HR: 11:00h
AN: A42B-03    [Abstracts]
TI: Statistical Characteristics of Atlantic Hurricanes From Time Series Observations
AU: * Andronache, C
EM: andronac@bc.edu
AF: Boston College, Gasson Hall 012 , Chestnut Hill, MA 02467, United States
AU: Phillips, V
EM: vaughanp@hawaii.edu
AF: Department of Meteorology, University of Hawaii at Manoa , Honolulu, HI , United States
AB: In the last decade there has been a series of active seasons for hurricanes, including that of 2005. The recent increase in hurricane frequency and intensity may be linked to the trend of increasing global temperatures. Several studies have shown that the rise in global temperatures is correlated with upward trends in sea surface temperature (SST). Such trends have been documented in all ocean regions where hurricanes are formed. The skill in forecasting the seasonal or inter-annual activity of Atlantic hurricanes (AH) with dynamical models is limited, due to a rapid decay of predictability in such models. Nevertheless, time series of data accumulated over more than 100 years yield some insight into the general dynamical features of AH systems. In particular, nonlinear time-series analysis is becoming a reliable tool for the study of complex dynamics from measurements. We present the AH characteristics by analyzing the statistics of long-term time series, illustrating the inter-annual and decadal variability. Hurricane trajectory data, peak wind speed and the "eye" or minimum pressure all display significant variability over the last century. Power spectrum density (PSD) analysis of time series of annual AH numbers shows periods of ~2-3 years and ~ 5 years. These periods are confirmed by PSDs of the annual SST anomaly, between latitudes of 30 S and 30 N, and of the annual CAR Index (the SST anomaly in the Caribbean region). The analysis presented here suggests that part of AH inter-annual variability can be directly linked to SST variations in the same region. The study underlines the potential role of time-series analysis to complement other statistical and dynamic methods used in the description and forecasting of hurricanes.
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 5445 Meteorology (3346)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly