Extreme events in high resolution CMCC regional and global climate models

Within the framework of the FUME EU project a set of climate projections covering the period 1970-2100 has been performed using a global General Circulation model (CMCC-Med) and a Regional Climate model (CMCC-CLM). Simulation outputs have been post-processed in order to investigate extreme events based on three principal weather parameters: precipitation, surface temperature and 10 metre wind. Using these parameters, several indexes for extreme event characterizations have been computed on daily time basis over 4 seasons. Trends and variability have been computed and examined both for the global and regional model

Analysis of Expected Climate Extreme Variability with Regional Climate Simulations over Napoli Capodichino Airport: A Contribution to a Climate Risk Assessment Framework

In recent years, the scientific community has paid particular attention to the analysis of extreme events, such as heat waves, droughts, and intense rain events that have caused loss of human life and significant economic damage. Climate-related extremes generally produce large impact on infrastructures, especially on those with insufficient design, while some infrastructures may become inadequate under the effects of severe extremes. In the particular case of airports, the increase in frequency and severity of extreme weather events will worsen their deterioration rate. This work presents an analysis of the expected climate variability over Napoli Capodichino Airport, using climate projections generated by the Regional Climate Model COSMO-CLM. Simulations were performed over Italy, employing a spatial resolution of approximately 8 km. The time period simulated was 1979–2100, and, in particular, the CMIP5 historical experiment (based on historical greenhouse gas concentrations) was used for the period 1979–2005, while, for the period 2006–2100, two different simulations were performed, employing the Representative Concentration Pathways IPCC RCP4.5 and RCP8.5 greenhouse gas concentrations. The meteorological situations over the airport have been analyzed, along with the identification of conditions that could cause relevant impact on airport environment. In particular, extreme summer temperatures may exceed design standards, leading to heat damage to surfaces, while runways or aprons may have trouble due to the surface melting during peak heat periods. Long term changes in the directions of wind can adversely affect the usability of runways, while changes in wind shear could modify strength and frequency of clear-air turbulence. Analyses have been performed considering suitable Extreme Events Indicators (EWI), both on past trends and on numerical projections over future periods, with the aim of contributing to the definition of a risk assessment methodology based on the combination of the frequency and of the severity of meteorological hazards

Climate change projections for the Middle East–North Africa domain with COSMO-CLM at different spatial resolutions

In this study, projected changes in the future climate conditions for the Middle East–North Africa domain over the 21st century have been investigated. Two simulations with the COSMO-CLM model have been conducted respectively, at a spatial resolution of 0.44° and 0.22°, over the period 1979–2100, employing the IPCC RCP4.5 scenario. Initial and boundary conditions have been derived by the global model CMCC-CM. The main aim of the work is to provide regional climate projections for this area, widening the range of the data already available, yet with higher resolution, useful for many applications, especially as an input for the impact models. The two different resolutions have been employed in order to quantify the differences due to the spatial scale effects, comparing the results also with the driving global model. Climate projections show a significant warming expected over the whole area considered at the end of the 21st century, along with a reduction in precipitation, which is particularly evident over the western part of the domain. Precipitation projections depend on the horizontal resolution, suggesting the need for additional simulations at higher resolution, especially for a proper representation of extreme weather events

Numerical Simulation of the Period 1971–2100 over the Mediterranean Area with a Regional Model, Scenario SRES-A1B

In this work, we discuss the results of numerical simulations performed with the regional model COSMO-CLM over the Mediterranean area at a spatial resolution of 14 km, employing an optimized model configuration. An assessment of model capabilities to reproduce the main features of the recent and past climate has been performed, using two different simulations: The first simulation is driven by the ERA40 Reanalysis and the second, by the CMCC-MED global model. Validation is performed through a comparison with the E-OBS dataset. Climate projections, according to the SRES A1B emission scenario, have been further analyzed in terms of change of 2-m temperature and precipitation, and have shown a significant warming expected at the end of the 21st Century, along with a general reduction in precipitation, particularly evident in spring and summer

Extreme events in high resolution CMCC regional and global climate models

Within the framework of the FUME EU project a set of climate projections covering the period 1970-2100 has been performed using a global General Circulation model (CMCC-Med) and a Regional Climate model (CMCC-CLM). Simulation outputs have been post-processed in order to investigate extreme events based on three principal weather parameters: precipitation, surface temperature and 10 metre wind. Using these parameters, several indexes for extreme event characterizations have been computed on daily time basis over 4 seasons. Trends and variability have been computed and examined both for the global and regional model.Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC)Published3.7. Dinamica del clima e dell'oceanoope

EXTREME EVENTS AS REPRESENTED BY HIGH RESOLUTION CMCC CLIMATE MODELS AT GLOBAL AND REGIONAL (Euro-Mediterranean) SCALE

One of the conclusions of the IPCC Fourth Assessment Report is that there are evidences that climate change affects the frequency, intensity, and length of many extreme events, such as floods, droughts, storms and extreme temperatures. At the same time, gradual and non-linear changes in ecosystems and natural resources further increase the consequences of extreme weather events. Climate extreme events are hard to study and even harder to predict because they are, by definition, rare and obey different statistical laws than averages. The availability of climate simulations (historical + sresA1B scenario) covering the period 1970-2100 from a global Coupled General Circulation Model (70 Km of atmospheric spatial resolution) and a Regional Climate Model (14 Km of spatial resolution) give the possibility to investigate three principal weather fields involved in extreme events conditions such as surface temperature, precipitation and wind velocity. For each of them the computation of several indicators has been done, at global and regional scale, on daily time basis over 4 seasons defined as December-February (DJF), March-May (MAM), June-August (JJA), September-November (SON). These indicators characterize each model grid point over the relative spatial model domain (global/regional). For each index we computed trend maps considering only grid points where the detected trend is statistically significant. Available trend maps are defined over five periods of 30 years: 1971-2000 1981-2010, 2011-2040, 2041-2070, 2071-2100, and two periods of 65 years: 1971-2035 and 2036-2100