P5.20 Spatial and temporal variability of North Atlantic hurricane tracks (2006

P5.20

Spatial and temporal variability of North Atlantic hurricane tracks

Tingzhuang Yan, Dept. of Marine. Earth and Atmospheric Sciences, NC State University, Raleigh, NC; and L. Xie, L. J. Pietrafesa, and T. R. Karl

Spatial and temporal variability of North Atlantic

hurricane tracks

Abstract

The spatial and temporal variability of North Atlantic

hurricane tracks and its association with the annual

hurricane landfall frequency along the United States East

Coast are studied using Principle Component Analysis (PCA)

of Hurricane Track Density Function (HTDF). Results show

that the North Atlantic HTDF is strongly modulated by,

among other climate factors, the dipole mode (DM) of

tropical Atlantic sea surface temperature (SST) as well as

North Atlantic Oscillation (NAO) and Arctic Oscillation

(AO). Specifically, we found that the first three dominant

EOF modes of HTDF are associated with the overall, the

zonal and the north-south gradients of the Atlantic

hurricane track density, respectively. Tropical Atlantic

SST DM is the only index that significantly correlates

with those EOF modes. ENSO and tropical Atlantic VWS are

negatively correlated with the overall hurricane track

density over the North Atlantic, positively correlated

with the third EOF of HTDF, but have no significant

correlation with the second EOF of North Atlantic HTDF.

The zonal gradient of the HTDF is associated with the

Atlantic SST DM, and extra-tropical processes including

NAO and AO. Since the preferred track patterns in a

hurricane season, together with the overall basin-wide

hurricane activity collectively determine the hurricane

landfall frequency along the U.S. East Coast, results

presented here provide a foundation for the construction

of a statistical model that projects the annual number of

hurricane landfall along the U.S. East Coast.

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Keywords: Tropical cyclone, climate variability, Arctic

Oscillation, North Atlantic Oscillation, El Niño, tropical

Atlantic SST dipole mode, Hurricane Track Density Function