Resolution-dependent jet stream representation in ICON aquaplanet experiments

作者：Mona Bukenberger, Sebastian Schemm, Anurag Dipankar, Praveen Pothapakula, Chia Rui Ong · 年份：2026 · DOI：10.22541/essoar.15006621/v1 · 研究领域：Oceanographic and Atmospheric Processes、Tropical and Extratropical Cyclones Research、Climate variability and models

The mid-latitude jet stream and its internal structure, including jet streaks, play a crucial role in shaping surface weather. Especially heavy precipitation and rapid cyclogenesis often co-occur with jet streaks. Resolution-dependence of the jet stream and jet streaks is hence important for the representation of surface weather phenomena. To investigate it, we conduct idealized aquaplanet simulations with a zonally symmetric background sea surface temperature distribution and a superimposed warm anomaly that generates a storm track. Such idealized experiments are valuable to study the impact of resolution on dynamics, as they exclude confounding factors such as topography and ocean-atmosphere coupling. We compare global convection-permitting (2.5\,km) to -parameterizing simulations (20\,km, 80\,km), and investigate how resolution affects the eddy-driven jet and its variability through a jet streak lense. We find that increasing resolution intensifies and shifts the eddy-driven jet poleward. The region of enhanced variability in jet stream position and intensity expands furthest downstream and poleward of the SST anomaly in the convection-permitting simulation, accompanied by a circumpolar geopotential height anomaly. Jet streak frequency changes mirror those of the region of largest jet variability, and the strongest jet streaks occur in the convection-permitting ensemble. Moreover, jet streaks co-evolve in...