(Top-left panel) Saildrone sea water salinity data overlays the sea surface salinity map from SMAP RSS Level 3 V3 70 km 8-day running mean (SMAP SSS DOI: 10.5067/SMP3A-3SPCS). (Top-right panel) Saildrone sea surface temperature (SST) data overlays the SST map from GHRSST Level 4 MUR V4.1 (MUR SST DOI: 10.5067/GHGMR-4FJ04). (Bottom-left panel) Saildrone sea water salinity data (black line), SMAP SSS data (green line), and Saildrone chlorophyll concentration (red line). (Bottom-right plot) Saildrone SST (black line), MUR SST (green line), and Saildrone sea water bulk temperature (red line). (Saildrone DOI: 10.5067/SDRON-SURF0).