DATE2016-06-01 07:42:38
IDABSTRACT20160601074238-1117
CONTACTknaus@pik-potsdam.de
PRESENTATIONPOSTER
INVITED0
IDSESSION3
TITLESHIFT IN EVAPORATIVE REGIME INTENSIFYING RECENT HEAT EXTREMES IN SOUTHEAST EUROPE
AUTHORSMaria Knaus (1), Dim Coumou (1), Alexander Robinson (1,2,3)
AFFILIATIONS
  1. Potsdam Institute For Climate Impact Research Potsdam (Germany)
  2. Universidad Complutense De Madrid Madrid (Spain)
  3. Instituto De Geociencias Madrid (Spain)
ABSTRACTThe Mediterranean region (MED) has experienced an over-proportional increase in summer heat extremes during the last few decades compared to other regions. CMIP5 models however clearly underestimate the observed increase in summer temperature variability over the region, highlighting the need for a better understanding of the underlying physical drivers. For example, the role of land-atmosphere feedbacks may have recently become more important due to the heat amplifying effect of dry soils. Here we investigate the effect of soil moisture changes on summer temperature extremes in the southeast European region (SEE). We include evaporative fraction in our analysis as an indicator for causality and analyze the temporal evolution of soil moisture-temperature interactions since 1979. Our findings indicate a shift in evaporative regimes during the late 20th century, which has triggered the region’s strong sensitivity to a negative soil moisture-temperature coupling. We show that in SEE, summer dryness has significantly contributed to recent summer heat extremes by limiting the effect of evaporative cooling. We thus conclude that land-atmosphere feedbacks have been an important driver for recent record-breaking heat waves and made the occurrence of the 2012 “3-sigma” summer heat extreme much more likely. We further find a distinct soil moisture signal in CMIP5 model simulations in relation to summer temperature anomalies. Based on a comparison with observations, we identify a reduced ensemble of 6 models that are most suitable for estimating summer heat extremes in the SEE region.
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