New climate modelling and new climate analysis tools
Samuel Somot, Météo-France/CNRM, France
In the CLIM-RUN project, the WP2 is in charge of developing and applying new climate modelling tools as well as new climate analysis tools in order to answer the stakeholder demands for climate services. This full bottom-up approach is quite new for most of the climate researchers involved in WP2, compared to former, less innovative EU projects dealing with climate modelling. However, we deeply believe that it prepares future climate service organisation system.
To full-fill this goal, WP2 had to hire specialists of various fields in climate modelling: Regional Climate Modelling (RCM), Global Climate Modelling (GCM), seasonal, decadal and centennial time scales, past variability and future scenario, uncertainty assessment, etc. with a common interest in exploring climate variability in the Mediterranean region. This could be achieved thanks to the participation of ENEA, ICTP, CMCC, USMD, IC3 and Météo-France/CNRM (WP2 leader) in WP2.
The main material used in WP2 to answer the stakeholder needs is as follows:
- past European project outputs available on-line or through agreement,
- development of a new analysis technique focusing in particular on (1) uncertainty assessment at the regional/local scale (see on the left) , (2) regional assessment of the recent decadal forecast and (3) climate variables less studied up to now (aerosol field, direct and diffuse shortwave, wind field over the sea, sea temperature),
- development of a new climate modelling technique dedicated to specific needs (very high-resolution modelling up to 12km with sub-grid tiling at 2 km (see figure on the right), lake modelling, Mediterranean sea level modelling, sea temperature modelling, aerosols modelling, improved cloud modelling).
The first project year was dedicated to the following main tasks:
- to list the available skills among the WP2 partners (type of climate models, participation in past projects, temporal horizon, spoken language, etc.),
- to develop guidance for the stakeholder meetings in order to be sure that outcomes of the meetings includes required specifications for climate modellers to work in WP2,
- to help in the so-called translation step leading to a translation of the stakeholder needs in terms of climate variables, geographical area, temporal horizon, etc.,
- to perform the first analysis of the regional climate change uncertainty for the various CLIM-RUN case studies, ranging from tourism, over wild-fire, to energy as well as an integrated assessment,
- to perform a first assessment of the potential skill of the decadal forecast experiment over the Mediterranean area,
- to list the possible developments of the new regional climate modelling tools to be carried out during the next years.
The figure on the left shows the domain of the new high-resolution RCM models (12 km + sub-grid tiling at 2 km) to be developed within CLIM-RUN by ICTP and CNRM and dedicated to the study of the Mediterranean climate change. It is worth noting the quality of the representation of the Mediterranean orography and coastline as well as the possibility for the first time to study small Mediterranean islands. On the right hand, an illustration of a probability way of assessing regional climate change using the ENSEMBLES RCM runs for temperature and precipitation for a given case study is provided. Comment: the most probable change is here +1.7°C and -0.2 mm/d but this figure also allows to underline that the sign of the precipitation change is highly uncertain and that the “no warming” state is quite impossible whereas a warming less than 3°C has a probability of 90%. We let you guess where it is and for which temporal horizon!