Changes in extremes and hydroclimatic regimes in the CREMA ensemble projections
- 922 Downloads
We analyze changes of four extreme hydroclimatic indices in the RCP8.5 projections of the Phase I CREMA experiment, which includes 21st century projections over 5 CORDEX domains (Africa, Central America, South America, South Asia, Mediterranean) with the ICTP regional model RegCM4 driven by three CMIP5 global models. The indices are: Heat Wave Day Index (HWD), Maximum Consecutive Dry Day index (CDD), fraction of precipitation above the 95th intensity percentile (R95) and Hydroclimatic Intensity index (HY-INT). Comparison with coarse (GPCP) and high (TRMM) resolution daily precipitation data for the present day conditions shows that the precipitation intensity distributions from the GCMs are close to the GPCP data, while the RegCM4 ones are closer to TRMM, illustrating the added value of the increased resolution of the regional model. All global and regional model simulations project predominant increases in HWD, CDD, R95 and HY-INT, implying a regime shift towards more intense, less frequent rain events and increasing risk of heat wave, drought and flood with global warming. However, the magnitudes of the changes are generally larger in the global than the regional models, likely because of the relatively low “climate sensitivity” of the RegCM4, especially when using the CLM land surface scheme. In addition, pronounced regional differences in the change signals are found. The data from these simulations are available for use in impact assessment studies.
KeywordsHeat Wave Global Climate Model Extreme Index Impact Assessment Study Global Climate Model Simulation
This work was partially supported by grants from the project NextDATA funded by the Italian Consiglio Nazionale della Ricerca (CNR).
- Coppola E et al. (2014) Present and future climatologies in the Phase I CREMA experiment. Climatic change, this issueGoogle Scholar
- Dickinson RE, Henderson-Sellers A, Kennedy PJ (1993) Biosphere—atmosphere transfer scheme, BATS: version 1E as coupled to the NCAR Community Climate Model. Technical Note NCAR/TN—387 + STR, 72pGoogle Scholar
- Donat MG et al (2013) Updated analyses of temperature and precipitation extreme indices since the beginning of the twentieth century: the HadEX2 dataset. J Geophys Res—Atmos 118:20998–22118Google Scholar
- Giorgi F (2014) The Phase I CORDEX RegCM hyper-Matrix (CREMA) experiment. Introduction to the special issue. Climatic Change, this issueGoogle Scholar
- Giorgi F, Jones C, Asrar G (2009) Addressing climate information needs at the regional level: the CORDEX framework. WMO Bull 175–183Google Scholar
- IPCC (2012) In: Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner G-K, Allen SK, Tignor M, Midgley PM (eds) Managing the risks of extreme events and disasters to advance climate change adaptation. A special report of Working Groups I and II of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, p 582Google Scholar
- Meehl GA et al (2007) In: Solomon S (ed) Global climate projections, chapter 10 of climate change 2007, The physical science basis, WGI contribution to the fourth assessment report of the intergovernmental panel on climate change (IPCC). Cambridge University Press, New York, pp 747–845Google Scholar
- Sillmann J, Kharin VV, Zwiers FW, Zhang X, Bronaugh D (2013) Climate extreme indices in the CMIP5 multimodel ensemble: Part 2. Future climate projections. J Geophys Res—Atmos 118:2473–2493Google Scholar