| Abstrakt: |
The annual number of global tropical cyclones (TCs) has remained rather stable at ∼90 in the past decades, yet the underlying physics and mechanisms remain elusive. This study utilizes observational data to assess TC‐environment interactions, such as atmospheric drying, stabilization, and oceanic cooling, which occur after TC passage and inhibit subsequent TC formation. Focused on the recovery of TC‐induced hostile environment, we construct an idealized toy model incorporating the global main development region (MDR), recovery time and influencing radius. The model well captures the spatial and temporal characteristics of TC activity. Then we propose a new scaling of annual TC number, framed as a spatiotemporal packing problem determined by the total spatiotemporal area available for TC formation and the average area occupied by each TC. The recovery time is included as a new temporal constraint, and this scaling is validated by toy model simulations and offers insights into observations. Specifically, based on TC attributes in the current climate, the scaling yields an estimate of ∼100 TCs per year given a recovery time of 2–3 weeks. It also implies that a warming climate might lead to fewer TCs due to increased TC size and longer recovery times. Plain Language Summary: The number of tropical cyclones (TCs) around the world stays around 90 each year. Despite years of study, we still don't fully understand the reasons behind this stability. In this study, we use observational data to assess how environmental conditions after TC passage (e.g., drying air, stabilization, and cooling oceans) would affect the formation of subsequent TCs. By focusing on these interactions between TCs and the environment, we built a simple toy model to help understand the annual number of TCs. The toy model has a good performance in reproducing observed TC activity, and we come up with a new scaling to estimate the global annual TC number as a spatiotemporal packing problem. Our research suggests that the typical size and duration of TCs and the recovery time it takes for the environment to return to pre‐TC conditions may be the reason why we usually see about 90 TCs each year. Key Points: Tropical cyclone‐environment interactions are emphasized as a constraint on the annual number of tropical cyclonesA toy model is constructed and well captures the tropical cyclone activity through temporal and spatial constraintsA new scaling of the global tropical cyclone number is proposed as a spatiotemporal packing problem [ABSTRACT FROM AUTHOR] |
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