The response of the Southern Annular Mode, the East Australian Current, and the southern mid‐latitude ocean circulation to global warming

Cai, Wenju; Shi, Ge; Cowan, Tim; Bi, Daohua; Ribbe, Joachim

doi:10.1029/2005gl024701

Cited by 269 publications

(269 citation statements)

References 16 publications

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“…The rainfall tends to be enhanced by a warmer surface, similarly to changes off South Africa simulated by Reason and Mulenga (1999). Cai et al (2005) examined these SST patterns in the late 21st century climate from Mk3 and suggested that the anomalies may be consistent with a change in the oceanic circulation. They showed that the simulated change in the curl of the wind stress on the ocean surface should theoretically drive a spin-up of the entire Southern Ocean circulation.…”

Section: Discussionmentioning

confidence: 99%

Components of precipitation and temperature anomalies and change associated with modes of the Southern Hemisphere

Watterson

2008

Intl Journal of Climatology

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A long simulation of climate by the CSIRO Mark 3 coupled atmosphere -ocean model is analysed to assess the role of three modes of the Southern Hemisphere (SH) circulation on the inter-annual variability of precipitation and surface temperature and the contribution of the modes to patterns of change under global warming. Indices of El Niño-southern oscillation (ENSO) and the high-and low-latitude modes (HLM, LLM) of zonal mean zonal wind are extracted from monthly means during the period 1871-1970. The model El Niño brings mostly drier and warmer conditions to Australia -New Zealand (NZ), South America and southern Africa in both annual and seasonal means. The HLM and LLM modes impact rainfall and temperature in banded patterns. Positive HLM [which is closely related to the southern annular mode (SAM) in pressure] moistens and cools around 20-35°S particularly near the east coast of each continent. Farther south it mostly dries and warms, especially in the austral winter. The LLM has some impacts, including increased summer rain in western Australia, and temperature anomalies in eastern South America in autumn. Mostly similar patterns are found in the ERA40 observational data. Changes in the indices in the 22nd century, following warming forced by the A1B greenhouse gas (GHG) scenario, are positive, in most cases, and similar in magnitude to their inter-annual variability. The drying and warming of Australia associated with an El Niño-like change are largely countered by the HLM-like change, and similar effects are seen in parts of the other continents. The far south of NZ and South America are dried and warmed by the HLM change, but these relative changes are countered by non-modal effects in the Southern Ocean.

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Section: Discussionmentioning

confidence: 99%

Components of precipitation and temperature anomalies and change associated with modes of the Southern Hemisphere

Watterson

2008

Intl Journal of Climatology

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“…If the SAM continues to become increasingly positive, in particular during the summer (Fyfe et al, 1999;Kwok and Comiso, 2002;Thompson and Solomon, 2002;Marshall, 2003;Renwick, 2004;Cai et al, 2005), the conditions such as those described in Figure 10 would tend to become more frequent even when the relation between SAM and blocking in the SA is not straightforward, triggering future possible large-scale events where the potential of further transitioning cases may be enhanced. However, it is also worth mentioning that at least during the SH spring time the positive trend in the SAM is at least partially expected to decrease as the stratospheric O 3 levels gradually recover (Shindell and Schmidt, 2004).…”

Section: Concluding Discussionmentioning

confidence: 99%

“…As discussed in the next paragraphs, high-latitude activity can be seen to be a precursor of Catarina's development. In addition, the trend to more positive SAM under global warming and ozone losses (Fyfe et al, 1999;Kwok and Comiso, 2002;Thompson and Solomon, 2002;Marshall, 2003;Renwick, 2004;Cai et al, 2005) suggests an increase in such blocking events. Figure 7 shows the time series (every 6 h) of the BI and the EVWS superimposed on the regional and hemispheric AAO indices.…”

Section: The 'South Atlantic Index' and High-latitude Interactionsmentioning

confidence: 99%

“…McDonald et al, 2005;Oouchi et al, 2006). Pezza and Simmonds (2005) suggested that SA transitioning events like Catarina could be made more likely under circulation changes, partially those associated with the significant increased positive polarity of Southern Annular Mode (SAM) during the warmer months in the SH (Fyfe et al, 1999;Kwok and Comiso, 2002;Thompson and Solomon, 2002;Marshall, 2003;Renwick, 2004;Cai et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

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Climate perspective on the large‐scale circulation associated with the transition of the first South Atlantic hurricane

Pezza

Simmonds

Filho

2008

Intl Journal of Climatology

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ABSTRACT:The landfall of Cyclone Catarina on the Brazilian coast in March 2004 became known as the first documented hurricane in the South Atlantic Ocean, promoting a new view on how large-scale features can contribute to tropical transition. The aim of this paper is to put the large-scale circulation associated with Catarina's transition in climate perspective. This is discussed in the light of a robust pattern of spatial correlations between thermodynamic and dynamic variables of importance for hurricane formation. A discussion on how transition mechanisms respond to the present-day circulation is presented. These associations help in understanding why Catarina was formed in a region previously thought to be hurricane-free.Catarina developed over a large-scale area of thermodynamically favourable air/sea temperature contrast. This aspect explains the paradox that such a rare system developed when the sea surface temperature was slightly below average. But, although thermodynamics played an important role, it is apparent that Catarina would not have formed without the key dynamic interplay triggered by a high latitude blocking. The blocking was associated with an extreme positive phase of the Southern Annular Mode (SAM) both hemispherically and locally, and the nearby area where Catarina developed is found to be more cyclonic during the positive phase of the SAM. A conceptual model is developed and a 'South Atlantic index' is introduced as a useful diagnostic of potential conditions leading to tropical transition in the area, where large-scale indices indicate trends towards more favourable atmospheric conditions for tropical cyclone formation.

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“…Accordingly, the associated trans-Pacific tilt of the near-equatorial oceanic thermocline (Bjerknes 1966) can be expected to lessen, and the coupled Pacific oceanatmosphere system to become more chronically ''El Niño''-like (Quinn 1974;Wyrtki 1975) in its underlying mean background state. Climate change is also predicted to drive a strengthening of the EAC itself and a general southward shift of the South Pacific Gyre (Cai et al 2005, Steinberg 2007), of which the EAC represents the far western limb. Effects on local ecosystems are expected to be influenced in two potentially opposing ways by an intensification of EAC flow adjacent to the Capricorn Eddy.…”

Section: The Implications Of Climate Change For Eddy-related Effectsmentioning

confidence: 99%

The Capricorn Eddy: a prominent driver of the ecology and future of the southern Great Barrier Reef

et al. 2010

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This study focuses on a mesoscale eddy feature, the 'Capricorn Eddy', that typically forms within an indentation of the continental shelf in the southern GBR system. Satellite data at moderate resolution (1 km) are used to examine relevant mesoscale and sub-mesoscale sea surface dynamics. Available in situ measurements and model data are used to validate the satellite observations and to specify the nature of the processes occurring within the water column itself. The characteristic features are identified and physical theory employed to develop an understanding of associated processes. In particular, the effect of the eddy in raising cooler, nutrient-enriched oceanic subsurface water and transporting it to the reef zone, and eventually into the lagoon, is shown. This study demonstrates that the linkages between large-scale oceanography and the meso-and sub-mesoscale patterns are crucial to determining biologic responses on the scale of reef communities and may be key to understanding climate change impacts at the relevant spatial scales.

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The response of the Southern Annular Mode, the East Australian Current, and the southern mid‐latitude ocean circulation to global warming

Cited by 269 publications

References 16 publications

Components of precipitation and temperature anomalies and change associated with modes of the Southern Hemisphere

Components of precipitation and temperature anomalies and change associated with modes of the Southern Hemisphere

Climate perspective on the large‐scale circulation associated with the transition of the first South Atlantic hurricane

The Capricorn Eddy: a prominent driver of the ecology and future of the southern Great Barrier Reef

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