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Similar a Js arctic amplification and the jet stream
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Js arctic amplification and the jet stream
- 1. Connecting the Arctic to your backyard Polar amplification and the jet stream
- 2. New England Climate Here’s the plan.
- 3. 2000-2009 anomaly w/r/t 1951-1980 mean NASA's Goddard Space Flight Center Polar Amplification. The What.
- 4. Polar Amplification. The Why.
- 5. Polar Amplification. The Why. 1979-2000 median extent
- 6. Polar Amplification. The Why.
- 7. Polar Amplification. The Future. http://nca2014.globalchange.gov/report/our-changing-climate/melting-ice
- 8. Polar Amplification. The Future.
- 9. New England Climate Here’s the plan.
- 10. The Jet Stream. Simplified.
- 15. NASA's Goddard Space Flight Center The Jet Stream in reality
- 16. The Jet Stream & Arctic Amplification.
- 17. The Jet Stream & Arctic Amplification.
- 18. The Jet Stream & Arctic Amplification.
- 19. The Jet Stream & Arctic Amplification.
- 20. The Jet Stream & Arctic Amplification.
- 21. source: National Climate Assessment 2014 data set: Global Historical Climatology Network - Daily It’s already raining more.
- 22. Rawlins, GRL, 2012 Future – warmer winters.
- 23. Rawlins, GRL, 2012 Future – wetter winters.
- 24. In summary. 1. Loss of Arctic sea ice and snow cover 2. Decrease in Equator to Pole temperature gradient 3. More N-S movement in JS 4. Warmer, wetter winters 5. More extreme and longer lasting events
- 25. Connecting the Arctic to your backyard Polar amplification and the jet stream
Notas del editor
- Goal is to make the stuff we’ve been talking about all week, and the work we’ve been doing on Lake E, real in a local sense. The past is the key to the future. How does what is happening today in the Arctic affect MA and New England and what does that mean for the future?
- First we’ll go over arctic amplification, what it is, what we think is causing it. Then I’ll introduce the Jet Stream, what it is and what causes it and variations in it. And then we’ll look at the whole system under current and future Arctic amplifications.
- The Arctic is warming nearly twice as fast as the rest of the planet
- Drastic and unforeseen decreases in sea ice. Plot doesn’t show 2012 which was the new minimum with less than 4 million sq kilometers.
- Sea ice minimum for Sept 2011 Albedo and positive feedback. 50% of the area that was covered with bright reflective ice and snow at this time of year is now dark heat absorbing water. And this heat is reemitted into the Arctic.
- Similar thing happening with snow cover. With dark ground replacing snow.
- We are consistently worse than the worst case scenario and may be ice free in 35 years
- Polar amplification is a robust feature of the Earth’s climate system and may lead to 8C temp increase in the Arctic effectively decreasing the temperature gradient between the EQ, where most of the heat comes into the system, and the poles, where most of it leaves.
- So that’s Arctic amplification. Now what about the Jet Stream.
- Simplified cartoon showing migration of the JS between seasons. Winds and storms move W to E, but there is also a n to S component to the flow because of planetary waves, called Rossby Waves, set up by the atmospheric dynamics involved with moving fluids on a rotating sphere.
- Simple 2 cell system on a non-rotating sphere leads to heat migrating toward the poles in a straight line
- More realistic 4 cell system on a rotating sphere leads to easterlies (like the trade winds) and westerlies (like those that dominate our weather). Where warm air from the subtropics (subtropical HIGH) meets cold air from the Arctic (subpolar LOW) a large pressure gradient can exist leading to very strong westerly winds due to the pressure gradient force and the Coriolis Effect.
- This is the Jet Stream and it itself generally migrates from W to E along Rossy Waves discussed earlier.
- Look for E – W and N – S components of both winds and the JS itself. Note how sometimes it’s more E-W and at others more N-S. Very dynamic system that is impacted by things we’re not covering today. But the basic story is there.
- So what does Arctic amplification do to the JS?