POWER BLACKOUTS IN SOUTH AMERICA
Climate impact indicators
Global essential climate variables/indicators used
- Daily precipitation sum
- Daily mean temperature
- Daily minimum temperature
- Daily maximum temperature
Regional/local indicators used and produced
- Effective precipitation index (EPI)
Global data to regional/local scale
Step 1: Selection of emission scenario and time periods. The reference period for local bias-correction and for the baseline climate relative to which the future periods are compared, were defined. For all those periods, the effective precipitation index (EPI) is being estimated. The selection of the representative concentration pathway is made.
Step 2: Evaluation and download of GCM and reanalysis data. Downscaled and bias-corrected GCMs data from the C3S_422_Lot1_SMHI contract and available in the CDS catalogue, were downloaded (daily mean precipitation and mean, maximum and minimum temperature). The data are evaluated to meet basic requirements for the calculation of the EPI over the domain of study. The bias-corrected GCMs data on 0.5 deg grid are compared to a local reference data set.
Step 3: Selection of method for Potential Evapotranspiration (ETP) estimation. Effective precipitation is defined as the difference between precipitation (P) and potential evapotranspiration (PET). The estimation of PET depends on the chosen parameterization method. Different methods are evaluated based on their accuracy and data requirements. As optimal method, the Hargreaves-Samani parametrization was selected.
Step 4: Statistical downscaling to 0.125° x 0.125° grid. The EPI is required on the catchment size resolution in order to provide relevant information to the customers in the water management and energy sector. Those catchments extend typically from some hundreds to some thousands km2. As it is describable to have several grid boxes per catchment, a further downscaling to 0.125x0.125 degree is made. The downscaling takes into account the topography using the digital elevation model (DEM) (15’’ x 15’’) provided by Viewfinder Panoramas as a reference for the high resolution topography.
Step 5: Calculation of the Effective Precipitation Index (EPI). The calculation of the EPI is done on the 0.125x0.125 degree grid using the data of step2 as input.
Step 6: Communication. The results are prepared for visualization in the interactive climate atlas and are communicated to the customers by means of video-conference or face-to-face meetings.