Influences of the Interdecadal Pacific Oscillation on the Locally Amplified Ningaloo Niño

2020 ◽  
Vol 47 (15) ◽  
Author(s):  
Natsumi Tanuma ◽  
Tomoki Tozuka
Keyword(s):  
Interdecadal Pacific Oscillation

Reconstructing an Interdecadal Pacific Oscillation Index from a Pacific Basin–Wide Collection of Ice Core Records

2021 ◽  
Vol 34 (10) ◽  
pp. 3839-3852
Author(s):  
Stacy E. Porter ◽  
Ellen Mosley-Thompson ◽  
Lonnie G. Thompson ◽  
Aaron B. Wilson
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Tropical Pacific ◽  
Ice Age ◽  
Pacific Basin ◽  
Interdecadal Pacific Oscillation ◽  
The Pacific ◽  
Instrumental Period ◽  
The Tropical Pacific ◽  
Ice Core Records

AbstractUsing an assemblage of four ice cores collected around the Pacific basin, one of the first basinwide histories of Pacific climate variability has been created. This ice core–derived index of the interdecadal Pacific oscillation (IPO) incorporates ice core records from South America, the Himalayas, the Antarctic Peninsula, and northwestern North America. The reconstructed IPO is annually resolved and dates to 1450 CE. The IPO index compares well with observations during the instrumental period and with paleo-proxy assimilated datasets throughout the entire record, which indicates a robust and temporally stationary IPO signal for the last ~550 years. Paleoclimate reconstructions from the tropical Pacific region vary greatly during the Little Ice Age (LIA), although the reconstructed IPO index in this study suggests that the LIA was primarily defined by a weak, negative IPO phase and hence more La Niña–like conditions. Although the mean state of the tropical Pacific Ocean during the LIA remains uncertain, the reconstructed IPO reveals some interesting dynamical relationships with the intertropical convergence zone (ITCZ). In the current warm period, a positive (negative) IPO coincides with an expansion (contraction) of the seasonal latitudinal range of the ITCZ. This relationship is not stationary, however, and is virtually absent throughout the LIA, suggesting that external forcing, such as that from volcanoes and/or reduced solar irradiance, could be driving either the ITCZ shifts or the climate dominating the ice core sites used in the IPO reconstruction.

scholarly journals South Asian summer monsoon projections constrained by the interdecadal Pacific oscillation

2020 ◽  
Vol 6 (11) ◽  
pp. eaay6546 ◽  
Author(s):  
Xin Huang ◽  
Tianjun Zhou ◽  
Aiguo Dai ◽  
Hongmei Li ◽  
Chao Li ◽  
...  
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
System Model ◽  
Earth System ◽  
South Asian Summer Monsoon ◽  
Interdecadal Pacific Oscillation ◽  
Asian Summer ◽  
Near Term ◽  
Ensemble Of Simulations

A reliable projection of future South Asian summer monsoon (SASM) benefits a large population in Asia. Using a 100-member ensemble of simulations by the Max Planck Institute Earth System Model (MPI-ESM) and a 50-member ensemble of simulations by the Canadian Earth System Model (CanESM2), we find that internal variability can overshadow the forced SASM rainfall trend, leading to large projection uncertainties for the next 15 to 30 years. We further identify that the Interdecadal Pacific Oscillation (IPO) is, in part, responsible for the uncertainties. Removing the IPO-related rainfall variations reduces the uncertainties in the near-term projection of the SASM rainfall by 13 to 15% and 26 to 30% in the MPI-ESM and CanESM2 ensembles, respectively. Our results demonstrate that the uncertainties in near-term projections of the SASM rainfall can be reduced by improving prediction of near-future IPO and other internal modes of climate variability.

scholarly journals Variability in Severe Coastal Flooding, Associated Storms, and Death Tolls in Southeastern Australia since the Mid–Nineteenth Century

2016 ◽  
Vol 55 (5) ◽  
pp. 1139-1149 ◽  
Author(s):  
Scott B. Power ◽  
Jeff Callaghan
Keyword(s):  
Nineteenth Century ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Coastal Flooding ◽  
La Niña ◽  
Interdecadal Pacific Oscillation ◽  
Weather Types ◽  
Southeastern Australia ◽  
La Nina

AbstractThe variability in the number of severe floods that occurred in coastal catchments in southeastern Australia since the mid–nineteenth century, along with the variability in both the frequency of the weather types that triggered the floods and the associated death tolls, is analyzed. Previous research has shown that all of the severe floods identified were associated with one of two major weather types: east coast lows (ECLs) and tropical interactions (TIs). El Niño–Southern Oscillation (ENSO) is shown to strongly modulate the frequency of severe coastal flooding, weather types, and the number of associated deaths. The analysis presented herein, which examines links over more than a century, provides one of very few known statistically significant links between ENSO and death tolls anywhere in the world. Over the period 1876/77–2013/14 the average numbers of coastal floods, ECLs, TIs, and deaths associated with freshwater drowning in La Niña years are 92%, 55%, 150%, and 220% higher than the corresponding averages in El Niño years. The average number of deaths per flood in La Niña years is 3.2, which is 66% higher than the average in El Niño years. Death tolls of 10 or more occurred in only 5% of El Niño years, but in 27% of La Niña years. The interdecadal Pacific oscillation also modulates the frequency of severe floods, weather types, and death tolls. The results of this study are consistent with earlier research over shorter periods and broader regions, using less-complete datasets.

scholarly journals Contributions of Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation to Global Ocean Heat Content Distribution

2018 ◽  
Vol 31 (3) ◽  
pp. 1227-1244 ◽  
Author(s):  
Zeyuan Hu ◽  
Aixue Hu ◽  
Yongyun Hu
Keyword(s):  
Pacific Ocean ◽  
Surface Temperature ◽  
Heat Content ◽  
Atlantic Multidecadal Oscillation ◽  
Meridional Overturning Circulation ◽  
Ocean Heat Content ◽  
Global Ocean ◽  
Negative Phase ◽  
Heat Distribution ◽  
Interdecadal Pacific Oscillation

Abstract Regional sea surface temperature (SST) mode variabilities, especially the La Niña–like Pacific Ocean temperature pattern known as the negative phase of the interdecadal Pacific oscillation (IPO) and the associated heat redistribution within the ocean, are the leading mechanisms explaining the recent global warming hiatus. Here version 1 of the Community Earth System Model (CESM) is used to examine how different phases of two leading decadal time scale SST modes, namely the IPO and the Atlantic multidecadal oscillation (AMO), contribute to heat redistribution in the global ocean in the absence of time-evolving external forcings. The results show that both the IPO and AMO contribute a similar magnitude to global mean surface temperature and ocean heat redistribution. Both modes contribute warmer surface temperature and higher upper ocean heat content in their positive phase, and the reverse in their negative phase. Regionally, patterns of ocean heat distribution in the upper few hundred meters of the tropical and subtropical Pacific Ocean depend highly on the IPO phase via the IPO-associated changes in the subtropical cell. In the Atlantic, ocean heat content is primarily associated with the state of the AMO. The interconnections between the IPO, AMO, and global ocean heat distribution are established through the atmospheric bridge and the Atlantic meridional overturning circulation. An in-phase variant of the IPO and AMO can lead to much higher surface temperatures and heat content changes than an out-of-phase variation. This result suggests that changes in the IPO and AMO are potentially capable of modulating externally forced SST and heat content trends.

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