scholarly journals Decadal Variability in Salinity of the Indian Ocean Subtropical Underwater During the Argo Period

2020 ◽  
Vol 47 (22) ◽  
Author(s):  
Xunwei Nie ◽  
Zexun Wei ◽  
Ying Li
Keyword(s):  
Indian Ocean ◽  
Decadal Variability ◽  
The Indian Ocean ◽  
Subtropical Underwater

scholarly journals Decadal Variability of the Indian and Pacific Walker Cells since the 1960s: Do They Covary on Decadal Time Scales?

2017 ◽  
Vol 30 (21) ◽  
pp. 8447-8468 ◽  
Author(s):  
Weiqing Han ◽  
Gerald A. Meehl ◽  
Aixue Hu ◽  
Jian Zheng ◽  
Jessica Kenigson ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Decadal Variability ◽  
Tropical Indian Ocean ◽  
Warm Pool ◽  
Past Century ◽  
The Pacific ◽  
Decadal Variations ◽  
Long Term Trends ◽  
The Indian Ocean ◽  
The 1960S

Previous studies have investigated the centennial and multidecadal trends of the Pacific and Indian Ocean Walker cells (WCs) during the past century, but have obtained no consensus owing to data uncertainties and weak signals of the long-term trends. This paper focuses on decadal variability (periods of one to few decades) by first documenting the variability of the WCs and warm-pool convection, and their covariability since the 1960s, using in situ and satellite observations and reanalysis products. The causes for the variability and covariability are then explored using a Bayesian dynamic linear model, which can extract nonstationary effects of climate modes. The warm-pool convection exhibits apparent decadal variability, generally covarying with the Indian and Pacific Ocean WCs during winter (November–April) with enhanced convection corresponding to intensified WCs, and the Indian–Pacific WCs covary. During summer (May–October), the warm-pool convection still highly covaries with the Pacific WC but does not covary with the Indian Ocean WC, and the Indian–Pacific WCs are uncorrelated. The wintertime coherent variability results from the vital influence of ENSO decadal variation, which reduces warm-pool convection and weakens the WCs during El Niño–like conditions. During summer, while ENSO decadal variability still dominates the Pacific WC, decadal variations of ENSO, the Indian Ocean dipole, Indian summer monsoon convection, and tropical Indian Ocean SST have comparable effects on the Indian Ocean WC overall, with monsoon convection having the largest effect since the 1990s. The complex causes for the Indian Ocean WC during summer result in its poor covariability with the Pacific WC and warm-pool convection.

scholarly journals Why Has the Relationship between Indian and Pacific Ocean Decadal Variability Changed in Recent Decades?

2017 ◽  
Vol 30 (6) ◽  
pp. 1971-1983 ◽  
Author(s):  
Lu Dong ◽  
Michael J. McPhaden
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Climate Models ◽  
Climate Model ◽  
Decadal Variability ◽  
Negative Phase ◽  
External Forcing ◽  
Indian Ocean Basin Mode ◽  
The Indian Ocean ◽  
The Relationship

Abstract Both the Indian and Pacific Oceans exhibit prominent decadal time scale variations in sea surface temperature (SST), linked dynamically via atmospheric and oceanic processes. However, the relationship between SST in these two basins underwent a dramatic transformation beginning around 1985. Prior to that, SST variations associated with the Indian Ocean basin mode (IOB) and the interdecadal Pacific oscillation (IPO) were positively correlated, whereas afterward they were much less clearly synchronized. Evidence is presented from both observations and coupled state-of-the-art climate models that enhanced external forcing, particularly from increased anthropogenic greenhouse gases, was the principal cause of this changed relationship. Using coupled climate model experiments, it is shown that without external forcing, the evolution of the IOB would be strongly forced by variations in the IPO. However, with strong external forcing, the dynamical linkage between the IOB and the IPO weakens so that the negative phase IPO after 2000 is unable to force a negative phase IOB-induced cooling of the Indian Ocean. This changed relationship in the IOB and IPO led to unique SST patterns in the Indo-Pacific region after 2000, which favored exceptionally strong easterly trade winds over the tropical Pacific Ocean and a pronounced global warming hiatus in the first decade of the twenty-first century.

scholarly journals Indian Ocean Decadal Variability: A Review

2014 ◽  
Vol 95 (11) ◽  
pp. 1679-1703 ◽  
Author(s):  
Weiqing Han ◽  
Jérôme Vialard ◽  
Michael J. McPhaden ◽  
Tong Lee ◽  
Yukio Masumoto ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Climate Variability ◽  
Decadal Variability ◽  
International Scientific Community ◽  
Climate Research ◽  
Physical Mechanisms ◽  
The Pacific ◽  
Climatic Impacts ◽  
The Indian Ocean ◽  
Multidecadal Climate Variability

The international scientific community has highlighted decadal and multidecadal climate variability as a priority area for climate research. The Indian Ocean rim region is home to one-third of the world's population, mostly living in developing countries that are vulnerable to climate variability and to the increasing pressure of anthropogenic climate change. Yet, while prominent decadal and multidecadal variations occur in the Indian Ocean, they have been less studied than those in the Pacific and Atlantic Oceans. This paper reviews existing literature on these Indian Ocean variations, including observational evidence, physical mechanisms, and climatic impacts. This paper also identifies major issues and challenges for future Indian Ocean research on decadal and multidecadal variability.

scholarly journals Decadal variability of the Indian Ocean cross-equatorial exchange in SODA

2006 ◽  
Vol 33 (8) ◽  
Author(s):  
Rena Schoenefeldt ◽  
Friedrich A. Schott
Keyword(s):  
Indian Ocean ◽  
Decadal Variability ◽  
The Indian Ocean

scholarly journals Regime shift in the decadal variability of the Indian Ocean subsurface temperature

2021 ◽  
Vol 216 ◽  
pp. 103511
Author(s):  
Shuangwen Sun ◽  
Yue Fang ◽  
Lin Liu ◽  
Huiwu Wang ◽  
Yanliang Liu ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Regime Shift ◽  
Decadal Variability ◽  
Subsurface Temperature ◽  
The Indian Ocean

scholarly journals Multi-Decadal Trend and Decadal Variability of the Regional Sea Level over the Indian Ocean since the 1960s: Roles of Climate Modes and External Forcing

Climate ◽  
2018 ◽  
Vol 6 (2) ◽  
pp. 51 ◽  
Author(s):  
Weiqing Han ◽  
Detlef Stammer ◽  
Gerald Meehl ◽  
Aixue Hu ◽  
Frank Sienz ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Sea Level ◽  
Decadal Variability ◽  
External Forcing ◽  
Climate Modes ◽  
Decadal Trend ◽  
Regional Sea Level ◽  
The Indian Ocean ◽  
The 1960S

scholarly journals Interannual to Decadal Variability of Upper-Ocean Salinity in the Southern Indian Ocean and the Role of the Indonesian Throughflow

2019 ◽  
Vol 32 (19) ◽  
pp. 6403-6421 ◽  
Author(s):  
Shijian Hu ◽  
Ying Zhang ◽  
Ming Feng ◽  
Yan Du ◽  
Janet Sprintall ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Decadal Variability ◽  
Southern Indian Ocean ◽  
Upper Ocean ◽  
Freshwater Flux ◽  
Indonesian Throughflow ◽  
Salinity Variability ◽  
Basin Scale ◽  
Ocean Salinity ◽  
The Indian Ocean

Abstract Variability of oceanic salinity, an indicator of the global hydrological cycle, plays an important role in the basin-scale ocean circulation. In this study, interannual to decadal variability of salinity in the upper layer of the Indian Ocean is investigated using Argo observations since 2004 and data assimilating model outputs (1992–2015). The southeastern Indian Ocean shows the strongest interannual to decadal variability of upper-ocean salinity in the Indian Ocean. Westward propagation of salinity anomalies along isopycnal surfaces is detected in the southern Indian Ocean and attributed to zonal salinity advection anomalies associated with the Indonesian Throughflow and the South Equatorial Current. Composite and salinity budget analyses show that horizontal advection is a major contributor to the interannual to decadal salinity variability of the southern Indian Ocean, and the local air–sea freshwater flux plays a secondary role. The Pacific decadal oscillation (PDO) and El Niño–Southern Oscillation (ENSO) modulate the salinity variability in the southeastern Indian Ocean, with low salinity anomalies occurring during the negative phases of the PDO and ENSO and high salinity anomalies during their positive phases. The Indonesian Throughflow plays an essential role in transmitting the PDO- and ENSO-related salinity signals into the Indian Ocean. A statistical model is proposed based on the PDO index, which successfully predicts the southeastern Indian Ocean salinity variability with a lead time of 10 months.

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