A method to quantify the influence of kinetically modeled biogeochemical processes on the pH of an ecosystem with time variable acid-base dissociation constants is presented and applied to the heterotrophic, turbid Scheldt estuary (SW Netherlands, N Belgium). Nitrification is identified as the main process governing the pH profile of this estuary, while CO2 degassing and advective-dispersive transport "buffer" the effect of nitrification. CO2 degassing accounts for the largest proton turnover per year in the whole estuary. There is a clear inverse correlation between oxygen turnover and proton turnover. The main driver of long-term changes in the mean estuarine pH from 2001 to 2004 is a changing freshwater flow which influences the pH "directly" via [?CO2] and [TA] and to a significant amount also "indirectly" via [?NH4+] and the nitrification rates in the estuary.
All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy
Web site hosted and maintained by Flanders Marine Institute (VLIZ)
Webmaster info@vliz.be Number of visitors: 2709357 - Total hits: 10373028 (since 2006-01-17)
