Total inorganic carbon
（重定向自Dissolved inorganic carbon）
![](/Images/godic/202501/09/WOA05_GLODAP_pd_DIC_AYool1123.png")
![Pre-industrial (1700s) sea surface DIC concentration (from the GLODAP climatology).](/Images/godic/202501/09/WOA05_GLODAP_pi_DIC_AYool1123.png")
![Concentration du TIC à la surface des océans dans les années 1990, d'après le Global Ocean Data Analysis Project.](/Images/godic/202501/09/TIC_oceans1123.png")
The total inorganic carbon (CT, or TIC) or dissolved inorganic carbon (DIC) is the sum of inorganic carbon species in a solution. The inorganic carbon species include carbon dioxide, carbonic acid, bicarbonate anion, and carbonate. It is customary to express carbon dioxide and carbonic acid simultaneously as CO2* . CT is a key parameter when making measurements related to the pH of natural aqueous systems, and carbon dioxide flux estimates.