My recent trip to Europe, to attend the Ocean Optics XXI conference and European Space Agency workshop preparing for the launch of their new satellite, was a great opportunity for me to meet a huge number of people from the research community I am now part of.
I’d been a little nervous about these events, with a few stumbling blocks in my work in recent months and the potential for major embarrassment and criticism from respected experts in the field. However, these worries appeared totally unfounded as I’ve never before experienced the support and sense of community that I did during the last two weeks.
At the ESA workshop in Frascati, Italy I joined a mixed group of scientists from Universities and governmental institutions, to lament the loss of ENVISAT this year and discuss what this means for our community going forward in preparation for the launch of ENVISATs replacement – the Sentinels. Though it was apparent from personal and group discussions, that the funding situation for science is making things strenuous for nearly everyone at the moment, I think this has only forced the community at large to come together more and plan ever more integrated work to make the most of limited resources. The Earth is a big place and our newest satellites will be collecting data that will cover the entire surface of the Earth every one to two days. You can imagine how difficult it would be thoroughly “validate” (check the accuracy) of this data over the entire Earth with unlimited funds. And we only have very limited funds, so a massive community effort will be needed to make sure our new satellite is giving us accurate data across the variety of land and water types we have on Earth. My task for the meeting was to show why the old and new satellite sensors have been and will be vital for South African research and resource management. South Africa is a microcosm of the rest of the world in terms of its water types with open ocean, sediment influenced coastal waters and extremely productive coastal and inland waters all found in close proximity to this vast and socio-economically challenging country. We often have to exploit many different techniques to address the challenges faced for understand and managing these water from a climate, health and economical perspective. I received a lot of encouraging comments after my whistle-stop tour through mine and my colleagues work and we will certainly be submitted a proposal towards the validation efforts for Sentinel 3 later this year.
I’d heard that discussions at the ocean optics conferences could get a little heated as the latest in optics research is presented, so I was understandably terrified at the prospect of standing up in front of +/- 300 people and putting my hard earned research results in the firing line. Happily, my doomsday scenario never manifested. I was placed in the middle of a session in which all results and comments supported my work, a great confidence booster. Following my talk I received some really interesting questions and ideas for further work and my poster attracted lots of discussion from people interested in a range of topics – from particle modelling, to Harmful Algal Bloom monitoring and the use of different satellite sensors.
The conference was held with a tinge of sadness for many, as the ocean optics community lost two of its founding fathers this year – André Morel and Charlie Yentsch. Although I never got to meet either of these men, their work underpins the foundations of my research. The ocean optics community was full of people who had worked with and had their careers shaped by André and Charlie and there were two special tribute sessions dedicated to them. There were not many dry eyes left in the room as several academics took the stage to share, not just the scientific achievements of André and Charlie, but examples of how they had helped encourage many young students to build the community that exists today. Stories of Charlie helping a keen but young student to start his own company so he could be paid for helping out in the lab, and his ability to make even those much less experienced than him feel engaged in science, were particularly touching. Arguably satellite ocean color would not exist (at least not in its present form) without the work of Charlie and André, however I think their greatest legacy is the one that become apparent to me during the course of the conference. As I saw their ex-students talk about how these great teachers and researchers had supported and influenced their careers I began to wonder if they realised that they themselves were now continuing this, through the encouragement given to me and other terrified PhD students attending the conference?
I am pleased to be part of this community and hope that, even if only in small ways right now, I can offer friends and colleagues the encouragement that has been given to me these last few weeks.
More to come soon about guest speakers and other thoughts about the future of ocean colour/ocean optics from my trip!
October optics adventures!
Lack of blogging (particularly on the food side) is a good indication that I’m working towards something pretty special in my scientific research.
During the last month I’ve been pushing my programming skills to the limit with my PhD research to get as much done as possible before jetting off from Cape Town to attend the biggest conference of my career so far, followed by a meeting with the European Space Agency in preparation for the launch of their new ocean colour satellite.
The ocean optics conference is held every two years. This year it is being held in Glasgow, which is where I’m writing to you from right now! Oral presentation and poster sessions will cover a huge range of topics within the field of optics in the global oceans, including: Remote sensing, shallow water, ecosystem models, high latitudes, phytoplankton, particles and environmental management. It promises to be a great conference, with workshops on processing and data management and various meetings taking place around the central event. I will be presenting both an oral presentation and a poster about my work so far – see my abstract here. I’ll also be attending a user meeting to discuss the fantastic instrument HICO – located on the international space station.
Following ocean optics, I’ll be jumping on another plane to Frascati, just outside of Rome, Italy to visit the European Space Research Institute (ESRIN) for the Sentinel-3 OLCI/SLSTR and MERIS/(A)ATSR workshop. After the loss of ENVISAT and the MERIS instrument aboard earlier this year, we’ve struggled to get good satellite coverage of my research region. Though we are now pursuing the use of hyperspectral data from HICO, we could really do with getting data regularly, as we did with ENVISAT/MERIS. The European Space Agency (ESA) will be launching a constellation of replacements for the ENVISAT satellite from next year. The workshop in Frascati will focus on one of these satellites (Sentinel 3) and one instrument in particular – the Ocean Land Colour Instrument (OLCI). I’ll be presenting a broad overview of our current and future research in South Africa and hopefully will learn a lot on both the technical side of the launch plans and from other researchers hoping to use the data.
Follow me on twitter – @HayleyEversKing for day to day updates about both ocean optics (I’ll be encouraging others to tweet under the hashtag #oceanoptics2012) and the ESA workshop. I’ll be doing some follow up posts on thoughts and overviews of some talks when I get back to Cape Town!
Some healthy, cheap recipes for runners.
I realised today that it’s been ages since I blogged a recipe. However I also found two really great recipes that I wrote a little while ago, whilst we were in the middle of the Wild Runner Cape Winter Trail Series. The series consists of 4 races in various beautiful settings around Cape Town. The first race, at the Paul Cluver wine estate was my first ever race and I really enjoyed it. The following 3 were also good, though a long lasting cold dampened my enjoyment, I was very pleased to receive my first ever medal at the end!
Anyway, here are two cheap and simple dishes suitable for runners on a budget.
Winter cous cous
Student life is full of pressure work and financial so I’m always trying to come up with cheap, healthy but filling recipes – particularly for lunches, which we are so bad at missing during our desk bound weeks at work. We both love cous cous and the little box goes pretty far, particularly when supplemented with any variety of bits and pieces from the house and garden. This is a particularly delicious recipe, which makes the most of some warming Moroccan/Indian and Israeli flavours for a delicious lunch suitable all year round.
Ingredients
Serves two – feel free to add more or less of the ingredients to taste!
1 cup cous cous (plus enough water to make it – check your packet)
1 can of mixed pulses (kidney beans/chickpeas etc)
Cucumber (thinly sliced)
Handful of fresh mint and parsley (roughly chopped)
Juice of one lemon
1 tsp coriander (ground)
1 tsp cumin (ground)
1 tsp fenugreek (ground)
1/2 tsp cayenne pepper (ground)
Method
Make up the cous cous according to packet instructions. Lightly mix the spices through the cous cous, then add the lemon, fresh herbs, cucumber and pulses. Serve topped with some toasted pumpkin seeds (great tossed in a little soy sauce) or in a wholewheat pitta with fresh salad leaves and a dollop of greek yoghurt.
Glazed root veg pasta
Continuing our budget/health kick, I came up with this recipe to use up some lovely sweet potatoes and carrots and make a delicious, meatless meal.
Ingredients
Serves 2
250g spinach tagliatelle (you could use plain, but the delightful color really adds something to the dish)
2 medium sized sweet potatoes
2 medium sized carrots
1 tsp butter
1 tbsp olive oil
1 tbsp honey
1 tbsp balsamic vinegar
10 or so sage leaves
Parsley to garnish
Method
Peel the potatoes and carrots and then continue to make slices using the potato peeler. Drain these well in a colander. Add the butter and oil to a large pan (wok worked well for me). Once the butter has melted, add the carrot and sweet potato slices and toss well to coat with the oil/butter. Fry for 5 minutes then add the sage, balsamic and honey. Continue cooking until the sweet potatoes are just soft and the carrots still have some bite. Cook the pasta for 7 mins or so in boiling salted water until al dente or however you prefer. Drain the pasta and add to the wok. Gently toss the pasta with the vegetables and serve with some chopped parsley and a nice glass of white wine (Riesling works well).
You only really understand something if you can teach it: Academia and adventures in Zanzibar
Parts of this post first appeared as a contribution to the MA-RE student blog. Definitely check out this new venture, organised by a couple of fellow students and I, to see the exciting research and activities taking place at the Marine Research (MA-RE) institute in Cape Town.
I can remember many teachers from my years in education. From my first school teachers who got me extra books to fuel my reading, to the supervisors who’ve inspired me to pursue research, they’ve been some of the most influential people in the way my life has progressed. I’ve now got to the point where opportunities are arising for me to teach, and they’ve been some of the most rewarding experiences of my time as a PhD student.
Last month I was asked to give lectures on ocean colour remote sensing at a Europe Africa Marine Earth Observation Network (EAMNET)/Western Indian Ocean Marine Science Association (WIOMSA) sponsored workshop at the Institute for Marine Sciences in Stone Town, Zanzibar. It was pretty intimidating, knowing I had to prepare and present two days worth of lectures and practicals, but I couldn’t pass up to the chance to meet people from all around east Africa and pass on some of the things I’ve learnt so far during my PhD.
Most of my work involves using data from satellites that measure the colour of the ocean. We can tell a lot about what’s going in the ocean by the light that leaves it (it’s “colour”) including the amount of life (phytoplankton), the amount of sediment and how hot or cold it is. This information has a huge number of applications. In Zanzibar I got to meet many people who want to use this data to help manage coral reefs and fisheries. There’s a lot of quite intimidating maths, physics and computer programming involved in ocean colour data, so explaining how to use it best in 2 days was quite a challenge! The participants eagerly took on learning new software to manage the data, asking lots of questions about how they could use these new skills in their own work.
I feel like I’ve gained a lot of very worthwhile skills from being involved in this and other similar workshops. I really think the saying that “you don’t really understand something properly until you can teach it” is true. In addition, I now have lots of new contacts from all over Africa, who knows what exciting work this could lead to in the future! Undertaking a PhD is hard work and can be very demoralising, but getting involved in projects like this is one of the positives that gets you through those times. Of course there’s always the benefit of getting to see beautiful places too!
From a foodie perspective, Zanzibar doesn’t get it’s spicy reputation without good reason. I had a delicious variety of food during my visit, particularly indulging my love of good curry. For dinner one night we ate at the Silk Route restaurant in Stone Town, which serves Indian inspired fusion foods. The coconut calamari and butter chicken were perfectly spiced and very good value, leaving plenty of spare allowance for us to sample the local beers. Tusker, Kilimanjaro, Safari and Ndovu beers were all good, with Kilimanjaro proving my personal favourite!
A definite highlight for any foodie visiting Zanzibar is the Fordhani market. We were visiting during the Eid festival and each night the market was absolutely packed with families, dressed up for the occasion, the women were particularly striking in their brightly coloured dresses and headscarves. There are loads of street vendors at this outdoor market, you’d have to be in Zanzibar for a year to sample all their wares. Myself and Philip (a South African workshop participant) were drawn to the “lekker lekker” pizza man, an entertaining character, obviously well versed in South African slang, who was making “Zanzibar pizzas”. These pizzas are more like a thick pancake, fried on a large scottle pan, filled with any variety of sweet/savoury fillings. I started with a savoury choice, filled with egg, mince, onions and chilli. This got quickly washed down with a cold glass of juice, made from sugar cane, freshly squeezed in front of me. I couldn’t resist another pizza, opting for a banana and nutella combination – very reminiscent of my time in the tropics in South East Asia.
It’s always nice to find places a little off the beaten track when you visit somewhere new and Stone Town is a great place to do this, with a maze of back streets full of tiny shops to explore. Philip found a tiny little shop called Luis yoghurt parlour – selling fresh, homemade yoghurt, lassis and vegetarian thali. Very quaint and the lady owner is lovely, plus the yoghurt is the best I’ve ever tasted – definitely stop by for lunch.
There’s lots of snorkelling and diving to be done around Zanzibar, however I think most of the best sites are far from Stone Town, so I could not fit in a visit. I did get a small boat out to one of the small islands that you can see off Stone Town. It was nice to see the fish and be in tropical waters again, however the reefs are fairly damaged and I would recommend trying to go elsewhere to get a better experience – Mnemba marine park comes highly recommended.
A few notes on travel and hotels in Zanzibar. I flew from Johannesburg with Precision air, who provided great on board service and were timely on my outward leg. However in Dar es Salaam we were significantly delayed (we waited 5 hours and eventually left at midnight) and many were denied boarding to our over booked flight to Zanzibar and offered no hotel and minimal compensation. Apparently this happens fairly often, so perhaps take this in to consideration if booking a trip to Zanzibar. Saying this, the flights in and out of Zanzibar are frequent and quick (only 15 mins) so may be preferable to a ferry. I stayed at the Al Johari hotel in Stone Town, which I enjoyed until the last day when I realised $200 had been stolen from (a well hidden spot) in my room. The management were not around to deal with this and have failed to respond to both the complaint left with the reception and subsequent contact when I returned to Cape Town. For this reason I would totally avoid this hotel in future.
Luckily I had people to cheer me up! Connie and Angela from Uganda and Elke and Philip (working in Seychelles) joined me for dinner at a local Ethiopian restaurant – Abyssinia Maritim. We ate a delicious meal with lots of different dishes, all served on one large Ethiopian flatbread (injera) to share. Definitely visit here with a group if you go to Stone Town!
I would like to thank EAMNET and WIOMSA for funding this workshop, the IMS for hosting and for their exceptional organisation and hospitality (particularly Dr Yohanna Shaghude) and finally the participants for being welcoming, enthusiastic and ensuring I never had dinner by myself 
The recently published study about organic foods from Stanford University, has generated huge responses across all types of media. From national broadcasting organisations to personal blogs, the last 2 weeks have seen an explosion of media commentary on this article published in a scientific journal. I’ve found the responses probably more interesting than the article itself. It’s been a great time to assess how scientific publications interface with popular media and public opinion.
One thing that’s struck me is that there seems to be differences in expectation between what answers science can provide and what people expect. Maybe it’s a difference in understanding of what the scientific method is, I’m not sure, but from my point of view, as someone who regularly reads scientific articles, many comments have generated a “well, what did you expect?!” response from my inner scientist. With that in mind, I decided to write a short piece on how I use science to inform my decisions about things, particularly that most important of questions to any food blogger: “What should I eat?”.
Foodie folk are very passionate, that’s what makes them some of the most wonderful people to know, to share a glass of wine with and discuss the latest in food trends and products. It’s understandably common to see people defend their passions, we invest substantial amounts of our time and money in them, usually for very good reasons. But being a scientist, you become all too aware of getting too close to your work. No one really goes in to science for money (there are decent but not huge amounts of it!), it’s passion and love for the subject that gets you through the long hours it takes to get a PhD or finish an article for submission to a scientific journal. The most fundamental thing in science though, is change. You can expect that your work will be superceded at some point, it’s the nature of the scientific method. The main reason this happens, particularly in natural science, is that the world is incredibly complex. This means we cannot explain everything with one grand theory, we have to make simplifications and extract lots of questions that we can test experimentally. The question “what should I eat?” is a perfect example of such complexity that science could not possibly address with 1 study, or even 1000.
One major common criticism I saw within the media responses to the Stanford article was that it was oversimplified, that it failed to address most of the reasons why people buy organic produce. “Of course it hasn’t” was my instant response, but one that I thought needed explaining to a passionate group of people who generally sounded offended. If you’ve read the Stanford article (which definitely has room for methodological criticism – but I’ll get to that) you’ll see how much work has to go in to just addressing one question, a question that has a potentially testable and quantifiable answer (in this case, is one type of food more nutritional than the other?). “Hypothesis” testing like this is a major part of any scientific study and creating a testable hypothesis from broad questions is probably the key skill that researchers must learn. “Reductionism” – making a complex system or questions in to smaller, simpler, more manageable components to study, is very powerful in science and often the only way we can proceed. Imagine trying to understand how something is made and how it works – say your laptop for example. It’d be hard to tell just by looking at the laptop itself, but start looking at the components, how they are made, where they come from, and you can piece together a full understanding of how something as complex as a laptop is made and functions. The authors of the Stanford article discussed themselves how their finding went against “what they expected” and that ““If you look beyond health effects, there are plenty of other reasons to buy organic instead of conventional,”. Indeed cited within some of the more comprehensive defenses of organic food I’ve read in response to the Standford article, is a wealth of literature that addresses these very reasons.
So how do I take lots of answers to lots of little questions to form my views on such complex questions as “what should I eat?”. Unfortunately, it does require a fair bit of reading and thinking and often, being prepared to change my mind in the pursuit of what is most “true” regardless of how much passion I have for the subject. I can’t count the number of times I’ve changed my mind on various environmental issues, as I’ve added new information – nuclear energy, climate change, conservation methods, how I think about these things changes all the time. In fact I think some parts of the questions I have about food are beyond the ability of science to answers. Science can’t assign value as such, for example. How much does the suffering of a pig bother me? Sure, science can probably give me some insight in to the extent of disease suffered in various farming conditions, or maybe even an idea about the amount of pain or stress animals feel. But how much value I place on the happiness of a pig versus not eating bacon is still a personal decision and not something I can look to science to resolve entirely for me.
Of course we’re not all scientists, and even those who are aren’t expert enough to understand everything in detail. We can’t all read huge volumes of scientific articles in the peer reviewed journals. So where does that leave us, if we want to use the latest information to help inform our decisions about food? I’ve harped on about the importance of science communication before and scientists and journalists alike have a terribly hard job of taking a reduced concept and communicating it accurately to an information hungry public who want to know how it fits in to the big picture. A few thoughts from me:
Be critical…
Critical thinking and evaluation is key in science and anyone can assess scientific data and methods in a critical manner. An easy way to do this is with media delivered science is to compare sources. What do different media sources think of the same scientific results? Scientific articles will usually give a couple of specific conclusions. But as has been the case with this Stanford article, you’ll see different responses – if the article is really saying one thing, why do we then see so many different responses in the media?
…but check your bias and other peoples!
Naturally I want my science to be right, I’ve spent hours on it, but I know as a scientist that I mustn’t let this desire get in the way of finding the most accurate answers to questions. As bitter as that pill might be to swallow, I must constantly make sure I don’t let my desire to be right get in the way of determining the most accurate information – I must check I don’t get biased. The same goes for assessing media sources of information. Is there a reason that a specific media outlet might be inclined to spin the results of science a particular way? Going back to the paper itself and seeing if you agree with the way a media source has reported the findings is a great way to see if this bias exists. This was the first thing I did when reading the various responses to the Stanford article. Being sceptical does not mean automatically taking the opposite view to someone else or thinking something is automatically wrong, it does mean asking more questions.
There should usually be more questions than answers and that’s ok!
With the idea that science is inherently reductionist through necessity in mind, it’s totally expected that a study doesn’t address every aspect of a broad topic. In fact often the only thing a study may be able to say is that we need to study something more. I get lost on huge google expeditions as a result of this sort of approach, but I think it’s probably the only way to be sure you’ve got to the most current and best information at your disposal. Luckily we live in a world where information is at our fingertips and scientific findings are becoming more available in the public domain, in ever more digestible forms without compromising their accuracy. Even if you only read the abstract or conclusions from a paper, I can recommend getting as close to as many original sources of information as you can. Then you can question both the media you read and science itself. Why didn’t they use more samples? Perhaps they should have looked at a different area/type of plant? – These are examples of valid questions and criticisms of an approach.
Know the limitations.
Keeping the scientific method in mind, you’ll know that no study can answer everything and that’s ok. Keep an eye out for follow up papers, follow the references within one you’ve read, look for reviews on the topic and you can extend the simple questions from single studies to find answers to complex questions. And if you really have many questions, maybe it’s time to become the one doing the studies, that’s how I ended up here
Addressing the Stanford study in particular, I’ve seen a number of interesting criticisms of the methodology and some hints of bias. I’ll be treating these criticisms the same way I treat any science – with scepticism and a demand for evidence. I look forward to seeing how the responses develop over the next few months. For me, the debate over the value of organic farming practices is still open for inquiry. I try and buy local and organic produce where I can for a number of reasons, some supported by scientific studies, others a result of personal preferences. I’m not expecting a single study to answer whether I should or shouldn’t buy organic soon, but I look forward to reading all of those that seek to answer at least a small number of the myriad of questions that this topic raises.
How do you use scientific studies to inform your opinions on certain topics? Where do you hear about scientific studies? What makes you more inclined to accept one study as reasonable and another not? As someone striving the bridge the gaps between science and society, I’d really like to hear from you.
A mornings musings on science communication
With environmental and health concerns rising in the last few decades, science (and the work of those who work within it) has been thrust in to the media spotlight more and more often.
Whilst those of us who work within the scientific arena are aware of the methods used and can understand and interpret the uncertainties associated with results, within the media realm, things are not always so clear. I think it’s important for science and society to interact more, many of us go in to science because of our search for knowledge but I think it’s legitimate to ask why we’re funding science if not to offer some information on public concerns. I’d like to see more scientists engaging with the public. Their work deserves recognition, I know how much hard work and diligence often goes in to it and it seems more and more that the public wants to engage in debates around the issues to which science contributes information.
I get a lot out of the science communication I’m involved in. Sharing the things you are passionate about with interested people is just about the most rewarding thing I think you can do. I guess I wouldn’t be writing this blog if that wasn’t the case! But it’s not without difficulty. When the quantifiable uncertainty of science mixes in to moral and ethical decision making, the clear(ish) waters of scientific debate can get muddied by personal views and it takes a lot of care for messages and meaningful discussion not to be lost.
Anyway, the inspiration for this mini-post was a couple of things.
First a beautiful example of how to share research in an inspirational way. Check out this video from Lauren De Vos about False Bay.
Second, this very interesting piece by Wendee Holtcamp entitled “Flavors of Uncertainty: The Difference between Denial and Debate”, which summarises and discusses some of my feelings about science communication very nicely. I particularly identified with this quote from Naomi Oreskes – professor of history and science studies at the University of California, San Diego:
““I’m here with the very depressing conclusion that knowledge isn’t power”
When you’re in the business of furthering knowledge and passionate about it, the way that hard earned insight can be dismissed by people who don’t like it’s implications can be pretty depressing. It’s not easy for everyone for draw boundaries between where science ends and ethical decision making begins. The article goes on to discuss ways this can be addressed to inspire mutually beneficial engagement for both parties with great advice from Atmospheric scientist, Katharine Hayhoe:
“offer a positive message about what we can do right as opposed to a negative message about all the things we’ve done wrong…refrain from alarmism…give concrete examples of ways to take action…It’s better to connect than to dismiss, and to encourage than to shame.”
I hope that science communication will continue to be a big part of my future, regardless of the focus of my work. I can’t imagine we’re going to run out of science to discuss or problems to solve any time soon.
I’m sorry for sporadic posting, I’ve recently been finishing off a book chapter and I’m about to head off to Zanzibar to teach on an EAMNet/WIOMSA sponsored Operational Oceanography course for a week. It’s been a fair amount of work (for those of you who think I’m just swanning off to have fun in the tropics) but I’m sure I will get a lot out of sharing my science with new colleagues from around Africa. Expect a post about my experiences soon!
Frontiers in Ocean Optics and Ocean Colour Science – An IOCCG lecture series: Thoughts and South African perspectives.
(This one may be a little geeky for those of you who read mainly for the poached eggs, I apologise 
)
For two weeks in July I was one of a very privileged few chosen to attend a summer lecture series organised by the International Ocean Colour Coordinating Group (IOCCG). The IOCCG operates as a voice for the ocean colour community, encouraging collaborative calibration and validation exercises, producing synthesis reports and providing training for those who work with ocean colour data. Our two week course was designed to expose early career scientists to the current frontline research in ocean optics and create an environment where students could discuss questions arising with the very best academics from the field.
I think the course will prove absolutely invaluable for my PhD research and for my future career, but I also came away with a number of thoughts and ideas for how frontiers in ocean optics and ocean colour research fit in a broad South African context.
Regional questions for a global data set
A lot of the major problems with using ocean colour data, from atmospheric corrections to chlorophyll and suspended sediment algorithms, result from differences in fundamental optical properties at a regional level, making it hard to find a “one size fits all” solution. The Case 1/Case 2 definition has been used to help separate waters to address this in some algorithm applications. However there are always exceptions and today many approaches are expanding on these old distinctions, classifying water types based on their optical properties. In South Africa we have a huge diversity of water types, allowing us the opportunity to really look in depth at the natural range of variability in optical properties and the consequences for ocean colour data. We have highly productive waters, waters with high sediment content, in land lakes carpeted in cyanobacteria and the deep, open ocean waters of the Southern Ocean, all within relatively easy access.
New technology
With the recent demise of ENVISAT it has become apparent how much we can come to rely on the specific characteristics of technology to help answer our scientific questions. For my research in the Benguela, the bands available on a satellite (how often the satellite measures the different colours over the light spectrum) are really important, particularly those in the red. The resolution of these measurements i.e. the number of and placement of the bands, can be crucial for resolving oceanic components of interest – high chlorophyll biomass, and the pigments indicative of different phytoplankton species. A fascinating lecture by Curtiss Davis (Oregon State University) awakened my curiosity through the use of HICO data – hyper spectral radiometry from the International Space Station. Although the data from this amazing instrument is not regularly available, the wavelength resolution is more comparable to our in water radiometers – unveiling massive potential to resolve things like pigment induced absorption peaks. Great for helping to identify potentially toxic phytoplankton species. A series of lectures from Richard Stumpf (NOAA, National Ocean Service) highlighted these specific requirements for Harmful Algal Bloom monitoring, a major focus of my research work. With the occurrence of high biomass, mono-specific blooms in South African waters, there’s real potential for us to evaluate and develop these methods.
Models
Modelling is a key component in many modern oceanographic studies. Whether you are looking at currents, biological production or (as in our case) interactions between light (physics!) and phytoplankton (biology!), you can be sure there’ll be some modelling to be done. As we progress in asking more interdisciplinary questions, it is becoming more and more necessary to couple our models together to understand interactions between components. During the IOCCG course, I got to use Hydrolight for the first time. Hydrolight is a model which allows you to investigate the impact of different water properties on the light field that is observed by instruments like our satellite mounted radiometers. As we found out in a series of lectures from Curtis Mobley (Sequoia Scientific), Hydrolight now has the potential to be coupled to more complex physical and biological models – providing greater insight in to how incident light heats water and how much is available for biology at different depths. Crucially, this model coupling allows us to investigate the extent that biology can feed back in to these processes. With expertise in modelling already existing in South Africa using the Regional Ocean Modelling System (ROMS), the potential to investigate these coupling methods could be enormous.
Uncertainties
Understanding and quantifying uncertainty in measurements is an essential background that must be in place to investigate trends in observations. How to “know what you don’t know” was a major component of a lot of the lectures during the IOCCG course. Errors in ocean color data can come from many sources, including the instruments themselves, atmospheric corrections, extrapolations to ocean surface signals and algorithm assumptions. For our applications in South African waters, the diversity of sources of uncertainty are as numerous as the water types themselves.
In highly turbid waters such as those dominated by high biomass or sediment content, typical atmospheric correction methods fail due to the bright reflectances caused by these conditions. In high latitude waters, additional uncertainties are introduced. The viewing angle of the satellite and unique inherent optical properties have to be accounted for.
For long term applications such as the investigation of global climate change impacts, further uncertainties can be introduced. To detect trends and attribute causal mechanisms, long time series are needed. Current thinking suggests we may need between 18 and 60 years (location dependent) to detect trends from ocean color data. Whilst ocean color data collection has been happening since the 1970′s, the data is not continuous with respect to spatial and temporal sampling, or instrument used. As mentioned above, the specifications of particular instruments can make them more or less suitable for certain applications. Changing these specifications over time, as instruments change, can introduce error in the parameters generated. However the pay off for establishing usable, long time series with appropriate errors, is potentially massive, with something like just 1/8th of a satellite orbit providing more data than even our longest in situ biomass estimates.
Future perspectives
So where is ocean colour science going from here? And where does South Africa in particular fit in to this? Well, we have several new satellites to work with. From an SA perspective, this particularly means OLCI aboard Sentinel 3 to replace our use of MERIS. The diverse range of water types in SA should provide a great chance to test the capabilities of this new instrument and hopefully in return it will provide us with continued time series of data for Harmful Algal Bloom and water quality monitoring. The global push towards understanding high latitude regions, thought to be so susceptible to climate change, shows no signs of abating. The Antarctic still remains poorly understood and undersampled, perhaps even more so than the Arctic. With the arrival of the new SA Agulhas II, South Africa has the potential to address this. Add in the new suit of optical instrumentation and developing expertise in this field and there is an exciting amount of work to be done in the near future! With great opportunities to gather in situ data, new satellites on the horizon, modelling expertise and some of the most interesting waters in the world, I think it’s safe to say that South Africa can definitely be at the frontiers of ocean optics and ocean colour science.
I would like to thank the IOCCG for this amazing opportunity and in particular David Antoine and Tatiana Donnay for their fantastic organisational skills and welcoming hospitality. Also many thanks to all the lecturers for their content which has inspired this post. Final thanks to the great group of students who I look forward to seeing again at conferences and on the seas in the future!
