RAFAEL RASSE
An Integrated Perspective on Biogeochemical Cycles
I am a chemist with pluridisciplinary skills, holding a PhD in Chemistry (Earth Science) and a Postgraduate Certificate in Ocean Observatories. My solid multidisciplinary background and skills allow me to have a wide understanding and a unique integrative view on: (1) how various mechanisms concurrently drive the biogeochemical cycles of key elements in the planet’s main reservoirs (i.e. atmosphere, land, ocean and rivers); (2) how such cycles are interconnected within (and between) the reservoirs and partially drive the Earth’s climate; and (3) key biogeochemical knowledge gaps, which I ultimately aim to fill by proposing novel solutions combining traditional and ground-breaking cross-disciplinary approaches, particularly in the poorly oxygenated tropical oceans.
General Topic of Research
Investigating the biogeochemical cycles of carbon and nitrogen in the Earth’s main reservoirs by combining conventional and revolutionary approaches of quantification.
Current and Major Topic of Interest
Biogeochemical cycles of carbon, oxygen, and nitrogen in oxygen minimum zones (OMZs) and anoxic basins.
Career Goal
Contributing to unravel the key set of mechanisms that concurrently modulate the carbon, oxygen, and nitrogen cycles in OMZs and anoxic basins to ultimately contribute to refining their mechanistic predictions.
Main Independent International Multidisciplinary Projects
- Marie Sklodowska-Curie Fellowship. Key factors driving particulate organic matter fluxes and related dinitrogen losses in the main anoxic oxygen minimum zones of the world oceans (Noceanic). Award Period: 2019-2021.PI: R. Rasse. France.
- Royal Society. Autonomous observations of oceanic carbon fluxes in the oxygen minimum zones (Atlantic OMZ). Award Period: 2016-2018. PI: R. Rasse. UK.
- Monitoring seasonal changes of carbonate chemistry off tropical coasts: implications for emissions of CO2 to the atmosphere.Sponsor: Venezuelan Institute for Scientific Research. Award Period:(2015, cancelled). PI:R. Rasse. Venezuela
Pluridisciplinary Research Programmes
- REFINE. Robots Explore plankton-driven Fluxes in the marine twilight zoNE. PI: Hervé Claustre. Award Period: 2019-2024.Website
- Atlantic Meridional Transect. This multi-decadal oceanographic programme undertook biological, chemical and physical research during annual voyages between the UK and destinations in the South Atlantic. 2014, 2016-2018. PI: Andy Rees website
- Nitrogen cycling in Latin America: drivers, impacts and vulnerabilities (CRN 3005). Sponsor: Inter-American for Global Change Research. PIs: Dr J. Ometto (PI), Dr T. Pérez (Co-PI) and others. Award Period: 2012-2017.Website
- Cariaco Basin Time Series. Climatic and Oceanographic Changes in this basin. This programme sought to understand the relationship between surface primary production, physical forcing variables like the wind, and the settling flux of particles in this unique location. Sponsor: National Fund for Science and Technology (FONACIT-MCTI No 201200404). PIs: Dr Irene Astor (PI), Dr T. Pérez (Co-PI) and others. Website
- Bermuda Atlantic Time Series (BATS). A long-term oceanographic study by the Bermuda Institute of Ocean Sciences (BIOS). 2010-2011.Website
International Cross-Disciplinary Training
- On-board training on an Atlantic Meridional Transect (AMT) cruise. Royal Research Ship James Clark Ross and Plymouth Marine Laboratory, UK. 2014.
- Pan-American Advanced Studies Institute (PASI) Programme “Toward a Sustained Operational River-to-Shelf Observation & Prediction System for the Amazon. Brazil. 2013.
- Nippon Foundation-Partnership for Observation of the Global Ocean (NF-POGO) Centre of Excellence in Observational Oceanography (CoFe). Bermuda. 2011.
- Third Surface Ocean Lower Atmosphere (SOLAS) Study. France.2007.
Graduate Courses (> 40 credits, Period: 2007-2012)
- Earth Science
- Introduction to Environmental Sciences
- Climate Change: Causes, Effects, and Mitigation
- Surface Ocean Lower Atmosphere Summer School
- Atmospheric Chemistry
- Effects of Global Change on the Terrestrial Biosphere
- Chemical, Physical, and Biological Oceanography
- Ocean Colour/Satellite Observatories
- Moored Observatories
- Ecological Modelling
- Ocean Data Management
- Carbon Cycle/Ocean Acidification
- Chemistry
- Analytical Chemistry
- Advanced Inorganic Chemistry
- Chemical Kinetics
- Chemical Thermodynamics
Selected Communication and Outreach
- Float posters for global dissemination. 2021.[PDF]
- Participation in an institutional POGO film to promote its role in global ocean observations in the developing world. 2021. video
- Instructive videos on how to securely attach a UVP sensor on a BGC-Argo float video, as well as how to successfully deploy floats in the open ocean. 2020. video.2020.
Skills by Topics
My research into different aspects of the Earth’s reservoir has led me to develop a range of skills, as described below:
Ocean-Sea.
- Exploiting and merging standard and new-generation Biogeochemical Argo floats (ground-breaking approach) and remote-sensing data products to explore and investigate remote oceanic regions in the tropics.
- Using CTD-rosette measurements to study the biogeochemical and optical characteristics of the surface and mesopelagic layer of the ocean.
Atmosphere. Applying high-volume cascade impactor, only-wet deposition sampler, meteorological station, and satellite products (i.e. backward air-masses trajectories) during investigations.
Rivers. Automatic pumping sampler, multiparametric ultrasound, general oceanic speedometer, and satellite products for rivers basins (i.e. precipitation).
Land. Closed chamber methods to collect and then measure greenhouse gases emitted from corn fields via gas chromatography (i.e. CO2 & N2O).
Instruments in the Lab
- Technicon Auto-Analyzer II to analyse macronutrients.
- UV combustion system to convert dissolved organic matter into dissolved inorganic ions.
- Gas chromatography to quantify dissolved organic matter and ions, and gases (CO2 & N2O )
- CHN analyser to quantify particulate organic matter.
- Automatic titration to determine alkalinity and investigate carbonate chemistry in rivers and seawater.
Deployment of Biogeochemical (BGC) Argo Floats, Field Work, and Cruise Expeditions
Deployment of BGC-Argo floats in tropical OMZs. Since 2014, I have been directly involved in coordinating the deployment of the first BGC-Argo floats in OMZs of the eastern tropical north Atlantic and north Pacific. More recently (2020), I deployed the first float attached with an underwater video profiler (UVP) along with an array of sensors that will allow me to generate key information on how diverse mechanisms modulate the cycles of C, O, and N. video
Field work, and cruise expeditions Atlantic Meridional Transect 24 and 26. (80 days). Activities. AMT24: Collecting suspended POM in the surface and mesopelagic layer of the main Atlantic provinces, and processing optical data collected by WETLabs spectral absorption and attenuation meter (role: participant). AMT26: Collecting suspended POM in the surface and mesopelagic layer of the ETNA OMZ, and measuring optical properties. Building and testing an enclosed filtration system with positive pressure to collect suspended POM (role: independent international researcher).
Carbonate Chemistry in Coastal tropical regions (15 days). Activities. Periodic measurements of the physicochemical and biological parameters in coastal zones at subtropical (Bermuda, see acknowledgements here:website) and tropical (Venezuela) latitudes to evaluate the exchange of greenhouse gases (i.e. CO2).
Bermuda Atlantic Time series (BATS, 30 days).
- Processing sampling for the analysis of biogeochemical parameters, and active participation in the deployment of deep sea mooring.
- I conducted a short intensive independent project (~ 3 month), where I designed in collaboration with Dr. Michael Lomas, a bioassay experiment to investigate the effect of ocean acidification in the Redfield ratio. For this purpose, I used conventional methods to collect, process, and quantify biogeochemical variables (i.e. alkalinity and carbonate chemistry, chlorophyll-a, nutrients (nitrate, phosphate, and POM). Dr. Lomas and his collaborators used this preliminary data set as part of a project submitted to the National Science Foundation, USA (Source: Gerry Plumley, Director of CoE-NF POGO programme at BIOS).
Atmospheric deposition at the northeast of the anoxic Cariaco basin (3 months). Activities. Carrying out a selected strategy at the best sampling location to collect atmospheric samples and quantify atmospheric deposition of dissolved nutrients over the anoxic Cariaco basin (role: scientist leader).
Dissolved nitrogen loaded by tropical rivers (48 days over a time series of one year). Activities. Monthly measurements of the in-situ physicochemical parameters, and collecting samples for the analysis of dissolved nitrogen and carbon, and suspended organic matter (role: scientist leader).
- GHG emitted from cornfield (45 days). Daily in situ measurements of emissions of NO, N2O and CO2 from soil. Collecting and processing soil samples for the analysis of physical and biogeochemical parameters.
Ongoing International Collaborations
- Hervé Claustre.LOV-CNRS.France. webpage
- Giorgio Dall’Olmo.PML.UK. webpage
- Mark Altabet. University of Massachusetts.USA. webpage
- Bess Ward. Princeton University.USA. webpage
- Laura Bristow. University of Southern Denmark.Denmark. webpage
- Bo Thamdrup. University of Southern Denmark.Denmark. webpage
Peer Reviewed Publications
- R. Rasse, et al. (2021). Refining the N budget of the anoxic Cariaco basin (to be submitted to Frontiers in Marine Science)
- P. Strubinger Sandoval, G. Dall’Olmo, K. Haines, R. Rasse, and J. Ross (2021).Uncertainties of particulate organic carbon concentrations in the mesopelagic zone of the Atlantic ocean. Open Research Europe.1:43. [PDF]
- R. Rasse, H. Claustre, and A. Poteau (2020). The suspended small-particle layer in the oxygen-poor Black Sea: a proxy for delineating the effective N2-yielding section. Biogeoscience. 17, 6491–6505. [PDF]
- R. Rasse, G. and Dall’Olmo (2019). Do oceanic hypoxic regions act as barriers for sinking particles? A case study in the eastern tropical north Atlantic. Global Biogeochemical Cycles.33, 1611–1630. [PDF]
- R. Rasse, T. T. Pérez, A. Guiliante, and L. Donoso (2018). Total dissolved atmospheric nitrogen deposition in the anoxic Cariaco Basin. Atmospheric Environment. 179, 118-131.[PDF]
- R. Rasse, G. Dall’Olmo, J. Graff, T.K. Westberry, V. van Dongen-Vogels, M.J. Behrenfeld (2017). Evaluating optical proxies of particulate organic carbon across the surface Atlantic Ocean. Frontiers in Marine Science-Ocean Observations. 4, 367.[PDF].
- M. Bustamante, J. Ometto, L. Martinelli, T. Pérez, R. Rasse, et al. (2015). Nitrogen management challenges in major watersheds of Latin America. Environmental Research Letters, 10(6), 065007. [PDF]
- S. Marquina, T. Pérez, L. Donoso, A. Giuliante, R. Rasse and F. Herrera (2015). NO, N2O and CO2 soil emissions from Venezuelan corn fields under tillage and no-tillage agriculture. Nutrient Cycling in Agroecosystems. 101:123-137.[PDF]
- R. Rasse, R. Domínguez, A. Herize, M. Tosta, D. Brusco, and G. Chuchani (2007). “Catalysis by hydrogen chloride in the gas-phase elimination kinetics of 2-phenyl-2-propanol and 3-methyl-1-buten-3-ol”. Journal of Physical Organic Chemistry. 20: 44-48.[PDF]
Published Dataset
G. Dall’Olmo; G. Ross, Rasse Boada R. J. and Strubinger P.A. 2021. Particulate organic carbon (POC) measurements from CTD bottle samples collected during the Atlantic Meridional Transect cruise AMT24 (JR20140922/JR303) between September and November 2014. [data]
Venezuelan and International Funding Agencies (Trainings and Fellowships)
Illustration Credits
AMT Programme, BATS Programme, CARIACO Ocean Time-Series Programme, Victoria Cheung, Thomas Boniface, Robert Brewin, Rodrigo Cab, Hervé Claustre, Giorgio Dall’Olmo, Fernanda Giannini, Adriana Guiliante, Thomas Jessin, José Lozano, Sorena Marquina, Megly Mendoza, N-NET project, POGO, Antoine Poteau, Rafael Rasse, REFINE project, Avery Snyder, SOLAS, and Bess Ward.