Preprints
https://doi.org/10.5194/egusphere-2025-4367
https://doi.org/10.5194/egusphere-2025-4367
23 Sep 2025
 | 23 Sep 2025

Impact of the Indian Ocean Sea Surface Temperature on the Southern Hemisphere Middle Atmosphere

Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue

Abstract. An index representing the midlatitude Indian Ocean Dipole (MIOD) is derived from the second empirical orthogonal function (EOF) mode of austral winter (JJA) sea surface temperature (SST) anomalies to examine its impact on the Southern Hemisphere middle and upper atmosphere. Observational datasets from HALOE (1991–2004) and SABER (2002–2020), together with simulations from WACCM6, are analyzed using composite and regression methods. Results reveal asymmetric atmospheric responses between positive and negative MIOD events. Positive MIOD events are associated with substantial stratospheric and mesospheric temperature perturbations and with vertically and meridionally structured zonal-wind anomalies, including height-dependent sign reversals at high latitudes. In contrast, negative events generally yield weaker and less statistically robust signals. The underlying processes involve enhanced planetary-wave propagation from the Indian Ocean sector, which deposits momentum and modifies zonal winds and the residual meridional circulation, accompanied by thermal-wind adjustments. The altered circulation redistributes ozone in the midlatitude stratosphere, while changes in stratospheric zonal winds regulate gravity-wave filtering and contribute to additional variability in the mesosphere. These findings highlight the importance of incorporating Indian Ocean variability into stratospheric and climate modeling to improve understanding of atmosphere–ocean coupling mechanisms and their implications for polar climate change.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Share

Journal article(s) based on this preprint

21 Jan 2026
Impact of the Indian Ocean sea surface temperature on the Southern Hemisphere middle atmosphere
Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue
Atmos. Chem. Phys., 26, 1021–1039, https://doi.org/10.5194/acp-26-1021-2026,https://doi.org/10.5194/acp-26-1021-2026, 2026
Short summary
Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2025-4367', Anonymous Referee #1, 03 Oct 2025
  • RC2: 'Comment on egusphere-2025-4367', Anonymous Referee #2, 09 Oct 2025

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2025-4367', Anonymous Referee #1, 03 Oct 2025
  • RC2: 'Comment on egusphere-2025-4367', Anonymous Referee #2, 09 Oct 2025

Peer review completion

AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload
AR by Chengyun Yang on behalf of the Authors (16 Dec 2025)  Author's response   Author's tracked changes   Manuscript 
ED: Referee Nomination & Report Request started (16 Dec 2025) by John Plane
RR by Anonymous Referee #1 (22 Dec 2025)
RR by Anonymous Referee #3 (31 Dec 2025)
ED: Publish as is (31 Dec 2025) by John Plane
AR by Chengyun Yang on behalf of the Authors (01 Jan 2026)  Author's response   Manuscript 

Journal article(s) based on this preprint

21 Jan 2026
Impact of the Indian Ocean sea surface temperature on the Southern Hemisphere middle atmosphere
Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue
Atmos. Chem. Phys., 26, 1021–1039, https://doi.org/10.5194/acp-26-1021-2026,https://doi.org/10.5194/acp-26-1021-2026, 2026
Short summary
Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue
Chengyun Yang, Xiang Guo, Tao Li, Xinyue Wang, Jun Zhang, Xin Fang, and Xianghui Xue

Viewed

Total article views: 1,447 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
1,150 271 26 1,447 19 22
  • HTML: 1,150
  • PDF: 271
  • XML: 26
  • Total: 1,447
  • BibTeX: 19
  • EndNote: 22
Views and downloads (calculated since 23 Sep 2025)
Cumulative views and downloads (calculated since 23 Sep 2025)

Viewed (geographical distribution)

Total article views: 1,428 (including HTML, PDF, and XML) Thereof 1,428 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 21 Jan 2026
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
The Indian Ocean strongly influences weather and climate far beyond its region. We found that unusual sea surface warming patterns in the midlatitude Indian Ocean can disrupt winds and temperatures in the middle atmosphere, including the stratosphere and mesosphere, of the Southern Hemisphere. These disturbances alter ozone and air movement and may affect polar climate. Our results highlight the need to include Indian Ocean variability in climate models for better predictions.
Share