Seasonal to decadal variability of Rossby wave packet properties
Abstract
Transient Rossby wave packets (RWPs) are a prominent feature of the synoptic to planetary upper-tropospheric flow and play an important role in shaping surface weather in the extratropics. Recently developed diagnostic methods are employed here to identify and investigate the spatiotemporal evolution of key RWP properties. These diagnostics are based on the analytic signal of upper-tropospheric meridional wind speed and thus provide insight into large-scale wave features locally in space and time. In this study, global climatologies of RWP amplitude, wavenumber, phase speed, and group velocity are produced using reanalysis data for the time period 1979 - 2018 and aspects of pronounced seasonal and interannual variability are discussed. Furthermore, the long-term variability in these RWP properties is explored and significant linear decadal trends in these respects are highlighted. The presented diagnostics and climatological analyses can be further utilized in observational and modeling frameworks for the investigation of processes affecting the extratropical large-scale circulation at weather and climate time scales.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA152.0015F
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3319 General circulation;
- ATMOSPHERIC PROCESSES;
- 3320 Idealized model;
- ATMOSPHERIC PROCESSES;
- 3363 Stratospheric dynamics;
- ATMOSPHERIC PROCESSES