold conditions prevailing over the ice sheet during this period, though at the same time very high melt and low surface mass balance from the ice sheet due to the clear skies.

Graphs showing area of the Greenland ice sheet experiencing melt conditions, compared with the average (dark grey line) and range of past summers (1990-2012), for more detail see the DMI website
Graphs showing area of the Greenland ice sheet experiencing melt conditions, compared with the average (dark grey line) and range of past summers (1990-2012), for more detail see the DMI website
Temperature record from Summit Camp for the last month.
Temperature record from Summit Camp for the last month.

Fortunately, due to the American Summit Camp we have access to a back-up dataset very close to this location and after a quick web search John Cappelen was able to confirm that indeed this measurement was an error as the nearby station has not seen anything like that during the period in question (see right).

This kind of thing happens all the time and is therefore not at all newsworthy or interesting enough to write a publication about. However, when a recent record high temperature in the UK can lead to 2 critical articles in the Daily Telegraph and a particularly vigorous exchange on twitter for Met Office scientist Mark McCarthy, as well as this corrective piece on the Carbon Brief blog, perhaps we should be more vocal about just how careful and critical we as scientists are about observations, including the ones we decide to discard as well as the ones we keep.

Surface mass balance of the Greenland ice sheet on the 15th July 2015. Intense melting around the margins led to very negative SMB (the red colours) during this period.
Surface mass balance of the Greenland ice sheet on the 15th July 2015. Intense melting around the margins led to very negative SMB (the red colours) during this period.

Addendum: I was alerted by this tweet from Gareth Jones, also a Met Office scientist, to some slightly strange cherry picking in the blogosphere of climate records from a couple of DMI stations in Greenland. These have apparently been used to claim no climatic warming trend in Greenland over the 20th Century (I’m not going to link to it).

Screenshot of tweet

Anyone who is really interested in the observational data could try checking these reports by Mr Greenland observations himself instead, here is a quick summary: 

Mean annual temperature in Copenhagen, Torshavn (Faeroes) and selected DMI weather stations in Greenland from 1873 - 2014. Figure from DMI
Mean annual temperature in Copenhagen, Torshavn (Faeroes) and selected DMI weather stations in Greenland from 1873 – 2014. Figure from DMI

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!

Changes in SW Greenland ice sheet melt

A paper my colleague Peter Langen wrote together with myself and various other collaborators and colleagues has just come out in the Journal of Climate. I notice that the Climate Lab Book regularly present summaries of their papers so here I try to give a quick overview of ours. The model output used in this run is available now for download.

The climate of Greenland has been changing over the last 20 or so years, especially in the south. In this paper we showed that the amount of melt and liquid water run off from the ice sheet in the south west has increased at the same time as the equilibrium line (roughly analogous to the snow line at the end of summer on the ice sheet) has started to move up the ice sheet. Unlike previous periods when we infer the same thing happened this can be attributed to warmer summers rather than drier winters.

Map showing area around Nuuk
The area we focus on in this study is in SW Greenland close to Nuuk, the capital. White shows glaciers, blue is sea, brown is land not covered by ice.

We focused on the area close to Nuuk, the capital of Greenland, as we had access to a rather useful but unusual (in Greenland) dataset gathered by Asiaq the Greenland survey. They have been measuring the run off from a lake near the margin of the ice sheet for some years and made this available to us in order to test the model predictions. This kind of measurement is particularly useful as it integrates melt and run-off from a wider area than the usual point measurements. As our model is run at 5.5 km resolution, one grid cell has to approximate all the properties of a 5.5 km grid cell. Imagine your house and how much land varies in type, shape and use in a 5.5 km square centred on your house and you begin to appreciate the problems of using a single point observation to assess what is essentially an area simulation! This is even more difficult in mountainous areas close to the sea, like the fjords of Norway or err, around south west Greenland (see below).

Represent this in a 5.5km grid cell, include glacier, sea and mountain...  Godthåbsfjord near Nuuk in August
The beautiful fjords near Nuuk. Represent this in a 5.5km grid cell…

The HIRHAM5 model is one of very few regional climate models that are run at sufficiently high resolution to start to clearly see the climate influences of mountains, fjords etc in Greenland, which meant we didn’t need to do additional statistical downscaling to see results that matched quite closely the measured discharge from the lake.

Graph comparing modelled versus measured discharge as a daily mean from Lake Tasersuaq near Nuuk, Greenland. The model output was summed over the Tasersuaq drainage basin and smoothed by averaging over the previous 7 days. This is because the model does not have a meltwater routing scheme so we estimated how long it takes for melt and run-off fromt he ice sheet to reach this point.
Graph comparing modelled versus measured discharge as a daily mean from Lake Tasersuaq near Nuuk, Greenland. The model output was summed over the Tasersuaq drainage basin and smoothed by averaging over the previous 7 days. This is because the model does not have a meltwater routing scheme so we estimated how long it takes for melt and run-off from the ice sheet to reach this point.

We were pretty happy to see that HIRHAM5 manages to reproduce this record well. There’s tons of other interesting stuff in the paper including a nice comparison of the first decade of the simulation with the last decade of the simulation, showing that the two look quite different with much more melt, and a lower surface mass balance (the amount of snowfall minus the amount of melt and run – off) per year in recent years.

Red shows where more snow and ice melts than falls and blue shows where more snow falls than is melted on average each year.
Red shows where more snow and ice melts than falls and blue shows where more snow falls than is melted on average each year.

Now, as we work at DMI, we have access to lots of climate records for Greenland. (Actually everyone does, the data is open access and can be downloaded). This means we can compare the measurements in the nearest location, Nuuk, for a bit more than a century. Statistically we can see the last few years have been particularly warm, maybe even warmer than the well known warm spell in the 1920s – 1940s  in Greenland.

Graphs comparing and extending the model simulation back in time with Nuuk observations
Graphs comparing and extending the model simulation back in time with Nuuk observations

There is lots more to be said about this paper, we confirm for example the role of increasing incoming solar radiation (largely a consequence of large scale atmospheric flow leading to clearer skies) and we show some nice results which show how the model is able to reproduce observations at the surface, so I urge you to read it (pdf here) but hopefully this summary has given a decent overview of our model simulations and what we can use them for.

I may get to the future projections next time…

The Present Day and Future Climate of Greenland

Regional Climate Model Data from HIRHAM5 for Greenland

In this post I am linking to a dataset I have made available for the climate of Greenland. In my day job I run a Regional Climate Model (RCM) over Greenland called HIRHAM5 . I will write a simple post soon to explain what that means in less technical terms but for now I just wanted to post a link to a dataset I have prepared based on output from an earlier simulation.

Mean annual 2m  temperature over Greenland (1989 - 2012) from HIRHAM5 forced by ERA-Interim on the boundaries
Mean annual 2m temperature over Greenland at 5km resolution (1989 – 2012) from HIRHAM5 forced by ERA-Interim on the boundaries [Yes I know it’s a rainbow scale. Sorry! it’s an old image – will update soon honest…]

This tar file gives the annual means for selected variables at 0.05degrees (5.5km) resolution over the Greenland/Iceland domain.

I am currently running a newly updated version of the model but the old run gave us pretty reasonable and could be used for lots of different purposes. I am very happy for other scientists to use it as they see fit, though do please acknowledge us, and we especially like co-authorships (we also have to justify our existence to funding agencies and governments!).

This is just a sample dataset we have lots of other variables and they are available at 3 hourly, daily, monthly, annual, decadal timescales so send me an email (rum [at] dmi [dot] dk) if you would like more/a subset/different/help with analysis of data. This one is for the period 1989 – 2012. I have now updated it to cover up to the end of 2014. The new run starts in 1979 and will continue to the present and has a significantly updated surface scheme plus different SST/sea ice forcing and a better ice mask.

I have also done some simulations of future climate change in Greenland at the same high resolution of 5km using the EC-Earth GCM at the boundaries for RCP4.5 and RCP8.5 scenarios which could be fun to play with if you are interested in climate change impacts in Greenland, Iceland and Arctic Canada.

Mean annual 2m temperature change between control period (1990 - 2010) and end of the century (2081 - 2100) under RCP45 from HIRHAM5 climate model runs forced by EC-Earth GCM at the boundaries
Mean annual 2m temperature change between control period (1990 – 2010) and end of the century (2081 – 2100) under RCP45 from HIRHAM5 climate model runs forced by EC-Earth GCM at the boundaries.  This plot shows the full domain I have data for in the simulations.

This run should be referenced with this paper:

Quantifying energy and mass fluxes controlling Godthåbsfjord freshwater input in a 5 km simulation (1991-2012), Langen, P. L., Mottram, R. H., Christensen, J. H., Boberg, F., Rodehacke, C. B., Stendel, M., van As, D., Ahlstrøm, A. P., Mortensen, J., Rysgaard, S., Petersen, D., Svendsen, K. H., Aðalgeirsdóttir, G.,Cappelen, J., Journal of Climate (2015)

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-14-00271.1 

PDF here

Finally I should acknowledge that this work has been funded by a lot of different projects:

Picture4

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.