@article{fdi:010084349,
  title = {{E}valuating the {A}rabian {S}ea as a regional source of atmospheric {CO}2 : seasonal variability and drivers},
  author = {de {V}erneil, {A}. and {L}achkar, {Z}. and {S}mith, {S}. and {L}evy, {M}arina},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {A}rabian {S}ea ({AS}) was confirmed to be a net emitter of {CO}2 to the atmosphere during the international {J}oint {G}lobal {O}cean {F}lux {S}tudy program of the 1990s, but since then few in situ data have been collected, leaving data-based methods to calculate air-sea exchange with fewer and potentially out-of-date data. {A}dditionally, coarse-resolution models underestimate {CO}2 flux compared to other approaches. {T}o address these shortcomings, we employ a high-resolution (1/24 degrees) regional model to quantify the seasonal cycle of air-sea {CO}2 exchange in the {AS} by focusing on two main contributing factors, p{CO}(2) and winds. {W}e compare the model to available in situ p{CO}(2) data and find that uncertainties in dissolved inorganic carbon ({DIC}) and total alkalinity ({TA}) lead to the greatest discrepancies. {N}evertheless, the model is more successful than neural network approaches in replicating the large variability in summertime p{CO}(2) because it captures the {AS}'s intense monsoon dynamics. {I}n the seasonal p{CO}(2) cycle, temperature plays the major role in determining surface p{CO}(2) except where {DIC} delivery is important in summer upwelling areas. {S}ince seasonal temperature forcing is relatively uniform, p{CO}(2) differences between the {AS}'s subregions are mostly caused by geographic {DIC} gradients. {W}e find that primary productivity during both summer and winter monsoon blooms, but also generally, is insufficient to offset the physical delivery of {DIC} to the surface, resulting in limited biological control of {CO}2 release. {T}he most intense air-sea {CO}2 exchange occurs during the summer monsoon when outgassing rates reach similar to 6 mol{C}m(-2)yr(-1) in the upwelling regions of {O}man and {S}omalia, but the entire {AS} contributes {CO}2 to the atmosphere. {D}espite a regional spring maximum of p{CO}(2) driven by surface heating, {CO}2 exchange rates peak in summer due to winds, which account for similar to 90 % of the summer {CO}2 flux variability vs. 6 % for p{CO}(2). {I}n comparison with other estimates, we find that the {AS} emits similar to 160 {T}g{C}yr(-1), slightly higher than previously reported. {A}ltogether, there is 2x variability in annual flux magnitude across methodologies considered. {F}uture attempts to reduce the variability in estimates will likely require more in situ carbon data. {S}ince summer monsoon winds are critical in determining flux both directly and indirectly through temperature, {DIC}, {TA}, mixing, and primary production effects on p{CO}(2), studies looking to predict {CO}2 emissions in the {AS} with ongoing climate change will need to correctly resolve their timing, strength, and upwelling dynamics.},
  keywords = {{ARABIE} {MER}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {19},
  numero = {3},
  pages = {907--929},
  ISSN = {1726-4170},
  year = {2022},
  DOI = {10.5194/bg-19-907-2022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010084349},
}