Method of Calculation of the Convective Seasonal and Yearly Genesis Parameter

Given that the formulation of the Seasonal and Yearly Genesis Parameter (resp. SGP and YGP) of Gray (1968, 1975) is not appropriate for climate change purposes, as indicated in the introduction, Royer et al. (1998) suggested to replace all the thermal contributions by a new thermal potential which can be represented by convective precipitation. This diagnostic is indeed a good integration of the three components of the Gray's YGP thermal potential. It combines the stability of the atmosphere,...

Contributors

Risk Management Solutions, London, UK Zafer Boybeyi College of Science, George Mason University, Fairfax, VA 22030, USA John A.T. Bye The University of Melbourne, Melbourne, Victoria, Australia Wenju Cai CSIRO Marine and Atmospheric Research, Melbourne, Victoria, Australia Fabrice Chauvin GAME CNRM (Meteo-France CNRS), 42 Avenue Coriolis, 31057 Toulouse Cedex 01, France RSMAS University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA NASA Marshall Space Flight Center, Huntsville, AL,...

Contents

Detection and Attribution of Climate Change Effects Kevin Walsh, David Karoly, and Neville Nicholls Electrification in Hurricanes Implications for Water Vapor in the Tropical Tropopause 21 Jasna V. Pittman, Themis G. Chronis, Franklin R. Robertson, and Timothy L. Miller Long-Term Natural Variability of Tropical Cyclones in Australia 35 Statistical Link Between United States Tropical Cyclone James B. Elsner and Thomas H. Jagger Five Year Prediction of the Number of Hurricanes that Stephen...

Model for Daily Tropical Cyclone Intensity

To examine the hurricane-sun relationship in more detail we consider daily data. We first spline interpolate the 6-hr positions and maximum wind speeds to hourly values (Jagger and Elsner 2006) using the U.S. National Hurricane Center besttrack data (Neumann et al. 1999) for all tropical storms and hurricanes over the 63-year period 1944-2006. Tropical cyclones over the Caribbean Sea and near the United States were routinely monitored with aircraft reconnaissance during this time period. We...

Shell and Sand Beach Ridges

Tropical cyclone storm tides and waves can deposit ridges composed of other materials besides coral shingle depending upon the source material availability. Princess Charlotte Bay (PCB) in the northern GBR has a sequence of 12 ridges composed of sand and matrix supported marine shells. Here the sequence spans the past 2,500 years with an average interval between ridge emplacement of 177 years. Near Pormpuraaw on the western side of Cape York Peninsula over 30 ridges have been emplaced over the...

Discussion and Conclusions

Graupel Charge Separation

The potential effects of continental aerosol penetrated into the circulation of TC approaching the land on the cloud structure and the lightning rate in hurricane clouds has been investigated using a 2-D cloud model with spectral bin microphysics and a 3D mesoscale model WRF with bulk microphysics. Numerical experiments with the 2D cloud model with the resolution of 250 m and 125 m in the horizontal and vertical directions, respectively, show that the continental aerosols with the CCN...

Simple Hurricane Model

We now look at the significance of H from another point of view, using a simple cyclostrophic model of a tropical cyclone applied in a region where H < 0. For H locally constant, (6) can be integrated to yield, where u u0 at T T0. Hence if H < 0, u increases as T decreases. This is precisely the situation in a hurricane, which is characterised by a warm core. Conversely in the tropics in regions in which H > 0, there is a tendency for hurricane development to be suppressed. In order to...

Review of Boundary Layer Models

The focus of this review is on BL models for moving tropical cyclones, but studies of stationary TCs that are relevant to what follows are also mentioned. Boundary layer models differ mainly in their treatment of altitude Z and the surface boundary conditions. In one of the earlier studies of moving TCs, Myers and Malkin (1961) used a Lagrangian parcel trajectory approach to study the horizontal winds inside the BL. The authors assume that the frictional drag force is proportional to the square...

Trend in TC Frequency

Although an interannual variation with a period of about 5 years is dominant in the time series of annual number of the model TCs over the North Atlantic (Fig. 7), there is also an upward trend in annual number of the model TCs (Fig. 7a). Since no any trend is found in time series of model Nino3 SST anomaly (Fig. 5), other forcing might induce the change. In the present CGCM, an increase of any anthropogenic forcing is not considered. Therefore, one may consider that the SST change induced...

Preface Of Cyclone

Tropical cyclones are becoming more powerful with the most dramatic increase occurring over the North Atlantic. The increase is correlated with an increase in ocean temperature. A debate concerns the nature of this increase with some researchers attributing it to natural climate fluctuations while other researchers attributing it to anthropogenic increases in forcing from greenhouse gases. A Summit on Hurricanes and Climate Change held May 27-30, 2007 at the Aldemar Knossos Royal Village in...

Non Stationarity of Hurricane Number Time Series

As a method for predicting future hurricane numbers, the long baseline method is only appropriate if the landfalling hurricane number record is stationary, or at least close to stationary. A large number of studies have looked at the stationary of hurricane number records. With respect to hurricane numbers in the basin, it has been clearly shown that the record is not stationary. For instance, Elsner et al. (2001) detected the presence of statistically significant change-points in the cat 3-5...

The Global Community

While the United States has refrained from adhering to the principles of the Kyoto Protocol, other members of the global community have made efforts, some substantial, some nominal regarding the commitment to reduce greenhouse gas emissions. Among the 168 countries that have ratified the Kyoto Protocol are seven of the world's wealthiest and industrialized countries including Canada, France, Germany, Italy, Japan, Russia and the United Kingdom. In contrast, along with the United States,...

Discussion and Summary

An explanation for this geographic difference in the SSN-hurricane intensity relationship centers on the difference in the limiting factors associated with tropical cyclone intensity. As mentioned over the western Atlantic cloud top temperature appears to be the limiting factor, whereas over the eastern and central tropical Atlantic, the limiting factor in the thermodynamic potential for intensity is oceanic heat content. Since there is a direct relationship between SST and MPI, an active sun...

Relationship between ENSO and North Atlantic Tropical Cyclone Frequency Simulated in a Coupled General Circulation Model

Satoshi Iizuka and Tomonori Matsuura Abstract Relationship between El Nino Southern Oscillation (ENSO) and tropical cyclone (TC) frequency over the North Atlantic simulated in a high-resolution (T213) coupled ocean-atmosphere general circulation model is described. The high-resolution model succeeded to simulate TCs with a maximum surface wind speed at 10 m more than 17 m s. In La Nina (El Nino) years, the annual number of model TCs as well as hurricanes in the North Atlantic increases...

References

Holliday, 1977 Tropical cyclone minimum sea level pressure maximum sustained wind relationship for the western North Pacific. Mon. Wea. Rev., 105, 421-427. Barnett, T.P., D.W. Pierce, K.M. AchutaRao, P.J. Gleckler, B.D. Santer, J.M. Gregory, and W.M. Washington, 2005 Penetration of a warming signal in the world's oceans human impacts. Berliner, L.M., C.K. Wikle, and N. Cressie, 2002 Long-lead prediction of Pacific SSTs via Bayesian dynamic modeling. J. Climate, 13,...

The Science and Politics Problem Policymaking Climate Change and Hurricanes

Abstract In February 2007, the Intergovernmental Panel on Climate Change released its Fourth Assessment Report that discussed the progress made in our understanding of the impact of natural and anthropogenic activities involving global warming and climate change. On the basis of this report, policy makers and citizens alike now have a scientific basis upon which to assess the problem of global climate change and should be encouraged to implement appropriate national and international actions in...

Migration of the Tropical Cyclone Zone Throughout the Holocene

Knowles Abstract This paper proposes that a combination of short and long term atmospheric oscillations have resulted in latitudinal movement of the tropical cyclone (TC) zone and location of landfall through the Holocene. A GIS-based approach demonstrates that currently intensity changes of the Bermuda High (BH) result in a large latitudinal spread of TC track and landfall location across the western North Atlantic (NA), while a literature-based examination...

Adaptation Positive and Negative Effects

Since the analysis uses normalized losses that remove the influence of inflation, population and wealth, one can then use scenarios about how these parameters will change in the future to estimate the value of future losses. But this approach cannot take into account other changes, like building norms, protection measures, etc. Only physical models can explicitly take into account how, for example, a change in building norms could reduce hurricane losses. Numerous actions have been undertaken...

From Direct Losses to Indirect Losses

Different actors in climate change risk management process are interested in different types of information. City planners and flood protection designers are mainly interested in landfall probabilities insurers focus on average annual direct losses and probabilities of exceeding a given level of damages. But national and local governments, when they perform cost-benefit analyses to assess the desirability of new infrastructure, cannot consider only direct losses. The communities they represent,...

Background and Motivation

Insurance and reinsurance rates for property on the gulf and east coasts of the United States are strongly influenced by predictions of the possible number and intensity of future hurricanes making landfall in these regions. The insurance industry is interested in such predictions on a wide range of time-scales. In particular, there is interest in predictions of the number of hurricanes in the next one to five years. Such predictions are used for the pricing of insurance and reinsurance...

Response of Tropical Cyclogenesis to Global Warming in an Ipcc Ar4 Scenario

Jean-Francois Royer and Fabrice Chauvin Abstract Since currently very few models can reach the high resolutions necessary for a detailed representation of tropical cyclones, most assessments of their response to climate change in coupled scenarios have to be based on indirect estimates of the hurricane activity potential. A modified Convective Yearly Genesis Potential index (CYGP) proposed by Royer et al. (1998) is applied here to the analysis of TC genesis in 15 coupled general circulation...

Wxs 0U VEC0 [ nf

The complex argument of WX(s,t) can be interpreted as the instantaneous phases of X f 1 , fN at the scale s. We utilize the strength of the instantaneous phase angle difference between two series (X and Y), also known as the mean phase coherence, p(X,Y) (Mokhov and Smirnov, 2006). We are interested in causative relations, so it is appropriate to measure p between the instantaneous phases f and 0 of the two time series We vary the relative phase delay between the two series by lagging f relative...

ENSO and TC Frequency

Figure 7a shows the time series of annual number of the model TCs over the North Atlantic. There is an interannual variation with a period of about 5 years in the time series (Fig. 7b). Although the variation on decadal time scales as in the actual TC frequency observed over the North Atlantic is not found in this model, there is an upward trend in annual number of the model TCs (0.5 decade). This increase will be discussed later. It has been accepted that SST is one of the key environmental...

US Hurricanes

Our interest here is a network of hurricanes affecting the United States. First we take an exploratory look at the data that will be used in creating the network. A chronological list of all hurricanes that have affected the continental United States in the period 1851-2005, updated from Jarrell et al. (1992) is available from the U. S. National Oceanic and Atmospheric Administration (NOAA) at http www.aoml. noaa.gov hrd hurdat ushurrlist.htm. We use the May 2006 version of the data. A...