The West Pacific Gradient tracks ENSO and zonal Pacific sea surface temperature gradient during the last Millennium

Small changes in Pacific temperature gradients connected with the El Niño Southern Oscillation (ENSO) influence the Walker Circulation and are related to global climate anomalies. Therefore, it is of paramount importance to develop robust indices of their past behavior. Here, we reconstruct the diff...

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Bibliographic Details
Published inScientific reports Vol. 11; no. 1; pp. 20395 - 16
Main Authors Zinke, J., Browning, S. A., Hoell, A., Goodwin, I. D.
Format Journal Article
LanguageEnglish
Published London Nature Publishing Group UK 14.10.2021
Nature Publishing Group
Nature Portfolio
Subjects
704/106/2738
704/106/413
704/106/694
Atmospheric circulation
Data collection
Drought
El Nino
Global climate
Humanities and Social Sciences
Hydrodynamics
La Nina
multidisciplinary
Science
Science (multidisciplinary)
Sea surface temperature
Southern Oscillation
Temperature
Temperature gradients
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Summary:Small changes in Pacific temperature gradients connected with the El Niño Southern Oscillation (ENSO) influence the Walker Circulation and are related to global climate anomalies. Therefore, it is of paramount importance to develop robust indices of their past behavior. Here, we reconstruct the difference in sea surface temperature between the west and central Pacific during ENSO, coined the West Pacific Gradient (WPG), based on the Last Millennium Paleo Hydrodynamics Data Assimilation. We show that the WPG tracks ENSO variability and strongly co-varies with the zonal gradient in Pacific sea surface temperature. We demonstrate that the WPG strength is related to significant atmospheric circulation and precipitation anomalies during historical El Niño and La Niña events by magnifying or weakening droughts and pluvials across the Indo-Pacific. We show that an extreme negative WPG coupled to a strong zonal Pacific temperature gradient is associated with enhanced megadroughts in North America between 1400 CE and the late sixteenth century. The twentieth century stands out in showing the most extreme swings between positive and negative WPG conditions over the past Millennium. We conclude that the WPG is a robust index together with ENSO indices to reveal past changes in Pacific zonal sea surface temperature gradient variability.
ISSN:2045-2322
2045-2322
DOI:10.1038/s41598-021-99738-3