Severe Hurricanes Research Articles

For neurologists in Cuba, hope is not embargoed

For neurologists in Cuba, hope is not embargoed

MOSAICS OF MAYA LIVELIHOODS: READJUSTING TO GLOBAL AND LOCAL FOOD CRISES

The particularities of how residents in Southern Belize encounter the vagaries of what is commonly referred to as a “global food crisis” (between 2006 and 2008) are explored in this paper. Belize, like many other nation states around the globe, has been structurally (and sequentially) “readjusted” by transnational lending institutions over the last several decades. Cyclical shifts in agricultural practices have taken place in many Maya communities in Southern Belize in the last decade, partly in response to migration, a severe hurricane, land tenure conflicts, and within the last year, skyrocketing staple prices and food scarcity. The costs of basic staples such as corn, wheat, and rice have nearly doubled, in parallel with much of the rest of the globe during the same time frame. Shifts in subsistence strategies have significant implications for the power and politics of land use, access, and mobility. Furthermore, they reflect centuries‐old ways of adjusting to changing circumstances in global markets and colonial and postcolonial realities. I conclude by emphasizing the importance of incorporating political and historical ecologies of land use and food production when considering the local impacts of global food crises.

Radiocarbon deficiencies of US Gulf Coast lakes compromise paleo-hurricane records

Radiocarbon assays of sediments from Lake Shelby, US Gulf Coast, exhibit substantial 14C deficiencies of 9.3% and 4.7% for the limnic sapropel and associated fresh-water clams Rangia cuneata, respectively. Measured radiocarbon dates from the sapropel and clams require corrections of 785 ± 80 and 365 ± 90 14C yr (1 σ), respectively, in order to achieve consistency with the radiocarbon time scale. Lake sediments of the US Gulf Coast serve as unique repositories of pre-historic hurricane strikes. Previously unrecognized radiocarbon deficiencies likely render compromised chronologies of the paleo-hurricane records, and erroneous estimates of return period and landfall probability that are derived from the storm chronologies. The recalculated severe hurricane chronologies suggest that the annual landfall probabilities of the last millennium on the US Gulf Coast are equal to, or higher than, the preceding three millennia.

The Perfect Storm: Hurricanes, Insurance, and Regulation

AbstractThe intense hurricane seasons of 2004 and 2005 caused considerable instability in property insurance markets in coastal states with the greatest problems occurring in Florida and the Southeast. Insurers have substantially raised rates and decreased their exposures. While no severe hurricanes struck the United States in 2006 and 2007, market pressures remain strong given the high risk still facing coastal states. These developments generate considerable concern and controversy among various stakeholder groups. Government responses have varied. In Florida, political pressures prompted a wave of legislation and regulations to expand government underwriting and subsidization of hurricane risk and constrain insurers' rates and market adjustments. Other states' actions seem more moderate. In this context, it is important to understand how property insurance markets have been changing and governments have been responding to increased catastrophe risk. This article examines important market developments and evaluates associated government policies. We comment on how regulation is affecting the equilibration of insurance markets and offer opinions on policies that are helpful and harmful.

Assessment of Forest Fuel Loadings in Puerto Rico and the US Virgin Islands

Quantification of the downed woody materials that comprise forest fuels has gained importance in Caribbean forest ecosystems due to the increasing incidence and severity of wildfires on island ecosystems. Because large-scale assessments of forest fuels have rarely been conducted for these ecosystems, forest fuels were assessed at 121 US Department of Agriculture forest service inventory plots on Puerto Rico, Vieques, and the US Virgin Islands. Results indicated that fuel loadings averaged 24.05 Mg ha(-1) in 2004-2006. Forest litter decreased from wetter to drier forest life zones. These island forests showed a paucity of coarse woody fuels (CWD) (2.91 Mg ha(-1)) and relatively greater quantities of smaller-sized fine woody fuels (FWD) (10.18 Mg ha(-1) for FWD and 10.82 Mg ha(-1) for duff/litter) when compared to continental tropical forests. Between 2001 and 2006, CWD fuel loads decreased, while fine fuels and litter increased, such that total fuel loads remained constant on a subset of plots on Puerto Rico. This trend indicates that continued decomposition of CWD deposited by the last severe hurricane is balanced by increasing inputs of FWD from recovering and maturing secondary forests. Forest disturbance cycles and successional development must be taken into account by agencies charged with fire protection and risk assessment.

Landscape-level variation in forest response to hurricane disturbance across a storm track

Hurricane wind speeds at a given site are related to the intensity of the storm and the distance and direction from the storm center. As a result, forest damage is expected to vary predictably with respect to location relative to the storm track. To determine whether patterns of forest response along the track of a major hurricane in coastal New England were consistent with the expected patterns of wind damage, we investigated tree growth responses to the storm in several study sites that are similar with respect to site conditions, vegetation, and disturbance history. Growth responses to a severe hurricane in 1944 varied predictably among study sites with respect to distance from the storm track. Sites closest to the storm track experienced lesser wind damage and exhibited minimal growth responses, whereas sites farther east of the storm track and closer to the area of maximum estimated wind speed were characterized by greater wind damage and growth changes. Variation in estimated wind speed among our study sites (5–10 m/s) is not much greater than anticipated increases in hurricane intensity predicted under future climate scenarios (3–7 m/s). Thus, our results suggest that the magnitude of anticipated increases in wind speeds associated with Atlantic hurricanes may be sufficient to cause changes in forest response.

Temporal Variation in Adult Survival Rates of Roseate Terns During Periods of Increasing and Declining Populations

Abstract We used 19 years of mark-recapture/resighting data collected on 11,020 birds from 1988-2006 at five colony sites in Massachusetts, New York, and Connecticut, USA, to examine temporal variation in the survival rates of adult Roseate Terns (Sterna dougallii) during periods of overall population increase (1988-2000) and decline (2000-2006). Roseate Terns nested at only one colony site in Buzzards Bay, Massachusetts at the start of this period, but two more sites in this area were recolonized as the study progressed. Adult survival rates varied temporally in different ways at the different colony sites, but for the five sites combined they did not differ between the period of overall population increase (0.835 ± 0.006 SE) and the period of population decline (0.835 ± 0.008 SE). As expected based on previous work, adult survival from 1991 to 1992 was lowered as a result of a severe hurricane in August 1991. An oil spill in Buzzards Bay in April 2003 did not appear to result in lower survival of the bi...

Exposure to Hurricane Katrina, Post-traumatic Stress Disorder and Birth Outcomes

Little is known about the effects of natural disasters on pregnancy outcomes. We studied mental health and birth outcomes among women exposed to Hurricane Katrina. We collected data prospectively from a cohort of 301 women from New Orleans and Baton Rouge. Pregnant women were interviewed during pregnancy about their experiences during the hurricane, and whether they had experienced symptoms of post-traumatic stress disorder (PTSD) and/or depression. High hurricane exposure was defined as having 3 or more of the 8 severe hurricane experiences, such as feeling that one's life was in danger, walking through floodwaters, or having a loved one die. The frequency of low birth weight was higher in women with high hurricane exposure (14.0%) than women without high hurricane exposure (4.7%), with an adjusted odds ratio (aOR): 3.3; 95% confidence interval (CI): 1.13-9.89; P < 0.01. The frequency of preterm birth was higher in women with high hurricane exposure (14.0%) than women without high hurricane exposure (6.3%), with aOR: 2.3; 95% CI: 0.82-6.38; P > 0.05. There were no significant differences in the frequency of low birth weight or preterm birth between women with PTSD or depression and women without PTSD or depression (P > 0.05). Women who had high hurricane exposure were at an increased risk of having low birth weight infants. Rather than a general exposure to disaster, exposure to specific severe disaster events and the intensity of the disaster experience may be better predictors of poor pregnancy outcomes. To prevent poor pregnancy outcomes during and after disasters, future disaster preparedness may need to include the planning of earlier evacuation of pregnant women to minimize their exposure to severe disaster events.

Characteristics of severe Atlantic hurricanes in the United States: 1949–2006

Property insurance data available for 1949–2006 were assessed to get definitive measures of hurricane losses in the U.S. Catastrophes, events causing >$1 million in losses, were most frequent in the Southeast and South climate regions. Losses in these two regions totaled $127 billion, 85% of the nation’s total losses. During the period 1949–2006 there were 79 hurricane catastrophes, causing $150.6 billion in losses and averaging $2.6 billion per year. All aspects of these hurricanes showed increases in post-1990 years. Sizes of loss areas averaged one state in 1949–1967, but grew to 3 states during 1990–2006. Seven of the ten most damaging hurricanes came in 2004 (4) and 2005 (3). The number of hurricanes also peaked during 1984–2006, increasing from an annual average of 1.2 during 1949–1983 to 2.1 per year. Losses were $49.3 billion in 1991–2006, 32% of the 58-year total. Various reasons have been offered for such recent increases in hurricane losses including more hurricanes, more intense tropical storms, increased societal vulnerability in storm-prone areas, and a change in climate due to global warming, although this is debatable.

Tax-Deductible Pre-Event Catastrophe Loss Reserves: The Case of Florida

After Hurricane Andrew the U.S. Congress entertained proposals to allow insurers to employ tax-deferred loss reserves. Interest was strong at first, but as the events receded interest waned. However, after the most recent severe hurricane seasons the proposals are again being discussed. In this paper we examine the institution of catastrophe loss reserves in a stylized model of insurance provisions. First, we find that the benefits of the tax-deferred loss reserves depend on the actuarial assumptions regarding the expected loss distribution. Second, we make the first attempt at estimating the change in consumer behavior and the social welfare implications for permitting tax deferred loss reserves. In sum, we find under specific circumstances there are large welfare gains for allowing the tax deferral of reserves.

Tax-Deductible Pre-Event Catastrophe Loss Reserves: The Case of Florida

After Hurricane Andrew the U.S. Congress entertained proposals to allow insurers to employ tax-deferred loss reserves. Interest was strong at first, but as the events receded interest waned. However, after the most recent severe hurricane seasons the proposals are again being discussed. In this paper we examine the institution of catastrophe loss reserves in a stylized model of insurance provisions. First, we find that the benefits of the tax-deferred loss reserves depend on the actuarial assumptions regarding the expected loss distribution. Second, we make the first attempt at estimating the change in consumer behavior and the social welfare implications for permitting tax deferred loss reserves. In sum, we find under specific circumstances there are large welfare gains for allowing the tax deferral of reserves.

Numerical prediction of MODUs drift during Hurricane Katrina

Severe hurricanes, such as Katrina, broke the mooring lines of a number of mobile offshore drilling units (MODU) deployed in the Gulf of Mexico and some of those MODUs went adrift. A drifting MODU may damage other critical elements of the offshore oil and gas infrastructure by colliding with floating or fixed production systems and transportation hubs, or by rupturing pipelines owing to their dragging anchors over the seabed. To avoid or mitigate the damage caused by a drifting MODU, it is desirable to understand the mechanics of the drift of a MODU under the impact of severe wind, wave and current and have the capability of predicting the trajectory of the drift. To explore the feasibility and accuracy of predicting the trajectory of a drifting MODU based on hindcast met-ocean conditions and limited knowledge of the condition of the drifting MODU, this study employed a simplified equation describing only the horizontal (surge, sway and yaw) motions of a MODU under the impact of steady wind, current and wave forces. The simplified hydrodynamic model neglects the first- and second-order oscillatory wave forces, unsteady wind forces (owing to wind gustiness), wave drift damping, and the effects of the body oscillation on the steady wind and current forces. It was assumed that the net effects of the oscillatory forces on the steady motion are insignificant. To verify the accuracy and feasibility of our simplified approach, the predicted drifting trajectories of two MODUs were compared with the corresponding measurements recorded by the global positioning system (GPS).

Multiple and interacting disturbances lead to Fagus grandifolia dominance in coastal New England

Recent studies have emphasized the importance of multiple and interacting disturbances in controlling plant community dynamics. However, detailed information on disturbance history and changes in species abundance are unavailable for many forest ecosystems. As a result, it is often difficult to evaluate the influence of disturbance interactions on changes in species composition over time. This study examines the history and dynamics of Fagus grandifolia-dominated forests in coastal New England to evaluate the role of multiple disturbances in the development of Fagus dominance. Detailed historical and dendroecological data were used to reconstruct disturbance history and compositional trends for the past > 300 years. At the time of European settlement, the study area supported mixed forests of Quercus, Fagus, Carya, and Pinus. Intensive harvesting in the early 19th century resulted in abundant Quercus alba, Q. velutina, and Fagus regeneration. Thereafter, harvesting and fire were limited, but repeated low-moderate intensity hurricanes allowed Fagus but not Quercus species to establish and persist in the forest understory. A severe hurricane in 1944, accompanied by intense herbivory from a high deer population, accelerated the development of Fagus dominance by releasing Fagus saplings, initiating Fagus establishment, and preventing Quercus establishment. The extreme shade tolerance of Fagus, in combination with its flexible regeneration strategy (i.e., the ability to regenerate from seed or from root sprouts), and low palatability to deer, contributed to the increase in abundance of Fagus in response to this complex disturbance history. Thus, long-term changes in forest composition and reduced species richness resulted from species-specific responses to multiple, interacting disturbances.

A late Holocene palaeoenvironmental record from Altona Bay, St. Croix, US Virgin Islands

Geografisk Tidsskrift, Danish Journal of Geography 108(2):59–70, 2008 A reconstruction of the palaeoenvironmental development of Altona Bay, St. Croix, northeastern Caribbean, has been made based on the sedimentological, geochemical and pollen analyses of a 1.83 m long vibracore. For chronological control, AMS 14C measurements were made at 5 levels downcore. The sedimentary sequence covers the last c. 4,700 years, containing both (mangrove) peat and fine-grained clastic sediment units. Comparison with regional Holocene sea level data demonstrates a gradual marine flooding of a mangrove environment around 3,500 cal BP was presumably related to a regional late Holocene sea-level rise, from a position, c. 2 m lower than present. After a c. 1,000 year period of marine sedimentation lasting until c. 2,500 cal BP, renewed formation of tropical wetland occurred at the site. This development may be attributed to the increased isolation of the shallow Altona Bay, most likely due to sea- ward formation of a well-developed spit system and possibly under the influence of enhanced storm-wave action in the period between c. 4,000 and 2,200 cal BP. Since the 1960's the repeated passage of severe hurricanes (e.g. Hugo, 1989) has had a significant impact on the sedimentation pattern of the bay and has caused a major hiatus and the recent deposition of sediments immediately overlying the c. 2,500 year old peat.

Hurricane Katrina (2005). Part I: Complex Life Cycle of an Intense Tropical Cyclone

Abstract The devastating effects of Hurricane Katrina (2005) on the Gulf Coast of the United States are without compare for natural disasters in recent times in North America. With over 1800 dead and insured losses near $40 billion (U.S. dollars), Katrina ranks as the costliest and one of the deadliest Atlantic hurricanes in history. This study documents the complex life cycle of Katrina, a storm that was initiated by a tropical transition event in the Bahamas. Katrina intensified to a category-1 hurricane shortly before striking Miami, Florida; however, little weakening was observed as the system crossed the Florida peninsula. An analog climatology is used to show that this behavior is consistent with the historical record for storms crossing the southern extremity of the peninsula. Over the warm Gulf of Mexico waters, Katrina underwent two periods of rapid intensification associated with a warm core ring shed by the Loop Current. Between these spinup stages, the storm doubled in size, leading to a monotonic increase in power dissipation until Katrina reached a superintense state on 28 September. A pair of extremely destructive landfalls in Louisiana followed the weakening of the system over shelf waters. Despite its strength as a hurricane, Katrina did not reintensify following extratropical transition. The evolution of the storm’s outflow anticyclone, however, led to a perturbation of the midlatitude flow that is shown in a companion study to influence the Northern Hemisphere over a period of 2 weeks. An understanding of the varied components of Katrina’s complex evolution is necessary for further developing analysis and forecasting techniques as they apply to storms that form near the North American continent and rapidly intensify over the Gulf of Mexico. Given the observed overall increase in Atlantic hurricane activity since the mid-1990s, an enhanced appreciation for the forcings involved in such events could help to mitigate the impact of similar severe hurricanes in the future.

Spatiotemporal Patterns and Return Periods of Tropical Storm and Hurricane Strikes from Texas to Maine

AbstractThe authors analyze 105 yr (1901–2005) of tropical cyclone strikes at 45 coastal locations from Brownsville, Texas, to Eastport, Maine, with the primary objective of examining spatiotemporal patterns of storm activity. Interpretation of the data suggests that geographically, three focal points for activity are evident: south Florida, the Outer Banks of North Carolina, and the north-central Gulf Coast. Temporally, clusters of hyperactivity are evident in south Florida from the 1920s through the 1950s and then again during the most recent years. North Carolina was a region of enhanced activity in the 1950s and again in the 1990s. A more consistent rate of occurrence was found along the north-central Gulf Coast; the last two years, however, were active in this region. Return periods of tropical storm strength systems or greater range from a frequency of once every 2 yr along the Outer Banks of North Carolina, every three years on average in southeast Texas, southeastern Louisiana, and southern Florida, and about once every 10–15 yr in northern New England. Hurricane return periods range from 5 yr in southern Florida to 105+ years at several sheltered portions of the coastline (e.g., near Cedar Key, Florida, Georgia, and the northeastern seaboard), where some locations experienced only one strike, or no strikes through the entire period of record. Severe hurricane (category 3–5) return periods range from once every 15 yr in South Florida to 105+ in New England.

Tempests in time

The frequency of severe hurricanes in the North Atlantic has increased during the past decade. Scrutiny of the prehistoric record left by such storms helps to assess the factors contributing to hurricane activity.

Employment and Self-Employment in the Wake of Hurricane Katrina

Year 2005 brought four severe hurricanes to the U.S. Gulf states, including Hurricane Katrina, an exceptional storm in terms of its magnitude of destruction. The authors examine the short- and long-term effects of Hurricane Katrina on the labor market outcomes of prime age individuals in the states most affected by the hurricane and for evacuees using data from the monthly Current Population Survey. They find that in the states most affected by Hurricane Katrina-Alabama, Florida, Louisiana and Mississippi-employment and unemployment by the end of 2006 were at similar rates as the end of 2003 with the exception of Mississippi, which still had lower employment and higher unemployment at the end of 2006 compared with pre-Katrina levels. By one year after the hurricane, evacuees that returned to their pre-Katrina state of residence have labor force participation rates and unemployment rates at the same level or near that of non-evacuees. Evacuees that relocated (non-returnees) have lower employment rates and higher unemployment rates, both immediately following the hurricane and one year later. Self-employment rates are higher for returning evacuees in all states compared with non-evacuees in those states in the months immediately following the hurricane but are no different one year later. There is some evidence of higher self-employment rates among non-returnees that may be due to poor job prospects in the wage and salary sector or due to new opportunities for starting businesses in the wake of Hurricane Katrina.

Effects of Hurricane Ivan on water quality in Pensacola Bay, Florida

Pensacola Bay, Florida, was in the strong northeast quadrant of Hurricane Ivan when it made landfall on September 16, 2004 as a category 3 hurricane on the Saffir-Simpson scale. We present data describing the timeline and maximum height of the storm surge, the extent of flooding of coastal land, and the magnitude of the freshwater inflow pulse that followed the storm. We computed the magnitude of tidal flushing associated with the surge using a tidal prism model. We also evaluated hurricane effects on water quality using water quality surveys conducted 20 and 50 d after the storm, which we compared with a survey 14 d before landfall. We evaluated the scale of hurricane effects relative to normal variability using a 5-yr monthly record. Ivan's 3.5 m storm surge inundated 165 km2 of land, increasing the surface area of Pensacola Bay by 50% and its volume by 230%. The model suggests that 60% of the Bay's volume was flushed, initially increasing the average salinity of Bay waters from 23 to 30 and lowering nutrient and chlorophylla concentrations. Additional computations suggest that wind forcing was sufficient to completely mix the water column during the storm. Freshwater discharge from the largest river increased twentyfold during the subsequent 4 d, stimulating a modest phytoplankton bloom (chlorophyll up to 18 μg l−1) and maintaining hypoxia for several months. Although the immediate physical perturbation was extreme, the water quality effects that persisted beyond the first several days were within the normal range of variability for this system. In terms of water quality and phytoplankton productivity effects, this ecosystem appears to be quite resilient in the face of a severe hurricane effect.

The behaviour of a hawksbill turtle data-logged during the passage of hurricane Georges through the Caribbean

Recent severe hurricanes in the Caribbean and south-east United States have had devastating socio-economic effects, and there is a pressing need to learn how animals are impacted by such events. We serendipitously deployed a multi-channel data logger onto a hawksbill turtle (Eretmochelys imbricata) during the breeding season in 1998 and logged various aspects of her behaviour before, during and after passage of hurricane Georges. As Georges passed by, the turtle made shorter dives, became more active and spent less time at the surface between dives compared with its baseline, non-storm activity. However, after passage of the hurricane the turtle quickly resumed its pre-hurricane behaviour and nested successfully a few days later. These results show that, in this case, the hurricane had a minor impact on the submerged animal presumably because of the dampening effect of depth on high winds over water.