This title appears in the Scientific Report :
2020
Please use the identifier:
http://dx.doi.org/10.5194/amt-13-7025-2020 in citations.
Please use the identifier: http://hdl.handle.net/2128/26645 in citations.
Cirrus cloud shape detection by tomographic extinction retrievals from infrared limb emission sounder measurements
Cirrus cloud shape detection by tomographic extinction retrievals from infrared limb emission sounder measurements
We investigate the impact of model trace gas transport schemes on the representation of transport processes in the upper troposphere and lower stratosphere. Towards this end, the Chemical Lagrangian Model of the Stratosphere (CLaMS) was coupled to the ECHAM/MESSy Atmospheric Chemistry (EMAC) model a...
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Personal Name(s): | Ungermann, Jörn (Corresponding author) |
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Bartolome, Irene / Griessbach, Sabine / Spang, Reinhold / Rolf, Christian / Krämer, Martina / Höpfner, Michael / Riese, Martin | |
Contributing Institute: |
JARA - HPC; JARA-HPC Jülich Supercomputing Center; JSC Stratosphäre; IEK-7 |
Published in: | Atmospheric measurement techniques, 13 (2020) 12, S. 7025 - 7045 |
Imprint: |
Katlenburg-Lindau
Copernicus
2020
|
DOI: |
10.5194/amt-13-7025-2020 |
Document Type: |
Journal Article |
Research Program: |
Tomographic retrievals of temperature and trace gasses from GLORIA measurements Computational Science and Mathematical Methods Composition and dynamics of the upper troposphere and middle atmosphere |
Link: |
Get full text OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/26645 in citations.
We investigate the impact of model trace gas transport schemes on the representation of transport processes in the upper troposphere and lower stratosphere. Towards this end, the Chemical Lagrangian Model of the Stratosphere (CLaMS) was coupled to the ECHAM/MESSy Atmospheric Chemistry (EMAC) model and results from the two transport schemes (Lagrangian critical Lyapunov scheme and flux-form semi-Lagrangian, respectively) were compared. Advection in CLaMS was driven by the EMAC simulation winds, and thereby the only differences in transport between the two sets of results were caused by differences in the transport schemes. To analyze the timescales of large-scale transport, multiple tropical-surface-emitted tracer pulses were performed to calculate age of air spectra, while smaller-scale transport was analyzed via idealized, radioactively decaying tracers emitted in smaller regions (nine grid cells) within the stratosphere. The results show that stratospheric transport barriers are significantly stronger for Lagrangian EMAC-CLaMS transport due to reduced numerical diffusion. In particular, stronger tracer gradients emerge around the polar vortex, at the subtropical jets, and at the edge of the tropical pipe. Inside the polar vortex, the more diffusive EMAC flux-form semi-Lagrangian transport scheme results in a substantially higher amount of air with ages from 0 to 2 years (up to a factor of 5 higher). In the lowermost stratosphere, mean age of air is much smaller in EMAC, owing to stronger diffusive cross-tropopause transport. Conversely, EMAC-CLaMS shows a summertime lowermost stratosphere age inversion – a layer of older air residing below younger air (an “eave”). This pattern is caused by strong poleward transport above the subtropical jet and is entirely blurred by diffusive cross-tropopause transport in EMAC. Potential consequences from the choice of the transport scheme on chemistry–climate and geoengineering simulations are discussed. |