Physical Sciences and Mathematics Commons^™

Long-Term And Seasonal Variations In Co2: Linkages To Catchment Alkalinity Generation, Stephen A. Norton, B. J. Cosby, I. J. Fernandez, J. S. Kahl, M. Robbins Church

Earth Science Faculty Scholarship

As atmospheric emissions of S have declined in the Northern Hemisphere, there has been an expectation of increased pH and alkalinity in streams believed to have been acidified by excess S and N. Many streams and lakes have not recovered. Evidence from East Bear Brook in Maine, USA and modelling with the groundwater acid-base model MAGIC (Cosby et al. 1985a,b) indicate that seasonal and yearly variations in soil PCO2 are adequate to enhance or even reverse acid-base (alkalinity) changes anticipated from modest decreases of SO4 in surface waters. Alkalinity is generated in the soil by exchange of H+ from dissociation …