Temperature‐Precipitation Scaling Rates: A Rainfall Event‐Based Perspective
Alexis Pérez Bello, Alain Mailhot, Dominique Paquin, Danahé Paquin‐Ricard
Abstract
Abstract The intensity of extreme rainfall is expected to increase in a future climate at a rate close to 7%/°C estimated from the Clausius‐Clapeyron (CC) relationship, which represents the rate of change of the atmospheric water holding capacity with temperature. Previous studies using fixed‐interval extremes (e.g., hourly or daily) have shown that extreme rainfall can also respond to temperature increases at a rate larger than the CC scaling (super CC scaling). Temperature‐precipitation scaling rates (TPSR) were estimated through an event‐based analysis for the Northeastern North American (NNA) region, using a 50‐member large ensemble of climate simulations over the 1956–2099 period. Rainfall events (REs), in which 1‐hr annual maximums (AMs) are embedded, were analyzed. Results show that the TPSR of the RE peak intensity is determined by the duration of the RE in which they are embedded. Rainfall event duration, indicative of rainfall types (large‐scale or convective), therefore plays an essential role and should be considered when estimating the TPSR. Super CC scaling observed for 1‐hr AM in southern regions of the domain was explained by a change in the dominant rainfall type. This study also confirms previously reported results that the more extreme 1‐hr AM will be part of a shorter and probably more convective dominant RE in a future climate.