Scholarlink

<p>Tropical cyclone rain rates are projected to increase under warming, yet many climate models produce weaker rain-rate responses than expected from Clausius–Clapeyron scaling, which predicts that atmospheric moisture-holding capacity increases by approximately 7% per degree of warming. Here we use large-ensemble simulations, satellite observations and reanalysis data to identify what suppresses these rain-rate increases below Clausius–Clapeyron expectations. We show that future increases in tropical cyclone rain rate are constrained by the amplified absolute dryness of the warming atmosphere, quantified by the saturation deficit. Whereas atmospheric moistening elevates column water vapour at near-Clausius–Clapeyron rates and storm intensification further boosts rain rate, these gains are systematically offset by saturation-deficit-driven reductions in precipitation efficiency through enhanced evaporation. The negative relationship between precipitation efficiency and column saturation deficit is corroborated by satellite-based precipitation observations. Although precipitation efficiency correlates positively with storm intensity, attribution analyses reveal that increases in column saturation deficit can dominate intensity effects under warming, leading to net declines in precipitation efficiency and smaller rain rates. Our results highlight increased absolute dryness as the principal thermodynamic limiter of future tropical cyclone rain rate, uncovering a mechanism overlooked by prior projections focused solely on storm intensification and moisture increases.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Future tropical cyclone rainfall constrained by increased atmospheric dryness

  • 期刊论文

  • 发表日期：

    2026年7月24日

查看全文
  • Jianan Chen,
  • Ralf Toumi,
  • Dazhi Xi

摘要

Tropical cyclone rain rates are projected to increase under warming, yet many climate models produce weaker rain-rate responses than expected from Clausius–Clapeyron scaling, which predicts that atmospheric moisture-holding capacity increases by approximately 7% per degree of warming. Here we use large-ensemble simulations, satellite observations and reanalysis data to identify what suppresses these rain-rate increases below Clausius–Clapeyron expectations. We show that future increases in tropical cyclone rain rate are constrained by the amplified absolute dryness of the warming atmosphere, quantified by the saturation deficit. Whereas atmospheric moistening elevates column water vapour at near-Clausius–Clapeyron rates and storm intensification further boosts rain rate, these gains are systematically offset by saturation-deficit-driven reductions in precipitation efficiency through enhanced evaporation. The negative relationship between precipitation efficiency and column saturation deficit is corroborated by satellite-based precipitation observations. Although precipitation efficiency correlates positively with storm intensity, attribution analyses reveal that increases in column saturation deficit can dominate intensity effects under warming, leading to net declines in precipitation efficiency and smaller rain rates. Our results highlight increased absolute dryness as the principal thermodynamic limiter of future tropical cyclone rain rate, uncovering a mechanism overlooked by prior projections focused solely on storm intensification and moisture increases.