Ig. Watterson et al., SEASONAL AND INTERANNUAL VARIABILITY OF TROPICAL CYCLOGENESIS - DIAGNOSTICS FROM LARGE-SCALE FIELDS, Journal of climate, 8(12), 1995, pp. 3052-3066
Gray's seasonal genesis parameter (SGP) is reassessed as a diagnostic
quantity for both climatological and single-season tropical cyclogenes
is. The SGP applied to global analyses from recent years is able to lo
cate the regions of genesis activity during 1967-86. The SGP based on
the climatology of a simulation by the CSIRO9 atmospheric model using
prescribed ocean temperatures for 1979-88 has similar skill. The SGP a
pplied to single-season means is then assessed as a diagnostic for int
erannual variation of cyclogenesis. Increased cyclo-genesis in the cen
tral Pacific during the 1982/83 El Nino coincides with increased SGP.
CSIRO9 simulated similar variations in the SGP. Moderate correlations
are found between the time series of the observed and inferred simulat
ed cyclogenesis numbers in the central Pacific, eastern North Pacific,
and North Atlantic regions during 1979-88. However, elsewhere the cor
relations were poor.