Understanding catastrophic wind disturbance 21 Concepts

Despite extensive previous work on catastrophic wind disturbance and subsequent ecological effects, there has been no specific definition of wind disturbance. Defining catastrophic wind disturbance is difficult because wind varies within between events in intensity, size and frequency. In this review, we refer to catastrophic wind disturbance as including high wind events, mainly hurricanes, tornados, downbursts, gales and severe windstorms that may result in substantial tree damage or...

Multitemporal analyses

The assessment of a hurricane-impacted forest region and forest damage severity at regional scales has been traditionally based on a ground survey, aerial photography (Gardner et al. 1992), satellite imagery (Kovacs et al. 2001), topographic exposure models (Boose et al. 1994), or simulated by ecological models or storm models. Hurricanes frequently damage and fragment the forested landscape (Boose et al. 1994 Foster and Boose 1992), and Hurricane Katrina was no exception. Large areas of the...

Introduction

Although the forecasts of hurricane track have steadily improved during the past two decades, intensity forecasts remain unsatisfactory (Elsberry, 2005). Previous studies have shown that vortex structures can significantly affect the behavior of hurricane intensity (Ross & Kurihara, 1995 Willoughby & Black, 1996 Xiao et al., 2000). The initialization of hurricane vortex as well as its environment using an advanced data assimilation technique is a key procedure to improve the accuracy of...

Damage extent and severity model

Hurricane damage potential concepts were reviewed by researchers at the Institute for Clean Energy Technology (ICET), the Forest Products Laboratory (FPL) the Geosystems Research Institute (GRI), the Geosciences Department, the Signal Research Center at the University of Southern Mississippi (USM) and the Savannah River National Laboratory (SRNL). Identification of specific measurements used as input variables for modeling damage potential was primarily a collaborative effort among researchers...

Regrowth of surviving trees by sprouting

Regrowth plays an important role in tree recovery from catastrophic wind disturbances, especially in temperate hardwood forests. After damage by intensive winds, a high portion of hardwood trees can regrow from sprouts. Although several researchers have reported differences among species in sprouting ability in both tropical (Walker et al., 1992 Zimmerman et al., 1994 Bellingham et al., 1994) and temperate forests (Perterson & Pickett, 1991 DeCoster, 1996 Busby et al., 2009), this capability...

Jesper Ryden

Discussions on climate change are intense the following quotation, by G.H. Liljequist (1949), is valid also today The recent climatic fluctuation, which seems to embrace the whole earth, has been the object of many discussions and investigations. This is quite natural its consequences have been far-reaching and have come to influence the everyday life of man in many ways. Broadly speaking, one aspect is whether certain events, for instance storms or hurricanes, have been more common recently...

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V V0 (-) cos 3- U0 -) sin 3 + V1 (-)dA eikZ1 (28a) X U cos 3 + V sin 3 + X1 -)dA eikZ1 (28b) Equations for complex amplitudes & i(y) Xi(n) Vi(n) are obtained by linearization of system (26a,b), (27). (OoX - o - ( - k2j(X1V) -2 2 - 2kAe-kn(O v (29a) d2< tl - fc2 X - 2ke-k 0 (29b) We consider solutions to the system (29a,b), (30) decreasing at large distances from the surface, i.e. Boundary conditions at the water surface for the system (29a,b) follow from (20) and (21) expressed in...

Wind speed

Clearly once of the main effects of the arrival of the tail-end of hurricanes and tropical storms is severe winds, both in terms of gusts and sustained winds and this is one of the principal agents of damage associated with these events. Typical maximum recorded wind speeds on land from Western Europe for the events in this survey vary from 70km h gusts all the way up to nearly 200km h gusts with values in excess of 100km h not being uncommon. The highest recorded value of any of the events in...

The hurricane vulnerability index

In order to rank the susceptibility of coastal areas to hurricane damage we calculate a Hurricane Vulnerability Index (HVI) which is a composite of the elements that contribute to hurricane damage. Three elements contribute to the degree to which communities experience hurricane damage (1) the level of exposure, (2) physical susceptibility to the hurricane, and (3) the hurricane's frequency and intensity. Each element is comprised of several indicators that represent characteristics of risk....

References

Agency for Toxic Substances and Disease Registry. (2005a). Hazardous Substances Emergency Events Surveillance Annual Report 2005. U.S. Department of Health and Human Services, Public Health Service, ATSDR, Atlanta. http www.atsdr.cdc.gov HS HSEES annual2005.html. Agency for Toxic Substances and Disease Registry. (2005b). Health Consultation Murphy Oil Spill. U.S. Department of Health and Human Services, Public Health Service, ATSDR, Atlanta. Agency for Toxic Substances and Disease Registry....

A framework for understanding large infrequent catastrophic winds

Before reviewing past work, we briefly provide a conceptual framework for understanding the impact of large, infrequent catastrophic winds on temperate forests. Our proposed framework for understanding large, infrequent catastrophic winds includes the following key elements 1. The catastrophic-wind-induced changes (including changes in community structure, tree mortality, and species diversity) are complex and highly variable. In temperate forests, the most conspicuous changes caused by...

How Vertical Wind Shear Affects Tropical Cyclone Intensity Change An Overview

Over the last 30 years tropical cyclone (TC) intensity forecasts, for various (yet somewhat puzzling) reasons, have not achieved near the level of improvement of the TC track forecast. Although TCs have been studied intensively throughout the twentieth century, the community has surprisingly little quantitative knowledge as to how these storms interact with their environments, particularly with respect to changes in core structure (Frank & Ritchie, 1999). Rogers et al. (2006) stated that the...

Airsea Interaction under Hurricane Wind Conditions

Wind Driven Rain Drag Coefficient

Yuliya Troitskaya, Daniil Sergeev, Alexander Kandaurov and Vasilii Kazakov Institute of Applied Physics Russia One of the main characteristics appearing in the models of forecasting wind over the sea is the roughness of the sea surface determined by the parameters of the wind waves, quantitatively parameterised by the sea surface drag coefficient CD. To define it we introduce the turbulent shear stress or turbulent momentum flux far from the sea surface where p is the air density, u* is the...

Longterm effects on species composition and diversity

Hurricane Composition

A widely accepted view among forest ecologists is that severe hurricanes have relatively minor long-term effects on species composition and diversity in tropical forest regions and coastal temperate regions where hurricanes are common. Many case studies in the tropics, including studies in Puerto Rico, Nicaragua, Jamaica, and Kolombangara, support this general conclusion (but see Vandermeer, 2000). For example, Burslem and others (2000) found that historical hurricanes had only limited effects...

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Same as Fig. 10 but for northward track type from October to January. M < < WWVsNJ -ss f r y M < < WWVsNJ -ss f r y Fig. 13. Same as Fig. 10 but for northward track type from October to January. The wind fields display the corresponding circulation flow and potential effective local weather systems. In this study, the West Pacific Subtropical High of winter-time may be the critical modulator of TC tracks in this region, specifically during post-winter-monsoon period. Moreover,...

Methods of analysis

The simplest and widely known technique to investigate common periodicities between two series of data is the Fourier Transform, the Fast Fourier transform and Regression Analysis. However, while useful for stationary time series, these methods are not the best for time series that are not of stationary nature ((35) (116), (117)), as those analyzed in this work. A nice description of the limitations and drawbacks of Fourier Analysis, (including the short-time-Garbor or the windowed Fourier...

Factors that influence hurricane damage costs

Most damage from hurricanes is caused by high winds and storm surge, which is the water that a hurricane's wind pushes toward shore. A major hurricane, which would be a category 3, 4, or 5 on the Saffir Sampson Hurricane Scale, has winds that exceed 110 miles per hour. A storm surge of up to twenty-eight feet above average sea level was recorded in Mississippi during Katrina (Masters, 2010). If the storm surge is accompanied with high tide, the damage is even greater. Three interacting elements...

The hurricane Ike evacuation

UTMB emergency management officials and executive leadership began tracking hurricane Ike late in the week of September 1st, and participating in the Texas Division of Emergency Management State Operations Center conference calls with the National Weather Service (NWS) on Sunday September 7th. Predicted paths varied from the lower Rio Grande Valley to the Florida panhandle early on, but it was assumed that a Texas landfall was likely. By Tuesday it was felt that the storm track would make...

INTECH open

Free online editions of InTech Books and Journals can be found at www.intechopen.com Part 1 Climatology and Climatological Factors 1 Chapter 1 The Interannual and Interdecadal Variability in Hurricane Activity 3 Chapter 2 Influence of Cosmophysical Phenomena and African Dust on Hurricanes Genesis 41 Jorge Perez-Peraza, Victor Manuel Velasco Herrera and Igor Libin Chapter 4 The Effects of Space Weather on Hurricane Activity 85 Chapter 5 Hurricane Intensity, Sea Surface Temperature, and...

Scales

Catastrophic wind damage and subsequent forest recovery are scale-dependent phenomena and both spatial and temporal scales are important in understanding effects of catastrophic winds. As Levin (1992) pointed out, no single mechanism explains pattern on all scales. Consequently, it is essential to clarify both the spatial and temporal scale over which wind damage and recovery patterns occur and are examined. Windstorms are often distributed over a broad range of spatial scales, and certain...

Coherence analysis of terrestrial and cosmophysical forcings

Data.- To assess the long-term relations between space phenomena and indicators of the global climate it is often necessary to use reconstructions of Galactic Cosmic Rays (CR), solar activity (SS) and climate phenomena. Direct measurements of solar activity based on sunspot numbers exist since 1749, but trustable CR data is only available since the 1950s decade when the neutron Monitor Stations began to operate. Records of climatic phenomena exist from the end of the 19th century. For the AMO...

Bogus data assimilation

To better define the vortex structure in hurricane initial conditions, a bogus data assimilation (BDA) scheme is developed in the WRF-Var. The BDA algorithm includes a) bogus vortex construction and error specification, and b) assimilation of the bogus data with the WRF-Var system. In our studies (Xiao et al., 2006 2009b Zhang et al., 2007), the bogus vortex is constructed according to the method of Ueno (1989 1995). There are two components (symmetric and asymmetric) in the bogus observations....

Atlantic hurricanes

Hurricanes are considered one of the most astonishing meteorological phenomena in our planet. Strong winds, clouds of great size and intense storms unite to advance for the ocean and to reach mainland, razing with everything to their passage, fallen trees, damages in buildings, changes in the natural landscape and, fatal victims, are alone some of the consequences that these unpredictable events can generate. Due to the great intensity that they reach, with winds that can overcome the 350 km...

SAR images segmentation based on undecimated wavelet transform and mean shift

Synthetic Aperture Radar (SAR) has been a useful tool in domains such as disaster detection, cartography and crop monitoring. The images usually have inferior illumination quality mainly due to different type of environmental distributions. So the segmentation of different land covered regions is an important but difficult step in SAR image processing. It is also significant to understand how information changes over different scales of SAR image. Undecimated wavelet transform is good in...

WDM6 MAR 72 h

Fields of maximum snow and graupel contents in the WDM6 simulations at t 72 h. Fig. 19. Fields of maximum snow and graupel contents in the WDM6 simulations at t 72 h. Results obtained using the first simulations of landfalling hurricanes and developing tropical depressions using spectral bin microphysics are quite encouraging. The utilization of SBM based on solving microphysical equations showed significant potential for both further investigation of physical processes in tropical...