Project EARTH-17-HB2: Relationship between phytoplankton and marine aerosols at the global scale: exploring underlying mechanisms and implications for Earth’s climate, using satellite data

Supervisors: Dr. Heather Bouman, Department of Earth Sciences, University of Oxford,

Dr. Shubha Sathyendranath, Plymouth Marine Laboratory, Dr. Caroline Poulsen, Rutherford Appleton Laboratory

Both aerosols and phytoplankton are important players in Earth’s climate. Aerosols affect the radiation budget of Earth, whereas phytoplankton modulate the absorption of solar radiation in the surface layers of the ocean. Phytoplankton are the primary producers of the ocean, responsible for fixing some 50GT of carbon per year. Phytoplankton and aerosols are also coupled to each other. Micronutrients in terrestrial aerosols brought to the ocean by winds may enhance phytoplankton growth. On the other hand, biological material from the ocean can escape into the atmosphere and act as cloud condensation nuclei. In particular, it has been proposed that some dimethyl sulphide (DMS), a volatile compound derived from dimethyl sulfoniopropionate (DMSP) produced by phytoplankton, can escape into the atmosphere and can act as cloud condensation nuclei. In this project, we propose to use satellite-derived fields of aerosols and phytoplankton to investigate the strengths of the coupling between the two, to identify the mechanisms responsible for the coupling, to explore feedback mechanisms, and identify implications for the Earth’s climate system. The work will use ocean-colour and aerosol data from ESA’s Climate Change Initiative (CCI), and build on work that is being carried out at present within CCI. The student will also work with an in situ database of phytoplankton physiology and community structure provided by Dr. Bouman’s research group.  Dr. Bouman will provide additional expertise on phytoplankton physiology and community structure and how that might impact the phytoplankton-aerosol interactions.  Dr. Sathyendranath (PML) will provide expertise in ocean-colour remote sensing for estimating phytoplankton concentration. Dr. Poulsen (RAL) will provide expertise in satellite aerosol, cloud and derived surface radiative fluxes.

The successful applicant, whose first degree might be marine, atmospheric or earth sciences, will have a strong interest in multidisciplinary research, good quantitative and computing skills.  There may be the opportunity to participate in fieldwork should the student wish