Teleconnection and the Antarctic response to the Indian Ocean Dipole in CMIP5 and CMIP6 models

Sen, Arnab, Deb, Pranab, Matthews, Adrian J. ORCID: https://orcid.org/0000-0003-0492-1168 and Joshi, Manoj M. ORCID: https://orcid.org/0000-0002-2948-2811 (2024) Teleconnection and the Antarctic response to the Indian Ocean Dipole in CMIP5 and CMIP6 models. Quarterly Journal of the Royal Meteorological Society. ISSN 0035-9009 (In Press)

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Abstract

Tropical-Antarctic teleconnections are known to have large impacts on Antarctic climate variability at multiple timescales. Anomalous tropical convection triggers upper-level quasistationary Rossby waves, which propagate to high southern latitudes and impact the local environment. Here the teleconnection between the Indian Ocean Dipole (IOD) and Antarctica was examined using daily gridded reanalysis data and the Linear Response Theory Method (LRTM) during September–November of 1980–2015. The individual contribution of the IOD over the Antarctic climate is challenging to quantify as positive IOD events often co-occur with El Nino events. However, using the LRTM, the extratropical response due to a positive IOD was successfully extracted from the combined signal in the composite map of anomalous 250-hPa geopotential height. Applying the method to a set of models from phase 5 and 6 of the Coupled Model Intercomparison Project (CMIP5 and CMIP6), significant differences were observed in the extratropical response to the IOD among the models due to bias in Rossby waveguide and IOD precipitation pattern. The LRTM was then applied to evaluate the extratropical response of the 850-hPa temperature, wind anomalies, and sea ice concentration anomalies in observation data, and models that adequately represented both the IOD precipitation and the extratropical waveguide. The IOD-induced cold southerly flow over the west of the Ross Sea, the Weddell Sea, and the Antarctic Peninsula, causing cold surface temperature anomalies and the increase of sea ice, and warm northerly flow over the east of the Ross Sea and the Amundsen Sea, causing warm surface temperature anomalies and the decrease of sea ice. We recommend the LRTM as a complementary method to standard analysis of climate variability from observations and global climate models.

Item Type:	Article
Additional Information:	ACKNOWLEDGEMENTS: We acknowledge the World Climate Research Programme and the climate modeling groups for producing and sharing the CMIP outputs, which can be accessed from https://esgf-index1.ceda.ac.uk/projects/esgf-ceda/. NSIDC dataset was downloaded from https://nsidc.org/data. NCEP/DOE Reanalysis II and CMAP datasets were downloaded from SEN ET AL. NOAA PSL, Boulder, Colorado, USA, from their website at https://psl.noaa.gov. ERA5 dataset can be downloaded from https://cds.climate.copernicus.eu. The HadISST dataset was downloaded from the UK Met Office Hadley Centre, from their website at https://www.metoffice.gov.uk/hadobs/. AS and PD were supported by Indian Institute of Technology Kharagpur. We sincerely thank the anonymous reviewers whose valuable comments and suggestions helped to improve the readability of our paper.
Uncontrolled Keywords:	sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School:	Faculty of Science > School of Environmental Sciences University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups:	Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Science > Research Groups > Climatic Research Unit University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
Depositing User:	LivePure Connector
Date Deposited:	28 Aug 2024 10:30
Last Modified:	02 Sep 2024 00:43
URI:	https://ueaeprints.uea.ac.uk/id/eprint/96370
DOI:	10.1002/qj.4854

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