DATE2018-05-20 12:25:34
IDABSTRACT20180520122534-0120
CONTACTpiero.lionello@unisalento.it
PRESENTATIONPOSTER
INVITED0
IDSESSION2
TITLECOMPARING THE SIMULATED MEDITERRANEAN CLIMATE IN DIFFERENT CONDITIONS: LAST GLACIAL MAXIMUM, MID-HOLOCENE AND THE RCP8.5 PROJECTION AT THE END OF THE 21ST CENTURY
AUTHORSP Lionello (1,2), R D'Agostino (3)
AFFILIATIONS
  1. Univ.of Salento, Lecce, Italy
  2. CMCC, Lecce, Italy
  3. Max Planck Institute for Meteorology, Hamburg, Germany
ABSTRACTCMIP5 and PMIP3 global climate simulations allow to analyze a large set of climate conditions reproducing the last glacial maximum (LGM), the Mid-Holocene (MidH), the pre-industrial period (PIC, Control) , the historical (HIST) and a high emission Representative Concentration Pathway(RCP8.5). The comparison between the two most distant climate conditions (LGM and RCP8.5) shows contrasting changes of precipitation with respect to temperature. Temperature increases from LGM to PIC and from PIC to RCP8.5 (in both cases changes are about 4K), while precipitation during PIC is larger than during both LGM and RCP8.5 (about 30 and 90 mm more annual totals, respectively). Evaporation behaves differently with respect to precipitation: it is lower during LGM than during PIC, and larger during RCP8.5 than PIC. As a result, the decreased evaporation in the LGM overcompensates for the decreased precipitation, so that LGM is appreciably wetter then PIC. On the contrary, both increased evaporation and reduced precipitation lead to much drier conditions in RCP8.5 and larger water deficit of the Mediterranean basin with respect to PIC. These changes are supported by an increased atmospheric stability during RCP8.5 and a geopotential height trough extending over the Mediterranean during LGM. Model simulations in the MidH show small changes with respect to PIC for mean annual temperature and total precipitation. This is because contrasting changes along the annual cycle of MidH compensate each other: the MidH summer is warmer than PIC, while the rest of the year is mildly colder; the MidH spring is wetter, while the rest of the year is slightly drier than PIC.
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