NSF Award
1353177
The proposal will build and validate a set of 6 pH and nitrate sensors for profiling floats that will be deployed in the Southern Ocean. These sensors will be integrated with floats supplied by the University of Washington Float lab. In addition to the pH and oxygen sensors, the floats will also carry fluorescence optode oxygen sensors together with biooptical sensors for chlorophyll fluorescence and backscatter. Each float will operate for approximately 330 profiles from 1700 m depth to the surface. This should equate to a 5 year endurance at profiling intervals near 7 days. The profiling floats will be deployed along the decadal CLIVAR P16S cruise, scheduled to leave New Zealand in March 2014. The P16S line will go north from the ice edge along 150 degrees W. Three of the floats with chemical sensors will be deployed at latitudes where there should be seasonal ice cover and three will be deployed to the north of the ice covered ocean.<br/><br/>The pH data collected by the floats should provide one of the first records of the annual cycle of pH in a region that is expected to become undersaturated with aragonite as atmospheric CO2 continues to increase. This will allow a unique assessment of the ability of current generation climate models to predict ocean pH trajectories.
