Saruhashi published her landmark paper on carbonic acid equilibrium in natural water, introducing the reference system known as Saruhashi's Table.
On December 1, 1955, Katsuko Saruhashi published her seminal paper, "On the Equilibrium Concentration Ratio of Carbonic Acid Substances Dissolved in Natural Water," a work that would become foundational to the field of ocean chemistry.
The paper introduced what became known as Saruhashi's Table, a comprehensive reference system that allowed scientists to accurately calculate the amount of carbonic acid species — including dissolved CO2, carbonate, and bicarbonate — present in seawater based on measurements of temperature, pH, and chlorinity.
Before this work, quantifying the carbon dioxide content of seawater was imprecise and cumbersome. Saruhashi's meticulous calculations, requiring immense manual computation in an era before modern computing, provided oceanographers and geochemists worldwide with a reliable, standardized method still referenced in climate science today.
This table became instrumental in later research on ocean acidification and the ocean's role in the global carbon cycle, cementing her reputation as a rigorous and innovative scientist. It was one of the first major achievements to establish her as a leading authority in geochemistry, laying the intellectual groundwork for her subsequent, more publicly consequential work tracing radioactive fallout across the Pacific Ocean.