MERIDA - MEteorological Reanalysis Italian DAtaset

The new MEteorological Reanalysis Italian DAtaset (MERIDA) has been developed to cope with the increasing weather extremes of the last 20 years, which caused several disruptions to the Italian electric system. This work has been developed following the indications emerged from the “Resilience Working Table” set up by the Italian Regulatory Authority for Energy, Networks and the Environment (ARERA). MERIDA is able to respond to the energy stakeholders, who need reliable meteorological data to implement effective adaptation strategies to operate the electric system safely.

MERIDA consists of a dynamical downscaling of the ERA5 global reanalysis using the mesoscale model WRF-ARW. ERA5 data are retrieved with a 3-hourly temporal resolution to assure good temporal consistency. Temperature data from the SYNOP Air Force stations are also retrieved to be ingested in the WRF simulations at 3-hourly temporal resolution.

The computational domain of MERIDA consists of 2 grids with horizontal resolution of 21 km and 7 km respectively, with the internal grid centered over Italy.

The meteorological fields of MERIDA are open access and distributed in NETCDF file format on a regular lat-lon grid of 0.07° resolution.

A subset of the dataset is available here for download for the period 2000-2018. The full dataset covering the period 1990-2019, and continuoulsy updated, is available at the following website: http://merida.rse-web.it/ 

The following subset of meteorological fields is available here for download:

• T2 - 2m temperature (K)
• PREC - Total Precipitation (mm/h)
• U10 - 10m u-component of wind (m/s)
• V10 - 10m v-component of wind (m/s)
• PSFC - Surface pressure (Pa)
• Q2 - 2m Specific Humidity (Kg/Kg)
• SWDIR - Direct global short-wave radiation (W/m²)
• SWDIF - Diffuse global short-wave radiation (W/m²)
• MSLP - Mean Sea Level Pressure (Pa)
• SNEQV - Snow Water Equivalent (mm)
• SOIL_T - Soil Temperature - Layer 5 cm (K)
• SOIL_M - Soil Moisture - Layer 5 cm (m³/m³)

The following variables are available under request:

• SOIL_T - Soil Temperature (K, Layers: 5,25,70,150 cm)
• SOIL_M - Soil Moisture - Layer 5 cm (m³/m³, Layers: 5,25,70,150 cm)
• TT - Temperature (K, Pressure levels: 850,700,500 hPa)
• RH - Relative Humidity (%, Pressure levels: 850,700,500 hPa)
• GHT - Geopotential Height (gpm, Pressure levels: 850,700,500 hPa)
• UU - u-component of wind (m/s, Pressure levels: 850,700,500 hPa)
• VV - v-component of wind (m/s, Pressure levels: 850,700,500 hPa)
• TG - Ground Temperature (K)
• HFX - Sensible Heat Flux (W/m²)
• LH - Latent Heat Flux (W/m²)
• GRDFLX - Ground Flux (W/m²)
• TR - Transpiration Flux (W/m²)

All the variables not included for download may be downloaded at : http://merida.rse-web.it/

or requested at:

• riccardo.bonanno@rse-web.it
• matteo.lacavalla@rse-web.it
• simone.sperati@rse-web.it