Global Warming and Climate Change

Over the years, the environmental policy domain has become diversified into a variety of issues demanding attention. As Michael Kraft (2001 15) has suggested, we are now facing a third generation'' of environmental problems that are quite distinct from earlier concerns about first generation issues involving air and water pollution and second generation issues dealing with toxic chemicals and hazardous wastes. As Kraft (2001 15) explains, third generation policy problems including global...

New Index for Tropical Cyclone Development from Sea Surface Temperature and Evaporation Fields

Bye, Wenju Cai, and Tim Cowan Abstract In this study, we present a new index (called the H-index) which is the spatial mean gradient of the logarithm of the surface wind speed with respect to sea surface temperature (SST), and can be easily computed from large scale fields of evaporation and SST Two independent physically based arguments indicate that tropical cyclones would tend to be spun-up in regions of negative H of large magnitude (< 1). In these regions which only occur in...

Improving Initial Condition Adaptive Data Assimilation

Numerical forecasts of chaotic systems like the atmosphere are limited by the use of imperfect initial conditions. Lorenz (1965) pointed out that any minor discrepancies, between either the natural system and its model or the actual and the analyzed state of the system at the initial time of a forecast, will lead to a loss of predictability within a finite time period. The size of these discrepancies will, in general, determine the time period for which useful forecasts can be made. Improving...

Adaptation to Reduce Indirect Losses

Adaptation options able to reduce direct losses were discussed in Section 4.2. But different adaptation options may be able to reduce indirect losses, independently of direct losses. As explained in Section 5.1, indirect losses arise mainly from propagation between sectors and from production losses during the reconstruction. Measures can be implemented to limit these two sources of indirect losses. First, a resilient economic, i.e. an economy able to cope with a disaster in an efficient...

Boundary Layer Model for Moving Tropical Cyclones

Andreas Langousis, Daniele Veneziano, and Shuyi Chen Abstract We propose a simple theoretical model for the boundary layer (BL) of moving tropical cyclones (TCs). The model estimates the horizontal and vertical wind velocity fields from a few TC characteristics the maximum tangential wind speed Vmax, the radius of maximum winds Rmax, and Holland's B parameter away from the surface boundary where gradient balance is approximately valid, in addition to the storm translation velocity Vt, the...

Conclusions

We developed a simple theoretical model for the boundary layer (BL) of translating tropical cyclones (TCs). The model estimates the tangential, radial and vertical wind fields from a given radial profile of the tangential wind speed under geostrophic conditions (e.g. Holland's profile in Eq. (1)) and surface stress boundary conditions. The model is based on Smith's (1968) formulation, which is corrected for the general case of a stress surface boundary (see Proposed Model) and modified to...

Theoretical Interpretation of the Global Fields

The interpretation of these observations can be made using the classical aerodynamic bulk relationship, which for the evaporative mass flux (Bye 1996), is, where F pE, in which p and pa are respectively the densities of freshwater and air, KE is the drag coefficient for water vapour, qs qs(T) is the saturated specific humidity at the sea surface where T is the sea surface temperature (SST), rs qi0 qs is the 10 m relative humidity with respect to T (which reduces to the relative humidity at 10 m...

Global Warming Climate Change and Hurricanes

The hurricane season for the Atlantic region begins on June 1 and ends on November 30. Since these ''intense tropical storms'' require warm ocean temperatures, the ''more heat available in the surface water, the more potential there is to generate heavy rain and high wind'' (Pew Center on Global Climate Change 2007). Notwithstanding natural factors that influence the development of hurricanes, the question has been raised whether and to what extent anthropogenic activities have played a role in...

Numerical Modeling of Tropical Storms

Over the past four decades, numerical modeling of the atmosphere has also undergone a steady progression from 2D simulations to high fidelity 3D real time simulations. NWP models use predictive equations to describe the model variables (i.e., they are prognostic). In other words, NWP models are described by appropriate differential equations, which represent the time-variability of the state and dynamical variables. The model variables are quantities that are conserved under spatial motion....

Aerosol Effects on TC Approaching the Land Design of Numerical Simulations

A two nested grid WRF model was used to simulate landfall of hurricane Katrina. The resolution of the finest and the outer grid was 3 km and 9 km, respectively. A modified version of the bulk-parameterization by Thompson et al. (2006) was applied. The WRF lateral boundary conditions were updated every six hours using Global Forecast System Reanalysis data. The Gulf of Mexico's surface water temperatures were initialized at 28 August 12 Z, and were not updated during the experiments described...

Long Term BHTC

Sedimentary evidence indicates that the control the BH currently exerts over TCs operates over longer scales as well. Liu and Fearn (2000) have identified a period of hyperactivity on the northern Gulf coast (Louisiana-Florida), for the period 3400-1000 14C yr BP., with periods of reduced activity before and after. They suggest millennial-scale positional movement of the BH as the proximate cause of this oscillation in frequency of landfall, with positions to the southwest funneling storms into...

References

Artaxo, A.A. Costa. G.P. Frank, K.M. Longlo, and M.A.F. SilvaDias (2004) Smoking rain clouds over the Amazon. Science, 303, 1337-1342. Black R.A. and Hallett J (1999). Electrification of the hurricane, J. Atmos. Sci, 56, 2004-2028. Cecil D.J., E.J. Zipser, and S.W. Nebitt (2002a) Reflectivity, ice scattering, and lightning characteristics of hurricane eyewalls and rainbands. Part 1 Quantitative description. Mon Wea. Rev. 130, 769-784. Cecil D.J., E.J. Zipser, and...

Info

B 900fiPa-600hPc Thermal Wind (m) Fig. 7b As Fig. 6a, but for the most intense cyclone in PROMES SCEN simulation PRUDENCE simulations shows an average SST increase of 3.1 C (Somot et al., 2007) for the same emissions scenario, which is about half a degree less than the SST increase of HadCM3 model. The GCMs can also differ in the frequency and duration of blocking episodes, which would modify the environment for the development of tropical cyclones. The observed SSTs (Smith et al., 1996) used...

Conclusion

The global community is being confronted with new challenges of global change that involve both the scientific and political communities. As John Dutton (1994 78-79) persuasively argues, the challenge facing the scientific community involves the task of understanding a complex and fascinating system and the responsibility of providing a reliable basis for policy decisions concerning possible modification of human activities in order to mitigate or adapt to global change.'' In the political...

A3408 A8408

Here, N(i, n) denotes n neighborhoods of grid point i,Vj850 is a relative vorticity 1 s at the pressure level of 850 hPa at grid point j. H 000 is height field m at the pressure level of 1000 hPa at grid point l. wj is velocity m s at the pressure level j hPa at grid point k. Ajn aj 1 XjeN( ' n) aj stands for air temperature anomalies k from average of n neighborhoods of grid point i at the pressure level of j hPa , where aj is air temperature k at the pressure level of j hPa at grid point i....

Queesnland Coral Rubble Ridges

Coral rubble shingle ridges occur in locations where coral reefs occur close to shore. Most of the paleorecords derived from these ridges comes from sites along the Great Barrier Reef region offshore from Queensland's east coast. Coral rubble ridges also occur on the Abrolhos Islands off the southwest Western Australian coast but to date no detailed work has been published from this site. The ridges are formed when coral fragments are eroded from near-shore reefs by wave action during a tempest...

Improving Model Grid Resolution Solution Adaptive Modeling Technique

Even, given the improved model initial condition, predictions of hurricanes can not be improved without accurately resolving the fine scale structure of the eye (cloud scale) and the steering large-scale environment (synoptic scale). Numerical models of the atmosphere are derived fundamentally from the Taylor series approximation which relates the value of a continuous function f(x) to the known values of the function and its derivatives at a set of discrete points, x . f (x) f (xi) + (x - xf +...

Energy Exchange Processes for the Ocean Mixed Layer

Of great importance in tropical cyclone dynamics is the ocean mixed layer, which provides the energy required for development. The basic processes which maintain the mixed layer are (a) surface solar heating, (b) heat loss from the surface by evaporation and other processes, and (c) stirring by turbulence which entrains water from below which is then homogenized by vertical mixing. (a) decreases the potential energy (PE) of the mixed layer, and (b) and (c) increase the PE. Over the time scale...

Introduction and Motivation

Estimating the economic consequences of climate change is a tricky task for various reasons. The first one is that climate and weather influence, more or less, almost all human activities from leisure to industrial production. Assessing this influence is made difficult by the multiplicity of these human activities. But even when considering only a few activities, the task remains problematic. Indeed, uncertainties are large in all components of the analysis. The future economy that will be...

Aerosol Effects on Lightning and Intensity of Landfalling Hurricanes

Abstract Intense and persistent lightning in landfalling hurricanes takes place within the 250-300 km-radius ring around the hurricane center. At the same time the lightning activity in the eye wall takes place only during comparatively short periods of tropical cyclone (TC) intensification related to the replacement of old eyewall by the new one. As soon as the hurricane weakens, the lightning in the eye wall disappears. The mechanisms responsible for most of the phenomena are unknown. In this...

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,...

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...

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...