Decadal Spiciness Variability in the Subtropical-Tropical Pacific in the CESM2 Large Ensemble.
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| Title: | Decadal Spiciness Variability in the Subtropical-Tropical Pacific in the CESM2 Large Ensemble. |
|---|---|
| Authors: | STOCKMAYER, VERA1 verasto@hawaii.edu, SCHNEIDER, NIKLAS1,2,3, STUECKER, MALTE F.1,2, LÜBBECKE, JOKE F.4,5 |
| Source: | Journal of Climate. Jun2026, Vol. 39 Issue 11, p1-16. 16p. |
| Subjects: | Ocean dynamics, Climate change, Ocean |
| Geographic Terms: | Pacific Ocean, Southern Hemisphere |
| Abstract: | Tropical Pacific decadal variations impact weather and climate around the world and are also linked to variations in the global warming trend. The mechanisms driving these long-term modulations, particularly the role of subsurface ocean dynamics, are still debated. Here, we investigate the dynamics of spiciness (density-compensated temperature and salinity) anomalies in the tropical and subtropical Pacific, which are hypothesized as a possible driving mechanism of decadal climate variability. Based on the analysis of 100 realizations from the Community Earth System Model Version 2 Large Ensemble (CESM2-LE), we demonstrate a coupling between the subtropics and the equatorial Pacific by propagating spiciness anomalies at decadal time scales. The CESM2-LE simulates spiciness variability along a subduction path from the subtropics to the equator with frequency spectra that show the highest power at low frequencies and a power decay proportional to a −4 slope for frequencies greater than 0.01 cycles per months, corresponding to periods smaller than ∼8.5 years. Signals that originate in the Southern Hemisphere (SH) dominate and arrive with a larger magnitude at the equator compared to spiciness anomalies from the Northern Hemisphere (NH). Spiciness anomalies from the SH have shorter propagation times and are strengthened along their pathway as stochastic wind stress curl forcing generates anomalous baroclinic ocean pressure gradients. These pressure gradients generate spiciness anomalies via anomalous advection across climatological spiciness gradients in the SH. We conclude that the observed spiciness variance at decadal time scales is consistent with a forcing by stochastic wind variations that are low-pass filtered by ocean dynamics. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Climate is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
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| Header | DbId: egs DbLabel: Engineering Source An: 194578136 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Decadal Spiciness Variability in the Subtropical-Tropical Pacific in the CESM2 Large Ensemble. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22STOCKMAYER%2C+VERA%22">STOCKMAYER, VERA</searchLink><relatesTo>1</relatesTo><i> verasto@hawaii.edu</i><br /><searchLink fieldCode="AR" term="%22SCHNEIDER%2C+NIKLAS%22">SCHNEIDER, NIKLAS</searchLink><relatesTo>1,2,3</relatesTo><br /><searchLink fieldCode="AR" term="%22STUECKER%2C+MALTE+F%2E%22">STUECKER, MALTE F.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22LÜBBECKE%2C+JOKE+F%2E%22">LÜBBECKE, JOKE F.</searchLink><relatesTo>4,5</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Climate%22">Journal of Climate</searchLink>. Jun2026, Vol. 39 Issue 11, p1-16. 16p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Ocean+dynamics%22">Ocean dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Climate+change%22">Climate change</searchLink><br /><searchLink fieldCode="DE" term="%22Ocean%22">Ocean</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Pacific+Ocean%22">Pacific Ocean</searchLink><br /><searchLink fieldCode="DE" term="%22Southern+Hemisphere%22">Southern Hemisphere</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Tropical Pacific decadal variations impact weather and climate around the world and are also linked to variations in the global warming trend. The mechanisms driving these long-term modulations, particularly the role of subsurface ocean dynamics, are still debated. Here, we investigate the dynamics of spiciness (density-compensated temperature and salinity) anomalies in the tropical and subtropical Pacific, which are hypothesized as a possible driving mechanism of decadal climate variability. Based on the analysis of 100 realizations from the Community Earth System Model Version 2 Large Ensemble (CESM2-LE), we demonstrate a coupling between the subtropics and the equatorial Pacific by propagating spiciness anomalies at decadal time scales. The CESM2-LE simulates spiciness variability along a subduction path from the subtropics to the equator with frequency spectra that show the highest power at low frequencies and a power decay proportional to a −4 slope for frequencies greater than 0.01 cycles per months, corresponding to periods smaller than ∼8.5 years. Signals that originate in the Southern Hemisphere (SH) dominate and arrive with a larger magnitude at the equator compared to spiciness anomalies from the Northern Hemisphere (NH). Spiciness anomalies from the SH have shorter propagation times and are strengthened along their pathway as stochastic wind stress curl forcing generates anomalous baroclinic ocean pressure gradients. These pressure gradients generate spiciness anomalies via anomalous advection across climatological spiciness gradients in the SH. We conclude that the observed spiciness variance at decadal time scales is consistent with a forcing by stochastic wind variations that are low-pass filtered by ocean dynamics. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Climate is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1175/JCLI-D-25-0518.1 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 16 StartPage: 1 Subjects: – SubjectFull: Ocean dynamics Type: general – SubjectFull: Climate change Type: general – SubjectFull: Ocean Type: general – SubjectFull: Pacific Ocean Type: general – SubjectFull: Southern Hemisphere Type: general Titles: – TitleFull: Decadal Spiciness Variability in the Subtropical-Tropical Pacific in the CESM2 Large Ensemble. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: STOCKMAYER, VERA – PersonEntity: Name: NameFull: SCHNEIDER, NIKLAS – PersonEntity: Name: NameFull: STUECKER, MALTE F. – PersonEntity: Name: NameFull: LÜBBECKE, JOKE F. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 08948755 Numbering: – Type: volume Value: 39 – Type: issue Value: 11 Titles: – TitleFull: Journal of Climate Type: main |
| ResultId | 1 |
