@article{fdi:010082088,
  title = {{D}istribution and long-term change of the sea surface carbonate system in the {M}ozambique {C}hannel (1963-2019)},
  author = {{L}o {M}onaco, {C}. and {M}etzl, {N}. and {F}in, {J}. and {M}ignon, {C}. and {C}uet, {P}. and {D}ouville, {E}. and {G}ehlen, {M}. and {C}hau, {T}. {T}. {T}. and {T}ribollet, {A}line},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e report new oceanic carbonate system observations obtained during two cruises conducted in {J}anuary 2004 ({OISO}-11) and {A}pril 2019 ({CLIM}-{EPARSES}) in the {M}ozambique {C}hannel and estimate the long-term trend of sea surface fugacity of {CO}2 (f{CO}(2)) and p{H} using historical data. {W}hile in {J}anuary 2004 the region was a large {CO}2 source, the ocean was near equilibrium in {A}pril 2019. {A}lthough this region experienced a dramatic cyclone event "{I}dai" in {M}arch 2019 leading to low salinity and low dissolved inorganic carbon ({C}-{T}) and total alkalinity ({A}({T})) concentrations in the central channel, salinity normalized {A}({T}) were unchanged and {C}-{T} concentrations were higher in 2019 compared to 2004 by about 12 mu mol.kg(-1), likely due to anthropogenic {CO}2 uptake over 15 years. {C}ompared to f{CO}(2) observations of 1963 in the channel, the oceanic f{CO}(2) was higher in 2004/2019 by about 100 mu atm, an increase close to that observed in the atmosphere (90 ppm). {A} part of the f{CO}(2) increase from 1963 to 2019 (about +10 mu atm) is due to the long-term ocean warming in this region (+0.011.{C}.decade(-1)). {W}e estimated a mean decrease of 0.087 (+/- 0.007) p{H} unit between 1963 and 2019, typical of the preindustrial versus modern change in the global ocean. {U}sing other observations in the southern part of the {M}ozambique {C}hannel (around 25.{S}) we estimated a p{H} trend of 0.0129.decade(-1) (+/- 0.0042) for 1963-1995 and 0.0227.decade-1 (+/- 0.0048) for 1995-2019 suggesting a strengthening of acidification trend in the {M}ozambique {C}hannel in agreement with the anthropogenic {CO}2 forcing. {F}or the recent period, these rates were confirmed by reconstructed f{CO}(2) and p{H} monthly fields using a neural network model. {W}e noted however that the p{H} trend in the {M}ozambique {C}hannel appeared lower than previous estimates at the scale of the {I}ndian {O}cean. {B}ased on historical atmospheric {CO}2 data we estimated that p{H} in the {M}ozambique {C}hannel was about 8.18 (+/- 0.014) in the year 1800, i.e. 0.13 higher than in 2019. {T}he concentration of {C}-{T} in the year 1800 was likely around 1915 (+/- 10) mu mol.kg(-1). {T}hese results will contribute to a better understanding of the impacts of ocean acidification on coral reefs since the industrial revolution by (1) providing a reference level for the reconstruction of p{H} from coral core samples that were collected at different locations in this region in 2019 and (2) by informing environmental authorities aiming at preserving and protecting those threatened ecosystems.},
  keywords = {{M}ozambique {C}hannel ; {O}cean {CO}2 ; {A}cidification ; {L}ong-term trends ; {OCEAN} {INDIEN} ; {MOZAMBIQUE} {CANAL}},
  booktitle = {},
  journal = {{D}eep-{S}ea {R}esearch {P}art {II} : {T}opical {S}tudies in {O}ceanography},
  volume = {186},
  numero = {},
  pages = {104936 [22 p.]},
  ISSN = {0967-0645},
  year = {2021},
  DOI = {10.1016/j.dsr2.2021.104936},
  URL = {https://www.documentation.ird.fr/hor/fdi:010082088},
}