The Mascarene High (MH) is a semi-permanent subtropical high-pressure zone in the South Indian Ocean. Apart from its large influence on African and Australian weather patterns, it also helps in driving the inter-hemispheric circulation between the Indian Ocean in the south and subcontinental landmass in the north. Using observations and reanalysis products, this study for the first time investigates recent warming trend observed in the MH region during the Global Warming Hiatus (GWH) period (1998-2016). Significant positive trends are observed in sea surface temperature (SST), sea surface height (SSH) and oceanic heat content (OHC) during this period in the MH region. Mixed layer heat budget analysis reveals the dominant role of heat advection in the observed warming trend. During the GWH period, stronger zonal currents advect the warm waters from the Western Pacific (WP) towards the MH region via the Indonesian Throughflow (ITF). This warming in the MH reduces the sea level pressure therein and establishes a weak pressure gradient between the MH and the northern hemisphere landmass. This in-turn weakens the cross-equatorial winds in the western Indian Ocean.
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http://dx.doi.org/10.1038/s41598-020-59964-7 | DOI Listing |
Sci Total Environ
January 2025
Programa de Pós-Graduação em Clima e Ambiente, Instituto Nacional de Pesquisas da Amazônia, Universidade do Estado do Amazonas, Av. André Araújo, 2936, Bairro Aleixo, 69060-001 Manaus, AM, Brazil.
The teleconnections between El Niño-Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), and Tropical North Atlantic warming (+TNA) play a critical role in characterizing extreme drought events in the Amazon Basin (AB). This study examines the seven most recent drought extreme events up to 2023, using seasonal composites of the sea surface temperature and atmospheric variables over a five-quarter period starting at the austral spring(-1) of the year preceding that when the lowest water level at Manaus port was recorded. Two distinct patterns emerge, driven by consecutive ENSO events with opposite phases, referred to as cyclic La Niña-El Niño and cyclic El Niño-La Niña drought events.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Earth System Science, University of California, Irvine, CA, USA.
The deep oceans are environments of complex carbon dynamics that have the potential to significantly impact the global carbon cycle. However, the role of hadal zones, particularly hadal trenches (water depth > 6 km), in the oceanic dissolved organic carbon (DOC) cycle is not thoroughly investigated. Here we report distinct DOC signatures in the Japan Trench bottom water.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai, India.
Tsunamis are massive waves generated by sudden water displacement on the ocean surface, causing devastation as they sweep across the coastlines, posing a global threat. The aftermath of the 2004 Indian Ocean tsunami led to the establishment of the Indian Tsunami Early Warning System (ITEWS). Predicting real-time tsunami heights and the resulting coastal inundation is crucial in ITEWS to safeguard the coastal communities.
View Article and Find Full Text PDFFront Antibiot
April 2024
Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius.
Introduction: This study aims at determining the pattern of antibiotic consumption and resistance in Mauritius, a tropical island in the Indian Ocean.
Methodology: Antibiotic consumption was measured in kilograms of purchased antibiotics and also in defined daily dose (DDD) in different health institutions from 2015 to 2017. Data on antibiotic resistance was collected at the Central Health Laboratory (CHL) at Victoria Hospital and at Jeetoo Hospital Laboratory, where antibiotic sensitivity testing is done for all public health institutions.
Mar Pollut Bull
January 2025
College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan 430074, China; Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China. Electronic address:
To fully understand variation in phytoplankton community structure in the Eastern Indian Ocean (EIO), two research cruises were carried out during September-November 2020, and March-May 2021. The phytoplankton community in the EIO was mainly composed of cyanobacteria and diatoms in 2020, cyanobacteria in 2021. Trichodesmium thiebaultii was the dominant specie in both years.
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