Diabatic effects on the evolution of stormtracks ...

• Main Authors: Marcheggiani, Andrea, Spengler, Thomas
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Pacific; Tilting; North Atlantic
• Online Access: https://dx.doi.org/10.57757/iugg23-0301; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016163

<!--!introduction!--> We investigate the role of diabatic processes in the evolution of Northern Hemispheric stormtracks using an isentropic slope framework as a measure of baroclinicity. Baroclinicity is depleted through isentropic tilting by eddies while it is restored by diabatic heating. We find, however, that the phasing of depletion and restoration of baroclinicity in the near-surface troposphere is opposite to that in the free troposphere. The opposite phasing of baroclinicity depletion and restoration across the troposphere is observed both in upstream and downstream sectors of the North Atlantic and North Pacific stormtracks, suggesting a common feature of midlatitude stormtracks. Near the surface (900--800hPa), cold air advection, often associated with cold air outbreaks, initially flattens isentropic surfaces, thus reducing near-surface baroclinicity, which is then restored by air-sea heat exchange. Composites of geopotential height at 1000hPa and 500hPa corroborate these stages in the ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...