Skip to main content
Log in

The asymmetry of air-sea coupled strength between the first-year and second-year La Niña events

  • Published:
Climate Dynamics Aims and scope Submit manuscript

Abstract

Compared to the La Niña event in the first-year, the air-sea system is not well coupled during the second-year. This is evidenced by the generally weaker anomalous sea surface temperature (SST) and the significantly stronger easterly wind anomalies. According to the Bjerknes positive feedback, the strong easterly wind anomalies are challenging to explain using only the zonal gradient of the sea level pressure (SLP) anomaly. This is due to the incursion of the off-equatorial southeasterly wind originating from the southeast Pacific before the onset of the second-year event. It results in a distinctive development feature in the event, distinguishing it from the first-year event, which is a typical result of equatorial ocean–atmosphere interaction. The different roles of the off-equatorial signal and equatorial easterly wind indicate a relay process in which the former mainly plays a triggering role, while the latter primarily acts as a reinforcing role in the second-year event. Furthermore, the zonal advective feedback plays a crucial role in determining the amplitude of the second-year cold event, which is a main difference from the first-year event. The reduced intensity produces a relatively weaker SST amplitude during the second-year La Niña event due to the thicker mixed layer depth.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

Data availability

The monthly wind stress, current field, and subsurface temperature data from NCEP Global Ocean Data Assimilation System (GODAS) can be obtained at https://psl.noaa.gov/data/gridded/data.godas.html. The monthly precipitation data from Climate Prediction Center (NOAA) Merged Analysis of Precipitation data was obtained https://psl.noaa.gov/data/gridded/data.cmap.html. The monthly sea surface temperature data can be derived from extended reconstructed SST (NOAA), v5 (https://psl.noaa.gov/data/gridded/data.noaa.ersst.v5.html), and the monthly sea level pressure and associated radiation flux data from the NCEP Reanalysis II (R2) can be obtained from https://psl.noaa.gov/data/gridded/data.ncep.reanalysis2.html.

References

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 42175045), the Key Research Program of Frontier Sciences, CAS (Grant No. ZDBS-LY-DQC010), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB42000000).

Funding

The authors have not disclosed any funding.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Fei Zheng.

Ethics declarations

Ethical statements

This study strictly adheres to ethical standards, and we affirm that we have no conflicts of interest with any individual, institution, or organization involved in this study, and we have not received any form of external funding. We are dedicated to upholding the authenticity and integrity of the study's results, and the data has been processed and analyzed in compliance with ethical standards, ensuring there has been no manipulation or fabrication of data. Throughout the study, we have upheld the principle of non-discrimination and have not exhibited bias against study participants based on their race, gender, age, or religious beliefs.

Competing interests

The authors declare no competing interests.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cao, TW., Zheng, F. & Fang, XH. The asymmetry of air-sea coupled strength between the first-year and second-year La Niña events. Clim Dyn (2024). https://doi.org/10.1007/s00382-024-07259-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00382-024-07259-2

Keywords

Navigation