Extreme rainfall in Mediterranean France during the fall: added value of the CNRM-AROME Convection-Permitting Regional Climate Model

International audienceSouth-East France is a region often affected by heavy precipitating events the characteristics of which are likely to be significantly impacted in the future climate. In this study, uc(cnrm-arome), a Convection-Permitting Regional Climate Model with a 2.5 km horizontal resolution is compared to its forcing model, the Regional Climate Model uc(aladin-c)limate at a horizontal resolution of 12.5 km, self-driven by the uc(era-i)nterim reanalysis. An hourly observation dataset with a resolution of 1 km, uc(comephore), is used in order to assess simulated surface precipitation from a seasonal to hourly scale. The representation of the spatial pattern of fall precipitation climatology is improved by uc(cnrm-arome). It also shows a clear added value with respect to uc(aladin-c)limate through the improvement of the localization and intensity of extreme rainfall on a daily and hourly time scale on both fine and coarse spatial scales (2.5, 12.5 and 50 km). uc(cnrm-arome) in particular is able to simulate intense rainfall on lowlands and makes sub-daily rainfall events more intense than uc(aladin-c)limate. uc(cnrm-arome) still underestimates very extreme precipitation from above 30 mm/h or 230 mm/day

Correction to: Extreme rainfall in Mediterranean France during the fall: added value of the CNRM‑AROME Convection‑Permitting Regional Climate Model

Unfortunately, the article “Extreme rainfall in Mediterranean France during the fall: added value of the CNRM‑AROME Convection‑Permitting Regional Climate Model”, written by Quentin Fumière was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 24 July 2019 without open access with incorrect copyright holder as “© Springer-Verlag GmbH Germany, part of Springer Nature 2019”.</jats:p

Correction to: Extreme rainfall in Mediterranean France during the fall: added value of the CNRM-AROME Convection-Permitting Regional Climate Model

International audienceUnfortunately, the article "Extreme rainfall in Mediterranean France during the fall: added value of the CNRM-AROME Convection-Permitting Regional Climate Model", written by Quentin Fumière was originally published electronically on the publisher's internet portal (currently SpringerLink) on 24 July 2019 without open access with incorrect copyright holder as "Springer-Verlag GmbH Germany, part of Springer Nature 2019"

Modelling Mediterranean heavy precipitation events at climate scale: an object-oriented evaluation of the CNRM-AROME convection-permitting regional climate model

AbstractModelling the rare but high-impact Mediterranean Heavy Precipitation Events (HPEs) at climate scale remains a largely open scientific challenge. The issue is adressed here by running a 38-year-long continuous simulation of the CNRM-AROME Convection-Permitting Regional Climate Model (CP-RCM) at a 2.5 km horizontal resolution and over a large pan-Alpine domain. First, the simulation is evaluated through a basic Eulerian statistical approach via a comparison with selected high spatial and temporal resolution observational datasets. Northwestern Mediterranean fall extreme precipitation is correctly represented by CNRM-AROME at a daily scale and even better at an hourly scale, in terms of location, intensity, frequency and interannual variability, despite an underestimation of daily and hourly highest intensities above 200 mm/day and 40 mm/h, respectively. A comparison of the CP-RCM with its forcing convection-parameterised 12.5 km Regional Climate Model (RCM) demonstrates a clear added value for the CP-RCM, confirming previous studies. Secondly, an object-oriented Lagrangian approach is proposed with the implementation of a precipitating system detection and tracking algorithm, applied to the model and the reference COMEPHORE precipitation dataset for twenty fall seasons. Using French Mediterranean HPEs as objects, CNRM-AROME’s ability to represent the main characteristics of fall convective systems and tracks is highlighted in terms of number, intensity, area, duration, velocity and severity. Further, the model is able to simulate long-lasting and severe extreme fall events similar to observations. However, it fails to reproduce the precipitating systems and tracks with the highest intensities (maximum intensities above 40 mm/h) well, and the model’s tendency to overestimate the cell size increases with intensity.</jats:p

Modelling Mediterranean heavy precipitation events at climate scale: an object-oriented evaluation of the CNRM-AROME convection-permitting regional climate model

International audienceModelling the rare but high-impact Mediterranean Heavy Precipitation Events (HPEs) at climate scale remains a largely open scientific challenge. The issue is adressed here by running a 38-year-long continuous simulation of the CNRM-AROME Convection-Permitting Regional Climate Model (CP-RCM) at a 2.5 km horizontal resolution and over a large pan-Alpine domain. First, the simulation is evaluated through a basic Eulerian statistical approach via a comparison with selected high spatial and temporal resolution observational datasets. Northwestern Mediterranean fall extreme precipitation is correctly represented by CNRM-AROME at a daily scale and even better at an hourly scale, in terms of location, intensity, frequency and interannual variability, despite an underestimation of daily and hourly highest intensities above 200 mm/day and 40 mm/h, respectively. A comparison of the CP-RCM with its forcing convection-parameterised 12.5 km Regional Climate Model (RCM) demonstrates a clear added value for the CP-RCM, confirming previous studies. Secondly, an object-oriented Lagrangian approach is proposed with the implementation of a precipitating system detection and tracking algorithm, applied to the model and the reference COMEPHORE precipitation dataset for twenty fall seasons. Using French Mediterranean HPEs as objects, CNRM-AROME's ability to represent the main characteristics of fall convective systems and tracks is highlighted in terms of number, intensity, area, duration, velocity and severity. Further, the model is able to simulate long-lasting and severe extreme fall events similar to observations. However, it fails to reproduce the precipitating systems and tracks with the highest intensities (maximum intensities above 40 mm/h) well, and the model's tendency to overestimate the cell size increases with intensity

Correction to: Modelling Mediterranean heavy precipitation events at climate scale: an object-oriented evaluation of the CNRM-AROME convection-permitting regional climate model

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Long-term Outcomes of Cerebral Aneurysms in Children

BACKGROUND: Our aim was to report the long-term clinical and imaging outcomes of ≤15-year-old children treated for ruptured or symptomatic cerebral aneurysms and to identify prognostic factors for clinical outcome, recurrence, and rebleeding. METHODS: We retrospectively identified all pediatric cases of cerebral aneurysm from 2000 to 2015 and then prospectively evaluated long-term occlusion using brain MRI and clinical outcome measures: outcome was considered favorable if King’s Outcome Scale for Childhood Head Injury score was ≥5. We performed univariate analysis and logistic binary regression to identify variables associated with clinical and imaging outcomes. RESULTS: Fifty-one children (aged 8.5 ± 1.1 years [mean ± SD], with 37 ruptured and 14 symptomatic aneurysms) were included, and endovascular treatments (84%) or microsurgical procedures (16%) were performed. Despite a 19.6% death rate, at a mean follow-up of 8.3 years, 35 children (68.6%) had a favorable outcome. Annual bleeding and aneurysm recurrence rates were 1.4% ± 1.1% and 2.6% ± 1.8%, respectively. Cerebral ischemia, whether initial or delayed within the first month, was predictive of poor clinical outcome in multivariate analysis (odds ratio: 25; 95% confidence interval: 0.43–143; P &amp;lt; .0001), whereas aneurysm size &amp;gt;5 mm was the only factor associated with recurrence (odds ratio: 14.6; 95% confidence interval: 2.4–86.1; P = .003). CONCLUSIONS: Two-thirds of studied ≤15-year-old children suffering from ruptured or symptomatic cerebral aneurysms had long-term favorable outcome. Annual bleeding and aneurysm recurrence rates have shown to be low after endovascular or surgical treatment. Long-term imaging follow-up helps to depict aneurysm recurrence or de novo aneurysm formation and to prevent rebleeding. </jats:sec