Cruise Name: Gradients 4 , TN397 Vessel: R/V Thompson Funding: Simons Collaboration on Ocean Processes and Ecology (SCOPE) 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. Soluble reactive phosphate (SRP) and Nitrate + Nitrite (N+N) were measured by sampling directly from the ship's underway uncontaminated seawater system (intake depth 8m). Samples were collected at roughly 0600 and 1800 local time for the duration of the cruise by filling 120ml bottles and freezing them for laboratory analysis. Phosphate and nitrate+nitrite were determined colormetrically on two SEAL Analytical Autoanalyzers. Samples were corrected for a DI water blank and a reagent standard curve (4 concentrations for both SRP and N+N). Lat/lon were logged in person during sample collection and may not exactly match cruise log.