No abstract

terror-related casualty risks on the order of 0.5%-a level 2 to 3 orders of magnitude more than those experienced in OR that increased ~100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14 to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2.5% (or 10%) of harm-ranked events in OR (or IS). Extreme values of victim/event rates were approximated fairly well by generalized Pareto models (typically used to fit to data on forest fires, sea levels, earthquakes, etc.). These results were in turn used to forecast maximum ORand IS-specific victims/event rates through 2080, illustrating empirically based methods that could be applied to improve strategies to assess, prevent and manage terror-related risks and consequences.

No abstract

Forecasting destructive hurricane potential is complicated by substantial, unexplained intraannual variation in storm-specific power dissipation index (PDI, or integrated third power of wind speed), and interannual variation in annual accumulated PDI (APDI). A growing controversy concerns the recent hypothesis that the clearly positive trend in North Atlantic Ocean (NAO) sea surface temperature (SST) since 1970 explains increased hurricane intensities over this period, and so implies ominous PDI and APDI growth as global warming continues. To test this "SST hypothesis" and examine its quantitative implications, a combination of statistical and probabilistic methods were applied to National Hurricane Center HURDAT best-track data on NAO hurricanes during 1880-2002, and corresponding National Oceanographic and Atmospheric Administration Extended Reconstruction SST estimates. Notably, hurricane behavior was compared to corresponding hurricane-specific (i.e., spatiotemporally linked) SST; previous similar comparisons considered only SST averaged over large NAO regions. Contrary to the SST hypothesis, SST was found to vary in a monthly pattern inconsistent with that of corresponding PDI, and to be at best weakly associated with PDI or APDI despite strong correlation with corresponding mean latitude (R(2)= 0.55) or with combined mean location and a approximately 90-year periodic trend (R(2)= 0.70). Over the last century, the lower 75% of APDIs appear randomly sampled from a nearly uniform distribution, and the upper 25% of APDIs from a nearly lognormal distribution. From the latter distribution, a baseline (SST-independent) stochastic model was derived predicting that over the next half century, APDI will not likely exceed its maximum value over the last half century by more than a factor of 1.5. This factor increased to 2 using a baseline model modified to assume SST-dependence conditioned on an upper bound of the increasing NAO SST trend observed since 1970. An additional model was developed that predicts PDI statistics conditional on APDI. These PDI and APDI models can be used to estimate upper bounds on indices of hurricane power likely to be realized over the next century, under divergent assumptions regarding SST influence.

It is assumed that the dark energy observed today is frozen as a result of a phase transition involving the source of that energy. Postulating that the dark energy de-coherence which results from this phase transition drives statistical variations in the energy density specifies a class of cosmological models in which the cosmic microwave background (CMB) fluctuation amplitude at last scattering is approximately 10 −5 .PACS numbers: 98.80. Bp, 98.80.Jk, 95.30.Sf In a previous paper (reference [1], equation 14), it has been shown that the fluctuation amplitude of the Cosmic Microwave Background (CMB) can be theoretically estimated to be of the order 10 −5 , in agreement with observational evidence, using a minimal set of assumptions. Although the scale parameter of the cosmological expansion at the time of dark energy de-coherence (as defined in reference [1]) enters the calculation, the final result depends only on the normalized dark energy density Ω Λ , the red shift at last scattering z LS , and the red shift at the time when the energy density of the non-relativistic pressure-less matter observed today was equal to the radiation energy density z eq . The observation that the final result was independent of any specifics at the time of de-coherence suggested to the authors of this paper that *