1. Clouds, climate, cities and challengesHerman RusschenbergTUDelft Climate Institute2-6-2012h.w.j.russchenberg@tudelft.nl Challenge the future

2. Our Earthis slowly warming 3. The world populationis moving into the cities 4. and gets prone to severe weather 5. and gets prone to congestion 6. and gets prone to heat 7. and gets prone to pollution 8. Gets prone does not have to mean will experience 9. The challenge is to make cities a nice place to live for 60 % of the world population summer, spring, autumn and winter 10. What to expect in The Netherlands?Source: KNMI 11. Rainfall in a changing climate Higher temperature > more water vapour More rainfall and severe weatherObservations during the 20th century: an increase of 20 %Predictions for the 21st century: more extreme rainfall in the summer more rainfall in the winter 12. Extreme rainfall in a metropolis Larger vulnerability modern societyAccurate information needed Better understanding rainfall formationDetailed observations of whats going on in the clouds needed Integrated model-observation warning systems 13. RAINGAIN high resolution rainfall data in citiesXband/Improved Cband radars in 4 Pilots: Rotterdam (NL)Leuven (B) Paris (F)London (UK) 14. Will rainfall radar work in urban area with high rise? What spatial and time resolutions do we need ? Interaction between rainfall and runoff processes ? High resolution data on flood occurrence ? Forecast of heavy rainfall ? Use of social media in collection of rainfall and flood data ? 15. The Opportunity:community-based sensing 16. SHINE project: participitory science How to get home as quickly as possible?potentially useful information resources: rain gauges, radar, tweets about flooded streets, .... 17. Cesar Observatory Groeten uit CabauwDelft University of Technology, KNMI, Wageningen University and ResearchUtrecht University, RIVM, ECN, TNO , European Space Agency 18. Clouds and rainfall Courtesy of Tobias Otto, Yann Dufournet, Christine Unal 19. High resolution rain R= 1 kmobservations File name: R2008-4-15/7-30-0Par Number of blocks: 143R= 30 m Central Frequency: 9.475000 GHz Frequency Sweep: 5.000000 MHz Sweep time: 409.600006 us Transmitted power: 20.000000 W Polarization: Polarimetric 20. Derived rainfall; impact of resolution10 GHz; 30 m5 GHz; 1000 m 21. Rainfall: variability in 1 km 22. Spatial variability in 1 km^230 m 23. Variability: cumulative rainfall 30 m, location 1 30 m, location 2 1000 m, total 24. The future? Pilot in Rotterdam 2012Composite networks:- Small range radars- Large scale radars- Satellites- Forecast models