title: The exposure of the Great Barrier Reef to ocean acidification.
abstract: The Great Barrier Reef (GBR) is founded on reef-building corals. Corals build their exoskeleton with aragonite, but ocean acidification is lowering the aragonite saturation state of seawater (Ωa). The downscaling of ocean acidification projections from global to GBR scales requires the set of regional drivers controlling Ωa to be resolved. Here we use a regional coupled circulation-biogeochemical model and observations to estimate the Ωa experienced by the 3,581 reefs of the GBR, and to apportion the contributions of the hydrological cycle, regional hydrodynamics and metabolism on Ωa variability. We find more detail, and a greater range (1.43), than previously compiled coarse maps of Ωa of the region (0.4), or in observations (1.0). Most of the variability in Ωa is due to processes upstream of the reef in question. As a result, future decline in Ωa is likely to be steeper on the GBR than currently projected by the IPCC assessment report.
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Mongin
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Baird
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.|Antarctic Climate and Ecosystems Co-operative Research Centre, Hobart, Tasmania 7000, Australia.
authors.forename: Bronte
authors.initials: B
authors.lastname: Tilbrook
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Matear
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lenton
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Herzfeld
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Wild-Allen
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Skerratt
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Nugzar
authors.initials: N
authors.lastname: Margvelashvili
authors.affiliation: CSIRO Land and Water, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Robson
authors.affiliation: Red Sea Research Center, King Abdullah University of Science and Technology, Thuval 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Duarte
authors.affiliation: Plant Functional Biology and Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, Sydney, New South Wales 2007, Australia.
authors.forename: Malin S M
authors.initials: MS
authors.lastname: Gustafsson
authors.affiliation: Plant Functional Biology and Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, Sydney, New South Wales 2007, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Ralph
authors.affiliation: CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia.
authors.forename: Andrew D L
authors.initials: AD
authors.lastname: Steven
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism*; D002119:Calcium Carbonate / Q000378:metabolism*; D057894:Coral Reefs; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008956:Models, Chemical; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*
chemical_list: D002119:Calcium Carbonate