Gradients 4 - TN397 - HPLC - CTD

Cruise Name: Gradients 4 , TN397 Vessel: R/V Thompson Funding: Simons Collaboration on Ocean Processes and Ecology (SCOPE) Dataset description: This dataset was collected on the R/V Thompson during the Gradients IV cruise which departed from San Diego, CA and ended in Honolulu, HI. A transect was performed on the 140 degree longitude line from roughly 19 degrees N to 2.5 degrees S before heading to Honolulu. Samples were processed to detect and quantify phytoplankton pigments using a modified version of the high-performance liquid chromatography (HPLC) method of Wright et al. (1991) as described by Bidigare et al. (2005). HPLC samples were collected from CTD niskin bottles and filtered onto Whatman GF/F filters and stored at -80°C until analysis. Filters were extracted in 100% acetone for 24 h at 4°C. Extracts were processed in reverse-phase on a 250 mm C18 column using a Waters separations module and photodiode detector array. Empower chromatography software was used for integration and pigment quantification. The instrument was calibrated using chlorophyll a from Anacystis nidulans (Sigma USA) and mixed pigment standards were obtained from DHI in Denmark. Timestamps are in UTC time.