Northern Hemisphere Stratospheric Temperature Response to External Forcing in Decadal Climate Simulations

Northern Hemisphere Stratospheric Temperature Response to External Forcing in Decadal Climate Simulations | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Northern Hemisphere Stratospheric Temperature Response to External Forcing in Decadal Climate Simulations Abdullah A. Fahad, Andrea Molod, Dimitris Menemenlis, Patrick Heimbach, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1892797/v3 This work is licensed under a CC BY 4.0 License Status: Posted Version 3 posted You are reading this latest preprint version Show more versions Abstract To predict the future state of the Earth system on multiyear timescales, it is crucial to understand the response to changing external radiative forcing (CO2 and Ozone). Analyzing the Northern Hemisphere (NH) winter stratospheric polar vortex temperature, we found a general temperature decrease in the reanalysis data (1982–2020), the expected trend with increasing CO2, except for a sharp warming during period 1992–2000. Results from 1 degree GEOS-MITgcm coupled general circulation model simulations of past decades show a similar increase in the NH polar stratospheric temperature during 1992–2000 and a decrease during 2000–2020. To isolate the influence of external forcing, we conducted a series of 30-year-long “perpetual” time-slice experiments in which the external forcing for a particular year is held fixed at its values for 1992, 2000, and 2020. Each simulated year of these perpetual experiments is forced with the CO2, Ozone, anthropogenic aerosol emissions, and trace gases of that year, but none of the simulations include any explosive volcanic forcing. The increasing and then decreasing temperature trend is also manifest in the CMIP6 historical simulations performed with models that include a well-resolved stratosphere. The configuration of the perpetual experiments rules out a response to volcanic emissions or a change in the phase of decadal modes of variability as explanations for the warming rather than the expected cooling behavior. Analysis of the temperature budget showed (only significant terms are discussed) that the polar stratospheric temperature behavior is dictated by meridional eddy transport of heat resulting from changes in CO2 and Ozone over the past decades. Atmospheric Sciences stratosphere Seasonal to Decadal multi year climate prediction climate change Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 3 posted You are reading this latest preprint version Show more versions Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1892797","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":413866859,"identity":"b0976d22-aefc-42a8-bbb8-0ea15d6635c2","order_by":0,"name":"Abdullah A. 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Analyzing the Northern Hemisphere (NH) winter stratospheric polar vortex temperature, we found a general temperature decrease in the reanalysis data (1982–2020), the expected trend with increasing CO2, except for a sharp warming during period 1992–2000. Results from 1 degree GEOS-MITgcm coupled general circulation model simulations of past decades show a similar increase in the NH polar stratospheric temperature during 1992–2000 and a decrease during 2000–2020. To isolate the influence of external forcing, we conducted a series of 30-year-long “perpetual” time-slice experiments in which the external forcing for a particular year is held fixed at its values for 1992, 2000, and 2020. Each simulated year of these perpetual experiments is forced with the CO2, Ozone, anthropogenic aerosol emissions, and trace gases of that year, but none of the simulations include any explosive volcanic forcing. 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