Confirmation of ENSO-Southern Ocean Teleconnections Using Satellite-Derived SST

Brady Ferster,Alison Macdonald,Bulusu Subrahmanyam

doi:10.3390/rs10020331

Brady Ferster, Alison Macdonald + Show 1 more

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https://doi.org/10.3390/rs10020331

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Abstract

The Southern Ocean is the focus of many physical, chemical, and biological analyses due to its global importance and highly variable climate. This analysis of sea surface temperatures (SST) and global teleconnections shows that SSTs are significantly spatially correlated with both the Antarctic Oscillation and the Southern Oscillation, with spatial correlations between the indices and standardized SST anomalies approaching 1.0. Here, we report that the recent positive patterns in the Antarctic and Southern Oscillations are driving negative (cooling) trends in SST in the high latitude Southern Ocean and positive (warming) trends within the Southern Hemisphere sub-tropics and mid-latitudes. The coefficient of regression over the 35-year period analyzed implies that standardized temperatures have warmed at a rate of 0.0142 per year between 1982 and 2016 with a monthly standard error in the regression of 0.0008. Further regression calculations between the indices and SST indicate strong seasonality in response to changes in atmospheric circulation, with the strongest feedback occurring throughout the austral summer and autumn.

Highlights

Southern Ocean is a highly dynamic component of the global ocean circulation that plays a key role in the transport of heat, the uptake of carbon, and the global climate system [1,2,3,4,5,6,7,8]
The Southern Ocean is the focus of many physical, chemical, and biological analyses due to its global importance and highly variable climate. This analysis of sea surface temperatures (SST) and global teleconnections shows that SSTs are significantly spatially correlated with both the Antarctic Oscillation and the Southern Oscillation, with spatial correlations between the indices and standardized SST anomalies approaching 1.0
We find SSTs to be significantly correlated to both the Antarctic Oscillation (AAO) and the Southern Oscillation (SO), with larger magnitude of anomalies associated with the SO events

Summary

Introduction

Southern Ocean is a highly dynamic component of the global ocean circulation that plays a key role in the transport of heat, the uptake of carbon, and the global climate system [1,2,3,4,5,6,7,8]. The Southern Ocean circulation is largely wind driven. Changes in the Southern Hemisphere wind field drive sea surface temperature (SST) gradients that can support a feedback mechanism and influence both the latitude of the Antarctic Circumpolar Current (ACC) and the distributions of heat and nutrients [9,10,11,12,13]. Southern Hemisphere atmospheric variability exhibits a large number of modes, mostly influenced by large-scale low-frequency patterns [14] and has been known to play a major role in Southern Hemisphere weather and climate [15,16]. For a more in-depth analysis into the relationship between large-scale atmospheric teleconnections and Southern Ocean SST, refer to [17]. To analyze trends of Southern Hemisphere air-sea interactions, two patterns of atmospheric variability are compared with SST: the Antarctic Oscillation (AAO) and the Southern Oscillation (SO)

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