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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
ArcticN. 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
• http://www.youtube.com/watch?v=5rqREjFaRho
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•https://www.youtube.com/watch?v=kYySTtFcQlU
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