HEAT WAVES Gregorio Gomez Robert Sauermann Ben Lynton

2010 MOSCOW HEAT WAVE 55,000 deaths Annual crop production dropped by 25% 15 billion USD loss to the Russian economy Could it have been predicted?

Understanding changes in mean and variance Increases in mean increase incidence of heat waves Increases in variance increase incidences of hot and cold spells

Dole et al. (2011) Motivation: Was the magnitude of the 2010 Russian heat wave a result of anthropogenic influence, slowly evolving ocean boundary conditions, or natural variability? Concludes the Russian heat wave was primarily a result of internal atmospheric variability Suggests that the frequency of heat waves is expected to increase in the near future

The Russian 2010 heat wave High pressure zone traps hot air Wind patterns trap particulates and reduce cloudiness Severe drought amplifies heat wave intensity due to land-surface feedbacks 2010 event was classic “omega” blocking pattern

Paper 2: Rahmstorf & Coumou (2011) Motivation: has global warming affected the frequency of extreme temperature events? In proportion to the global warming trend, the frequency of record heat wave events has increased. Statistical models show an approximate 80% probability that the 2010 Russian heat wave would not have occurred without global warming.

Temperature Models Panels A, B, and C represent simulated temperature data sets with extremes marked Panels D and E show actual temperature increases for global and Moscow temperatures

Paper 3: Otto et al. (2012) Motivation: reconciling Dole et al.(2011) & Rahmstorf and Coumou (2011) “the difference in conclusion between these two papers illustrates the importance of specifying precisely what question is being asked” – Paper 1 finds natural causes for magnitude of heat wave – Paper 2 relates global warming to frequency of heat waves From empirical data and model simulations, global warming may be accountable for heat wave frequency

Epic March — The Washington Post (2012) Public opinion is varied, yet potentially influential Record Highs in Midwest, Great Lakes, Northeast Link to Global Warming? – U of Utah, TWC representatives attribute global warming – Accuweather representatives ask for more data Heat Dome Low Pressure