Gavin Tilstone from the Plymouth Marine Laboratory details the next part of his voyage through the Atlantic – as part of the AMT4 OceanSatFlux project, supported by ESA.
From 4 to 9 November 2019, we passed over the equator and into the South Atlantic Gyre.
The equator is an eerie place; humid, silent with no wind. The clouds hang so low that they almost touch the sea. It is a low-pressure area where the prevailing winds are calm and rain can be heavy. This equatorial region is also known as the Doldrums. Ancient mariners found it very difficult to navigate through this area due to the lack of wind. It is part of the Inter-tropical Convergence Zone where the northeast and southwest trade winds converge forming an equatorial trough – where there is high evaporation and precipitation.
The equatorial trough push surface waters westwards, creating a pressure gradient to allow deeper richer waters to advect to the surface. With them they replenish the photic zone with nutrients causing jets of patch phytoplankton blooms. This is rich pickings for many marine fish and mammals. Both the nutrients and temperature in this region can vary greatly depending on the strength of the ...