Nitrogen cycling
The nitrogen cycle has important impacts on ocean productivity,
carbon export and air-sea fluxes of greenhouse gases. In the
oceans, nitrogen is an essential nutrient for microbial activity
and, in several shelf-sea regions (including the Western English
Channel), primary production is limited by nitrogen availability.
It is therefore essential that rates of nitrogen fixation, the
process whereby nitrogen from the atmosphere can be taken up by
particular marine organisms then passed to others in a more
“digestible” form, in the ocean and loss in the coastal sediments
are quantified.
PML has a long history of work on the nitrogen cycle and is
focusing on the key uncertainties in the microbially driven cycling
of elements in the surface ocean and coastal seas, not only to
advance understanding but also for use in ecosystem models.
Projects
- Atlantic Meridional Transect
(AMT)
The Atlantic Meridional Transect is a
multidisciplinary programme, coordinated by PML, which undertakes
biological, chemical and physical oceanographic research during an
annual voyage between the UK and destinations in the South
Atlantic, a distance of up to 13,500km. This transect crosses a
range of ecosystems from sub-polar to tropical and from euphotic
shelf seas and upwelling systems to oligotrophic mid-ocean
gyres.