Hurricane Activity Research Articles

Public risk salience of sea level rise in Louisiana, United States

Understanding public perceptions of sea level rise (SLR) is essential for effective risk communication in coastal areas. Using cross-sectional data from a representative survey of 1042 Louisiana residents, we measured the role of sociodemographic factors (age, gender, education, income, race, and political affiliation), contextual factors (distance to coast, geographic vulnerability, perceived extreme weather, home ownership, and presence of children in the household), media measures (local television, local newspaper, and satisfaction with media coverage), and perceived causes of coastal land loss (natural erosion from waves, hurricane activity, oil and gas industry activity, and U.S. Army Corps of Engineers activity) on SLR risk salience. Ordinal logistic analysis showed perceived extreme weather and geographic vulnerability to be strong and positive predictors of SLR risk salience. Implications for risk communication are discussed.

A 1600 year-long sedimentary record of tsunamis and hurricanes in the Lesser Antilles (Scrub Island, Anguilla)

The Lesser Antilles are a densely populated region where local populations and industrial facilities are concentrated at the coastlines, and are therefore exposed to many rapid-onset hazards such as hurricanes and tsunamis. However, the historical catalog of these events is too short to allow risk assessment and return period estimations, and it needs to be completed with long-term records of washover deposits in coastal sedimentary environments such as lagoons. In this study, two sediment cores were taken in March 2018 in a small coastal lagoon on Scrub Island (northeastern Caribbean). Sedimentological, geochemical, microfaunal and chronological analyses enabled us to identify 25 sandy layers resulting from high-energy-marine floods. Two of these layers were interpreted as tsunami deposits based on sedimentological (rip-up clast of the underlying cohesive substrate and internal mud laminae), and geochemical evidence. The most recent deposit is associated with the transatlantic tsunami triggered by the 1755 CE Lisbon earthquake. The older one is the thickest sandy layer recorded in the lagoon, with an age range of 1364–1469 cal. CE, as determined using 14C dating. This event was recorded in sedimentary archives of both the northern and the southern part of the Caribbean, with its large spatial extent, supporting a distant tsunamigenic origin. The 23 remaining sandy layers were interpreted as storm deposits, based on sedimentological and chronological data, with the three most recent layers being correlated with historical hurricanes. This new 1600 year-long record displays similarities with that of the Bahamas, with the periods of intense hurricane activity being in antiphase with those of the north-eastern US coast. This regional comparison may provide evidence for a latitudinal forcing of hurricane tracks through time in relation to climate fluctuations.

Historically unprecedented Northern Gulf of Mexico hurricane activity from 650 to 1250 CE

Hurricane Michael (2018) was the first Category 5 storm on record to make landfall on the Florida panhandle since at least 1851 CE (Common Era), and it resulted in the loss of 59 lives and $25 billion in damages across the southeastern U.S. This event placed a spotlight on recent intense (exceeding Category 4 or 5 on the Saffir-Simpson Hurricane Wind Scale) hurricane landfalls, prompting questions about the natural range in variability of hurricane activity that the instrumental record is too short to address. Of particular interest is determining whether the frequency of recent intense hurricane landfalls in the northern Gulf of Mexico (GOM) is within or outside the natural range of intense hurricane activity prior to 1851 CE. In this study, we identify intense hurricane landfalls in northwest Florida during the past 2000 years based on coarse anomaly event detection from two coastal lacustrine sediment archives. We identified a historically unprecedented period of heightened storm activity common to four Florida panhandle localities from 650 to 1250 CE and a shift to a relatively quiescent storm climate in the GOM spanning the past six centuries. Our study provides long-term context for events like Hurricane Michael and suggests that the observational period 1851 CE to present may underrepresent the natural range in landfalling hurricane activity.

Bat Guano Traces Changes in Agriculture and Hurricane Activity

Researchers hiked and rappeled into two caves in Jamaica to collect over 40 kilograms of excrement.

Revising evidence of hurricane strikes on Abaco Island (The Bahamas) over the last 700\xa0years

The northern Bahamas have experienced more frequent intense-hurricane impacts than almost anywhere else in the Atlantic since 1850 CE. In 2019, category 5 (Saffir-Simpson scale) Hurricane Dorian demonstrated the destructive potential of these natural hazards. Problematically, determining whether high hurricane activity levels remained constant through time is difficult given the short observational record (< 170 years). We present a 700-year long, near-annually resolved stratigraphic record of hurricane passage near Thatchpoint Blue Hole (TPBH) on Abaco Island, The Bahamas. Using longer sediment cores (888 cm) and more reliable age-control, this study revises and temporally expands a previous study from TPBH that underestimated the sedimentation rate. TPBH records at least 13 ≥ category 2 hurricanes per century between 1500 to 1670 CE, which exceeds the 9 ≥ category 2 hurricanes per century within 50 km of TPBH since 1850 CE. The eastern United States also experienced frequent hurricanes from 1500 to 1670 CE, but frequency was depressed elsewhere in the Atlantic Ocean. This suggests that spatial heterogeneity in Atlantic hurricane activity since 1850 CE could have persisted throughout the last millennium. This heterogeneity is impacted by climatic and stochastic forcing, but additional high-resolution paleo-hurricane reconstructions are required to assess the mechanisms that impact regional variability.

Improved Rainfall Prediction through Nonlinear Autoregressive Network with Exogenous Variables: A Case Study in Andes High Mountain Region

Precipitation is the most relevant element in the hydrological cycle and vital for the biosphere. However, when extreme precipitation events occur, the consequences could be devastating for humans (droughts or floods). An accurate prediction of precipitation helps decision-makers to develop adequate mitigation plans. In this study, linear and nonlinear models with lagged predictors and the implementation of a nonlinear autoregressive model with exogenous variables (NARX) network were used to predict monthly rainfall in Labrado and Chirimachay meteorological stations. To define a suitable model, ridge regression, lasso, random forest (RF), support vector machine (SVM), and NARX network were used. Although the results were “unsatisfactory” with the linear models, the specific direct influences of variables such as Niño 1 + 2, Sahel rainfall, hurricane activity, North Pacific Oscillation, and the same delayed rainfall signal were identified. RF and SVM also demonstrated poor performance. However, RF had a better fit than linear models, and SVM has a better fit than RF models. Instead, the NARX model was trained using several architectures to identify an optimal one for the best prediction twelve months ahead. As an overall evaluation, the NARX model showed “good” results for Labrado and “satisfactory” results for Chirimachay. The predictions yielded by NARX models, for the first six months ahead, were entirely accurate. This study highlighted the strengths of NARX networks in the prediction of chaotic and nonlinear signals such as rainfall in regions that obey complex processes. The results would serve to make short-term plans and give support to decision-makers in the management of water resources.

A multiproxy analysis of extreme wave deposits in a tropical coastal lagoon in Jamaica, West Indies

The Small Island Developing States (SIDS) of the Caribbean Region are vulnerable to natural hazards including earthquakes, tsunamis and tropical cyclones that can cause widespread devastation. Sedimentary archives of these hazards are often well-preserved in coastal lagoons; however, few studies in the Caribbean have adopted a multiproxy approach to their reconstruction. Here, we present a 1200-year multiproxy record of extreme washover events deposited within a coastal mangrove lagoon on the south coast of Jamaica. Manatee Bay lagoon is a permanent fresh-brackish-water mangrove lagoon separated from the Caribbean Sea by a low-elevation carbonate beach. Fifteen sediment cores recovered along five shore-normal transects contain ostracod-rich authigenic carbonate lake muds interspersed with beds of organic lake mud and mangrove peat. The cores contain evidence of multiple palaeo-washover deposits that are readily distinguished by their sedimentology, geochemistry and microfossil assemblages. Hypersaline conditions dominated the early part of the record (~ 800 to 900 CE), and we infer a freshening of lagoonal waters and the subsequent expansion of the mangrove community following an extreme wave event that occurred some time before ~ 1290 to 1400 CE. We constrain the primary historical-washover deposit to 1810–1924 CE (2σ; 71% probability), a period characterised by extreme tectonic and meteorological events, which include the Great Kingston Earthquake of 1907 and a local episode of enhanced hurricane activity. Whilst the balance of circumstantial evidence indicates that the deposit was probably emplaced during the tsunami generated by the 1907 earthquake, we are currently unable to differentiate between tectonically and meteorologically driven washover events based on their sedimentological characteristics.

Hurricanes, climate change, and social welfare: evidence from the Caribbean

We examine whether Caribbean islands will be worse off as hurricane activity alters under climate change. To this end, we construct island level damages for synthetic storm tracks generated from four climate models under current and future climate settings. Using a flexible stochastic dominance preference ordering framework, we find that the fat-tailed and uncertain nature of the distribution of storms makes it difficult to conclude that the region will be worse off under climate change, and is likely to depend on the degree of adaptation.

Pollen assemblage and environmental DNA changes: A 4300-year-old bat guano deposit from Jamaica

The discovery of two undisturbed caves in Jamaica with 14C and 210Pb dating indicating that the oldest layers of guano were ca. 200 years old in the first cave (81 cm long core), and as much as 4300 years old in the second cave (129 cm long core) provides exciting possibilities to examine past ecological communities. We analyzed genetic and pollen profiles in these ancient bat guano deposits and revealed DNA sequences most similar to arthropods, mainly insects such as caddisflies (Trichoptera), butterflies (Lepidoptera) and mayflies (Ephemeroptera), suggesting a potential source for past dietary data. Palynological analysis failed to recover well-preserved pollen grains and spores older than ca. 200 years, however in layers preserving pollen, angiosperms were the most abundant plants observed, with a regular occurrence of the potato (Solanaceae) and pepper families (Piperaceae), which are frequently bat-dispersed. In general, changes in frequency of particular plant taxa appear to reflect changes of vegetation and land use in the cave vicinity; however, some changes could be linked to hurricanes, leading to forest canopy damage and promoting the growth of light-demanding species such as guarumo (Cecropia). Higher amounts of mangrove (Rhizophora) pollen have also been recorded in the periods of heavy hurricane activities. Our data highlight the value of bat guano deposits in caves as a resource for the analysis of past ecological systems and stress the conservation values of these deposits.

A Geochemical Record of Late‐Holocene Hurricane Events From the Florida Everglades

AbstractA 5.25‐m sediment core SRM‐1 and 45 surface samples from mangrove forests at the Shark River Estuary in the Everglades National Park, Florida, were examined by using X‐ray fluorescence and carbon isotopic analyses to study the history of intense hurricane landfall during the Late‐Holocene. Significance testing of the surface samples in relation to storm deposits from Hurricane Wilma suggests that elemental concentration of Sr and Cl and the ratio of Cl/Br are the most sensitive indicators for major hurricane events in our study area. The geochemical data sets of core SRM‐1 identified five active periods of intense hurricane activities during the last 3,500 years at ~3,400–3,000, ~2,200–1,500, ~1,000–800, ~600–300, and ~150 calibrated years before present to present. This is the longest paleohurricane record to date from South Florida. Our results are consistent with the view that intense hurricane activities in South Florida were modulated by Intertropical Convergence Zone (ITCZ) movements, El Niño/Southern Oscillation (ENSO) activities, and North Atlantic Oscillation (NAO) strength. This study contributes to the methodological advancement in paleotempestological studies by demonstrating that geochemical signals, particularly signals of saltwater intrusions, can be preserved in the sediment profiles on millennial time‐scale and measured by X‐ray fluorescence techniques, thereby enabling more storm records to be produced from otherwise suboptimal sand‐limited coastal systems such as the Florida Everglades. More work needs to be done to explore the use of geochemical and stable isotopic analyses in detecting storm signals from sand‐limited coastal environments.

The Impact of Hurricanes on Trade and Welfare: Evidence from US Port-level Exports

Hurricanes cause extensive damage and disruption to ports and coastal infrastructure. However, the overall economic consequences of these storms are not necessarily limited to coastal regions. This paper analyzes the indirect effect of hurricanes on trade by considering the connections between affected and unaffected regions through the reliance on coastal ports. The analysis takes advantage of the exogenous variation in hurricane wind speeds at US customs ports to estimate how hurricane activity influences exports shipments originating in unaffected US states. The findings demonstrate that hurricanes have a severe negative impact on bilateral trade flows. For example, a Category 1 storm hitting a port has a similar effect on exports from unaffected US states as a 4% ad valorem tariff. These port-level disruptions aggregate up to broader trade frictions between US states and importing countries through price indices. The empirical estimates and the structure of the theoretical model are used to evaluate counterfactual hurricane scenarios. For example, foreign importers would have been willing to pay over $4 billion to have avoided the additional trade frictions caused by the 2005 hurricane season. Overall, the results shed light on the role of transportation networks in propagating the potential impacts of stronger hurricanes due to climate change.

Robust predictors for seasonal Atlantic hurricane activity identified with causal effect networks

Abstract. Atlantic hurricane activity varies substantially from year to year and so does the associated damage. Longer-term forecasting of hurricane risks is a key element to reduce damage and societal vulnerabilities by enabling targeted disaster preparedness and risk reduction measures. While the immediate synoptic drivers of tropical cyclone formation and intensification are increasingly well understood, precursors of hurricane activity on longer time horizons are still not well established. Here we use a causal-network-based algorithm to identify physically interpretable late-spring precursors of seasonal Atlantic hurricane activity. Based on these precursors we construct statistical seasonal forecast models with competitive skill compared to operational forecasts. In particular, we present a skilful prediction model to forecast July to October tropical cyclone activity at the beginning of April. Our approach highlights the potential of applying causal effect network analysis to identify sources of predictability on seasonal timescales.

Hurricane effects on Neotropical lizards span geographic and phylogenetic scales

Extreme climate events such as droughts, cold snaps, and hurricanes can be powerful agents of natural selection, producing acute selective pressures very different from the everyday pressures acting on organisms. However, it remains unknown whether these infrequent but severe disruptions are quickly erased by quotidian selective forces, or whether they have the potential to durably shape biodiversity patterns across regions and clades. Here, we show that hurricanes have enduring evolutionary impacts on the morphology of anoles, a diverse Neotropical lizard clade. We first demonstrate a transgenerational effect of extreme selection on toepad area for two populations struck by hurricanes in 2017. Given this short-term effect of hurricanes, we then asked whether populations and species that more frequently experienced hurricanes have larger toepads. Using 70 y of historical hurricane data, we demonstrate that, indeed, toepad area positively correlates with hurricane activity for both 12 island populations of Anolis sagrei and 188 Anolis species throughout the Neotropics. Extreme climate events are intensifying due to climate change and may represent overlooked drivers of biogeographic and large-scale biodiversity patterns.

Decomposition of the Atlantic Multidecadal Variability in a Historical Climate Simulation

AbstractThe Atlantic multidecadal variability (AMV) modulates various climate features worldwide with enormous societal and economic implications, including variations in hurricane activity in the Atlantic, sea level, West African and Indian monsoon rainfall, European climate, and hemispheric-scale surface temperature. Leading hypotheses regarding the nature and origin of AMV focus primarily on its links with oceanic and coupled ocean–atmosphere internal variability, and on its response to external forcing. The role of another possible process, that of atmospheric noise forcing of the ocean, has received less attention. This is addressed here by means of historical coupled simulations and diagnostic experiments, which isolate the influences of external and atmospheric noise forcings. Our findings show that external forcing is an important driver of the simulated AMV. They also demonstrate that weather noise is key in driving the simulated internal AMV in the southern part (0°–60°N) of the AMV region, and that weather noise forcing is responsible for up to 10%–20% of the multidecadal internal SST variability in some isolated areas of the subpolar gyre region. Ocean dynamics independent from the weather noise forcing is found to be the dominant cause of multidecadal SST in the northern part of the AMV region.

Quantifying the Probability and Causes of the Surprisingly Active 2018 North Atlantic Hurricane Season

AbstractThe 2018 North Atlantic hurricane season was a destructive season with hurricanes Florence and Michael causing significant damage in the southeastern United States. In keeping with most destructive hurricane seasons, basinwide tropical cyclone activity was above average in 2018—by ~25% for named storm numbers, hurricane numbers, and Accumulated Cyclone Energy (ACE). In contrast to this above‐normal activity, the August–September tropical environmental fields that explain ~50% of the variance in Atlantic basin hurricane activity between 1950 and 2017 anticipated a well below‐average 2018 hurricane season. The surprisingly large mismatch between the observed and replicated levels of hurricane activity in 2018 is an extreme example of the uncertainty inherent in seasonal hurricane outlooks and highlights the need for these outlooks to be issued in terms of probability of exceedance. Such probabilistic information would better clarify the uncertainty associated with hurricane outlooks to the benefit of users. With retrospective knowledge of the August–September 2018 key tropical environmental fields, the chance that the observed 2018 Atlantic hurricane activity would occur is about 5%. The reasons for the surprisingly high hurricane activity in 2018 are a hurricane outbreak in early September and, in particular, the occurrence of unusually high tropical cyclone activity in the subtropical North Atlantic. The hyperactive subtropical activity was not anticipated because contemporary statistical models of seasonal Atlantic hurricane activity lack skill in anticipating subtropical ACE compared to tropical ACE.

Preparing individuals with spinal cord injury for extreme storms in the era of climate change

Preparing individuals with spinal cord injury for extreme storms in the era of climate change

Impacts of Extratropical Weather Perturbations on Tropical Cyclone Activity: Idealized Sensitivity Experiments With a Regional Atmospheric Model

Key Points Artificial suppression of extratropical weather perturbations along 45°N elevates hurricane activity at 30–40°N in idealized experiments The response is related to reduced equatorward mixing of extratropical dry air, which could occur to some degree in altered climate states The experimental results suggest mechanisms through which extratropical atmospheric variability could affect tropical cyclogenesis

Um Plano Municipal para Adaptação dos Efeitos das Mudanças Climáticas no Municipio de São Francisco do Sul - SC

As mudanças climáticas estão acontecendo em uma proporção sem precedentes e impactando muitas pessoas em todo o planeta, principalmente através da ocorrência da elevação do nível médio do mar e eventos extremos, como secas mais longas e freqüentes, elevação na atividade de furacões e enchentes; o que demanda esforços de adaptação. Tais mudanças alertam para um panorama preocupante no que se refere aos ecossistemas costeiros e a infraestrutura das cidades litorâneas, potencializando impactos socioambientais significativos. O presente trabalho tem como objetivo formular contribuições preliminares para um documento técnico sugerindo estratégias, ações de adaptação e gerenciamento de riscos às mudanças climáticas, aplicado à cidade litorânea de São Francisco Sul, localizada no norte de Santa Catarina, especificamente quanto aos eventos relacionados à processos erosivos na linha de costaOs resultados preliminares indicam que a área em estudo apresenta risco menor em sua extensão norte e risco crítico em sua extensão sul, sendo esta a área com maior vulnerabilidade Espera-se que essa metodologia possa ser aplicada posteriormente a outros ecossistemas do território municipal, gerando contribuições para um plano municipal de adaptação às mudanças climáticas, que eventualmente poderá ser replicado à outras cidades litorâneas, contribuindo com a melhoria da qualidade de vida da população costeira catarinense.

Intense Hurricane Activity Over the Past 1500 Years at South Andros Island, The Bahamas

AbstractHurricanes cause substantial loss of life and resources in coastal areas. Unfortunately, historical hurricane records are too short and incomplete to capture hurricane‐climate interactions on multi‐decadal and longer timescales. Coarse‐grained, hurricane‐induced deposits preserved in blue holes in the Caribbean can provide records of past hurricane activity extending back thousands of years. Here we present a high resolution record of intense hurricane events over the past 1500 years from a blue hole on South Andros Island on the Great Bahama Bank. This record is corroborated by shorter reconstructions from cores collected at two nearby blue holes. The record contains coarse‐grained event deposits attributable to known historical hurricane strikes within age uncertainties. Over the past 1500 years, South Andros shows evidence of four active periods of hurricane activity. None of these active intervals occurred in the past 163 years. We suggest that Intertropical Convergence Zone position modulates hurricane activity on the island based on a correlation with Cariaco Basin titanium concentrations. An anomalous gap in activity on South Andros Island in the early 13th century corresponds to a period of increased volcanism. The patterns of hurricane activity reconstructed from South Andros Island closely match those from the northeastern Gulf of Mexico but are anti‐phased with records from New England. We suggest that either changes in local environmental conditions (e.g., SSTs) or a northeastward shift in storm tracks can account for the increased activity in the western North Atlantic when the Gulf of Mexico and southeastern Caribbean are less active.

Adjusting catastrophe model ensembles using importance sampling, with application to damage estimation for varying levels of hurricane activity

AbstractRisk modellers in the insurance industry use catastrophe models to estimate the distribution of possible damage from natural catastrophes. The output from catastrophe models is often adjusted to create alternative risk scenarios. These adjustments are made for many reasons, such as to reflect different scientific hypotheses, different interpretations of historical data or different scenarios related to climate variability and climate change. Models that present the output in a list of simulated synthetic events with their associated damage (so‐called event loss tables) can be adjusted rather easily, since information about desired adjustments is typically expressed in terms of changes in the properties of events. Models that present the output in a list of simulated synthetic years (so‐called year loss tables) are harder to adjust, however, because the occurrences of the events are hard‐wired into the simulated years. A method is described that allows the adjustment of the results in a year loss table by the application of weights to the years. The weights are calculated in such a way as to capture the specified changes in properties of the underlying events. The method is demonstrated by applying it to output from a catastrophe model and using it to quantify the changes in US hurricane wind damage due to shifts between long‐term average, active and inactive levels of hurricane activity. It is shown that the method works well by comparing the results with more accurate results derived directly from the underlying event loss table.