Role of Quasi-Biweekly Cloud-Radiative Feedback in Modulating and Simulating Extreme Rainfall Intensity Over Asian Monsoon Regions

Although Cloud-radiative feedback (CRF) has been investigated in terms of its modulation of extreme precipitation over tropical oceans, the specific timeframe of CRF variability and the associated processes driving extreme rainfall over Asian monsoon regions remain unclear. Based on observational analyses and model sensitivity experiments, this study reveals that longwave CRF at the quasi-biweekly timescale is most closely linked to the intensity of persistent (≥3-day) heavy rainfall events in southern China and northern India by efficiently maintaining the large-scale convective perturbations. When CRF is disabled, the quasi-biweekly convective anomalies supporting extreme precipitation are weakened. Additional assessments of Coupled Model Intercomparison Project historical simulations confirm that models with more accurate quasi-biweekly longwave CRF exhibit smaller biases in capturing the amplitude of persistent heavy rainfall. These results have implications for improving model capability in simulating and forecasting quasi-biweekly CRF to mitigate the risks of extreme precipitation events in monsoonal Asia.