associated with a tropical cyclone (TC). The memory is quantified
through anomalous maximum potential intensity (MPI) evolution for 20 days
prior to the arrival of a TC through 60 days after the TC passage. The
MPI weakens and is not restored to the evolving climatology until weeks
after the TC has departed. Stabilization occurs through warming of the
atmosphere and cooling of the ocean surface on different timescales. The
timescale of MPI stabilization following TC passage is approximately 30-35
days for a tropical storm to 50-60 days for a category 3-5 hurricane, with
significant storm-specific and basin-specific variability. The
atmospheric stabilization begins with TC arrival and continues for
approximately 7-10 days after passage, when the troposphere cools below
normal. The rewarming of SST and the atmosphere to climatology occurs
within approximately 35 days for all intensities, despite a positive
(weakened) MPI anomaly through two months. This suggests that the
atmosphere warms beyond what can be attributable to sensible heating from
the rewarmed SST. The maintenance of a positive MPI anomaly beyond 35
days is thus attributed to a feedback on larger scales that requires
considerable further research.
A TC's passage through a region does not always lead to a weakening of the
MPI. In regions poleward of the sharp SST gradient, the MPI one month
after TC passage is often several millibars stronger than climatology.
There are also mesoscale regions of destabilization one month after TC
passage that may result partially from salinity changes driven by oceanic
mixing as well as changes in precipitation and evaporation.
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