000906514 001__ 906514 000906514 005__ 20220304143554.0 000906514 0247_ $$2doi$$a10.17874/800DEE57D13 000906514 037__ $$aFZJ-2022-01493 000906514 041__ $$aEnglish 000906514 1001_ $$0P:(DE-HGF)0$$aSantee, Michelle L.$$b0 000906514 245__ $$aChapter 10: Polar Processes 000906514 260__ $$aOberpfaffenhofen, Germany$$bSPARC Office$$c2022 000906514 29510 $$aSPARC Reanalysis Intercomparison Project (S-RIP) Final Report 000906514 300__ $$a491-532 000906514 3367_ $$2ORCID$$aBOOK_CHAPTER 000906514 3367_ $$07$$2EndNote$$aBook Section 000906514 3367_ $$2DRIVER$$abookPart 000906514 3367_ $$2BibTeX$$aINBOOK 000906514 3367_ $$2DataCite$$aOutput Types/Book chapter 000906514 3367_ $$0PUB:(DE-HGF)7$$2PUB:(DE-HGF)$$aContribution to a book$$bcontb$$mcontb$$s1646317958_25164 000906514 4900_ $$aSPARC Report No. 10, WCRP-6/2021 000906514 520__ $$aThis chapter focuses on microphysical and chemical processes in the winter polar lower stratosphere, such as polar stratospheric cloud (PSC) formation; denitrification and dehydration; heterogeneous chlorine activation and deactivation; and chemical ozone loss. These are “threshold” phenomena that depend critically on meteorological conditions. A range of diagnostics is examined to quantify differences between reanalyses and their impact on polar processing studies, including minimum lower stratospheric temperatures; area and volume of stratospheric air cold enough to support PSC formation; maximum latitudinal gradients in potential vorticity (a measure of the strength of the winter polar vortex); area of the vortex exposed to sunlight each day; vortex break-up dates; and polar cap average diabatic heating rates. For such diagnostics, the degree of agreement between reanalyses is an important direct indicator of the systems’ inherent uncertainties, and comparisons to independent measurements are frequently not feasible. For other diagnostics, however, comparisons with atmospheric observations are very valuable. The representation of small-scale temperature and horizontal wind fluctuations and the fidelity of Lagrangian trajectory calculations are evaluated using observations obtained during long-duration superpressure balloon flights launched from Antarctica. Comparisons with satellite measurements of various trace gases and PSCs are made to assess the thermodynamic consistency between reanalysis temperatures and theoretical PSC equilibrium curves. Finally, to explore how the spatially and temporally varying differences between reanalyses interact to affect the conclusions of typical polar processing studies, simulated fields of nitric acid, water vapour, several chlorine species, nitrous oxide, and ozone from a chemistry-transport model driven by the different reanalyses for specific Arctic and Antarctic winters are compared to satellite measurements. 000906514 536__ $$0G:(DE-HGF)POF4-5111$$a5111 - Domain-Specific Simulation & Data Life Cycle Labs (SDLs) and Research Groups (POF4-511)$$cPOF4-511$$fPOF IV$$x0 000906514 588__ $$aDataset connected to DataCite 000906514 650_7 $$2Other$$aFOS: Earth and related environmental sciences 000906514 7001_ $$0P:(DE-HGF)0$$aLambert, Alyn$$b1 000906514 7001_ $$0P:(DE-HGF)0$$aManney, Gloria L.$$b2 000906514 7001_ $$0P:(DE-HGF)0$$aLawrence, Zachary D.$$b3 000906514 7001_ $$0P:(DE-HGF)0$$aChabrillat, Simon$$b4 000906514 7001_ $$0P:(DE-Juel1)129125$$aHoffmann, Lars$$b5$$ufzj 000906514 7001_ $$0P:(DE-HGF)0$$aPalmer, Sean P.$$b6 000906514 7001_ $$0P:(DE-HGF)0$$aMinschwaner, Ken$$b7 000906514 773__ $$a10.17874/800DEE57D13 000906514 909CO $$ooai:juser.fz-juelich.de:906514$$pVDB 000906514 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)129125$$aForschungszentrum Jülich$$b5$$kFZJ 000906514 9131_ $$0G:(DE-HGF)POF4-511$$1G:(DE-HGF)POF4-510$$2G:(DE-HGF)POF4-500$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF4-5111$$aDE-HGF$$bKey Technologies$$lEngineering Digital Futures – Supercomputing, Data Management and Information Security for Knowledge and Action$$vEnabling Computational- & Data-Intensive Science and Engineering$$x0 000906514 9141_ $$y2022 000906514 920__ $$lyes 000906514 9201_ $$0I:(DE-Juel1)JSC-20090406$$kJSC$$lJülich Supercomputing Center$$x0 000906514 980__ $$acontb 000906514 980__ $$aVDB 000906514 980__ $$aI:(DE-Juel1)JSC-20090406 000906514 980__ $$aUNRESTRICTED