Zinke14_Agulhas.pdf (934.04 kB)
Madagascar corals track sea surface temperature variability in the Agulhas Current core region over the past 334 years
journal contribution
posted on 2019-10-22, 13:58 authored by J Zinke, BR Loveday, CJC Reason, W-C Dullo, D KroonThe Agulhas Current (AC) is the strongest western boundary current in the Southern Hemisphere and is key for weather and climate patterns, both regionally and globally. Its heat transfer into both the midlatitude South Indian Ocean and South Atlantic is of global significance. A new composite coral record (Ifaty and Tulear massive Porites corals), is linked to historical AC sea surface temperature (SST) instrumental data, showing robust correlations. The composite coral SST data start in 1660 and comprise 200 years more than the AC instrumental record. Numerical modelling exhibits that this new coral derived SST record is representative for the wider core region of the AC. AC SSTs variabilities show distinct cooling through the Little Ice Age and warming during the late 18th, 19th and 20th century, with significant decadal variability superimposed. Furthermore, the AC SSTs are teleconnected with the broad southern Indian and Atlantic Oceans, showing that the AC system is pivotal for inter-ocean heat exchange south of Africa.
Funding
This work was supported as part of the SINDOCOM grant under the Dutch NWO program ‘Climate Variability’, grant 854.00034/035. Additional support comes from the NWO ALW project CLIMATCH, grant 820.01.009, and the Western Indian Ocean Marine Science Association through the Marine Science for Management programme under grant MASMA/CC/2010/02. JZ was supported by an Indian Ocean Marine Research Centre UWA/AIMS/CSIRO collaborative assistant professorial fellowship. BL was supported by the European Community's Seventh Framework Programme FP7/2007-2013-Marie-Curie ‘GATEWAYS’ ITN, grant agreement 238512, and ICE-MASA. Financial support to WCD through the Leibniz Award (DU 129/33) is very much appreciated. Model simulations were performed at DST/CSIR CHPC, Cape Town. We acknowledge support from the SCOR/WCRP/IAPSO working group 136 on the climatic importance of the greater Agulhas system. We thank the VU University Amsterdam (Netherlands) for assistance with stable isotope analysis, especially Suzan Verdegaal. With thank Georg Heiss from the Free University of Berlin and the EU TESTREFF party for sampling the coral cores.
History
Citation
Scientific Reports, 2014, volume 4, Article number: 4393Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/School of Geography, Geology and the EnvironmentVersion
- VoR (Version of Record)
