Ocean colour science in the service of the Earth
By Beata Kolecka
(1) Bio-optical - The expression ‘bio-optical state of ocean waters was coined, in 1978, to acknowledge the fact that in many oceanic environments, the optical properties of water bodies are essentially subordinated to the biological activity, and ultimately to phytoplankton and their derivatives. More recently the adjective bio-optical has been associated with nouns like model or algorithms.
Ewa Kwiatkowska tells how her passion has driven her professional development and how monitoring ocean water colour helps us solve local and global problems.
Ocean colour remote sensing scientist
Ewa, you are an ocean colour remote sensing scientist, please, tell us about ocean colour ….
Ocean colour observed from satellites provides information on bio-optical (1) properties of the oceans. In the open ocean, these properties are primarily determined by marine phytoplankton (2) and their main photosynthetic pigment – chlorophyll-a.
Phytoplankton regulate carbon dioxide and oxygen levels in the oceans and the atmosphere, like plants do on the land, but they are more ancient. Cyanobacteria (3) evolved billions of years ago to use water and the energy of the sunlight to convert carbon dioxide to organic matter, sugars, amino acids and other biological molecules – the building blocks of all life on Earth. It’s enough to say that half of the oxygen we breathe is produced by marine phytoplankton. Thus they are critical to life on Earth and to the climate.
Phytoplankton have even been shaping the geology of our planet. A simple example is coccolithophores, a type of phytoplankton distinguished by special calcium carbonate plates, which are the main component of the chalk that forms the White Cliffs of Dover. Interestingly, the extent of the impact that marine phytoplankton currently have on the global carbon cycle was unknown until the advent of global ocean colour Earth observation from satellites in mid-1990s.
These sustained observations followed a mission launched by NASA in 1978 which demonstrated that these microscopic algae, their concentrations, the extent of their coverage and how they change over time, could be detected and monitored from space.
What other applications of ocean colour remote sensing do you work with?
Phytoplankton are also at the base of the marine food chain. They sustain life in the oceans and monitoring of them supports fisheries, aquaculture and marine resource management. Climate change with its increasing water temperatures and ocean acidification due to increasing CO2 absorption is affecting phytoplankton, as is eutrophication (4) from land run-off. Under certain conditions some species of phytoplankton develop into blooms that are toxic to other marine life and to humans. Monitoring and forecasting of these harmful algal blooms is critical.
In Europe we have two important pieces of legislation, the Water Framework Directive and the Marine Strategy Framework Directive impose the requirement on member states to routinely measure chlorophyll-a concentrations and the clarity of water (which is called turbidity); both of which are detected from ocean colour data. These frameworks aim to assure European water quality and Good Environmental Status by 2020.
Ocean colour data are also used to monitor marine and inland-water ecosystems, water clarity, and sediment transport which is often associated with tidal cycles, land run-off and human activities, such as dredging and off-shore construction.
You work for the Copernicus program. Could you tell us about it and what benefits it is bringing to the EU Member States?
Copernicus (5) is a European Commission Earth Observation programme which has been developed to provide environmental information and services. The work is divided into six areas: land, marine, atmosphere, climate change, emergency management and security. The space and ground segments as well as data and product services are currently being finalized to meet the Programme objectives. The space observation infrastructure for the programme is developed by the European Space Agency (ESA) (6).
Copernicus has been established to assure operational, sustained and synoptic measurements in support of European policies and public authorities that administer environmental legislation and emergency management.
The goal is also to boost value-added public and commercial services that will use the data and thus induce innovation and growth.
Furthermore, Copernicus is a vital European contribution to the Global Earth Observation System of Systems (GEOSS) (7) and the interest in Copernicus data and services is truly global. Just within the ocean colour domain we have teams from all over Europe, as well as from Africa, America, Asia, and Australia who want to gain early access to Copernicus data and to support us in validation of data products and in calibration of the space instruments. Critical to all users is the free, full and open policy on all environmental data generated within the Copernicus services.
What are the goals of Copernicus in the area of marine study?
Marine services involve applications such as the monitoring, managing and forecasting of marine resources; coastal and marine environments; weather, climate and seasonal forecasting; as well as maritime safety (14).
The first of the marine observation Sentinel-3 satellite series is scheduled for launch in the middle of 2015 and it will carry an ocean colour instrument - the Ocean and Land Colour Instrument (OLCI).
Can you give specific examples of practical applications of satellite ocean colour data?
One specific application is the detection and prediction of harmful algae blooms, or HABs. Marine biotoxins are some of the most potent toxins in the world and are extremely dangerous. In Europe they occur in all major seas and also in many lakes. HABs in the Baltic are particularly spectacular. Also called red tides, these blooms are deadly to marine life such as shellfish, fish and water birds and are harmful to humans.
In Europe, HABs threaten beaches and drinking water supplies and have a devastating economic impact on coastal fisheries and aquaculture. For example, in Greece, Italy and Spain HABs bring about € 300+ million/year losses in commercial and recreational fishing, tourism, and in damage to ecosystems. The North Sea mussel industry also suffers regularly. Monitoring and forecasting of these blooms is critical and there are a number of projects in Europe which are developing HAB detection and prediction services using ocean colour data in the context of regional ecosystems.
Another example of an ocean colour application is climate change monitoring. Ocean Colour Radiometry is an essential climate variable as defined by the Global Climate Observing System (GCOS) (8) and is required by the United Nations Framework Convention on Climate Change (UNFCCC) (9) and the Intergovernmental Panel on Climate Change (IPCC) (10).
Ocean colour data are used to determine marine biogeochemistry feedback on the climate and on the Earth system. Phytoplankton standing stocks, distribution and species composition determine the productivity of marine ecosystems and their effect on our planet’s ability to recycle carbon dioxide. Phytoplankton are, however, sensitive to changes in water temperatures, nutrient levels, acidification, and other chemical and physical exchanges with atmosphere and land.
Can you please tell us how you came to be working with ocean colour?
Actually my university degrees are in applied mathematics and computer science. The subject of my PhD was in artificial intelligence where I used satellite Earth Observation measurements as useful data during the research and development of my machine learning techniques.
It was during my post-doctoral studies at the Japanese Space Agency that my eyes were opened to the fascinating field of ocean colour remote sensing. The Agency operated the first ocean colour sensor with global coverage. I got to know the people in the ocean colour community and when my Japanese tenure finished I found a new opportunity at NASA’s Ocean Colour project. At NASA I learned the inner workings of a successful multi-mission ocean colour programme. This included satellite instrument calibration, product validation, algorithm development, multi-mission data merger, satellite data processing, data dissemination and user support.
But you came back to Europe…
One may say I am a beneficiary of European long-term thinking. I grew up in communist Poland. I was curious about the world and wanted to travel. After communism I took advantage of the opportunity to study abroad via the European Commission’s Tempus programme (11). The grant allowed me to pursue Master’s and PhD studies in Great Britain.
Five years ago I came back to Europe from the United States to be closer to my ageing parents. I took a position at the European Space Agency (ESA), where I worked on the calibration and validation of satellite data, in disciplines that varied from ocean colour to atmospheric chemistry, for the European flagship Earth Observation mission - ENVISAT (12).
Now I work at EUMETSAT (13), the European Organisation for the Exploitation of Meteorological Satellites. I am responsible for ocean colour science within the agency. EUMETSAT is engaged in marine data services and will operate the Copernicus Sentinel-3 series of satellites as well as the ocean colour instrument. I have thus completed a full circle: from initially benefitting from EC educational funding, to now supporting the EC’s Earth Observation programme.
What has the experience in these different institutions given to you?
At NASA, the practical American attitude taught me that the solutions to problems do not need to be the most sophisticated, but that quick turn-around on implementation, testing, and scientific scrutiny pave the way for steady progress.
Openness of data and information, as well as to the peer review process, stimulates both data use and further development of applications and services. Thinking big on what we can do and the emphasis on service – to the users, to the global community, to science and to our planet – inspire and drive the progress.
My European experience has been teaching me people skills. Typically research groups in Europe are widely distributed throughout the continent and across different cultures and languages. Highly diverse international working environments are stimulating but also challenging. Seeking consensus and reconciling a variety of interests are important skills and one can always become better. The diversity broadens individual and scientific horizons. It also teaches one to put additional effort into mutual understanding, interaction, and cohesiveness of goals.
The area of Earth satellite observation for weather forecasting and climate monitoring seems to require international cooperation, access to data and knowledge sharing. Is this correct?
International cooperation and coordination are absolutely critical. We need multiple satellite missions to provide global coverage. No single agency or country can now provide answers to all the global problems associated with climate change, severe weather and the depletion of ecosystems and the Earth’s resources. We need international cooperation in science and applications. We need coordination on data services and standardisation across the agencies. We need to learn from the best experts on the globe in order to push science and technology forward and to provide the best care for our planet. We also need to train new data users, scientists and the future generation of marine data experts including those in ocean colour.
How is EUMETSAT working together with other partners in ocean colour science?
EUMETSAT closely cooperates with its main marine data user, the EC’s MyOcean programme (14), which is now preparing and leading the demonstration phases of the future Copernicus Marine Environment Monitoring Service. EUMETSAT is also active on the global inter-agency forum and is a member of the International Ocean Colour Coordinating Group (IOCCG) as well as the Committee on Earth Observation Satellites Ocean Colour Radiometry - Virtual Constellation (CEOS OCR-VC). We lead the introduction of ocean colour to the international operational data services, the Coordinating Group on Meteorological Satellites (CGMS) and the European-scale Global Ocean Observing System (EuroGOOS).
In May 2013 EUMETSAT arranged a very successful international ocean colour science meeting, of which I was the local programme lead. The meeting was broadly attended by most of the global ocean colour community and gave EUMETSAT a chance to introduce itself to the scientists and data users. It was a working meeting which produced many community actions and recommendations that were put forward to the agencies operating ocean colour missions. These recommendations resulted in new working groups and new community organisational structures that are now being put into place to support global coordination on ocean colour Earth science and services.
Congratulations on this successful initiative. In your opinion, how will Earth satellite observation for ocean colour data develop in the coming years?
In the satellite business we talk about decades rather than years due to the long satellite programme development schedules. With regard to ocean colour data, two things spring to my mind.
- First is the implementation of an ocean colour monitoring geostationary network of satellites. Currently, ocean colour is monitored from satellites in polar orbits - circling the Earth from pole to pole. The Sentinel-3 satellite will operate in such a polar orbit. Polar orbits aim to provide global coverage, but the coverage of a specific geographic location (away from the poles) can be repeated only once a day or only every few days. In practical terms the oceans are viewed even less often because ocean colour observations are severely limited by cloud coverage.
With geostationary satellites –stably positioned over the equator– we could have repeated observations of the Earth disc every hour (or even more frequently) so that we could see in between the cloudy spells and discover the diurnal variability of marine conditions. The coverage of European waters, outside the northernmost areas, could be achieved by a single geostationary satellite. For global coverage we would need at least 3 such satellites positioned over the equator around the world and this fact highlights, again, the necessity of international cooperation. The first geostationary satellite carrying an ocean colour mission is currently operated by the Korea Ocean Satellite Center .
- Another area of progress in the coming years is the use of hyper-spectral ocean colour instruments viewing in the ultra-violet, visible and near-infrared ranges of the spectrum as well as in the short-wave infrared.
These would allow better atmospheric correction and better differentiation of phytoplankton species, including HABs, and other in-water constituents in marine, coastal, estuarine and lake ecosystems than current multi-spectral instruments do. Hyper-spectral measurements would allow a range of new products, applications and services.
Does Ocean colour science, though fascinating, leave you space for pursuing your personal interests. You like travelling and meeting people from other cultures. What else gives you energy and a sense of fulfilment?
Family and friends mean a lot to me. Going to the gym after a long day at work is a great way for me to relax, refocus and gain energy. I enjoy keeping up with current affairs and popular science. I like archaeology, architecture, music, going to theatres and cinemas, and biking to get to know my region better.
I used to play bridge competitively, draw, and learn languages, but now I have little time to pursue these interests.
Ewa, what advice would you give to young professionals, and in particular women, who are interested in an international career such as yours?
If I was advising young professionals, I would say the following:
- First build your professional network. Professional relations and cooperation with colleagues and the larger professional community in your discipline are always important and can help propel you through your career.
- Seize as many opportunities as you can and believe in your abilities to manage new challenges.
- Find a goal – something that excites you and in which you strongly believe. Do not worry if finding such a professional goal takes time. It may take you in totally different directions than you had originally intended, but finding a subject about which you are passionate is very important for professional accomplishment.
- Keep up your learning and branch out. Be aware of all the issues that affect your professional areas of interest.
- Remember that you will always find friends and your comfort zone wherever you are. In other locations, countries or on other continents, you can always make yourself feel at home.
Ewa, thank you for the interview and for introducing us to the fascinating world of ocean colour science. I wish you much success in your ocean colour data project, and in your endeavour to apply remote sensing science as well as your experience in the service of the Earth.
(6) European Space Agency (ESA)
(7) Global Earth Observation System of Systems (GEOSS)
(8) Global Climate Observing System (GCOS)
(9) United Nations Framework Convention on Climate Change (UNFCCC)
(10) Intergovernmental Panel on Climate Change (IPCC)
(11) Tempus programme
(13) EUMETSAT - the European Organisation for the Exploitation of Meteorological Satellites - is a global operational satellite agency at the heart of Europe.
(14) MyOcean programme
Ewa J. Kwiatkowska received an M.Sc. degree from the Department of Applied Mathematics at the Warsaw University of Technology in Poland, and M.Phil. and Ph.D. degrees from the Department of Computing, University of Bradford in the U.K. She was with the Japanese Space Agency’s Earth Observation Research Center for two years working on Ocean Colour and Temperature Sensor data. Subsequently, she moved to the United States and, for almost a decade, was with the Goddard Space Flight Center of the National Aeronautics and Space Administration (NASA) in Maryland. She worked at the Ocean Colour Project where she gained experience in calibration, validation, algorithm development, data merger, data dissemination and user support for ocean colour missions. She next worked at the European Space Research and Technology Centre of the European Space Agency (ESA) (5) in the Netherlands where she contributed to ENVISAT (6) calibration and validation projects. Currently, Ewa is a Remote Sensing Scientist in Ocean Colour at EUMETSAT in Darmstadt, Germany.
Ewa J. Kwiatkowska
Remote Sensing Scientist - Ocean Colour
EUMETSAT, Am Kavalleriesand 31, D-64295 Darmstadt, Germany
Tel: +49-6151-8077188, Fax: +49-6151-8078380
Any views and opinions presented in this article are solely those of the author and do not necessarily reflect those of EUMETSAT, nor do they constitute a legally binding agreement.