title: Elemental variability in the coralline alga Lithophyllum yemenense as an archive of past climate in the Gulf of Aden (NW Indian Ocean).
abstract: This study presents the first algal thallus (skeleton) archive of Asian monsoon strength and Red Sea influence in the Gulf of Aden. Mg/Ca, Li/Ca, and Ba/Ca were measured in Lithophyllum yemenense from Balhaf (Gulf of Aden) using laser ablation inductively coupled plasma mass spectrometry, and Mg/Ca ratio oscillation was used to reconstruct the chronology (34 y). Oscillations of element rates corresponding to the algal growth between 1974 and 2008 were compared with recorded climate and oceanographic variability. During this period, sea surface temperatures (SST) in Balhaf recorded a warming trend of 0.55°C, corresponding to an increase in Mg and Li content in the algal thallus of 2.1 mol-% and 1.87 μmol-%, respectively. Lithophyllum yemenense recorded decadal SST variability by Li/Ca, and the influence of the Pacific El-Niño Southern Oscillation on the NW Indian Ocean climate system by Ba/Ca. Additionally, algal Mg/Ca, Li/Ca, and Ba/Ca showed strong and significant correlations with All Indian Rainfall in the decadal range indicating that these proxies can be useful for tracking variability in the Indian monsoon system, possibly due to changes of the surface wind system, with deep water upwelling in summer, and a distinct seasonality.
authors.affiliation: Dipartimento di Scienze dell'Ambiente e della Terra, Sezione di Scienze Geologiche e Geotecnologie, Università degli Studi di Milano-Bicocca, CoNISMa, Piazza della Scienza, 4, 20126, Milano, Italy.|Institut pour la Recherche et le Developpement (IRD), UMR ENTROPIE & Laboratoire d'Excellence CORAIL, BP5, 98848, Nouméa, New Caledonia.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Caragnano
authors.affiliation: Dipartimento di Scienze dell'Ambiente e della Terra, Sezione di Scienze Geologiche e Geotecnologie, Università degli Studi di Milano-Bicocca, CoNISMa, Piazza della Scienza, 4, 20126, Milano, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Basso
authors.affiliation: Institut für Geowissenschaften, Goethe-Universität, 60438, Frankfurt am Main, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Storz
authors.affiliation: Department of Geosciences, Johannes Gutenberg-Universität, J.J.-Becherweg 21, D-55099, Mainz, Germany.|Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
authors.forename: Dorrit E
authors.initials: DE
authors.lastname: Jacob
authors.affiliation: Institute of Marine Sciences, Portsmouth University, Ferry Rd, Portsmouth, PO4 9LY, UK.
authors.forename: Federica
authors.initials: F
authors.lastname: Ragazzola
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Benzoni
authors.affiliation: CREOCEAN (Societé de Services et Conseils en Environment Littoral et Oceanographie), 128, avenue de Fès, 34080, Montpellier, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Dutrieux
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism / Q000502:physiology; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002980:Climate; D019156:Indian Ocean; D008094:Lithium / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D009791:Oceanography; D000461:Rhodophyta / Q000378:metabolism* / Q000502:physiology*; D012623:Seawater; D015006:Yemen
chemical_list: D001464:Barium; D008094:Lithium; D008274:Magnesium; D002118:Calcium
keywords: Asian monsoon proxy; Ba/Ca; Corallinales; Laser Ablation ICP-MS; Li/Ca; Mg/Ca; biogeochemistry