1. Geog 1900: Extreme Weather and Climate

2. Review of last lecture Atmosphere: A mixture of gas molecules, microscopically small particles of solid and liquid, and falling precipitation Meteorology: The study of the atmosphere and the processes that form weather Weather: The state of the atmosphere at a given time and place Climate: The statistical properties of the atmosphere. (i.e. averages and variability) Weather- and climate-related disasters: tropical cyclones, tornados, floods, droughts, winter storms, extreme heat, extreme cold, lightning, El Nino, global warming Impacts of weather/climate on public health, transportation, agriculture, business, international relationships, history, science, philosophy, education, …

3. Atmospheric Sciences at a Glance (2)

4. The modern climatology (meteorology) was born in the 1940s (a very young science!), but has been growing very fast! Carl-Gustaf Rossby (1898-1957) Generally considered as the “father of modern meteorology”. Founder of the “Chicago School of Meteorology”.

5. Observing the atmosphere: Surface weather stations 1875 (~100) 1975 (>1700)

6. Observing the atmosphere: Surface weather stations Now

7. Observing the atmosphere: Upper-air sounding stations Now (>1000)

8. Observing the atmosphere: Weather Radar First weather radar (NOAA NSSL) Current NEXRAD Doppler radar (NOAA NWS)

9. Observing the atmosphere: Shipborne radar From Mapes and Lin (2005)

10. Observing the atmosphere: Aircraft NOAA P3

11. Video clip: Flying into hurricanes http://www.youtube.com/watch?v=hAy fHqEW3gkhttp://www.youtube.com/watch?v=hAy fHqEW3gk

12. TIROS-1 (1960) World’s first weather satellite Observing the atmosphere: Satellite

13. NASA’s Earth Observation System A-Train Satellites Observing the atmosphere: Satellite

14. Observing the atmosphere: Proxy data (e.g. coral reef, tree ring, lake sediment, ice core) Coral reefTree ring Lake sedimentIce core

15. Climate Modeling on World’s Fastest Supercomputers Japan’s Earth Simulator (World’s #1 in 2004, #20 now) OSC’s new IBM machine among world’s top 100

16. World’s Major Global Climate Models

17. The current status of weather and climate predictions Weather prediction: Generally good within one week, not good beyond 10 days. The skill depends on season and location. Tropical cyclone (hurricane, typhoon) prediction: good in track, but bad in intensity Climate prediction: Seasonal prediction generally good within 6 months, but not good beyond. Skill depends on season. Climate projection: All models project global warming in the 21st century, but with a 3-fold difference in magnitude.

18. Why is it so difficult to understand and predict weather and climate?

19. Summary The modern climatology (meteorology) was born in the 1940s (a very young science!), but has been growing very fast! Now we have a global observational network with many satellites, ships, radars and surface stations, as well as very comprehensive prediction models running on the world ’ s fastest supercomputers. The current status of weather and climate predictions: (1) weather prediction good to 10 days, (2) tropical cyclone prediction good in track but not in intensity, (3) climate prediction good to two seasons, (4) climate change projections have a 3-fold difference in magnitude.