[22-Feb-2010] Lagerloef, G., Colomb, F.R., Le Vine, D., Wentz, F., Yueh, S., Ruf, C., Lilly, J., Gunn, J., Chao, Y., deCharon, A., Feldman, G., and Swift, C. In an Oceanography article published many years ago, three of the authors identified salinity measurements from satellites as the next ocean remote-sensing challenge. They argued that this represented the next "zeroth order" contribution to oceanography because salinity variations form part of the interaction between ocean circulation and the global water cycle, which in turn affects the ocean's capacity to store and transport heat and regulate Earth's climate.In this article, they report that a new satellite program scheduled for launch in the near future will provide data to reveal how the ocean responds to the combined effects of evaporation, precipitation, ice melt, and river runoff on seasonal and interannual time scales. These measurements can be used, for example, to close the marine hydrologic budget, constrain coupled climate models, monitor mode water formation, investigate the upper-ocean response to precipitation variability in the tropical convergence zones, and provide early detection of low-salinity intrusions in the subpolar Atlantic and Southern oceans.