Distorted Pacific–North American teleconnection at the Last Glacial Maximum
<p>The Pacific–North American (PNA) teleconnection is one of the most important climate modes in the present climate condition, and it enables climate variations in the tropical Pacific to exert a significant influence on North America. Here, we show climate simulations in which the PNA teleco...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-01-01
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| Series: | Climate of the Past |
| Online Access: | https://www.clim-past.net/16/199/2020/cp-16-199-2020.pdf |
| Summary: | <p>The Pacific–North American (PNA) teleconnection is one of the most important
climate modes in the present climate condition, and it enables climate
variations in the tropical Pacific to exert a significant influence on North
America. Here, we show climate simulations in which the PNA teleconnection was
largely distorted or broken at the Last Glacial Maximum (LGM). The distorted
PNA is caused by a split in the westerly jet stream, which is ultimately
forced by the large, thick Laurentide ice sheet that was present at the LGM. Changes in
the jet stream greatly alter the extratropical waveguide, distorting wave
propagation from the North Pacific to North America. The distorted PNA
suggests that climate variability in the tropical Pacific, notably El
Niño–Southern Oscillation (ENSO), would have little direct impact on
North American climate at the LGM.</p> |
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| ISSN: | 1814-9324 1814-9332 |