Future Changes in European Severe Convection Environments in a Regional Climate Model Ensemble
Authors | |
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Year of publication | 2017 |
Type | Article in Periodical |
Magazine / Source | Journal of Climate |
MU Faculty or unit | |
Citation | |
Web | http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0777.1 |
Doi | http://dx.doi.org/10.1175/JCLI-D-16-0777.1 |
Field | Atmosphere sciences, meteorology |
Keywords | Buoyancy; Climate change; Convective storms; Storm environments; Climate models; Ensembles |
Description | The occurrence of environmental conditions favorable for severe convective storms was assessed in an ensemble of 14 regional climate models covering Europe and the Mediterranean with a horizontal grid spacing of 0.448. These conditions included the collocated presence of latent instability and strong deep-layer (surface to 500 hPa) wind shear, which is conducive to the severe andwell-organized convective storms. The occurrence of precipitation in the models was used as a proxy for convective initiation. Two climate scenarios (RCP4.5 and RCP8.5) were investigated by comparing two future periods (2021–50 and 2071–2100) to a historical period (1971–2000) for each of these scenarios. The ensemble simulates a robust increase (change larger than twice the ensemble sample standard deviation) in the frequency of occurrence of unstable environments (lifted index < -2 K) across central and south-central Europe in the RCP8.5 scenario in the late twenty-first century. This increase coincides with the increase in lower-tropospheric moisture. Smaller, less robust changes were found until midcentury in the RCP8.5 scenario and in the RCP4.5 scenario.Changes in the frequency of situations with strong (> 15 m/s) deep-layer shear were found to be small and not robust, except across far northern Europe, where a decrease in shear is projected. By the end of the century, the simultaneous occurrence of latent instability, strong deep-layer shear, andmodel precipitation is simulated to increase by up to 100% across central and eastern Europe in the RCP8.5 and by 30%–50% in the RCP4.5 scenario. Until midcentury, increases in the 10%–25%range are forecast formost regions.Alarge intermodel variability is present in the ensemble and is primarily due to the uncertainties in the frequency of the occurrence of unstable environments. |
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