The relevance of Rossby wave breaking for precipitation in world's arid regions
| Autor: | De Vries, A., Armon, M., Klingmüller, K., Portmann, R., Domeisen, D. |
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| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-2437 |
| Popis: | Precipitation in arid regions can have large societal impacts. On the one hand, when rainfall comes in high intensities, it can lead to deadly floods. On the other hand, precipitation can also refill freshwater resources that are typically scarce in these dry regions. Atmospheric processes that can lead to precipitation in arid regions are often studied at the regional scale and remain poorly understood from a global perspective. In this study, we identify Rossby wave breaking based on the combination of potential vorticity streamers and cutoffs in ERA5 reanalysis data, and we quantify the contribution of this atmospheric process to precipitation at the global scale using different datasets. Rossby wave breaking significantly contributes to 80-90% of daily precipitation extremes and to 70-80% of total precipitation amounts in arid regions equatorward and downstream of the midlatitude storm tracks. Portions of land surface area where Rossby wave breaking significantly contributes to precipitation increases from 10-25% in humid regions to about 50% in regions with a hyper arid climate. In subtropical arid regions, Rossby wave breaking contributes to much of the precipitation during the transition seasons and winter, whereas extratropical arid regions receive precipitation under the influence of Rossby wave breaking throughout the year. This study shows that Rossby wave breaking is a key driver of precipitation in arid regions, offering new opportunities to improve medium-range prediction of flood hazards and to better understand the role of atmospheric dynamics in projections and uncertainties of future precipitation changes in climate model simulations. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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