Extreme value indicators in highly resolved climate change simulations for the Jordan River area

• Published in: Journal of Geophysical Research: Atmospheres Vol. 116; no. D24; pp. np - n/a
• Main Authors: Samuels, R., Smiatek, G., Krichak, S., Kunstmann, H., Alpert, P.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 27-12-2011; American Geophysical Union
• Subjects: Atmospheric sciences; Climate change; Climate models; Earth; Earth sciences; Earth, ocean, space; Exact sciences and technology; extreme values; Extreme weather; Geophysics; Hydrology; Jordan River; Rainfall; RCM; Regions; Rivers; Water resources management; Middle East; Jordan River; Asia; East Mediterranean; Mediterranean Sea; Israel, Jordan R; MED, Eastern Mediterranean; Wet spell; trend-surface analysis; simulation; adaptation; Summer; global; Spatial scale; frequency; agriculture; water resources; temperature; climate change; atmospheric precipitation; Heavy rain; Regional scope; topography; Climate models; indicators; intensity; planning; deserts; extreme value; water resource management; Dry spell; Mediterranean region
• ISSN: 0148-0227; 2169-897X; 2156-2202; 2169-8996
• DOI: 10.1029/2011JD016322

Understanding changing trends and frequency of extreme rainfall and temperature events is extremely important for optimal planning in many sectors, including agriculture, water resource management, health, and even economics. For people living in the Jordan River region of the Middle East such changes can have immediate devastating impacts as water resources are already scarce and overexploited and summer temperatures in the desert regions can reach 45°C or higher. Understanding shifts in frequency and intensity of extreme events can provide crucial information for planning and adaptation. In this paper we present results from regional climate model simulations with RegCM3 and MM5 centered on the eastern Mediterranean region. Our analysis focuses on changes in extreme temperature and rainfall events. We show that maximum daily summer temperature is expected to increase by between 2.5°C and 3°C, with an increase in warm spell length. Precipitation extremes are expected to increase with longer dry spells, shorter wet spells, and increases in heavy rainfall. Model agreement for the control period 1961–1990 is higher in the southern region than in the north, perhaps because of the complex topography, suggesting that even small differences in spatial scale play an important role. In addition, we notice that the chosen global model plays an important role in determining future temperature trends, while the choice of regional climate model is critical for understanding how precipitation is expected to evolve.
Key Points
The simulations show a future temperature increase in range of 2.5‐3 degrees
Dry spells are simulated to increase in the future
Increase in heavy rainfall despite the decrease in annual mean precipitation