scholarly journals Variability of sea surface temperature differences between western Pacific Ocean and eastern Indian Ocean related to ENSO events

2018 ◽  
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Western Pacific ◽  
Sea Surface ◽  
Eastern Indian Ocean ◽  
Western Pacific Ocean ◽  
Enso Events

Modulation of Australian Precipitation by Meridional Gradients in East Indian Ocean Sea Surface Temperature

2009 ◽  
Vol 22 (21) ◽  
pp. 5597-5610 ◽  
Author(s):  
Caroline C. Ummenhofer ◽  
Alexander Sen Gupta ◽  
Andréa S. Taschetto ◽  
Matthew H. England
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Eastern Indian Ocean ◽  
Southeastern Australia ◽  
The Impact ◽  
Sst Gradient ◽  
Meridional Sst Gradient ◽  
Australian Rainfall

Abstract This study explores the impact of meridional sea surface temperature (SST) gradients across the eastern Indian Ocean on interannual variations in Australian precipitation. Atmospheric general circulation model (AGCM) experiments are conducted in which the sign and magnitude of eastern Indian Ocean SST gradients are perturbed. This results in significant rainfall changes for western and southeastern Australia. A reduction (increase) in the meridional SST gradient drives a corresponding response in the atmospheric thickness gradients and results in anomalous dry (wet) conditions over Australia. During simulated wet years, this seems to be due to westerly anomalies in the thermal wind over Australia and anomalous onshore moisture advection, with a suggestion that the opposite occurs during dry conditions. Thus, an asymmetry is seen in the magnitude of the forced circulation and precipitation response between the dry and wet simulations. To assess the relative contribution of the SST anomalies making up the meridional gradient, the SST pattern is decomposed into its constituent “poles,” that is, the eastern tropical pole off the northwest shelf of Australia versus the southern pole in the central subtropical Indian Ocean. Overall, the simulated Australian rainfall response is linear with regard to the sign and magnitude of the eastern Indian Ocean SST gradient. The tropical eastern pole has a larger impact on the atmospheric circulation and Australian precipitation changes relative to the southern subtropical pole. However, there is clear evidence of the importance of the southern pole in enhancing the Australian rainfall response, when occurring in conjunction with but of opposite sign to the eastern tropical pole. The observed relationship between the meridional SST gradient in the eastern Indian Ocean and rainfall over western and southeastern Australia is also analyzed for the period 1970–2005. The observed relationship is found to be consistent with the AGCM results.

India and the Allure of the ‘Indo-Pacific’

2012 ◽  
Vol 49 (3-4) ◽  
pp. 165-188 ◽  
Author(s):  
David Scott
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Think Tanks ◽  
Western Pacific ◽  
Eastern Indian Ocean ◽  
Western Pacific Ocean ◽  
Indian Government ◽  
The Us ◽  
Inherent Part

This article looks at the attraction that the term ‘Indo-Pacific’ has gained in strategic discourse in and around the Indian government since 2010. A strong geopolitical and geo-economic sense of the Indo-Pacific has become apparent in this emergent Indo-Pacific discourse, which combines elements of India’s ‘Look South’ and ‘Look East’ policies, and in which a core Indo-Pacific of the eastern Indian Ocean and western Pacific Ocean has particular strategic coherence. Not only have government leaders adopted the term Indo-Pacific at various times, diplomats, navy service chiefs, influential think tanks and persuasive voices like Shyam Saran and C. Raja Mohan have also been noticeable in their use of the term. India’s bilateral and trilateral relations with Japan, Australia and the US have attracted particular Indo-Pacific associations in India. While a criticism of the term Indo-Pacific is that it has negative China-centric, balancing undertones, the article finds that although China-centric balancing frequently accompanies Indo-Pacific discourse, this is not an inherent part of the concept.

scholarly journals VARIABILITY OF SEA SURFACE TEMPERATURE (SST) AND CHLOROPHYLL-A (CHL-A) CONCENTRATIONS IN THE EASTERN INDIAN OCEAN DURING THE PERIOD 2002–2017

2019 ◽  
Vol 16 (1) ◽  
pp. 55
Author(s):  
Michelia Mashita ◽  
Jonson Lumban-Gaol
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Chlorophyll A ◽  
Sea Surface ◽  
Asia Pacific ◽  
Eastern Indian Ocean ◽  
Positive Anomaly ◽  
Chl A ◽  
Annual Variability

We analysed the variability of sea surface temperature (SST) and chlorophyll-a concentration (Chl-a) in the eastern Indian Ocean (EIO). We used monthly mean Chl-a and SST data with a 4-km spatial resolution derived from Level-3 Aqua Moderate-resolution Imaging Spectroradiometer (MODIS) distributed by the Asia-Pacific Data-Research Center (APDRC) for the period 2002–2017. Wavelet analysis shows the annual and interannual variability of SST and Chl-a concentration in the EIO. The annual variability of SST and Chl-a is influenced by monsoon systems. During a southeast monsoon, SST falls while Chl-a increases due to upwelling. The annual variability of SST and Chl-a is also influenced by the Indian Ocean Dipole (IOD). During positive phases of the IOD (2006, 2012 and 2015), there was more intense upwelling in the EIO caused by the negative anomaly of SST and the positive anomaly of Chl-a concentration.

scholarly journals Spatiotemporal Variability of Remote Sensing Ocean Net Primary Production and Major Forcing Factors in the Tropical Eastern Indian and Western Pacific Ocean

2019 ◽  
Vol 11 (4) ◽  
pp. 391 ◽  
Author(s):  
Fanping Kong ◽  
Qing Dong ◽  
Kunsheng Xiang ◽  
Zi Yin ◽  
Yanyan Li ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Pacific Ocean ◽  
Indian Ocean ◽  
Primary Production ◽  
El Nino ◽  
Net Primary Production ◽  
Western Pacific ◽  
Sea Surface ◽  
Spatiotemporal Variability ◽  
Western Pacific Ocean

Based on widely used remote sensing ocean net primary production (NPP) datasets, the spatiotemporal variability of NPP is first analyzed over the tropical eastern Indian and western Pacific Ocean for the period 1998–2016 using the conventional empirical orthogonal function (EOF), the lead–lag correlation and the ensemble empirical mode decomposition (EEMD) technique. Barnett and Preisendorfer’s improved Canonical Correlation Analysis (BPCCA) is also applied to derive covariability patterns of NPP with major forcing factors of the chlorophyll a concentration (Chla), sea surface temperature (SST), sea level anomaly (SLA), ocean rainfall (Rain), sea surface wind (Wind), and current (CUR) under climate changes of El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). We find that: (1) The first two seasonal EOF modes capture significant temporal and meridional NPP variability differences, as NPP reaches peaks approximately three months later in the western Pacific Ocean than that of in the eastern Indian Ocean. (2) The second and third interannual EOF modes are closely related with ENSO with a two-month lag and synchronous with IOD, respectively, characterized by southwesterly positive anomaly centers during positive IOD years. (3) NPP presents different varying tendencies and similar multiscale oscillation patterns with interannual and interdecadal cycles of 2~3 years, 5~8 years, and 9~19 years in subregions of the Bay of Bengal, the South China Sea, the southeastern Indian Ocean, and the northwestern Pacific Ocean. (4) The NPP variability is strongly coupled with negative SST, SLA, and Rain anomalies, as well as positive Chla, Wind and CUR anomalies in general during El Niño/positive IOD years. The results reveal the diversity and complexity of large-scale biophysical interactions in the key Indo-Pacific Warm Pool region, which improves our understanding of ocean productivity, ecosystems, and carbon budgets.

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