PPRuNe Forums - View Single Post - AA 757 loses 7500ft in turbulence encounter
Old 9th Sep 2014, 13:40
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Ian W
 
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The Accumulated Cyclone Energy (ACE) has dropped globally over the last few years. There have been less hurricanes and less tornadoes. The 'global average temperature' (which is not really a useful metric**) has risen by just over a degree Centigrade since the beginning of manned flight. In the last 17 years there has been no statistically significant atmospheric warming (called the 'Pause' by the IPCC).

What has happened is that over the last few years the jetstreams have become more latitudinal (i.e. more lobes and those lobes extending more equatorward - called the Polar Vortex by the weather men in the USA - see earth :: an animated map of global wind, weather, and ocean conditions) probably because the Hadley convection cells that are driven by the convection in the Intertropical Convergence Zone are less active (lots of discussion and research in that area). The latitudinal jetstreams could mean that associated turbulence with both jetstreams and jetstreaks, is found in areas where it normally would not be expected.





** The average global temperature has been described as being as useful as an average phone number.
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