WISE: Wave driven isentropic exchange
Final Report Abstract
Within this project the DFG-umbrella proposal for the WISE was realized, which constituted the prerequisite for the five DFG funded partners (JGU Mainz, Goethe University Frankfurt/Main, University Heidelberg, University Wuppertal, and PTB - Braunschweig). The campaign coordination particularly of the DFG funded partners was performed by university Mainz, and included several meetings and workshops Mainz and the Co-Lead Forschungszentrum Jülich. WISE was further supported by the KIT and DLR Oberpfaffenhofen. Four major science topics were defined by the WISE consortium and included: ST1: Transport and mixing in the region of the ExTL and the influence of the tropopause inversion layer (TIL); ST2: Horizontal Transport into the extratropical lower stratosphere above the ExTL ST3: The role of halogenated VSLS for ozone and radiative forcing in the UTLS region; ST4: Occurrence and effects of sub-visual cirrus (SVC) in the lowermost stratosphere. The WISE mission took place in September/October 2017 in Shannon/Ireland and constituted of 16 research flights with 140 flight hours in total. All research groups could successfully measure and provided a large data set. The scientific goals could all be addressed and first publications appeared. A special issue has been initialized which is currently building up, for which 15 persons will contribute. First results showed that cross tropopause mixing may occur in regions of high static stability in the ridge regions of extratropical cyclones. The vertical shear of horizontal winds overcompensates the enhanced static stability caused by vertical updrafts and the convergence of wind at the tropopause. Notably the WISE measurements confirmed theoretical studies from idealized models as well as the analysis of ECMWF operational data for the WISE season, which indicated these results. The combination of remote sensing measurements with forecast and high resolution in-situ measurement provided novel results particularly to process studies, where the high resolution from in-situ data were combined with the curtain view of atmospheric state parameters (temperature, static stability) to identify new processes for cross tropopause mixing. Several aspects of the factors contributing to the composition of the UTLS including horizontal transport across the subtropical jet was investigated by several groups. The chemical impact cross tropopause transport e.g. on the distribution of short-lived tracers could also be quantified and significant discrepancies between emission scenarios and observations concerning the upper tropospheric distribution of tracers identified. WISE data have been also used to investigate the distribution of age of air in the lowermost stratosphere and the representation of age spectra in this highly complex region. WISE also contributed to the detection methods of subvisible cirrus and the question of ice particle occurrence above the tropopause. In total, the WISE mission can be regarded as full success, since all mission targets could be addressed, all instruments provided data almost for the full campaign.
Publications
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Composite analysis of the tropopause inversion layer in extratropical baroclinic waves, Atmos. Chem. Phys., 19, 6621–6636
Kaluza, T., Kunkel, D., and Hoor, P.
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Evidence of small-scale quasi-isentropic mixing in ridges of extratropical baroclinic waves, Atmos. Chem. Phys., 19, 12607–12630
Kunkel, D., Hoor, P., Kaluza, T., Ungermann, J., Kluschat, B., Giez, A., Lachnitt, H.-C., Kaufmann, M., and Riese, M.
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A convolution of observational and model data to estimate age of air spectra in the northern hemispheric lower stratosphere, Atmos. Chem. Phys. Discuss.
Hauck, M., Bönisch, H., Hoor, P., Keber, T., Ploeger, F., Schuck, T. J., and Engel, A.
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Bromine from short-lived source gases in the extratropical northern hemispheric upper troposphere and lower stratosphere (UTLS), Atmos. Chem. Phys., 20, 4105–4132
Keber, T., Bönisch, H., Hartick, C., Hauck, M., Lefrancois, F., Obersteiner, F., Ringsdorf, A., Schohl, N., Schuck, T., Hossaini, R., Graf, P., Jöckel, P., and Engel, A.
