Parameters from discrete bottle samples on a hydrographic CTD (Conductivity Temperature Depth) cast during CCE LTER P0904 student cruise, April 2009.

Hydrographic CTD (Conductivity Temperature Depth) measurements from discrete water samples are taken on individual CTD rosette casts, deployed on CCE P0904 student cruise in the Southern California region. Seawater is collected in up to 24 Niskin bottles at specific depths (up to 1000m), determined by the chlorophyll maximum and mixed layer depth as the instrument is lowered through the water column. The samples are filtered and analyzed at sea and used to assess the CTD sensor data quality. Measurements include depth, temperature, salinity, density (sigma theta), oxygen, O2 saturation, PAR (radiation, surface radiation and irradiance), fluorescence and transmission. Salinity checks are performed with a salinometer back at the lab.