Geog 1900: ExtremeWeather and Climate

Review of last lecture 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.

Overview III: Why is it so difficult to predict weather and climate?

Problem I: Different parts of the world are strongly connected to each other (The “Teleconnection Problem”) Global atmospheric flow

Satellite image: Flow of water vapor in the atmosphere

Example 1: Global impacts of El Nino

The “Pineapple Express” connecting Hawaii and California

Example 2: Global impacts of the mini El Nino (Madden-Julian Oscillation)

Factors affecting US weather and climate El NinoMadden-Julian Oscillation Amazon Arctic N. Atlantic Atlantic/ Sahel

Any location is affected by all the other locations, and in turn is affecting all the other locations

Problem II: Different components of the earth system (atmosphere, land, ocean, ice, clouds, etc) are strongly interacting with each other (The “Feedback Problem”)

Example: Melting of Arctic sea ice

Video: Ice Albedo feedback

Problem III: The global climate models divide the earth into many small pixels (called grids), but the earth system composes of both very big objects (such as the whole Pacific Ocean) and very small objects (such as the cloud droplets), making it very difficult to draw them on the same page (The “Subgrid-Scale Problem”)

The limitation of concept/theory/model: Only approximation of real world Concepts cut reality into smaller pieces

Some Great Weather/Climate Scientists

Prof. Lonnie Thompson – OSU Father of Tropical Glaciology Spent an enormous amount of time above 5500 m Discovered solid record for Earth’s climate history Grown up in West Virginia Did three part-time jobs in high school to make a living Worked for many years with low salary Went back to the Himalayas after heart transplant

Prof. Robert Cess SUNY at Stony Brook World’s leading expert on climate change and Earth’s energy budget Organized the first international team for supercomputer prediction of global climate change, and many NASA and DOE projects Was not even an AMS Fellow when received the Charney Award Finished his Ph.D. in 3 years while doing a full-time job and taking care of his first child Hobby: Collectible cars

The young generation Video: Prof Dargan Frierson and Elizabeth Maroon sing The World of Daisies (lyrics by Prof Mike Wallace) in ATM S 111: Global Warming TtFcQlUhttps:// TtFcQlU

Summary The main reasons of the difficulties in weather and climate predictions: (1) Teleconnection problem, (2) Feedback problem, and (3) Subgrid-scale problem Some great weather/climate scientists