Synchronicity in southern hemisphere squid stocks and the influence of the Southern Oscillation and Trans Polar Index

2004 ◽  
Vol 13 (4) ◽  
pp. 255-266 ◽  
Author(s):  
C. M. Waluda ◽  
P. N. Trathan ◽  
P. G. Rodhouse
Keyword(s):  
Southern Hemisphere ◽  
Southern Oscillation ◽  
Polar Index

scholarly journals Seasonal and Secular Variations of Atmospheric 14Co2 Over the Western Pacific Since 1994

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 901-910 ◽  
Author(s):  
H Kitagawa ◽  
Hitoshi Mukai ◽  
Yukihiro Nojiri ◽  
Yasuyuki Shibata ◽  
Toshiyuki Kobayashi ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Southern Oscillation ◽  
Monitoring Program ◽  
Western Pacific ◽  
Environmental Research ◽  
Enso Events ◽  
Global Environmental ◽  
Secular Variations ◽  
The Western Pacific

Air sample collections over the western Pacific have continued since 1992 as a part of Center for Global Environmental Research, National Institute for Environmental Studies (CGER-NIES) global environmental monitoring program. The air samples collected on the Japan-Australia transect made it possible to trace the seasonal and secular 14CO2 variations, as well as an increasing trend of greenhouse gases over the western Pacific. A subset of CO2 samples from latitudes of 10–15°N and 23–28°S were chosen for accelerator mass spectrometry (AMS) 14C analysis using a NIES-TERRA AMS with a 0.3–0.4% precision. These 14CO2 records in maritime air show seasonal variations superimposed on normal exponential decreasing trends with a time constant of about 16 yr. The Δ14C values in the Northern Hemisphere are lower those in the Southern Hemisphere by 3–4 during 1994–2002. The Northern Hemisphere record shows relatively high seasonality (2.3 ± 1.5) as compared with the Southern Hemisphere (1.3 ± 1.2). The maximum values of seasonal cycles appear in late autumn and early winter in the Northern and Southern Hemispheres, respectively. Oscillations of 1–10 yr over the western Pacific are found to correlate possibly with the El Niño/Southern Oscillation (ENSO) events.

scholarly journals Quasi-biennial and quasi-triennial oscillations in the growth rates of atmospheric chlorofluorocarbons 11 and 12

MAUSAM ◽  
2022 ◽  
Vol 53 (3) ◽  
pp. 349-358
Author(s):  
R. P. KANE
Keyword(s):  
Southern Hemisphere ◽  
Growth Rates ◽  
Southern Oscillation ◽  
Spectral Characteristics ◽  
Linear Increase ◽  
Transport Processes ◽  
Emission Rates ◽  
Low Latitude ◽  
The Difference ◽  
Prominent Peak

The 12-monthly running means of CFC-11 and CFC-12 were examined for 1977-1992. As observed by earlier workers, during 1977-1988, there was a rapid, almost linear increase of these compounds, ~70% in the northern and ~77% in the southern hemisphere. From 1988 up to 1992, growth rates were slower, more so for CFC-11 in the northern hemisphere. Superposed on this pattern were QBO, QTO (Quasi-Biennial and Quasi-Triennial Oscillations). A spectral analysis of the various series indicated the following. The 50 hPa low latitude zonal wind had one prominent QBO peak at 2.58 years and much smaller peaks at 2.00 (QBO) and 5.1 years. The Southern oscillation index represented by (T-D), Tahiti minus Darwin atmospheric pressure, had a prominent peak at 4.1 years and a smaller peak at 2.31 years. CFC-11 had only one significant peak at 3.7 years in the southern hemisphere, roughly similar to the 4.1 year (T-D) peak. CFC-12 had prominent QBO (2.16-2.33 years) in both the hemispheres and a QTO (3.6 years) in the southern hemisphere. For individual locations, CFC-11 showed barely significant QBO in the range (1.95-3.07 years), while CFC 12 showed strong QBO in the range (1.86-2.38 years). The difference in the spectral characteristics of CFC-11 and CFC 12 time series is attributed to differences in their lifetimes (44 and 180 years), source emission rates and transport processes.

scholarly journals Triggering the Indian Ocean Dipole from the Southern Hemisphere

2021 ◽  
Author(s):  
Lian-Yi Zhang ◽  
Yan Du ◽  
Wenju Cai ◽  
Zesheng Chen ◽  
Tomoki Tozuka ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Indian Ocean Dipole ◽  
Southern Oscillation ◽  
Southern Annular Mode ◽  
Triggering Mechanism ◽  
Phase Development ◽  
The Indian Ocean ◽  
High System ◽  
The Tropics

<p>This study identifies a new triggering mechanism of the Indian Ocean Dipole (IOD) from the Southern Hemisphere. This mechanism is independent from the El Niño/Southern Oscillation (ENSO) and tends to induce the IOD before its canonical peak season. The joint effects of this mechanism and ENSO may explain different lifetimes and strengths of the IOD. During its positive phase, development of sea surface temperature cold anomalies commences in the southern Indian Ocean, accompanied by an anomalous subtropical high system and anomalous southeasterly winds. The eastward movement of these anomalies enhances the monsoon off Sumatra-Java during May-August, leading to an early positive IOD onset. The pressure variability in the subtropical area is related with the Southern Annular Mode, suggesting a teleconnection between high-latitude and mid-latitude climate that can further affect the tropics. To include the subtropical signals may help model prediction of the IOD event.</p>

Relationship between the Southern Oscillation Index and Australian sugarcane yields

1994 ◽  
Vol 45 (7) ◽  
pp. 1557 ◽  
Author(s):  
I Kuhnel
Keyword(s):  
Southern Hemisphere ◽  
Southern Oscillation Index ◽  
Southern Oscillation ◽  
Significance Testing ◽  
The Past ◽  
Northern Areas ◽  
Eastern Australia ◽  
North Eastern ◽  
Sugarcane Yield ◽  
The Relationship

This study examines the relationship between the Southern Oscillation Index and the sugarcane yield anomalies at 27 mills in north-eastern Australia (Queensland) for the period 1950-1989. The major results of this work indicate that the SO1 alone seems to have only a limited value as predictor of total sugarcane yields over large areas (i.e. the whole of Queensland). However, on a smaller scale, the SO1 appears to be a useful indicator of yields for the northern sugarcane districts. In these northern areas, the highest correlations with the SO1 are reached during the southern hemisphere spring and summer months 6 to 11 months prior to the harvest. They are negative and explain about 40% of the total variance. They also suggest that a positive SO1 during the spring and summer months tends to be followed by lower-than-normal yields at the following harvest and vice versa. This signal is rather robust and withstands rigorous significance testing. Moreover, it appears that the relationship between the SO1 and the sugarcane yields has been relatively strong and stable for the past 40 years, but weakened substantially during the 1930-1940 period.

scholarly journals Response of the Antarctic Circumpolar Current to Atmospheric Variability

2008 ◽  
Vol 21 (12) ◽  
pp. 3020-3039 ◽  
Author(s):  
J. B. Sallée ◽  
K. Speer ◽  
R. Morrow
Keyword(s):  
Sea Level ◽  
Southern Hemisphere ◽  
Antarctic Circumpolar Current ◽  
Southern Oscillation ◽  
Atmospheric Forcing ◽  
Atmospheric Variability ◽  
Central Pacific ◽  
Geographical Regions ◽  
Circumpolar Current ◽  
The Antarctic

Abstract Historical hydrographic profiles, combined with recent Argo profiles, are used to obtain an estimate of the mean geostrophic circulation in the Southern Ocean. Thirteen years of altimetric sea level anomaly data are then added to reconstruct the time variable sea level, and this new dataset is analyzed to identify and monitor the position of the two main fronts of the Antarctic Circumpolar Current (ACC) during the period 1993–2005. The authors relate their movements to the two main atmospheric climate modes of the Southern Hemisphere: the Southern Annular Mode (SAM) and the El Niño–Southern Oscillation (ENSO). The study finds that although the fronts are steered by the bathymetry, which sets their mean pathway on first order, in flat-bottom areas the fronts are subject to large meandering because of mesoscale activity and atmospheric forcing. While the dominant mode of atmospheric variability in the Southern Hemisphere, SAM, is relatively symmetric, the oceanic response of the fronts is not, showing substantial regional differences. Around the circumpolar belt the fronts vary in latitude, exposing them to different Ekman transport anomalies induced by the SAM. Three typical scenarios occur in response to atmospheric forcing: poleward movement of the frontal structure in the Indian Basin during positive SAM events, an equatorward movement in the central Pacific, and an intensification without substantial meridional movement in the Indo-Pacific basin. The study also shows the geographical regions that are dominated by a SAM or ENSO response at low and high frequencies.

Southern skies: Australian atmospheric research and global climate change

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ruth A. Morgan
Keyword(s):  
Climate Change ◽  
Environmental History ◽  
Southern Hemisphere ◽  
Southern Oscillation ◽  
Global Climate ◽  
Global Environmental Change ◽  
Published Data ◽  
Global Knowledge ◽  
Content Type ◽  
Leading Role

PurposeThe purpose of this paper is to examine the role of Australian climate scientists in advancing the state of knowledge about the causes and mechanisms of climatic change and variability in the Southern Hemisphere during the 1970 and 1980s.Design/methodology/approachThe paper uses the methods and insights of environmental history and the history of science to analyse archival and published data pertaining to research on atmospheric pollution, the Southern Oscillation and the regional impacts of climate change.FindingsAustralia's geopolitical position, political interests and environmental sensitivities encouraged Australian scientists and policymakers to take a leading role in the Southern Hemisphere in the study of global environmental change.Originality/valueThis article builds on critiques of the ways in which planetary and global knowledge and governance disguise the local and situated scientific and material processes that construct, sustain and configure them.

Seasonal climate summary for the southern hemisphere (spring 2016): strong negative Indian Ocean Dipole ends, bringing second wettest September to Australia

2019 ◽  
Vol 69 (1) ◽  
pp. 273
Author(s):  
Blair Trewin ◽  
Catherine Ganter
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Indian Ocean Dipole ◽  
Southern Oscillation ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
The Pacific ◽  
The Indian Ocean ◽  
Low Levels ◽  
Equatorial Climate

This summary looks at the southern hemisphere and equatorial climate patterns for spring 2016, with particular attention given to the Australasian and equatorial regions of the Pacific and Indian Ocean basins. Spring 2016 was marked by the later part of a strong negative phase of the Indian Ocean Dipole, alongside cool neutral El Niño–Southern Oscillation conditions. September was exceptionally wet over much of Australia, contributing to a wet spring with near-average temperatures. The spring was one of the warmest on record over the southern hemisphere as a whole, with Antarctic Sea ice extent dropping to record low levels for the season.

Does the El Niño–Southern Oscillation control the interhemispheric radiocarbon offset?

2007 ◽  
Vol 67 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Chris S.M. Turney ◽  
Jonathan G. Palmer
Keyword(s):  
Southern Hemisphere ◽  
El Niño ◽  
Atmospheric Carbon Dioxide ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Ice Age ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Mean Values

AbstractSince the 1970s it has been recognised that Southern Hemisphere samples have a lower radiocarbon content than contemporaneous material in the Northern Hemisphere. This interhemispheric radiocarbon offset has traditionally been considered to be the result of a greater surface area in the southern ocean and high-latitude deepwater formation. This is despite the fact that the El Niño–Southern Oscillation (ENSO) is known to play a significant role in controlling the interannual variability of atmospheric carbon dioxide by changing the flux of ‘old’ CO2 from the tropical Pacific. Here we demonstrate that over the past millennium, the Southern Hemisphere radiocarbon offset is characterised by a pervasive 80-yr cycle with a step shift in mean values coinciding with the transition from the Medieval Warm Period to the Little Ice Age. The observed changes suggest an ENSO-like role in influencing the interhemispheric radiocarbon difference, most probably modulated by the Interdecadal Pacific Oscillation, and supports a tropical role in forcing centennial-scale global climate change.

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