...
Section | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
This catalogue entry provides Regional Climate Model (RCM) data on single levels from a number of experiments, models, domains, resolutions, ensemble members, time frequencies and periods computed over several regional domains all over the World in the framework of the Coordinated Regional Climate Downscaling Experiment (CORDEX). The term "single levels" is used to express that the variables are 2D-matrices computed on one vertical level which can be surface (or a level close to the surface) or a dedicated pressure level in the atmosphere. Multiple vertical levels are excluded from this catalogue entry.
High-resolution Regional Climate Models (RCMs) can provide climate change information on regional and local scales in relatively fine detail, which cannot be obtained from coarse scale Global Climate Models (GCMs). This is manifested in better description of small-scale regional climate characteristics and also in more accurate representation of extreme events. Consequently, outputs of such RCMs are indispensable in supporting regional and local climate impact studies and adaptation decisions. RCMs are not independent from the GCMs, since the GCMs provide lateral and lower boundary conditions to the regional models. In that sense RCMs can be viewed as magnifying glasses of the GCMs.
The CORDEX experiments consist of RCM simulations representing different future socio-economic scenarios (forcings), different combinations of GCMs and RCMs and different ensemble members of the same GCM-RCM combinations. This experiment design through the ensemble members allows for studies addressing questions related to the key uncertainties in future climate change. These uncertainties come from differences in the scenarios of future socio-economic development, the imperfection of regional and global models used and the internal (natural) variability of the climate system. This experiment design allows for studies addressing questions related to the key uncertainties in future climate change:
- what will future climate forcing be?
- what will be the response of the climate system to changes in forcing?
- what is the uncertainty related to natural variability of the climate system?
The term "region" in the CDS form refers to the different regional domains, which are as follows:
- EUR: European domain from 27°N to 72°N and from 22°W to 45°E. The horizontal resolution for this domain is 0.11° x 0.11° (EUR-11).
- NAM: North-American domain from 12°N to 59°N and from 171°W to 24°W. The horizontal resolutions for this domain are 0.22° x 0.22° (NAM-22) and 0.44° x 0.44° (NAM-44).
Additional details on each CORDEX geographical domain are available at https://cordex.org/domains/.
The term "experiment" in the CDS form refers to three main categories:
- Evaluation: CORDEX experiment driven by ECMWF ERA-Interim reanalysis for a past period. These experiments can be used to evaluate the quality of the RCMs using perfect boundary conditions as provided by a reanalysis system. The period covered is typically 1980-2010;
- Historical: CORDEX experiment which covers a period for which modern climate observations exist. Boundary conditions are provided by GCMs. These experiments, that follow the observed changes in climate forcing, show how the RCMs perform for the past climate when forced by GCMs and can be used as a reference period for comparison with scenario runs for the future. The period covered is typically 1950-2005;
- Scenario: Ensemble of CORDEX climate projection experiments using RCP (Representative Concentration Pathways) forcing scenarios. These scenarios are the RCP 2.6, 4.5 and 8.5 scenarios providing different pathways of the future climate forcing. Boundary conditions are provided by GCMs. The period covered is typically 2006-2100.
In CORDEX, the same experiments were done using different RCMs (labelled as “Regional Climate Model” in the CDS form).
In addition, for each RCM, there is a variety of GCMs, which can be used as lateral boundary conditions. The GCMs used are coming from the CMIP5 (5th phase of the Coupled Model Intercomparison Project) archive. These GCM boundary conditions are labelled as “Global Climate Model” in the form and are also available in the CDS.
Additionally, the uncertainty related to internal variability of the climate system is sampled by running several simulations with the same RCM-GCM combination. On the forms, these are indexed as separate ensemble members (the naming convention for ensemble members is available in the documentation). For each GCM, the same experiment was repeatedly done using slightly different conditions (like initial conditions or different physical parameterisations for instance) producing in that way an ensemble of experiments closely related. More details behind these sequential ensemble numbers is available in the detailed documentation.
All known issues about the CORDEX data are documented through the ES-DOC Errata Service : https://errata.es-doc.org/.
The data are produced by the institutes and modelling centres participating in the different CORDEX domains with partial support from different international and national contributions (including support from COPERNICUS for some of the EURO-CORDEX runs and for helping in the data curation and ESGF archiving process in some domains).
Recommended search procedure:
- Select the CORDEX region of interest
- Select the spatial resolution of interest
- Select the CORDEX experiment (e.g., future scenario) of interest
- Select the required variable(s) for your analysis.
- Select the required time period (which depends on the experiment).
- The search interface will adapt the other selection fields according to the available data (e.g., which models provides the variable you aim for, how many ensemble are available, etc.)
...
evaluation runs are from 1989 to 2008
historical runs are from 1951 to 2005
scenario runs are from 2006 to 2100
...
The relative humidity is the percentage ratio of the water vapour mass to the water vapour mass at the saturation point given the temperature at that location. The data represents the mean over the aggregation period at 2m above the surface.
...
The air pressure at the lower boundary of the atmosphere. The data represents the mean over the aggregation period.
...
The downward longwave radiative flux of energy inciding on the surface from the above per unit area. The data represents the mean over the aggregation period.
...
The upward shortwave radiative flux of energy from the surface per unit area. The data represents the mean over the aggregation period at the surface.
...
The magnitude of the eastward component of the wind. The data represents the mean over the aggregation period at 200hPa above the surface.
...
The mass of surface and sub-surface liquid water per unit area and time, which drains from land. The data represents the mean over the aggregation period.
...
The mass of surface and sub-surface liquid water per unit area ant time, which evaporates from land. The data includes conversion to vapour phase from both the liquid and solid phase, i.e., includes sublimation, and represents the mean over the aggregation period.
...