Taking measurements in the Atlantic Ocean for ESA

From Bob Brewin (Plymouth Marine Laboratory, UK) 3 October 2013

Between the 3 October and the 4 November, I will be participating in the 23rd Atlantic Meridional Transect (AMT) cruise. Travelling on-board the RRS James Clark Ross, myself and other marine scientists depart from Immingham, UK, and take oceanographic measurements in the Atlantic Ocean for six weeks before arriving at the Falkland Islands.

RRS James Clark Ross (© NCEO)

These measurements will be used to help validate and parameterise a new bio-optical model being developed within the ESA STSE DECIPHER project.

The project that aims to better quantify marine-ecosystem variability, and its natural and anthropogenic physical, biological and geochemical forcing, using remote-sensing observations.

AMT is a unique time-series of data (1995–2013) taken along a meridional transect in the Atlantic Ocean It is one of the only spatially extensive and internally consistent datasets on the structure and biogeochemical properties of planktonic ecosystems in the Atlantic Ocean.

Cruse track from AMT 19, colours represent low (blue) to high (red) chlorophyll-a concentrations (Taken from Hardman-Mountford et al. (2008) Remote Sensing of Environment 112 (2008) 3341-3352).

So far, there have been 23 cruises, involving 223 scientists, supported over 200 publications and over 70 PhD theses.

My role on AMT 23 is to work on marine optics. I will be working alongside Dr Giorgio Dall’Olmo making the following measurements:

• Continuous ship measurements of above-water remote-sensing reflectance (ocean colour)
• Continuous under-way measurements of inherent optical properties (IOPs) including particle absorption and backscattering, and chlorophyll-a concentration.
• Water column profile measurements of IOPs (particle absorption, detrital absorption and particle backscattering) at 2 stations per day.
• Filtering water for measurements of phytoplankton pigments (using High Performance Liquid Chromatography); size-fractionated chlorophyll-a using fluorometry; Particulate Organic Carbon; fatty acids and suspended particulate matter.
• Measurements of atmospheric aerosol optical depth.