Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Insights into origin and processes from a coupled physical-biogeochemical model

Arnaud Laurent, Katja Fennel, Wei Jun Cai, Wei Jen Huang, Leticia Barbero, Rik Wanninkhof

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Nutrient inputs from the Mississippi/Atchafalaya River system into the northern Gulf of Mexico promote high phytoplankton production and lead to high respiration rates. Respiration coupled with water column stratification results in seasonal summer hypoxia in bottom waters on the shelf. In addition to consuming oxygen, respiration produces carbon dioxide (CO2), thus lowering the pH and acidifying bottom waters. Here we present a high-resolution biogeochemical model simulating this eutrophication-driven acidification and investigate the dominant underlying processes. The model shows the recurring development of an extended area of acidified bottom waters in summer on the northern Gulf of Mexico shelf that coincides with hypoxic waters. Not reported before, acidified waters are confined to a thin bottom boundary layer where the production of CO2 by benthic metabolic processes is dominant. Despite a reduced saturation state, acidified waters remain supersaturated with respect to aragonite.

Original languageEnglish (US)
Pages (from-to)946-956
Number of pages11
JournalGeophysical Research Letters
Volume44
Issue number2
DOIs
StatePublished - Jan 28 2017

Keywords

  • acidification
  • biogeochemical model
  • eutrophication
  • hypoxia
  • Mississippi
  • northern Gulf of Mexico

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Fingerprint

Dive into the research topics of 'Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Insights into origin and processes from a coupled physical-biogeochemical model'. Together they form a unique fingerprint.

Cite this