Locations of Tropical Cyclogenesis and Decay in the South Pacific Over the Period of Satellite Record Cyclone Zoe, December 2002 Minimum Pressure: 890 Hpa

James P. Terry Geography Department National University of Singapore

Gennady Gienko Division of Geography The University of the South Pacific

Locations of tropical cyclogenesis and decay in the South Pacific over the period of satellite record Cyclone Zoe, December 2002 minimum pressure: 890 hPa

Niue hospital Cyclone Heta, January 2004

Lau Islands, Fiji Cyclone Ami, January 2003 Intense rainfall and river flood responses

Ngalimbiu River, Honiara, Solomon Islands Wave damage Santo Island, Vanuatu

Coral reef destruction

1-week post-Cyclone Kina 1993 Ovalau Island Fiji Nukunonu Atoll, Tokelau Cyclone Percy, 2005

Storm surge Beach erosion Beachrock exposure Rampart formation, subsequent migration and island nourishment

Funafuti Atoll Tuvalu Regional Specialized Meteorological Centre, Nadi Equator Cyclogenesis: Often embedded within existing low pressure areas e.g. the South Pacific Convergence Zone Four stages in typical lifespan

Abbreviated life cycle of Cyclone Paula, April 2000 1. Formative stage: 11 April 2. Immature stage: 14 April 3. Mature stage (920 hPa): 15 April 4. Decay stage: 20 April Plotting storm tracks 6-hourly fixes indicate direction and speed

Problems Defining cyclone phase within storm lifespan Bias in defining end of tracks Effects of improved tracking technology Filtering Australian storms Matching FMS and NZMS data 1990s

End of tracks? Cyclone Tracks 1990's Sin 1.009388 - 1.080000 1.080001 - 2.200000 2.200001 - 20.000000 Analysis of cyclogenesis positions and track shapes Cyclone distribution and El Niño effects 5

ENSO 10 influence R2 = 0.471 on start position average season - S) o 15

-30 -20 -10 0 10 20

Cyclogenesis latitude ( latitude Cyclogenesis SOI - wet season average

200

190 E) - season average - season E) o 180 R2 = 0.171

170

Cyclogenesis longitude ( longitude Cyclogenesis 160 5 S) Identifying o 10 spatio-temporal patterns 15

Cyclogenesis Latitude Latitude ( Cyclogenesis NE shift Cyclogenesis 25

72 76 78 79 80 85 86 87 88 91 94 96 97 02 04 06 07 08 9 Position 1970 1971 19 1973 1974197519 1977 19 19 1 1981 1982 1983 1984 19 19 19 19 1989 199019 1992 1993 19 199519 19 1998 1999 20002001 202003 202005 20 20 20 240 SE

E) 220 shift o

200

180

160

140 Cyclogenesis Longitude ( Longitude Cyclogenesis

120