Modulation of the southern Indian Ocean dipole on the impact of El Niño–Southern Oscillation on Australian summer rainfall

Gong, Hainan; Zhou, Wen; Chen, Wen; Wang, Lin; Leung, Marco Y. T.; Cheung, Paxson K. Y.; Zhang, Y.

doi:10.1002/joc.5941

Cited by 10 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In tropical regions with seasonally variable precipitation, flowering pulses in palms often occur according to precipitation patterns (Abrahamson, 1999). We do not know what triggers the initiation of flowering in T. spectabilis plants; however, the flowering events recorded during this study appear to coincide with the El Niño Southern Oscillation (ENSO) cycle and possibly the interaction of this and the Indian Ocean Dipole (IOD) (Fedorov & Philander, 2000; Gong et al, 2019).…”

Section: Discussionmentioning

confidence: 85%

Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis

Shapcott

James

Simmons

et al. 2020

Ecology and Evolution

View full text Add to dashboard Cite

Madagascar is home to 208 indigenous palm species, almost all of them endemic and >80% of which are endangered. We undertook complete population census and sampling for genetic analysis of a relatively recently discovered giant fan palm, the Critically Endangered Tahina spectablis in 2008 and 2016. Our 2016 study included newly discovered populations and added to our genetic study. We incorporated these new populations into species distribution niche model (SDM) and projected these onto maps of the region. We developed population matrix models based on observed demographic data to model population change and predict the species vulnerability to extinction by undertaking population viability analysis (PVA). We investigated the potential conservation value of reintroduced planted populations within the species potential suitable habitat. We found that the population studied in 2008 had grown in size due to seedling regeneration but had declined in the number of reproductively mature plants, and we were able to estimate that the species reproduces and dies after approximately 70 years. Our models suggest that if the habitat where it resides continues to be protected the species is unlikely to go extinct due to inherent population decline and that it will likely experience significant population growth after approximately 80 years due to the reproductive and life cycle attributes of the species. The newly discovered populations contain more genetic diversity than the first discovered southern population which is genetically depauperate. The species appears to demonstrate a pattern of dispersal leading to isolated founder plants which may eventually lead to population development depending on local establishment opportunities. The conservation efforts currently put in place including the reintroduction of plants within the species potential suitable habitat if maintained are thought likely to enable the species to sustain itself but it remains vulnerable to anthropogenic impacts.

show abstract

Section: Discussionmentioning

confidence: 85%

Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis

Shapcott

James

Simmons

et al. 2020

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…Trade winds cause changes in upwelling, which lead to SST variability. Regarding the in uence of the SIOD on climate, it is obvious that the SIOD has some impact on climate at low, middle, and even high latitudes (Liu et al 2019;Gong et al 2019; Udy et al 2021). Reason (2001Reason ( , 2002 showed that positive SST anomalies of a positive SIOD enhance summer precipitation in the Southern Hemisphere through water vapor convergence.…”

Section: Introductionmentioning

confidence: 99%

“…The ITCZ is in uenced by a combination of SST and the monsoon in the Indian Ocean (Jiang 1988). Gong et al (2019) analyzed the correlation between Indian Ocean ITCZ variability and the Arctic Oscillation and found that vertical air motion at the location of the ITCZ was signi cantly correlated with the Arctic Oscillation. On the other hand, Chan and Evans (2002) demonstrated that the location of the ITCZ and the monsoon are crucial in controlling ow and precipitation patterns, the development of tropical cyclones, and the hydrological cycle in the area.…”

Section: Introductionmentioning

confidence: 99%

The Southern Indian Ocean Dipole and its effects on Precipitation in China

Dong

Guan

Zhou

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

This study analyzes and discusses the characteristics of sea surface temperature (SST) in the Southern Indian Ocean, the changes in the location of the Indian Ocean Intertropical Convergence Zone (ITCZ), and their impact on precipitation in China from 1979 to 2021. Results show that the Southern Indian Ocean Dipole (SIOD), an SST southwest-northeast dipole distribution between the subtropics and extratropics, is the dominant mode of interannual variability in the Southern Indian Ocean in observations. The SIOD displays an apparent seasonal phase-locking, with the anomaly pattern developing in boreal autumn, peaking in winter, and decaying in the ensuing spring and summer. Wavelet analysis shows that the SIOD mode has an interdecadal variation period of 6–7 years over the study period. Moreover, the SIOD has a strong correlation with the El Niño–Southern Oscillation (ENSO), and it is found that after separating ENSO signals, the Indian Ocean ITCZ positions (averaged over 35°–75°E) in boreal winter (DJF) of the same year and the spring (MAM) of the next year are significantly influenced by pure SIOD events, with a southward (northward) shift in the Indian Ocean ITCZ under pure positive SIOD (pure negative SIOD) events during DJF. In MAM, the Indian Ocean ITCZ moves in the opposite direction to that in DJF under pure positive and negative SIOD events, and the position changes are greater than those in DJF. Additionally, in boreal winter and spring, precipitation in China is associated with the position of the Indian Ocean ITCZ, which is positively (negatively) connected with precipitation in DJF (MAM) in the middle and lower reaches of the Yangtze River. In DJF and MAM, the precipitation in the middle and lower reaches of the Yangtze River decreases (increases) under pure positive SIOD (pure negative SIOD) events. That is, the position of the ITCZ in the Indian Ocean may be one of the intermediaries by which the SIOD affects precipitation in the middle and lower reaches of the Yangtze River.

show abstract

“…There exists significantly negative correlation between the SIOD and ENSO but some SIOD cases are formed without the effect of ENSO by Indian Ocean intrinsic processes through the changes of surface latent heat flux in relation with the wind speed fluctuations (Behera and Yamagata, 2001; Zhang et al ., 2020). Both the statistical and model studies have documented the significant impacts of SIOD on the climate variability over the Indian Ocean rim and remote regions (Rai and Pandey, 2008; Cao et al ., 2014; Zhang et al ., 2017; Gong et al ., 2019). Through the modulation of the anomalous convection heating over the Maritime Continent and vapour transportation, the SIOD could influence the summer rainfall distribution in China (Yang and Ding, 2007; Cao et al ., 2014; Jin et al ., 2017).…”

Section: Introductionmentioning

confidence: 99%

Possible impacts of spring subtropical Indian Ocean Dipole on the summer tropical cyclone genesis frequency over the western North Pacific

Zhou

Zhang

2022

Intl Journal of Climatology

View full text Add to dashboard Cite

The linkage between the spring subtropical Indian Ocean Dipole (SIOD) events and tropical cyclone genesis frequency over the western North Pacific (WNP) in the following summer is investigated in this study. It is found that their correlation is positive and statistically significant with a greater number of TCs genesis over the WNP in summer of a positive SIOD year. After removing the ENSO effects, diagnostic analysis reveals that under positive SIOD conditions the summertime WNP monsoon trough becomes intensified. Correspondingly, there are enhanced lower‐level vorticity, reduced vertical zonal wind shear, increased middle‐level relative humidity and vertical velocity over the WNP, conductive to generation of more TCs. Further examination indicates that the Mascarene high and Australian high are strengthened successively from spring to subsequent summer in a positive SIOD year, contributing to the maintenance of SIOD‐related SST dipole anomalies in southern Indian Ocean due to SST–wind–evaporation feedback mechanism. The resulting cyclonic anomaly is formed at lower troposphere over the WNP induced by the prominently enhanced cross‐equator airflows and the related Ekman upwelling. At upper troposphere, there tend to be remarkably WNP divergence anomalies of the interhemispheric vertical circulation forced by the summertime SST patterns closely associated with positive SIOD cases. By contrast, the monsoon trough is weakened and the dynamic and thermodynamic conditions are unfavourable for the WNP TC genesis in summer of a negative SIOD year, in agreement with a lower‐level anticyclonic anomaly and suppressed deep convection over the WNP forced by the SIOD‐related SST anomalies.

show abstract

Modulation of the southern Indian Ocean dipole on the impact of El Niño–Southern Oscillation on Australian summer rainfall

Cited by 10 publications

References 28 publications

Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis

Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis

The Southern Indian Ocean Dipole and its effects on Precipitation in China

Possible impacts of spring subtropical Indian Ocean Dipole on the summer tropical cyclone genesis frequency over the western North Pacific

Contact Info

Product

Resources

About