TITLE:
Modal Inter-Comparisons between North Atlantic Accumulated Cyclone Energy and the Atlantic Multi-Decadal Oscillation, and the Pathology of the 2013 Hurricane Season
AUTHORS:
Tingzhuang Yan, Shaowu Bao, Leonard J. Pietrafesa, Paul T. Gayes
KEYWORDS:
North Atlantic Hurricanes Season, ACE, AMO, EEMD, IMF, Mode
JOURNAL NAME:
Natural Science,
Vol.6 No.8,
April
28,
2014
ABSTRACT: It is a community wide
belief that the Atlantic Multi-decadal Oscillation (AMO) and the Accumulated
Cyclone Energy (ACE) are strongly positively correlated and in lock-step for
the characterization of a tropical cyclone (TC)—hurricane season; including how
many named TCs will form and how many will become hurricanes and major
hurricanes [1]-[4]. In this paper, we
decompose the AMO and ACE time series into their internal modes of variability
using the Hilbert-Huang Transform REF _Ref386094582 \r \h [5] and the Ensemble Empirical Modal Decomposition (EEMD) REF _Ref386094585 \r \h [6],
and look into the relationships that exist between the individual corresponding
modes of the AMO and the ACE. We then evaluate the degrees of frequency domain
correlations between the internal modes of variability of the AMO and the ACE
across the entire record length time series. The 2013 North Atlantic Hurricane
Season, which had been predicted to be “above normal”, with an ACE estimated to
be between 122 and 138 by the National Oceanic & Atmospheric Administration
(NOAA), turned out to be one of the quietest on record. The actual 2013
observed ACE was only 33 (unit: 104 kn2) or 29% of the 65
year (1948-2012) average of 103 (with a median of 89.5) and is the 5th lowest value since 1950. Following the visual correlations between the ACE and
the AMO in the past, and assuming past is prologue to the future, the “above
normal” forecast of the ACE led to a tropical cyclone community wide forecast
of a highly active 2013 hurricane season. So why the busted 2013 forecast? This
study will address the possible reasons.