Latitudinal Variation of the Lifetime Maximum Intensity Location of Atlantic Tropical Cyclones Controlled by the Atlantic Multidecadal Oscillation

초록

The latitude of lifetime maximum intensity (LMI) location (phi(LMI)) of Atlantic tropical cyclones (TCs) is related to the Atlantic Multidecadal Oscillation (AMO) with a significant negative correlation for 1948-2018. We objectively classify TC tracks into four patterns, to evaluate the effects of variations in dominant track patterns (track phi(LMI)) and intra-pattern phi(LMI) (pure phi(LMI)) on the total phi(LMI) variation. During the warm phases of AMO, the prevailed south-origin track patterns and equatorward pure phi(LMI) shifts have almost equally contributed to the equatorward migration of the total phi(LMI). The negative anomaly of potential intensity in the subtropics is responsible for the equatorward shift of pure phi(LMI). Moreover, weak vertical wind shear in the tropics increases the south-origin track patterns. These environmental conditions are associated with the east-strong and west-weak relative sea surface temperature warming during the warm phases that causes anomalous upward and downward motions in the eastern and western Atlantic, respectively.

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