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Titel |
Tropical cyclone genesis potential across palaeoclimates |
VerfasserIn |
J. H. Koh, C. M. Brierley |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 11, no. 10 ; Nr. 11, no. 10 (2015-10-21), S.1433-1451 |
Datensatznummer |
250117440
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Publikation (Nr.) |
copernicus.org/cp-11-1433-2015.pdf |
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Zusammenfassung |
The favourability of the mid-Pliocene, Last Glacial Maximum (LGM) and
mid-Holocene for tropical cyclone formation is investigated in five climate
models. This is measured by a genesis potential index, derived from
large-scale atmospheric properties known to be related to storm formation.
The mid-Pliocene and Last Glacial Maximum (LGM) were periods where carbon dioxide levels
were higher and lower than preindustrial levels respectively, while the
mid-Holocene differed primarily in its orbital configuration. The cumulative
global genesis potential is found to be fairly invariant across the
palaeoclimates in the multi-model mean. Despite this all ensemble members
agree on coherent responses in the spatial patterns of genesis potential
change.
During the mid-Pliocene and LGM, changes in carbon dioxide led to sea
surface temperature changes throughout the tropics, yet the potential
intensity (a measure associated with maximum tropical cyclone strength) is
calculated to be relatively insensitive to these changes. Changes in
tropical cyclone genesis potential during the mid-Holocene are found to be
asymmetric about the Equator: being reduced in the Northern Hemisphere but
enhanced in the Southern Hemisphere. This is clearly driven by the altered
seasonal insolation. Nonetheless, the enhanced seasonality drove localised
changes in genesis potential, by altering the strength of monsoons and
shifting the intertropical convergence zone. Trends in future tropical
cyclone genesis potential are consistent neither between the five models
studied nor with the palaeoclimate results. It is not clear why this should
be the case. |
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