%0 Conference Proceedings
%9 ACTI : Communications avec actes dans un congrès international
%A Marsac, Francis
%T Outline of climate and oceanographic conditions in the Indian Ocean : an update to August 2014
%S 16ème groupe de travail sur les thons tropicaux
%C Victoria
%D 2014
%L fdi:010063386
%G ENG
%I CTOI
%K INTERACTION OCEAN ATMOSPHERE ; CLIMAT ; TEMPERATURE DE SURFACE ; ANOMALIE DE TEMPERATURE ; THERMOCLINE ; UPWELLING ; EL NINO ; VARIATION PLURIANNUELLE
%K LA NINA
%K OCEAN INDIEN
%N IOTC-2014-WPTT16-24
%P 15
%U https://www.documentation.ird.fr/hor/fdi:010063386
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers15-03/010063386.pdf
%W Horizon (IRD)
%X In this paper, we provide an update on the trends of climate and oceanographic conditions in the Indian Ocean, at both basin and regional scales. The ENSO cycle has been largely fluctuating between ENSO-neutral and Niña conditions during the past 4 year and is considered being in a neutral state in 2014. Forecast coupled models give a 58% chance that an El Nino will develop by the end of 2014, but there is consensus that, if it does so, it will be a weak event. The sea surface temperature (SST) of the whole Indian Ocean has increased by +0.68°C from the 1950s to the 2000s (50 years) and this warming is still ongoing. Investigating the patterns of inter-annual variability between the East and West regions of the Indian Ocean, we found a good coherence for SST whereas the sea surface chlorophyll (SSC) had more contrasted patterns. The magnitude of SSC anomalies is also greater in the West compared to the East. Regional analyses for 5 sub-areas of the Indian Ocean were performed. The Somali basin and the Mozambique Channel are the most productive of the 5 sub-areas studied. In the Somali basin, the SST pattern is not related to the ENSO cycle, and SST and SSC are well correlated through an inverse relationship. Negative SST anomalies and high SSC content were observed in 2013. This area is under the influence of the Somalian coastal upwelling. In the Mozambique Channel, SST was back to the 1980-2005 average in 2012-2013 and warm anomalies appeared in 2014. The SSC has been depleted during several years since 2008 and the depletion intensified in 2014. The West equatorial area (WEQ) and the Maldives (MAL) exhibit similar trends. SST was back to normal in 2013-2014, and the depth of the thermocline (Z20) has been around the 1980-2005 average since 2012 (in the WEQ) and 2013 (in MAL). In those sub-areas, SSC has been depleted since the 2007 El Niño and remained in a depleted mode since then. The East tropical area is the least productive area. The SST has varied greatly with some relation to the ENSO and Dipole cycle. SSC has been low since 2007 and was still in a depleted state in 2014. The only dramatic enhancement in SSC occurred in 2011 in relation with a La Niña event.
%B GTTT : Groupe de Travail sur les Thons Tropicaux
%8 2014/11/15-19
%$ 032CLIMET