Robotic vehicles used in AlterEco

  • Ocean gliders: these vehicles uses changes in buoyancy to fly through the ocean in a see-saw fashion. Gliders typically measure temperature, salinity and depth down to a depth of 1000m but can also be equipped with specialist sensors measuring water properties such as chlorophyll fluorescence, optical backscatter, photosynthetically active radiation (PAR) and oxygen.
  • Nutrient Sensor Enabled Gliders (NSEG): These specialist gliders carry micro-fluidic 'lab-on-a-chip' sensors developed and manufactured at the National Oceanography Centre that can measure nutrients such as nitrate and phosphate. In AlterEco, NSEGs will be used to measure seasonal and episodic changes in ocean nutrient concentration.
  • Ocean Microstructure Glider (OMG): AlterEco gliders will also carry state-of-the-art sensors that will enable measurement of ocean mixing rates so that we can answer why the ocean is changing under different forcing from wind, waves and tides.
  • Wavegliders: These unmanned surface vehicles (USV) are propelled by wave motion. AlterEco Wavegliders are fitted with meteorological sensors for measuring wind speed and direction, air temperature, humidity and solar radiation). They will also measure surface temperature and salinity and will use newly developed underwater acoustics for identifying small fish and zooplankton.

Ocean gliders:

  • temperature, conductivity and depth (CTD),
  • chlorophyll a (chl a),
  • optical backscatter,
  • photosynthetically active radiation (PAR)
  • dissolved oxygen.
  • phytoplankton location, abundance and productivity (derived)
  • net community production (derived)

Ocean Microstructure Glider (OMG):

  • dissipation rate of turbulent kinetic energy (TKE)
  • diapycnal turbulent mixing rates
  • turbulent fluxes of heat, momentum, gas and nutrients (derived)

These fluxes are key to understanding the role of air-sea exchange, transfer across stratified interfaces, across the benthic-pelagic interface and variable tidal and meteorological forcing on physical and biogeochemical cycling.

Nutrient sensors enabled glider:

  • winter nutrient stocks (estimated)
  • organic matter remineralisation (estimated)

Nutrient data will be used to assess benthic-pelagic exchanges through coupling with simple models and other measurements (such as suspended particles, turbulent shear stress)


  • wind speed and direction
  • air temperature, humidity and solar radiation
  • air-sea heat and momentum fluxes (estimated)
  • zooplankton and small pelagic fish location and stock abundance (estimated)