Daily Operations

I had to write this for our cruise as an update of what we have been going on the cruise, so I thought I might as well post it on the blog and give you an idea of what we are actually out here for! We are only a few days away from Rio and you can definitely see the difference in everyone's moods. Everyone has a little bit more pep in there step knowing that home is not far away. It's pretty crazy to think that we have been away for over two months. There have been a lot of ups an downs, plagued with equipment failure nearly throughout the entire cruise, but we have managed to persevere somehow and get the science done that we set out to do. It would have been a shame to have invested all this time and energy with no end result. I think if you looked up Murphy's Law in the dictionary you would find us right there under it! Anyways here is the bulk of what we have been doing for the bast 30 days.

The CTD watch consists of monitoring and recording the real-time data depth profiles of the full water column as well as collecting water samples at predetermined depths. This is done with a package known as the CTD rosette. This consists of Niskin bottles attached to a cylindrical frame, which are designed with lids at both ends that are electronically triggered allowing for the sampling of individual parcels of water at different depths. Along with the Niskins, various electronic instruments are mounted on the frame of the rosette. These include a CTD, which records the salinity (via conductivity), temperature, depth (via pressure), as well as oxygen and density. Also attached is LADCP (lowered acoustic Doppler current profiler), which measures the currents by determining the Doppler shift of particulate in the water column. Also attached is a fluorometer to measure the fluorescence as an indicator of the biomass and an altimeter with allows profiles down to within 10 meters of the bottom of the sea floor.

CTD rosette being recovered (left) and a close up of ADCP as well as the CTD sensors (right).

Along with the CTD profiles done at each station, drifters and floats are also released throughout the cruise. They are equipped with GPS and use the ARGOS satellites to transfer the data back to land. The drifters allow for tracking the surface currents. The floats are designed to sink to a specific pressure traveling with subsurface currents while taking CTD profiles and returning to the surface periodically to upload the data. Both the drifters and the floats allow for continuous monitoring well after the cruise is complete.

Drifter on deck before deployment (left) and drifter deployed (right). Below is a diagram of how the float operates once deployed.

cheers,

-J