Benefit of convection permitting climate model simulations in the representation of convective precipitation

Abstract

and 2.8 km resolutions in the representation of precipitation at sub-daily timescales, and the atmospheric conditions leading to convection. Our results show that the highest resolution of RCM simulations significantly improves the representation of both hourly intensity distribution and diurnal cycle of precipitation. In addition, at convection permitting scale the atmospheric fields related to convective precipitation show a better agreement with each other. The results imply that higher spatial resolution partially improves the representation of the precipitation field, which must be the way forward for regional climate modelling.

Climate change in the next 30 years: What can a convection-permitting model tell us that we did not already know?

“…1 shows the flat Rhine valley along the western edge of the investigation domain surrounded by the sharp orography of the Black Forest, with its two main ridges in a south-west to north-east direction. The complex terrain favours orographically induced convective precipitation, which dominates in the summer period in this region (Khodayar et Fosser et al (2015) found that CLM2.8 represents well the diurnal cycle of precipitation as well as the hourly precipitation intensities in this region and season.…”

“…Although the convection parameterisation leads to the misrepresentation of the diurnal cycle of precipitation (e.g. Brockhaus et al 2008), a parameterisation for deep convection is still necessary at 7 km as shown by Fosser et al (2015). Both CLM7 and CLM2.8 use the Tiedtke scheme for shallow convection.…”

“…The setup used in this study (CLM version 4.8) is the same as in Fosser et al (2015). Namely, a Runge-Kutta time-stepping scheme and the radiation scheme of Ritter and Geleyn (1992) called every hour for CLM7, and every 15 min for CLM2.8.…”

“…Brockhaus et al 2008;Baldauf et al 2011;Fosser et al 2015). Reaching convection-permitting resolutions allows not only to eliminate a major source of uncertainties and errors, but also to improve the representation of hourly precipitation intensity and spatial distribution (Prein et al 2013;Fosser et al 2015) as well as the representation of surface fluxes (Tölle et al 2014).…”

Grenzen und Herausforderungen der regionalen Klimamodellierung

“…Für kleinere Regionen in Europa gibt es bereits Klimasimulationen mit einer Auflösung von 1-3 km (Hohenegger et al 2008;Prein und Gobiet 2011;Suklitsch et al 2011;Fosser et al 2015;Ban et al 2014;Kendon et al 2014). Bei diesen Auflösungen werden dabei zum Teil klimatische Phäno-mene simuliert, für die es bisher keine Beobachtungsdaten in der entsprechenden räumlichen und zeitlichen Dichte gibt, wie man sie aber für eine systematische Bewertung benötigt (Rummukainen 2010).…”