A Long-Term Shift in Flow Regimes over the Antarctic Peninsula

Maria Vittoria Guarino; Jeff K. Ridley; Steve R. Colwell; Riccardo Farneti; Graziano Guiliani; Neil Hindley; John C. King; Fred Kucharski; Inna Polichtchouk; Adrian Tompkins; Etienne Vignon; Corwin Wright

doi:10.1175/JCLI-D-25-0330.1

A Long-Term Shift in Flow Regimes over the Antarctic Peninsula

Maria Vittoria Guarino, Jeff K. Ridley, Steve R. Colwell, Riccardo Farneti, Graziano Guiliani, Neil Hindley, John C. King, Fred Kucharski, Inna Polichtchouk, Adrian Tompkins, Etienne Vignon, Corwin Wright

Research output: Contribution to journal › Article › peer-review

Abstract

Surface warming in the polar regions has important consequences for the stability of the lowest layers of the atmosphere and for atmospheric vertical movement. Here, using ERA5 reanalysis data and in situ measurements, we quantify the evolving static stability of the lowest 1 km of the Antarctic atmosphere and show that the Brunt–Vaisala frequency, a measure of atmospheric stability, has been steadily decreasing since the 1950s. Using satellite observations, reanalysis, and targeted climate simulations, we find that this reduced stability has prompted a shift in prevailing flow regimes over the Antarctic Peninsula by altering regional wind flow and enhancing the generation of orographic gravity waves. Increased gravity wave forcing from the Antarctic Peninsula can have important implications for lobal-scale circulation, polar vortex strength, ozone depletion, and midlatitude weather

Original language	English
Pages (from-to)	749-767
Journal	Journal of Climate
Volume	39
Issue number	2
Early online date	6 Jan 2026
DOIs	https://doi.org/10.1175/JCLI-D-25-0330.1
Publication status	Published - 15 Jan 2026

Data Availability Statement

HadGEM3-GC3.1-LL model data for the PI and HIST simulations used in this paper are available on the CMIP6 ESGF: https://esgf-data.dkrz.de/search/cmip6-dkrz/?mip_era=CMIP6&activity_id=CMIP&institution_id=MOHC&source_id=HadGEM3-GC31-LL. Model outputs from the HadGEM3 sensitivity experiments can be accessed here: https://doi.org/10.5281/zenodo.15043790. ERA5 reanalyses are freely accessible through the Climate Data Store: Data on pressure levels are available here: https://cds.climate.copernicus.eu/datasets/reanalysis-era5-pressure-levels-monthly-means?tab=download#variable, and data on single levels are available here: https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels-monthly-means?tab=download. Upper-air coarse-resolution Antarctic station data can be found here: https://www.bas.ac.uk/project/reader/#data. High-resolution radiosonde data are either freely distributed by or should be requested to national meteorological services; see Vignon et al. (2019) for details. The Unified Model is available for use through a licensing agreement; see https://www.metoffice.gov.uk/research/modelling-systems/unified-model. JULES is available under license free of charge; see https://jules.jchmr.org/. The NEMO model is available from https://www.nemo-ocean.eu. The model code for CICE can be downloaded from https://code.metoffice.gov.uk/trac/cice/browser.

Funding

We thank Hans Hersbach for providing detailed information and statistics on the ERA5 data assimilation system used in Fig. B1. J. K. R. was supported by the Met Office Hadley Centre Climate Programme funded by DSIT. C. W. is supported by UKRI-NERC Grants NE/V01837X/1, NE/W003201/1, and NE/Z50399X/1 and by the Royal Society University Research Fellowship URF/R/221023. N.H. is supported by UKRI-NERC Grants NE/X017842/1, NE/W003201/1, and NE/Z50399X/1. This work used Monsoon2, a collaborative high-performance computing facility funded by the Met Office and the Natural Environment Research Council. Authors declare that they have no competing interests. M. V. G. designed the study, ran HadGEM3 simulations, and processed and analyzed model, reanalysis, and station data. J. K. R. ran simulations and provided access to supercomputer facilities. N. H. processed and analyzed AIRS/Aqua satellite data. J. K, S. C., and É. V. provided Antarctic radiosonde data. G. G. provided ERA5 reanalysis data. R. F., A. M. T., F. K., C. W., N. H., I. P., J. K., E. V., and J. R. contributed to the scientific interpretation of the results. All authors read and revised the manuscript.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 12 Responsible Consumption and Production
SDG 13 Climate Action

Access to Document

10.1175/JCLI-D-25-0330.1Licence: CC BY

Cite this

@article{366b4120cc584dfb9629246c26f87b09,

title = "A Long-Term Shift in Flow Regimes over the Antarctic Peninsula",

abstract = "Surface warming in the polar regions has important consequences for the stability of the lowest layers of the atmosphere and for atmospheric vertical movement. Here, using ERA5 reanalysis data and in situ measurements, we quantify the evolving static stability of the lowest 1 km of the Antarctic atmosphere and show that the Brunt–Vaisala frequency, a measure of atmospheric stability, has been steadily decreasing since the 1950s. Using satellite observations, reanalysis, and targeted climate simulations, we find that this reduced stability has prompted a shift in prevailing flow regimes over the Antarctic Peninsula by altering regional wind flow and enhancing the generation of orographic gravity waves. Increased gravity wave forcing from the Antarctic Peninsula can have important implications for lobal-scale circulation, polar vortex strength, ozone depletion, and midlatitude weather",

author = "Guarino, \{Maria Vittoria\} and Ridley, \{Jeff K.\} and Colwell, \{Steve R.\} and Riccardo Farneti and Graziano Guiliani and Neil Hindley and King, \{John C.\} and Fred Kucharski and Inna Polichtchouk and Adrian Tompkins and Etienne Vignon and Corwin Wright",

year = "2026",

month = jan,

day = "15",

doi = "10.1175/JCLI-D-25-0330.1",

language = "English",

volume = "39",

pages = "749--767",

journal = "Journal of Climate",

number = "2",

}

TY - JOUR

T1 - A Long-Term Shift in Flow Regimes over the Antarctic Peninsula

AU - Guarino, Maria Vittoria

AU - Ridley, Jeff K.

AU - Colwell, Steve R.

AU - Farneti, Riccardo

AU - Guiliani, Graziano

AU - Hindley, Neil

AU - King, John C.

AU - Kucharski, Fred

AU - Polichtchouk, Inna

AU - Tompkins, Adrian

AU - Vignon, Etienne

AU - Wright, Corwin

PY - 2026/1/15

Y1 - 2026/1/15

N2 - Surface warming in the polar regions has important consequences for the stability of the lowest layers of the atmosphere and for atmospheric vertical movement. Here, using ERA5 reanalysis data and in situ measurements, we quantify the evolving static stability of the lowest 1 km of the Antarctic atmosphere and show that the Brunt–Vaisala frequency, a measure of atmospheric stability, has been steadily decreasing since the 1950s. Using satellite observations, reanalysis, and targeted climate simulations, we find that this reduced stability has prompted a shift in prevailing flow regimes over the Antarctic Peninsula by altering regional wind flow and enhancing the generation of orographic gravity waves. Increased gravity wave forcing from the Antarctic Peninsula can have important implications for lobal-scale circulation, polar vortex strength, ozone depletion, and midlatitude weather

AB - Surface warming in the polar regions has important consequences for the stability of the lowest layers of the atmosphere and for atmospheric vertical movement. Here, using ERA5 reanalysis data and in situ measurements, we quantify the evolving static stability of the lowest 1 km of the Antarctic atmosphere and show that the Brunt–Vaisala frequency, a measure of atmospheric stability, has been steadily decreasing since the 1950s. Using satellite observations, reanalysis, and targeted climate simulations, we find that this reduced stability has prompted a shift in prevailing flow regimes over the Antarctic Peninsula by altering regional wind flow and enhancing the generation of orographic gravity waves. Increased gravity wave forcing from the Antarctic Peninsula can have important implications for lobal-scale circulation, polar vortex strength, ozone depletion, and midlatitude weather

U2 - 10.1175/JCLI-D-25-0330.1

DO - 10.1175/JCLI-D-25-0330.1

M3 - Article

VL - 39

SP - 749

EP - 767

JO - Journal of Climate

JF - Journal of Climate

IS - 2

ER -

A Long-Term Shift in Flow Regimes over the Antarctic Peninsula

Abstract

Data Availability Statement

Funding

UN SDGs

Access to Document

Fingerprint

Cite this