Použití Lagrangeovských transportních modelů pro přezkoumání našich znalostí o transportu a dynamice atmosféry.
| Thesis title in Czech: | Použití Lagrangeovských transportních modelů pro přezkoumání našich znalostí o transportu a dynamice atmosféry. |
|---|---|
| Thesis title in English: | Utilization of Lagrangian transport and dispersion models for revisiting our understanding of atmospheric dynamics and transport. |
| Key words: | Lagrangeovské modely|vnitřní gravitační vlny|atmosférický transport|atmosférická dynamika. |
| English key words: | Lagrangian models|internal gravity waves|atmospheric transport|atmospheric dynamics. |
| Academic year of topic announcement: | 2023/2024 |
| Thesis type: | dissertation |
| Thesis language: | čeština |
| Department: | Department of Atmospheric Physics (32-KFA) |
| Supervisor: | RNDr. Petr Šácha, Ph.D. |
| Author: | hidden - assigned and confirmed by the Study Dept. |
| Date of registration: | 12.02.2024 |
| Date of assignment: | 12.02.2024 |
| Confirmed by Study dept. on: | 12.02.2024 |
| Advisors: | prof. RNDr. Petr Pišoft, Ph.D. |
| Guidelines |
| Within the thesis, Lagrangian modelling tools will be applied on state-of-the-art high-resolution atmospheric model simulations and reanalysis datasets. Two particular research questions will be pursued - whether and how do gravity waves influence the stratosphere-troposphere exchange and what role do gravity waves play in transport of pollutants in mountainous regions? Offline trajectories will be computed with problem-specific initialization methods to study the transport and dynamical budgets in the regions of interest and also, the Lagrangian model may be used for detection of gravity waves in high-resolution datasets as in Shakespeare et al. (2021). Starting from the second year, model results will be validated with fresh observations from the TEAMx observational campaign and specific research goals of the campaign will be contributed to within the thesis. |
| References |
| Charlesworth, E., Plöger, F., Birner, T. et al. Stratospheric water vapor affecting atmospheric circulation. Nat Commun 14, 3925 (2023). https://doi.org/10.1038/s41467-023-39559-2
Chen, B., Xu, X. D., Yang, S., and Zhao, T. L.: Climatological perspectives of air transport from atmospheric boundary layer to tropopause layer over Asian monsoon regions during boreal summer inferred from Lagrangian approach, Atmos. Chem. Phys., 12, 5827–5839, https://doi.org/10.5194/acp-12-5827-2012, 2012. Fritts, D. C., and Alexander, M. J. (2003), Gravity wave dynamics and effects in the middle atmosphere, Rev. Geophys., 41, 1003, doi:10.1029/2001RG000106, 1. Jansing, L. & Sprenger, M.(2022) Thermodynamics and airstreams of a south foehn event in different Alpine valleys. Quarterly Journal of the Royal Meteorological Society, 148(746), 2063–2085. Available from: https://doi.org/10.1002/qj.4285 Murto, S., Caballero, R., Svensson, G., and Papritz, L.: Interaction between Atlantic cyclones and Eurasian atmospheric blocking drives wintertime warm extremes in the high Arctic, Weather Clim. Dynam., 3, 21–44, https://doi.org/10.5194/wcd-3-21-2022, 2022. Ploeger, F., Konopka, P., Walker, K., and Riese, M.: Quantifying pollution transport from the Asian monsoon anticyclone into the lower stratosphere, Atmos. Chem. Phys., 17, 7055–7066, https://doi.org/10.5194/acp-17-7055-2017, 2017. Shakespeare, C. J., Gibson, A. H., Hogg, A. McC., Bachman, S. D., Keating, S. R., & Velzeboer, N. (2021). A new open source implementation of Lagrangian filtering: A method to identify internal waves in high-resolution simulations. Journal of Advances in Modeling Earth Systems, 13, e2021MS002616. https://doi.org/10.1029/2021MS002616 Spreitzer, E., R. Attinger, M. Boettcher, R. Forbes, H. Wernli, and H. Joos, 2019: Modification of Potential Vorticity near the Tropopause by Nonconservative Processes in the ECMWF Model. J. Atmos. Sci., 76, 1709–1726, https://doi.org/10.1175/JAS-D-18-0295.1. |
| Preliminary scope of work |
| Atmospheric composition and the chemical and physical processes that control it are central to two environmental issues of highest importance to society - climate change and air quality. Atmospheric composition is changing, besides pollutant precursor emissions a large part of this change can be attributed to changes in atmospheric transport. On the other hand, transport itself is nonlinearly determined by composition dependent radiative effects and dynamical driving mechanisms across spatial and temporal scales.
Prominently, atmospheric waves affect transport of momentum, energy, and mass and thereby atmospheric composition, which makes them one of the most important coupling mechanisms between atmospheric layers. Active research during recent decades has propelled our understanding of the origin of atmospheric waves, their propagation and influence. Still, many aspects of the wave lifecycle and wave effects are to a large extent unknown and not all wave types are fully resolved or properly parameterized in state-of-the-art atmospheric models. Therefore, uncertainties remain in our assessment of changes in atmospheric composition and the processes that control it, and their representation in models. These deficiencies emerge especially pronounced in mountainous regions, which are hotspots of climate change and boundary layer pollution on the one hand, on the other key regions of wave sourcing. Other region with demonstratively large model biases connected with improper characterization of transport (Charlesworth et al., 2023) is the upper troposphere/lower stratosphere region, where finite amplitude and wave transience effects team up for a complex mixture of mixing and advective transport. In the both aforementioned regions, where large gradients in tracer concentrations exist, utilization of Lagrangian modelling tools allowing to track individual air parcels and evaluate forcings and tendencies following the trajectories has brought valuable insights into the subtle transport features (Ploeger et al., 2017; Chen et al., 2012) and their dynamical drivers (Murto et al., 2022; Spreitzer et al., 2019; Jansing and Sprenger, 2022). Given the recent increases of availability of high-resolution simulations capable of resolving majority of the wave spectrum, the candidate will be in an ideal position to define a new research field by focusing especially on the internal gravity wave (GW) role for transport starting from the lower troposphere to the stratosphere and diagnosing the non-dissipative GW effects. The topic of this thesis is well connected with the efforts of the international research community and will guarantee an active participation of the applicant within the Multi-scale Transport and Exchange Processes in the Atmosphere over Mountains Programme and experiment (TEAMx; Serafin et al., 2020) that will conduct a major observational campaign in 2025. |
| Preliminary scope of work in English |
| Atmospheric composition and the chemical and physical processes that control it are central to two environmental issues of highest importance to society - climate change and air quality. Atmospheric composition is changing, besides pollutant precursor emissions a large part of this change can be attributed to changes in atmospheric transport. On the other hand, transport itself is nonlinearly determined by composition dependent radiative effects and dynamical driving mechanisms across spatial and temporal scales.
Prominently, atmospheric waves affect transport of momentum, energy, and mass and thereby atmospheric composition, which makes them one of the most important coupling mechanisms between atmospheric layers. Active research during recent decades has propelled our understanding of the origin of atmospheric waves, their propagation and influence. Still, many aspects of the wave lifecycle and wave effects are to a large extent unknown and not all wave types are fully resolved or properly parameterized in state-of-the-art atmospheric models. Therefore, uncertainties remain in our assessment of changes in atmospheric composition and the processes that control it, and their representation in models. These deficiencies emerge especially pronounced in mountainous regions, which are hotspots of climate change and boundary layer pollution on the one hand, on the other key regions of wave sourcing. Other region with demonstratively large model biases connected with improper characterization of transport (Charlesworth et al., 2023) is the upper troposphere/lower stratosphere region, where finite amplitude and wave transience effects team up for a complex mixture of mixing and advective transport. In the both aforementioned regions, where large gradients in tracer concentrations exist, utilization of Lagrangian modelling tools allowing to track individual air parcels and evaluate forcings and tendencies following the trajectories has brought valuable insights into the subtle transport features (Ploeger et al., 2017; Chen et al., 2012) and their dynamical drivers (Murto et al., 2022; Spreitzer et al., 2019; Jansing and Sprenger, 2022). Given the recent increases of availability of high-resolution simulations capable of resolving majority of the wave spectrum, the candidate will be in an ideal position to define a new research field by focusing especially on the internal gravity wave (GW) role for transport starting from the lower troposphere to the stratosphere and diagnosing the non-dissipative GW effects. The topic of this thesis is well connected with the efforts of the international research community and will guarantee an active participation of the applicant within the Multi-scale Transport and Exchange Processes in the Atmosphere over Mountains Programme and experiment (TEAMx; Serafin et al., 2020) that will conduct a major observational campaign in 2025. |