A week at COP23

From the 6th -17th of November the UNFCCC’s (United Nation Framework Convention on Climate Change) annual meeting or “Conference of the Parties” – COP took place. This year was COP23 and was hosted by Bonn in the UN’s world conference centre with Fiji taking the presidency.


Heading into the Bonn Zone on the first day of the COP. The Bonn Zone was the part of the conference for NGO stands and side events.

As part of the Walker Institutes Climate Action Studio another SCENARIO PhD and I attended the first week of the COP while students back in Reading participated remotely via the UNFCCC’s YouTube channel and through interviews with other participants of the COP.

There are many different components to the COP, it is primarily the meeting of a number of different international Climate agreements with lots of work currently being done on the implementation on the Paris Agreement. However it is also a space where many different civil society groups doing work connected to or impacted by climate change come together, to make connections with other NGOs as well as governments. This is done in an official capacity within the “exhibition zone” of the conference and with a vast array of side events taking place throughout the two weeks. Outside of these official events there are also many demonstrations both inside and outside of the conference space.

Demonstrations in the Bonn Zone

As an observer I was able to watch some of the official negotiations. On the Wednesday I attended the SBSTA (Subsidiary Body for Scientific and Technological Advice) informal consultation on research and systematic observations. It was an illuminating experience to see the negotiation process in action. At times it was frustrating to see how picky it feels like the negotiation teams can be, however over the week I did have a newfound appreciation for the complexity of the issues that are having to be resolved. This meeting was based on writing a short summary of the IPCC report and other scientific reports used by the COP, and so was less politically charged than a lot of the other meetings. However this didn’t stop an unexpected amount of debate over whether to include examples such as carbon-dioxide concentrations.

One of the most useful ways to learn about the COP was by talking to the different people and groups who we met at COP. It was interesting to see the different angles with which people were approaching the COP. From researchers who were observing the political process, to environmental and human rights NGO’s trying to get governments to engage with issues that they’re working on.

Interviewing other COP participants at the Walker Institutes stand

A particular highlight was the ex-leader of the Green Party Natalie Bennett, she spoke with us and the students back in Reading about a wide range of topics, from women’s involvement in the climate movement to discussing my PhD.

Kelly Stone from Action Aid provided a great insight into how charities operate at the COP. She spoke of making connections with other charities, often there are areas of overlap between their work but on other issues they had diverging opinions. However these differences have to be put aside to make progress on their shared interests. Kelly also discussed how it always amazes her that people are surprised that everyone who attends COP does not agree on everything, “we’re not deciding if climate change is real”. The issues being dealt with at the COP are complex dealing with human rights, economics, technology as well as climate change. Often serious compromises have to be made and this must be done by reaching a consensus between all 197 Parties to the UNFCCC.

To read more about the student experience of COP and summaries of specific talks and interviews you can view the COP CAS blog here. You can also read about last years COP on this blog here.

Clockwise from top left: The opening on the evening of Monday 6th November showed Fiji leaving its own mark as the President of the conference. The Norwegian Pavilion had a real Scandi feel, while the Fiji Pavilion transported visitors to a tropical island.


Sea ice is complicated, but do sea ice models need to be?

email: r.frew@pgr.reading.ac.uk

Sea ice is complex…

When sea water freezes it forms sea ice, a composite of ice and brine. Sea ice exhibits varying structural, thermodynamic and mechanical properties across a range of length- and time-scales. It can be subcategorised into numerous different types of sea ice depending on where is grows and how old it is.



Different sea ice growth processes and types 1.

However, climate models do not simulate the evolution of floes (they model floes as cylindrical) or the floe size distribution, which has implications for ice melt rates and exchange of heat with the atmosphere and ocean. Sea ice also hosts algae and small organisms within brine channels in the ice, which can be important for nutrient cycles. This is a developing area of earth system modelling.

Schematic of life within brine channels in sea ice 2.

How much complexity do global climate models need to sufficiently model the interactions of sea ice with the ocean and atmosphere?
The representation of sea ice in global climate models is actually very simple, with minimal sea ice types and thickness categories. The main important feature of sea ice for global climate models is its albedo, which is much greater than that of open water, making it important for the surface energy balance. So, it is important to get the correct area of sea ice. Global climate models need sea ice:

  • to get the correct heat exchange with the atmosphere and ocean
  • to get a realistic overturning circulation in the ocean.
  • because salt release during sea ice growth is important for the ocean salinity structure, and therefore important to get the correct amount of sea in/near deep water formation sites.
  • sea ice is not important for sea level projections.

So, do the complex features of sea ice matter, or are simple parameterisations sufficient?

Sea_ice_Drawing_General_features.svg Schematic showing some dynamic features of sea ice 3.

Which leads to a lot more questions…

  • Where does the balance between sufficient complexity and computational cost lie?
  • Does adding extra model complexity actually make it harder to understand what the model is doing and therefore to interpret the results?
  • Do climate models need any further improvements to sea ice in order to better simulate global climate? There is still large uncertainty surrounding other climate model components, such as clouds and ocean eddies, which are believed to explain a lot of the discrepancy between models and observations, particularly in the Southern Ocean.

A lot of these questions depend on the scientific question that is being asked. And the question is not necessarily always ‘how is global climate going to change in the future’. Sea ice is fascinating because of its complexity, and there are still many interesting questions to investigate, hopefully before it all melts!

 Images clockwise from top left: grease ice 4, pancake ice 5, surface melt ponds 6, ice floes 7

The Future Developments in Climate Sea Ice Modelling Workshop

This blog stems from a one day workshop I attended on ‘Future developments in climate sea ice modelling’ at the Isaac Newton Centre as part of a four month programme on the ‘Mathematics of Sea Ice Phenomena’. The format of the day was that three different strands of sea ice researchers gave 40 min talks giving their strand’s point of view of current sea ice developments and what the focus should be for sea ice modelers, each followed by 40 mins of open discussion with the audience.

The three (very good!) talks were:

  1. Dirk Notz: What do climate models need sea ice for? A top-down, system level view of what sea ice models should produce from the perspective of a climate modeller.
  2. Cecilia Bitz: What sea ice physics is missing from models? A bottom-up view of what is missing from current sea ice models from the perspective of a sea ice scientist.
  3. Elizabeth Hunke: What modelling approaches can be used to address the complexity of sea ice and the needs of climate models?


  1. https://nsidc.org/cryosphere/seaice/characteristics/formation.html.
  2. https://www.eduplace.com/science/hmxs/ls/mode/cricket/sect7cc.shtml
  3. https://en.wikipedia.org/wiki/Fast_ice
  4. https://www.travelblog.org/Photos/2101807
  5. http://www.antarctica.gov.au/about-antarctica/environment/icebergs-and-ice/sea-ice
  6. https://en.wikipedia.org/wiki/Sea_ice#/
  7. https://www.shutterstock.com/video/clip-15391768-stock-footage-flying-over-arctic-ice-floes.html

Adventures in Modelling – NCAS Climate Modelling Summer School

At the beginning of September 3 PhD students from Reading, including myself, went to Cambridge to attend the NCAS Climate Modelling Summer School. This is an annual event aimed at PhD students and early career scientists who want to develop their understanding of climate models, with topics covering parameterisations to supercomputers.

Staff and students of the course pose outside the Chemistry department, which played host to morning lectures

The course ran over two weeks with lectures on the components of climate models in the morning, covering fundamental dynamics and thermodynamics, numerical methods and different parameterisations. This was followed by an afternoon of computer practicals and then more topical lectures in the evening, such as “User engagement in climate science” and “The Sun and Earth’s climate system”. The lectures were very fast paced but this was a great opportunity to cover so many topics in a short space of time and get a grounding in lots of different topics that I will definitely be looking over in future. A poster session on the second evening gave us the chance to learn about other people’s work and make connections with other people starting out their careers in climate science, including a few readers of the blog, that will hopefully last throughout our careers.

One of the highlights of the course was the chance to run some (rather interesting) experiments with an earth system model. This involved breaking into groups with each being given a different project. It was exciting to go  through the whole process of having an idea, developing a hypothesis, thinking of specific experiments to answer the hypothesis and then analysing the results in just a week – something that takes much longer when you’re doing a PhD! My group worked on the Flat Earth experiment, which looked at the effect of removing all of the earth’s orography not, to our dismay, turning the earth into a flat disk. I learned a lot about how to run models, something which I have never done even though I use the output. It also developed my understanding of different climate processes that I don’t work with such as the monsoons, and even dynamical vegetation.

Flat earth experiment looking at the change in the monsoon winds

Throughout the course we stayed at St Catharine’s College. Right in the centre of Cambridge it quickly felt like a home from home, keeping us well fed to get through the intense science. Although the weekend was rainy, apparently breaking a run of excellent weather for the school, we still had plenty of time to explore beautiful Cambridge. A few people were even brave enough to go punting!

An interesting, hectic and inspiring two weeks later we may have been glad to head back to Reading for a good sleep but having thoroughly enjoyed the summer school.

The beautiful St Catharine’s College, image from http://www.caths.cam.ac.uk/


The 2017 SCENARIO Conference: Frontiers in Natural Environment Research

Every year students from the SCENARIO (Science of the Environment, Natural and Anthropogenic Processes, Impacts and Opportunities) Doctoral Training Partnership organise an annual conference. Those invited include SCENARIO students, NERC employees and industrial partners. This year, after last year’s successful collaboration with the University of Oklahoma, it was decided that we would run the conference (Frontiers in Natural Environment Research) with the Science and Solutions for a Changing Planet (SSCP) and London NERC DTPs, led by a variety of universities and institutions in London.

A similar conference was organised last year (Perspectives on Environmental Change) between SSCP and the London NERC DTP, which was a rousing success. This year, with the addition of Reading and Surrey, we had almost 200 delegates attending with a healthy proportion of supervisors and industry partners, with over 40 oral presentations and 40 posters from students at the various institutions. The conference was held in the Physics building at Imperial College, a literal stone’s throw away from the Royal Albert Hall.

Organising the conference was a daunting task; there was a lot of work involved between the nine PhD students on the committee! One of the challenges, (but also one of the most exciting parts of the conference), was the sheer variety of research being presented. Many of the attendees were from the Met department, but there were also students from Chemistry and Geography from SCENARIO, and students from the London institutions doing topics as varied as sociology, ecology, biology, materials science and plate tectonics. This made for a really interesting conference since there was so much on offer from such a wide range of fields, but made our lives quite difficult when trying to organise keynote speakers and sort abstracts!


As well as the student presentations we also ran workshops and panel discussions, and had two invited keynote speakers. The workshops were about communicating science through social media, and also on getting published in one of the Nature journals (similar to the successful workshop ran by SCENARIO here at Reading). The panel discussions were themed around “Science and Development” and “Science in a post-truth world”, looking at ways in which science (particularly that within the NERC remit) can help to solve the UN’s Sustainable Development Goals, and how we communicate science in a time of “fake news”.


Perhaps my favourite part of the conference were the two keynote speakers. Finding speakers who would appeal to the majority of people attending the conference was no easy task, given the huge range of disciplines!

Opening the conference, Marcus Munafo, Professor in Biological Psychology at Bristol University spoke about the “reproducibility crisis” and how incentive structures affect the scientific process. I can honestly say it was one of the most thought-provoking lectures I’ve ever been to. His main argument was that ultimately science is done by people who have an incentive to do certain things, (e.g. publish in high impact journals), for the benefit of their careers. However, this incentivisation means that often one “big result” can mean more for the career of someone than all the work they’ve done previously, even if that result ended up being retracted or proven false later on, (he went on to demonstrate that happens a lot). One of the statistics he presented was that the higher the impact factor of a journal, the higher the chance of retraction, which I thought was really interesting and certainly made me re-evaluate the way in which I approach my own work.

The other keynote speaker was Lucy Hawkes, Senior Lecturer in Physiological Ecology at Exeter, talking about her work and career, particularly “biologging” of animals and looking at their migratory patterns. Aside from all the great anecdotes and stories (like swimming with sharks in order to plant bio-tags on them), from a meteorologist’s perspective it was interesting listening to her talk about how these migratory patterns change with the climate.

Of course any conference worth its salt has entertainment and things outside work. A BBQ was hosted in the courtyard underneath the Queen’s Tower, and drinks and comedy (the Science Showoff) in the wonderfully titled hBar at Imperial. The Science Showoff in particular was really good, hosted by a professional comedian but with most of the material coming from PhD students at the various institutes (although shamefully no-one from Met volunteered).


One of the other really useful parts was meeting students from disparate fields at the other institutions. As Joanna Haigh (director of the SSCP DTP) said in her closing speech, the people we meet at these conferences will be our colleagues for our entire careers, so it’s really important to get to know people socially and professionally. In the end I think it went really well, and I’m certainly looking forward to seeing the London students again at next year’s conference!

Surviving the Viva

Email: d.l.a.flack@reading.ac.uk

Recently in the department we have had a fair number of students submitting their PhD theses and awaiting or completing their viva.

For many students at the start of the PhD the viva seems a long way off and can often be thought of as a terrifying experience. So why then do many PhD students come out of their viva saying that they enjoyed it? and is it really as XKCD portray it?

Thesis defense according to XKCD

With the help of some former PhD students (Hannah Bloomfield, Sammie Buzzard, Hannah Gough and Leo Saffin) we’ve come up with a summary of our own experiences and some advice for people just about to go in.

But before I get into that I’ll briefly explain a little bit about the viva. The viva is (alongside writing the thesis) the examination for the PhD. Its essentially an oral exam where you sit and talk about your thesis and the area surrounding your field. The viva can last anywhere between 90 minutes and 5 hours, depending on how much you have to talk about (and how much you or your examiners talk). The result from the viva is as follows: Fail; Major Corrections requiring another viva; Pass: Major corrections; Pass: Minor corrections (the most common) and Pass: No corrections (very rare), and at the end of the day it’s the pass or fail that matters.

So what can you expect from a viva? Well, as with each PhD each viva is different (hence why this post is a collaborative effort). Even people’s nerves are different, some go in feeling confident, whilst others are still fairly nervous about it (which of course is very understandable). I certainly was in the nervous camp, but I would have been disappointed if I wasn’t because I always feel I perform better if I am nervous beforehand. Indeed, many of us who are initially nervous become relaxed as soon as we get into the swing of things and the questions start flowing. Furthermore, many examiners (not all) will know and understand that you will be nervous so will immediately put you at ease by saying something along the lines of “I really enjoyed reading your thesis and you don’t need to be worried about the result.” This last statement is probably key for anyone going into the viva – by the time it gets to the viva your examiners have already decided the result, the viva is mainly to check that you did the work.

Looking at the recent experiences of the PhD students I have broadly classified the viva into three types, Presentation,Traditional” and Thesis covering described below.

Presentation (Hannah Gough):

Hannah was asked to produce a presentation for her viva. She did find this useful as it was a good way to settle into the viva and bring across the aims and key conclusions of her thesis, at the same time highlight what she felt was the most important figures in her thesis. After the presentation, the examiners asked questions on her entire thesis. These ranged from points of clarification, to the wider implications of her work.

Traditional” (Hannah Bloomfield, Sammie Buzzard and Leo Saffin):

The more “traditional” viva asks you to summarise your thesis for the first 3-5 minutes and then goes through the thesis asking about wider implications and where your work fits in, basic theory, parts of the thesis they are unsure about and implications of your work (amongst other things).

Thesis covering (myself):

Essentially, all we did was go through my thesis cover-to-cover discussing bits specifically related to my project (some minor wider implications/knowledge) and comments that they had on my work.

So why do people enjoy the viva then? Well, there is a fairly simple answer to this question. You’ve been doing work for between three and four years and now you get to discuss it in detail and the examiner can see that you know what you are talking about and will often ask some interesting and thought provoking questions that you either haven’t considered or didn’t necessarily view as important.

Other things that are worth mentioning about the viva, before going on to our collective advice, is that most of the time (unless you spend a while talking about basics of your area) the viva doesn’t feel it is taking as long as it actually is (2 hours feels like 15 minutes – I’m not just saying that, it really does!) – it’s essentially the old saying “time flies when you are having fun”.

So, that’s a brief overview of the viva and our experiences, so how do you actually survive it? Our collective advice would be as follows:

  1. You are the expert in your thesis – so don’t panic – your examiners don’t know as much about what you did as you do.
  2. The examiners are not there to trick you, they are just checking that you did your work – they’ve already made the pass/fail decision.
  3. Don’t be afraid to ask for breaks from time to time (your examiners may want a break too).
  4. Don’t look at the clock (if there is one in the room). All you will then do is think about how long you have been in the viva.
  5. Bring food (biscuits, etc) and enough to share with your examiners.
  6. Prepare a simple 3-5 minute overview of your thesis and know it well – generally you will be asked to summarise your thesis.
  7. It can be useful to read a couple of your external examiners papers – just to find out a little bit about them at the very least.
  8. Don’t be afraid to ask questions to be explained in more detail so you know exactly what they want.
  9. Eat something before you go in no matter how bad you feel.
  10. Try and get a good night’s sleep beforehand.
  11. Don’t be afraid to say how you would do things differently, after having had time to look back at it.
  12. You are the expert in your thesis – so don’t panic – your examiners don’t know as much about what you did as you do.

With that all I can say if you are facing a viva soon is good luck.

A special thanks to all the former PhD students that helped provide information for this blog: Hannah Gough, Hannah Bloomfield, Samantha Buzzard and Leo Saffin.

Two Weeks in Paris Learning about Fluid Dynamics and Sampling French Pastries

Email: r.frew@pgr.reading.ac.uk

The Fluid Dynamics of Sustainability and the Environment (FDSE) residential summer school runs every summer for two weeks, alternating between Cambridge University and Ecole polytechnique, which run the summer school in partnership. I attended this years hosted by Ecole polytechnique, situated to the South of Paris. 40 PhD students attended from institutes around the world, all working on a range of topics who want to learn more about environmental fluid dynamics.


The lectures covered topics on fundamentals of fluid dynamics, flow instabilities, environmental fluid dynamics, cryosphere, atmosphere, physical oceanography and renewable energy. The lectures went at a very fast pace (approximately triple speed!), aiming to familiarise us with as many concepts as possible in the two weeks, resulting in everyone taking home a large overflowing folder full of lecture notes to refer back to in the future.

We were kept very busy throughout the two weeks. Each day started with breakfast (coffee and croissants) between 7.30-8.20 am, followed by two back to back lectures 8.30-10.30 am. There was then half an hour for everyone to fuel their brain with coffee and (warm!) mini pastries before another hour lecture before lunch break. Lunch was roughly 12-1.30 pm, although typically there were so many interesting questions after each lecture that we ran progressively later relative to the schedule meaning that I think we only actually started lunch on time on the first day. There were also a number of guest speakers speaking on topics such as public engagement, climate policy, meteorology on mars and air quality.

After lunch we had the final lecture of the day, followed by a short break before numerical sessions and lab experiments, which ran until roughly 6 pm. These sessions gave us the chance to really learn about a particular topic in more detail and to have a more hands on experience with some of the material being lectured. My labs were on tidal energy where we explored the energy output and efficiency of tidal turbines, and Art and Science, which encouraged us to engage with Science in new and more playful ways and also to challenge us to look at it differently.

However the day didn’t end after the labs, the evenings were also jam packed! The first evening was a poster session, giving us all the opportunity to learn more about what all of the other students work on and to mingle. Other evenings consisted of learning to row sessions, visits to the observatory, movie nights and discussions about the ‘science’ in The Day After Tomorrow movie and barbeques enjoying the warm light evenings (definitely missing those now I’m back in Reading).

During the weekend sandwiched in the middle of the two weeks, we were all transferred to a hostel in the centre of Paris, setting us all up perfectly for some weekend sightseeing in Paris. On the Friday evening there was a boat party reception on the Siene, supplying us all with lots of wine, many difference French cheeses to sample and a lively dance floor.

The school ended on Friday July 14th, Bastille Day. After a morning presenting a few slides on the labs we had completed in groups to share what we had learnt, we travelled into the centre of Paris ready for an evening enjoying the spectacular Bastille Day fireworks around the Eiffel tower, ending the summer school with a bang.

Personally the main take away from the summer school was not to learn the entirety of the lecture content, but to become familiar with a wide range of topics gain more hands on experience of laboratory experiments and to have a (rather large) folder full of lecture notes to refer back to whenever I stumble across a particular concept again in the future. And of course, it was great having the opportunity to meet lots of other PhD students from around the world working on related topics and to be able to discuss, engage and get to know each other over the two weeks. I would like to thank all of the organisers and lecturers of the summer school for a really interesting and enjoyable two weeks!


Future of Cumulus Parametrization conference, Delft, July 10-14, 2017

Email: m.muetzelfeldt@pgr.reading.ac.uk

For a small city, Delft punches above its weight. It is famous for many things, including its celebrated Delftware (Figure 1). It was also the birthplace of one of the Dutch masters, Johannes Vermeer, who coincidentally painted some fine cityscapes with cumulus clouds in them (Figure 2). There is a university of technology with some impressive architecture (Figure 3). It holds the dubious honour of being the location of the first assassination using a pistol (or so we were told by our tour guide), when William of Orange was shot in 1584. To this list, it can now add hosting a one-week conference on the future of cumulus parametrization, and hopefully bringing about more of these conferences in the future.


Figure 1: Delftware.


Figure 2: Delft with canopy of cumulus clouds. By Johannes Vermeer, 1661.


Figure 3: AULA conference centre at Delft University of Technology – where we were based for the duration of the conference.

So what is a cumulus parametrization scheme? The key idea is as follows. Numerical weather and climate models work by splitting the atmosphere into a grid, with a corresponding grid length representing the length of each of the grid cells. By solving equations that govern how the wind, pressure and heating interact, models can then be used to predict what the weather will be like days in advance in the case of weather modelling. Or a model can predict how the climate will react to any forcings over longer timescales. However, any phenomena that are substantially smaller than this grid scale will not be “seen” by the models. For example, a large cumulonimbus cloud may have a horizontal extent of around 2km, whereas individual grid cells could be 50km in the case of a climate model. A cumulonimbus cloud will therefore not be explicitly modelled, but it will still have an effect on the grid cell in which it is located – in terms of how much heating and moistening it produces at different levels. To capture this effect, the clouds are parametrized, that is, the vertical profile of the heating and moistening due to the clouds are calculated based on the conditions in the grid cell, and this then affects the grid-scale values of these variables. A similar idea applies for shallow cumulus clouds, such as the cumulus humilis in Vermeer’s painting (Figure 2), or present-day Delft (Figure 3).

These cumulus parametrization schemes are a large source of uncertainty in current weather and climate models. The conference was aimed at bringing together the community of modellers working on these schemes, and working out which might be the best directions to go in to improve these schemes, and consequently weather and climate models.

Each day was a mixture of listening to presentations, looking at posters and breakout discussion groups in the afternoon, as well as plenty of time for coffee and meeting new people. The presentations covered a lot of ground: from presenting work on state-of-the-art parametrization schemes, to looking at how the schemes perform in operational models, to focusing on one small aspect of a scheme and modelling how that behaves in a high resolution model (50m resolution) that can explicitly model individual clouds. The posters were a great chance to see the in-depth work that had been done, and to talk to and exchange ideas with other scientists.

Certain ideas for improving the parametrization schemes resurfaced repeatedly. The need for scale-awareness, where the response of the parametrization scheme takes into account the model resolution, was discussed. One idea for doing this was the use of stochastic schemes to represent the uncertainty of the number of clouds in a given grid cell. The concept of memory also cropped up – where the scheme remembers if it had been active at a given grid cell in a previous point in time. This also ties into the idea of transitions between cloud regimes, e.g. when a stratocumulus layer splits up into individual cumulus clouds. Many other, sometimes esoteric, concepts were discussed, such as the role of cold pools, how much tuning of climate models is desirable and acceptable, how we should test our schemes, and what the process of developing the schemes should look like.

In the breakout groups, everyone was encouraged to contribute, which made for an inclusive atmosphere in which all points of view were taken on board. Some of the key points of agreement from these were that it was a good idea to have these conferences, and we should do it more often! Hopefully, in two years’ time, another PhD student will write a post on how the next meeting has gone. We also agreed that it would be beneficial to be able to share data from our different high resolution runs, as well as to be able to compare code for the different schemes.

The conference provided a picture of what the current thinking on cumulus parametrization is, as well as which directions people think are promising for the future. It also provided a means for the community to come together and discuss ideas for how to improve these schemes, and how to collaborate more closely with future projects such as ParaCon and HD(CP)2.