My love-hate relationship with clouds

(This blog originally appeared as an article in theWeather magazine of The Weather Club, altered with permission of RMetS)

“Window or aisle madam?” There is only one answer to this question for your average meteorologist/climate scientist. When I have to fly (and I avoid it as much as possible these days), I always opt for the window seat. On long haul to the US I may get to see sea ice, whilst on flights to Niger for a Saharan dust project it is the surprising colour variations of the world’s largest sand desert. On most flights however, it is the clouds that hold my attention. I alternate between thinking how beautiful is the multi-layered scattering of bubbly white water droplets, and despairing of ever being able to represent such an important component of our atmosphere in global climate models.

Clouds affect climate in several ways. Firstly, they are responsible for moving energy and water around our earth-atmosphere system – heat is released inside clouds when water vapour condenses to form water droplets (it’s the droplets we actually see). Secondly some (but not all) clouds lead to rainfall or other precipitation. Finally, clouds interact with both sunlight and the long-wavelength radiation emitted by the earth to space. Different types and thicknesses of clouds do this in different ways; for example high cirrus clouds mainly act like a blanket keeping the energy emitted by the earth from escaping to space. On the other hand, thick stratus clouds reflect lots of sunlight back to space preventing it from reaching the earth’s surface. Clouds change in response to surface and atmospheric temperature changes, changes in humidity and changes in atmospheric aerosol concentration (water vapour has to condense on to these tiny particles in order to form cloud droplets). Thus cloud changes are part of the atmosphere’s response to climate change, as well as being crucial for our everyday weather.

My main problem with clouds is their variability, from minute to minute and from place to place. The processes responsible for creating clouds (the condensation of water vapour onto tiny specks of “dust” (aerosol), the rising and sinking of air parcels and many others) take place on very small space and time scales. Computer models of weather and climate represent the quantities that describe our climate system (for example temperature, pressure, wind, humidity) on a stack of grids laid out across the earth. The equations that predict how these things change with time are then calculated at each of the crossing points of these grids. Any processes or events that happen between the crossing points can only be represented in some average way in these equations, and this can lead to uncertainty in our predictions. Climate models typically have grid points 10s to 100s of kilometres apart.  Even the best computer models for making weather predictions might have a resolution of 1 km (and due to computational expense this is only possible if you are considering a small area of the globe, e.g. the UK and a few days ahead at most). Most cloud processes happen on smaller scales even than this. The method of taking these into account somehow is called “parameterisation”, and considerable research effort is spent determining the best way to do this (see also the excellent PLOS blog about parameterisation and much much more by Tamsin Edwards) . We use field measurements or much more detailed models of the processes happening inside an individual cloud to develop relationships between the key quantities and those that are used in the equations of a weather or climate prediction model. Inevitably however we have to make simplifications or generalisations in some places and this can lead to diversity in how different models represent cloud and other processes and to differences in the resulting predictions.

Despite their variability and complexity, I agree with the founder of the Cloud Appreciation Society,  Gavin Pretor-Pinney, who wrote also in theWeather magazine, “life would be immeasurably poorer without them (clouds)”. My journeys by plane would however be somewhat less emotionally charged!

Professorial luxuries

I was promoted to full Professor in October 2011. Since then I have been asked on many occasions “how’s life as a Professor?”. The questioners usually fit into one of 3 categories:

  • a senior colleague who is making sure I’m ok (I assume!)
  • a peer who has also been recently promoted, who is  checking that our experiences are similar
  • a more junior colleague who is interested in my response in connection with their own career development.

It’s actually a very hard question to answer because I was asked to be a Head of Department (HoD) very soon after my promotion came into effect, and thus much of the experiences of the past 18 months have incorporated both the promotion to professor and the new responsibilities of Departmental leadership.

The “personal titles” or promotion process at our institution takes a long time and involves several hurdles. I may expound on this process in a different post at a later date, but the point here is that my change of status was made public in May 2011. I started preparing for my HoD role by shadowing the existing incumbent in Jan 2012 so I suppose I had 7 months in which to “just” be a Professor. Here are a few thoughts I had at the start of that time.

  1. Yes! Finally! I have made it to the top, and I must be doing something right after all.
  2. Phew. I’m tired.
  3. Now I don’t have to prove anything to anyone anymore, so I can afford myself the luxury of prioritising research and other activities as suits me, and not as I think suits the promotion process.
  4. Err… and what is that exactly?

If I am lucky, I will have around 20 years ahead of me as a professor (allowing for good behaviour and no further tweaking of the retirement age). The traditional image of professors is usually male, 50+ and somewhat absent minded.  Clearly, I don’t meet at least 2 of those criteria (my research group can probably comment on the other), and in my field at least I know many other “young” professors. It is no longer a role that we get for a few years before retirement. It is likely that I will have several “goes” at formal leadership roles, and will need to adjust from ”being in charge” to “not being  in charge” several times during that period.  In the longer term, there are two main routes, stay as a research and teaching based professor – perhaps developing a new area, or move towards University management, via Head of School, Dean etc. As yet, I have no clear ideas on this one, but I also don’t think I need to just yet!

At my first staff development review following my promotion, I was advised to spend some time thinking about what kind of professor I wanted to be. Most definitions of “professor”  are based on  “a scholarly teacher” or similar, but the precise meanings varies by country, and increasingly by university (at least within the UK). Wikipedia describes a professor in the UK as “a highly accomplished and recognized academic, and the title is in most cases awarded only after decades of scholarly work to senior academics”. The first of these definitions explicitly includes a reference to  teaching”, whilst the second doesn’t. In our research intensive Department, we have a lot of Professors, but their roles are diverse. Some are the leaders of national strategic research organisations, and tend not to be involved in lecturing although they do supervise PhD students and contribute substantially to the strategic direction of the Department. Others have specific links to external organisations or other academic institutions. Then there are those with the more conventional roles – a mix of research, teaching and administration duties.  I fit into the latter group, and that is where I have always felt at home – with a mix of roles.  For another view of professorial types, see Athene Donald’s excellent blog (see if you can spot me, you or your own closest professor amongst them – if not, invent a new one to fit!)

So, in answer to those questions, really it has been “business as usual”  since promotion in many ways, the main change is that the level of responsibilty of the administrative role has increased dramatically. I do feel like I can go my own way more – within reason I can decide whether or not to put in that proposal, go to that conference, do that outreach, tweet, or start that blog, without worrying about how it will look on my CV.  It does bring new opportunities for talks, contacts and experiences – not all of these have to be accepted (but those who know me will know that “no” has never been the easiest of words). The title of Professor does not provide immunity to imposter syndrome. It’s a bit like going up to the “big playground”  at school – the games and faces are new and a bit mysterious and you are not entirely sure how everything works but don’t want to ask. Nor does it mean you can stop thinking about your self-development. I also somehow feel more “visible” and therefore have to make sure I am more professional than ever before. Finally, it means a lot to my family, who are very proud of having a Professor amongst them, although some still aren’t sure what I actually do!

As to the luxuries in the title?

  • My professorial contract appears almost identical to the previous one except for a paragraph where I am apparently allowed to claim for 1st class rail travel – I have not yet tested this as I am usually travelling with others and that seems a bit unfriendly. I suspect my funding body doesn’t allow anyway it unless it’s the cheapest way to go.
  • Due to the increase in staff resulting from the University’s Academic Investment Programme, professors in Met no longer automatically get a larger office – I did, but that’s because I moved  to a different building as part of the expansion programme and the rooms over here are all large.
  • I do get a share in a PA –  without whom, the ship would definitely go down.

Proud to be a climate scientist

I really should know better than to discuss my job in public. Admitting to being a climate scientist tends to result in lengthy discussions of why we are told to reduce our carbon footprint when it’s developing nations that are “the problem”, why we think we can predict the climate in 100 years time when “tomorrow’s weather forecast is wrong”, and more recently defending our scientific integrity.

In fact there isn’t a typical “climate scientist” (leaving aside the generic “scientist” with his grey beard, white coat, socks and sandals that is!). Every one of my colleagues works in a very different way towards understanding the building blocks of our atmosphere and oceans and how changes in these affect day-to-day weather and year-to-year climate. My work concerns how particles in the atmosphere affect the way in which radiation from the sun reaches the ground. These “aerosols” are very small droplets of dissolved sulphate and nitrate chemicals and specks of soot from fossil fuel burning, desert dust picked up by Saharan winds, microscopic debris from volcanic eruptions and even sea salt from bursting bubbles on the ocean surface. One hundred times smaller than the droplets you might spray from an aerosol can, each one of these tiny particles suspended in the air has the potential to scatter or absorb radiation from the sun, preventing it from reaching the Earth’s surface and therefore potentially cooling the ground. Some of them can also attract enough water to spark the growth of cloud droplets – indeed without them it would take so long for enough water molecules to get together and grow that we’d never see clouds at all!

I fly through pollution plumes in the Facility for Airborne Atmospheric Measurement BAE146 aircraft. In recent years colleagues and I have measured aerosols from European pollution, African biomass burning and desert dust, and volcanic ash. Once I know how big the particles are and what they are made of, I use computer simulations of sunlight bouncing off them to calculate how much of the suns light is prevented from reaching the surface. I can also tell colleagues what characteristics they should give these particles in their global climate model so that they can simulate their impact on climate change. If I venture to the coffee room I can learn about glacier melt, ocean current modelling, how to extract useful data from satellite instruments, the physics of hurricanes, the impact of road transport or supervolcanoes on surface temperature, or changes in African rainfall over the past decades. Other colleagues will be in laboratories, recreating constituents of our atmosphere or ocean in a controlled environment, while still more will actually be out in the weather making observations of atmosphere, ocean, land or ice. There are so many exciting ways of probing our earth-atmosphere system, but whichever one an individual climate scientist chooses, we all have the same goal – to understand the processes that make up our earth-ocean-atmosphere system. This will help to improve the quality of those climate (and weather) predictions.

So, I think overall I’m proud to say that I am a climate scientist. It’s just as well really, my only other option is to say that I am a physicist and that tends to result in a glazed expression and an abrupt end to the conversation. Hmm…. wait a minute, that could be useful…..

This article was originally published in theWeather magazine of the Royal Meteorological Society in 2010

Back at the EGU

Back at the EGU (European Geosciences Union) after a 6 year absence, it felt both reassuringly familiar, and strikingly different. The throng of scientists moving around the conference building, the vast stretches of poster boards and the queues for coffee were all recognisable. The temperatures in the darkened rooms tended towards Saharan rather than glacial, and there were definitely some questions about  indoor air quality. Oral science sessions and posters aplenty kept us occupied from 8.30 am until 7.00pm. For the really keen, short courses and specialist town meetings (such as the EGU Women in Geosciences network) continued further into dinner time.

But there were also hints of the way that the life of a research scientist is changing. Some of the poster sessions were replaced by “PICO” (Presenting Interactive Content) sessions on large touch sensitive screens. Tweets allowed those of us who would have liked to have been in two places at once to keep up with the goings on in parallel sessions. A session on the use of social media in science was well attended and lively, and I went to my first ever “tweetup”. These new ways of interacting with colleagues, and the wider world, were unheard of when I started my PhD. As a somewhat under-confident PhD student, it would have been so much easier to contact the awesome “experts” in my subject area had I been able to check out their blog before asking a question on twitter.

Thanks #EGU2013 for allowing me to connect with old friends, hear about the latest work in aerosols, Saharan climate, biomass burning and rainfall, make new contacts, and  for inspiring me to finally get around to blogging.

Hello out there.

I am a professor of climate physics at the University of Reading in the UK. In this blog, the plan is to chart my journey through the worlds of atmospheric aerosols, climate change and academia. I hope it will explain a few things, highlight some fascinating science, and in due course explain to my two young sons what it is that I do all day!