Major Hurricanes Research Articles

Trends in Routine Checkup Within the Past Year Following a Hurricane.

The goal of this nationally representative, cross-sectional study is to evaluate the trends in routine checkup within the last year associated with exposure to a hurricane. We compared Puerto Rico (2017 Hurricane Irma, Hurricane Maria), Texas (2017 Hurricane Harvey), and Florida (2017 Hurricane Irma, Hurricane 2018 Michael) with states that had a category 1-2 hurricane make landfall from 2014 to 2019: Georgia, Louisiana, Mississippi, North Carolina, and South Carolina. We found that states impacted by a major hurricane in 2017 had a drop in routine checkup while the states that experienced a category 1-2 landfall did have a change in that year. By the following year, all states reported an increase in routine checkup suggesting that the disruption in routine care was temporary.

Physics-based modeling of climate change impact on hurricane-induced coastal erosion hazards

Coastal erosion is an adverse impact of extreme water levels during major hurricanes. A warmer climate is expected to increase storm surge and wave hazards due to hurricane climatology change (HCC) and sea level rise (SLR). We conduct physics-based morphodynamic modeling to quantify the regional impacts of HCC and SLR on erosion hazards to sandy beaches and dunes along the barrier islands of New Jersey in the United States. Under the RCP8.5 scenario, we find a substantial increase in erosion hazards from the late-20th-century to late-21st-century. The regionally averaged 100-year eroded volume of beach-dune systems would increase by 58 and 84%, respectively, under the HCC and HCC + SLR scenarios. Our projections show a large spatial variability in future changes to erosion hazards, suggesting that, in addition to HCC and SLR, the morphological characteristics of beach-dune systems play an important role in the impacts of climate change on coastal erosion.

Tropical cyclone impacts on crop condition ratings and yield in the Coastal Southern United States

Weather causes both positive and negative impacts to agriculture making it the most uncontrollable factor affecting crop production. Agriculture in the southern U.S. comprises over 40% of the annual commodity export from the U.S., and this region also experiences a relatively large frequency of tropical cyclones. Few previous studies have investigated the effects tropical cyclones have on agriculture; thus, this study quantified the role tropical cyclones have on crop quality and yield in the Coastal Southern U.S. region using United States Department of Agriculture National Agricultural Statistics Service crop condition data (May–October; 1986–2021). The greatest changes in condition ratings were observed in fields that were favorable for normal and above normal yield potential, which were downgraded to a less than normal condition more favorable for some extent of loss to yield. For crops considered in excellent or good condition, decreases in coverage were up to 5% which resulted in an increase in fair, poor, or very poor conditions (up to 3% on average). When aggregating all crops in this study (corn, cotton, peanuts, rice, sorghum, soybeans), the latter portion of the growing season was the most detrimental to conditions after tropical cyclone impact, even under drought conditions. The strongest correlation found was between crop condition declines and tropical cyclone intensity, as major hurricanes were more likely to cause crop loss than any other variable. Consequently, yield prospects decline after a tropical cyclone based on declines in coverage of excellent and good conditions (yield declines up to 6% on average); though, crop conditions tend to recover resulting in yield to also recover marginally by the end of the season (declines up to 3%). Overall, these results provide essential risk management information for producers and could be used to better inform resilience and sustainability decisions related to tropical cyclone impacts.

Climatology of Tropical Cyclone Rainfall Magnitude at Different Landfalling Stages: An Emphasis on After-Landfall Rain

Abstract Estimating the magnitude of tropical cyclone (TC) rainfall at different landfalling stages is an important aspect of the TC forecast that directly affects the level of response from emergency managers. In this study, a climatology of the TC rainfall magnitude as a function of the location of the TC centers within distance intervals from the coast and the percentage of the raining area over the land is presented on a global scale. A total of 1834 TCs in the period from 2000 until 2019 are analyzed using satellite information to characterize the precipitation magnitude, volumetric rain, rainfall area, and axial-symmetric properties within the proposed landfalling categories, with an emphasis on the postlandfall stages. We found that TCs experience rainfall maxima in regions adjacent to the coast when more than 50% of their rainfall area is over the water. TC rainfall is also analyzed over the entire TC extent and the portion over land. When the total extent is considered, rainfall intensity, volumetric rain, and rainfall area increase with wind speed intensity. However, once it is quantified over the land only, we found that rainfall intensity exhibits a nearly perfect inversely proportional relation with the increase in TC rainfall area. In addition, when a TC with life maximum intensity of a major hurricane makes landfall as a tropical depression or tropical storm, it usually produces the largest spatial extent and the highest volumetric rain. Significant Statement This study aims to describe the cycle of tropical cyclone (TC) precipitation magnitude through a new approach that defines the landfall categories as a function of the percentage of the TC precipitating area over the land and ocean, along with the location of the TC centers within distance intervals from the coast. Our central hypothesis is that TC rainfall should exhibit distinct features in the long-term satellite time series for each of the proposed stages. We particularly focused on the overland events due to their effects on human activities, finding that the TCs that at some point of their life cycle reached major hurricane strength and made landfall as a tropical storm or tropical depression produced the highest volumetric rain over the land surface. This research also presents key observational evidence of the relationship between the rain rate, raining area, and volumetric rain for landfalling TCs.

Hurricane Vulnerability and Constrained Choices among Mobile Home Park Residents in South Florida

Abstract South Florida experiences some of the highest coastal hurricane vulnerability in the United States. Mobile home communities in south Florida are particularly vulnerable to hurricanes due to the weaker structural integrity of the home or land and a mix of structural and sociodemographic factors. A mixed-methods study was conducted to assess hurricane risk perceptions, experiences, and decision-making among permanent mobile home park (MHP) residents in Broward and Miami-Dade Counties. Return-by-mail surveys were distributed in July 2016 after several years of nominal hurricane activity in south Florida (and before Hurricane Matthew’s formation in September 2016), and focus groups were conducted at MHPs in May 2018, eight months after Hurricane Irma’s September 2017 landfall. Quantitative analysis of 44 in-person and 57 return-by-mail survey responses revealed that respondents tended to be older, retired, or unemployed and had modest levels of education, with many expressing forms of social- and structural-level hurricane risk before Hurricane Matthew. Qualitative analysis of six focus group discussions conducted after Hurricane Irma revealed that the constraints and vulnerabilities experienced by residents coalesced into several primary themes related to preparation, evacuation, assistance, stress and anxiety, tree concerns, and recovery. Participants specifically highlighted their concerns about tree hazards, damages, and maintenance issues arising before, during, and after hurricanes in MHPs. These results build on the scholarship on hurricane risk by underscoring the structural and social vulnerability of residents living in MHPs that constrain building resilience, adaptive capacity, community restoration efforts, and advocating for policy changes. Significance Statement This study aims to understand local hurricane risk perceptions, experiences, and vulnerabilities among residents of mobile home parks after a decade-long hurricane drought in south Florida and also to understand the barriers residents faced after a major hurricane. A hurricane drought is critical to study because it can erode individual and community-level preparedness. Residents of mobile home parks may experience more flooding, higher winds, tornadoes, and other dangers during hurricanes. Residents also face county-, neighborhood-, and household-level structural vulnerabilities that restrict their options related to hurricane preparedness, safety during a storm, and resilience in its aftermath. Our study uses various forms of data collection to obtain insights from permanent residents of mobile home parks in south Florida. In addition, it discusses the social and economic disadvantages and opportunities that policy makers can address in climate change risk management.

Using Ground-Based Radar Observations to Evaluate Asymmetric Convection and Eyewall Dynamics during the Landfall of Hurricane Harvey (2017)

Abstract Asymmetric dynamics in tropical cyclones (TCs) are vital to understanding intensity change and convective distribution at landfall. The growth of barotropic–convective instability (e.g., mesovortices), vortical hot towers, and vortex Rossby waves (VRWs) have been considered through numerical modeling studies, often by mean–eddy partitioning of the tangential wind tendency. Unfortunately, few observational datasets exist that are sufficient for such study. A University of Oklahoma Shared Mobile Atmospheric Research and Teaching radar observed major Hurricane Harvey (2017) as it intensified just before landfall near Port Aransas, Texas. Combined with a coastal WSR-88D radar, dual-Doppler derived kinematic analyses were constructed every ∼6 min at 1-km spatial resolution during Hurricane Harvey’s landfall. In this study, observations of asymmetric mesovortices on the interior edge of Harvey’s eyewall are documented. The asymmetries promoted a dual exchange of vorticity in the TC eyewall and represent an example of an eddy mechanism of intensity change on various time scales. Considering the combined effects of resolvable asymmetries, we examine the change in the tangential wind as a function of mean–eddy kinematics before and after landfall. Before landfall, the low-level eddy contribution was positive to the low-level tangential wind tendency. Following landfall, the contribution from the low-level eddy became weakly positive to weakly negative. Finally, the evolution of some asymmetric features in Harvey’s eyewall are shown to manifest in a VRW-like response that initiates rainbands just outside of Harvey’s eyewall.

Dissolved organic carbon dynamics and fluxes in Mississippi-Atchafalaya deltaic system impacted by an extreme flood event and hurricanes: a multi-satellite approach using Sentinel-2/3 and Landsat-8/9 data

Transport of riverine and wetland-derived dissolved organic carbon (DOC) spanning tidal wetlands, estuaries, and continental shelf waters functionally connects terrestrial and aquatic carbon reservoirs, yet the magnitude and ecological significance of this variable and its spatiotemporal linkage remains uncertain for coastal deltaic regions, such as Mississippi River Delta Plain, which includes Mississippi (MR) and Atchafalaya (AR) rivers and estuaries with vast expanses of wetlands and coastal forests. We examined DOC dynamics and fluxes in this large river-dominated wetland-estuarine system for the period between 2019 and 2021 that included an extreme river flood event in 2019, two major hurricanes (Barry in 2019 and Ida in 2021), and cold front passage using an improved adaptive quasi-analytical algorithm (QAA-AD) applied to multi-satellite sensors (Sentinel 3A/B OLCI, Landsat-8/OLI and Sentinel-2A/B MSI) with varying spectral and spatial (10/30/300 m) resolutions. The DOC estimates from multi-satellite sensors in combination with water fluxes were used to assess DOC fluxes from two large rivers (MR and AR) and small channels across the delta plain. Overall, this system delivered a total of 6.7 Tg C yr-1(1 Tg = 1012g) into the estuarine zone and the northern Gulf of Mexico (nGoM) during 2019. High DOC fluxes from the AR (1.3 Tg C yr-1) and MR (4.5 Tg C yr-1) were associated with the extreme flood event in 2019. Hurricanes that occurred in the study period also contributed to the wetland and estuarine DOC fluxes into continental shelf waters; for example, the passage of Hurricane Barry in July 2019, delivered over a 3-day period ~1.33 ×109g DOC from Barataria Basin into the nGoM. Sentinel 2-MSI land and water classification revealed that Hurricane Ida eroded a total of 1.34×108m2of marshes in middle Barataria Basin, converting those habitats into open water with 3.0 m inundation depth and high DOC concentrations (16.4 mg L-1), a potentially large DOC source to the coastal waters. Overall, storms and flood events are major sources of DOC flux that facilitate transport of upstream carbon as well as transformation of carbon in the wetlands, through the conversion of vegetated wetland to open water.

Increase in Cape Verde hurricanes during Atlantic Niño

At seasonal-to-interannual timescales, Atlantic hurricane activity is greatly modulated by El Niño–Southern Oscillation and the Atlantic Meridional Mode. However, those climate modes develop predominantly in boreal winter or spring and are weaker during the Atlantic hurricane season (June–November). The leading mode of tropical Atlantic sea surface temperature (SST) variability during the Atlantic hurricane season is Atlantic Niño/Niña, which is characterized by warm/cold SST anomalies in the eastern equatorial Atlantic. However, the linkage between Atlantic Niño/Niña and hurricane activity has not been examined. Here, we use observations to show that Atlantic Niño, by strengthening the Atlantic inter-tropical convergence zone rainband, enhances African easterly wave activity and low-level cyclonic vorticity across the deep tropical eastern North Atlantic. We show that such conditions increase the likelihood of powerful hurricanes developing in the deep tropics near the Cape Verde islands, elevating the risk of major hurricanes impacting the Caribbean islands and the U.S.

Global Increase of the Intensity of Tropical Cyclones under Global Warming Based on their Maximum Potential Intensity and CMIP6 Models

Future changes in the intensity of tropical cyclones (TCs) under global warming are uncertain, although several studies have projected an upward trend in TC intensity. In this study, we examined the changes in the strength of TCs in the twenty-first century based on the Hurricane Maximum Potential Intensity (HuMPI) model forced with the sea surface temperature (SST) from the bias-corrected CMIP6 dataset. We first investigated the relationship between the mean lifetime maximum intensity (LMI) of major hurricanes (MHs) and the maximum potential intensity (MPI) using the SST from the Daily Optimum Interpolation SST database. The LMI of MHs and the MPI in the last two decades was, on average, 2–3% higher than mean values in the sub-period 1982–2000, suggesting a relationship between changes in MPI and LMI. From our findings, the projected changes in TC intensity in the near-future period (2016–2040) will be almost similar for SSP2-4.5 and SSP5-8.5 climate scenarios. However, TCs will be 9.5% and 17% more intense by the end (2071–2100) of the twenty-first century under both climate scenarios, respectively, compared with the mean intensity over the historical period (1985–2014). In addition, the MPI response to a warmed sea surface temperature per degree of warming is a 5–7% increase in maximum potential wind speed. These results should be interpreted as a projection of changes in TC intensity under global warming since the HuMPI formulation does not include environmental factors (i.e., vertical wind shear, mid-level moisture content and environmental stratification) that influence TC long-term intensity variations.HighlightsThe maximum potential intensity (MPI) of tropical cyclones is a predictor of their climatological intensities.Tropical cyclones will be 17% more intense than today by the end of the 21st Century.The maximum potential wind speed will increase by 5–7%/ºC under global warming.

Identifying trends in interpretation and responses to hurricane and climate change communication tools

Coastal regions such as the U.S. Atlantic and Gulf Coasts are highly vulnerable to extreme coastal hazards such as tropical cyclones and major hurricanes. The effects of these hazards pose a threat now and are expected to increase in the future, which highlights the need for coastal communities to receive and understand information regarding risks involved with these hazards. Through this study, we identify points of improvement in the tools used to communicate the short and long-term risk associated with hurricane hazards through three surveys in Mobile, AL, Savannah, GA, and Houston TX. These surveys identify public response to hurricane descriptions, Cone of Uncertainty graphics, and long-term trend graphics. Analysis of trends in responses to these communication tools identifies relationships between risk perceptions and existing factors in each study location. Further, public response to these tools is identified and analyzed using structural equation models for each location with a “response” latent variable containing information from endogenous variables in the survey. Response was measured as action intent, concern for the scenario, reported evacuation likelihood, and interpretation of long-term trends. We identify points of improvement for all three communication tools to aid in public comprehension of the information provided as well as to increase response to hurricane hazards by more effectively communicating risk information. These would help to improve comprehension and increase different responses to tropical storm and hurricane damage from high winds and storm surge with the intent to improve resident response to hazards along the U.S. Atlantic and Gulf Coasts.

Hurricanes affect diversification among individual life courses of a primate population.

Extreme climatic events may influence individual-level variability in phenotypes, survival and reproduction, and thereby drive the pace of evolution. Climate models predict increases in the frequency of intense hurricanes, but no study has measured their impact on individual life courses within animal populations. We used 45 years of demographic data of rhesus macaques to quantify the influence of major hurricanes on reproductive life courses using multiple metrics of dynamic heterogeneity accounting for life course variability and life-history trait variances. To reduce intraspecific competition, individuals may explore new reproductive stages during years of major hurricanes, resulting in higher temporal variation in reproductive trajectories. Alternatively, individuals may opt for a single optimal life-history strategy due to trade-offs between survival and reproduction. Our results show that heterogeneity in reproductive life courses increased by 4% during years of major hurricanes, despite a 2% reduction in the asymptotic growth rate due to an average decrease in mean fertility and survival by that is, shortened life courses and reduced reproductive output. In agreement with this, the population is expected to achieve stable population dynamics faster after being perturbed by a hurricane ( ; 95% CI: 1.488, 1.538), relative to ordinary years . Our work suggests that natural disasters force individuals into new demographic roles to potentially reduce competition during unfavourable environments where mean reproduction and survival are compromised. Variance in lifetime reproductive success and longevity are differently affected by hurricanes, and such variability is mostly driven by survival.

El Niño Southern Oscillation (ENSO) effects on local weather, arboviral diseases, and dynamics of managed and unmanaged populations of Aedes aegypti (Diptera: Culicidae) in Puerto Rico.

We investigated the effects of interannual El Niño Southern Oscillation (ENSO) events on local weather, Aedes aegypti populations, and combined cases of dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV) viruses in 2 communities with mass mosquito trapping and 2 communities without mosquito control in southern Puerto Rico (2013-2019). Gravid adult Ae. aegypti populations were monitored weekly using Autocidal Gravid Ovitraps (AGO traps). Managing Ae. aegypti populations was done using 3 AGO traps per home in most homes. There were drought conditions in 2014-2015 concurrent with the emergence of a strong El Niño (2014-2016), wetter conditions during La Niña (2016-2018), a major hurricane (2017), and a weaker El Niño (2018-2019). The main factor explaining differences in Ae. aegypti abundance across sites was mass trapping. Populations of Ae. aegypti reached maximum seasonal values during the wetter and warmer months of the year when arbovirus epidemics occurred. El Niño was significantly associated with severe droughts that did not impact the populations of Ae. aegypti. Arbovirus cases at the municipality level were positively correlated with lagged values (5-12 mo.) of the Oceanic El Niño Index (ONI), droughts, and abundance of Ae. aegypti. The onset of strong El Niño conditions in Puerto Rico may be useful as an early warning signal for arboviral epidemics in areas where the abundance of Ae. aegypti exceeds the mosquito density threshold value.

Isotopic niche of New Jersey terrapins suggests intraspecific resource partitioning, and little variability following a major hurricane

Diamondback terrapins (Malaclemys terrapin) are sexually dimorphic generalist turtles that inhabit salt marshes and estuaries along the Atlantic and Gulf coasts of the United States. On October 29th, 2012, Hurricane Sandy made landfall in New Jersey, USA, directly impacting terrapin populations inhabiting central and southern Barnegat Bay. To examine potential food web mediated impacts to the terrapin population and their foraging dynamics we examined carbon and nitrogen stable isotope values collected from terrapin tissues (2011, 2015, 2019) and resource taxa (2015, 2019) within Barnegat Bay. Isotopic analysis revealed that mature females had lower carbon and higher nitrogen values than immature females and males with almost no isotopic niche overlap, whereas males and immature females had statistically similar values with overlapping niches. Terrapins and resources collected from island habitats contained higher carbon and nitrogen values than those from mainland habitats, with little overlap in niche between habitats. There were no significant temporal variations detected in either carbon or nitrogen values from terrapins between years, or within each habitat pre- and post-Hurricane Sandy. These findings suggest long-term terrapin foraging dynamics have remained relatively stable, signifying resilience to disturbance events within the study site.

Employment impacts and industry workforce shifts in the Florida Panhandle post-Hurricane Michael

Disaster-impacted communities are expected to experience a brief economic disruption, but less resilient communities are at risk for prolonged economic decline, increased unemployment, and shifts in industries and workforces. Florida is historically susceptible to hurricanes, having experienced six major hurricanes (> 110 mph winds) from 2000 to 2021, including Hurricane Michael, a rare Category 5 (> 157 mph winds) in October 2018 that devastated the already economically vulnerable Florida Panhandle. The area experienced a stagnant recovery, and it wasn’t until 2021 that a state-funded economic revitalization program was implemented to aid business restoration. An analysis of unemployment and employment rate trends for all Florida counties that experienced a major hurricane between 2000 and 2021 was conducted to quantify Hurricane Michael's economic impact compared to the other major hurricanes. Using difference-in-differences analysis, results found that the coastal counties impacted by Hurricane Michael experienced up to 11 months of significantly increased unemployment compared to other major Florida storms, from which counties only experienced up to two months of increased unemployment. Additionally, to provide context to the results of Hurricane Michael, observations of the volume trend of employee counts by industry were used to show that during the post-storm year the area saw a reduction in the hospitality, retail, health care and social assistance, and educational services workforces, yet an increase in the construction sector. This study highlights the need for increased disaster resilience against economic disruptions, the anticipation of post-disaster workforce disruptions, as well as support services for workers in a longstanding disaster recovery area. Furthermore, while post-disaster revitalization programs can be beneficial, building economic resilience to support rapid adaptation and recovery is more sustainable.

In the Cone of Concern: Preparing Stroke Survivors for Extreme Hurricanes.

When disasters strike, individuals living with stroke-related disability experience unique challenges and hardships. Climate change is contributing to the increasing frequency and severity of extreme weather events, including major hurricanes. Cyclonic storms that threaten the health and safety of residents living in coastal and island communities may disproportionately impact stroke survivors. Stroke sequelae may impede individuals' abilities to engage in timely preparedness and self-protective actions when such storms approach. As such, it is imperative that physiatrists and other health care professionals caring for patients living with stroke proactively assist them in identifying their needs and in developing tailored, comprehensive emergency preparedness plans. In this paper, we examine the special needs of and considerations for persons living with stroke sequelae in the times leading up to, during, and after a major hurricane. We also put forward recommendations, specific to the phases of a disaster, regarding how physiatrists can assist patients living with stroke, and their caregivers, to optimize preparedness in advance of a hurricane, and facilitate effective response during storm impact and in the aftermath.

Long-term site fidelity and seasonal abundance estimates of common bottlenose dolphins (Tursiops truncatus) along the southwest coast of Florida and responses to natural perturbations

Information characterising site fidelity and abundance for common bottlenose dolphins (Tursiops truncatus) along the southwest coast of Florida is important for defining stock structure for management purposes. Long-term site fidelity and ranging patterns of bottlenose dolphins in Charlotte Harbor and Pine Island Sound, Florida were investigated using photo-ID data collected during 566 boat-based surveys from 1982 through 2007. Seasonal abundance estimates were generated from seven multi-week field seasons during 2001 through 2006, before and after a major hurricane and red tide event occurred in the area. In total, 1,154 distinctive dolphins were identified up to 34 times each with 84% of individuals resighted on more than one day. Multiple year residency rates were high with 81% of dolphins sighted in at least two years and 30% over ten or more years. Seventy-six percent of individuals with sightings on two or more days were observed in both summer and winter. Of 249 dolphins sighted on ten or more days in the study area, 83% were never observed outside the study area, indicating strong site-fidelity. Two years after a devastating Category 4 hurricane in 2004 and following two years of Karenia brevis harmful algal blooms, 94% of dolphins were observed in the same region within the study area and abundance estimates remained stable. Documenting range and site fidelity patterns of individuals over long periods of time is helpful for characterizing population structure and for examining changes attributable to environmental factors and perturbations such as hurricanes, harmful algal blooms and climate change.

Twenty-Seven Year Response of South Carolina Coastal Plain Forests Affected by Hurricane Hugo.

In 1989, Hurricane Hugo inflicted catastrophic damage on approximately 1.8 million ha of forested land in South Carolina. The purpose of this study was to monitor species compositional shifts and structural changes in several forest types following the hurricane's disturbance. The immediate consequences of hurricane damage are well documented, but there are few studies based on the long-term compositional and structural changes that may result from hurricane disturbance, especially in temperate forest ecosystems. Forty-two forested plots were monitored within four study areas that received varying degrees of hurricane damage. Inventories included species, damage class, tree diameter, and regeneration. The objectives of this study were (1) to compare the recovery speed of wetland forests (e.g., bottomland hardwood swamps and cypress-tupelo swamps) to that of upland pine and hardwood forests; (2) to discover how the degree of hurricane damage can affect the timing and the pattern of forest recovery in the coastal plain; and (3) to compare individual species response patterns across different forest types and at different levels of initial damage. Over the 27-year period following the hurricane, successional pathways have been variable among plots of different forest types and intensity of initial disturbance. We have observed an expected increase in basal area (BA) following the disturbance. Sapling populations in many species have increased dramatically, and some of these populations have begun to thin in recent years. In several forest types, loblolly pine (Pinus taeda L.-not a predominant species in these sites prior to the hurricane) responded quickly and overtook some dominant species in BA and tree/sapling abundance. Several other species that were not a major component of the tree strata (wax myrtle [Morella cerifera (L.) Small], green ash [Fraxinus pennsylvanica Marsh.], and the invasive Chinese tallow [Triadica sebifera (L.) Small]) showed a large increase in sapling population. Overall, recovery speed and species resilience were specific to forest types and damage severity. The intensity and frequency of hurricanes may increase in the future as sea surface temperatures rise. Understanding how coastal forests respond to major hurricanes in the short-term and the long-term will aid us in preparing for future hurricanes and for potential changes in disturbance regimes.

Detecting Episodes of Mildly Explosive Behavior in the Hurricane Resiliency Index to Examine Community Resilience to Hurricanes

Natural disasters such as hurricanes, earthquakes, and floods cause massive damage and losses around the world. Investigating their impact on affected communities and delineating them from nondisaster forces have major scientific and policy implications. To that end, a series of econometric tests were applied to the Hurricane Resiliency Index (HRI) for six selected study areas to identify and date-stamp periods of mildly explosive behavior (MEB). Evidence of MEB signals a structural break or nonlinearity in an otherwise stationary time series. The starting and ending points of multiple MEB episodes indicate the extent to which a community recovers toward normalcy. It is found that the recovery time associated with hurricanes is much shorter than that with economic recessions. The overall severity of MBE, when considering both duration and amplitude, is most pronounced when a major hurricane strikes dense populations. The findings also highlight that the compounding effect of economic recession and hurricane poses the most serious threat to a local economy. Finally, the Hurricane Resiliency Index is shown to outperform the Federal Reserve Bank of Dallas’s Metro Business-Cycle Index in capturing such behaviors.

Assessment of the Spatial Variation in the Occurrence and Intensity of Major Hurricanes in the Western Hemisphere

Major hurricanes are a critical hazard for North and Central America. The present study investigated the trends of occurrence, affectation, and intensity of major hurricanes in the North Atlantic and Northeast Pacific Oceans using GIS applications to the IBTrACS database. The study period ranged from 1970 to 2021. Tropical cyclones were sampled using a grid composed of 3.5° hexagonal cells; in addition, trends were obtained to assess the effect of long-term variability from natural phenomena and climate change. Critical factors influencing these trends at the oceanic scale and for each hexagon were determined using multivariate and multiscale analysis by the application of stepwise analysis and the related ANOVA. The integrated variables related to atmospheric and oceanographic oscillations and patterns, i.e., spatial variables resampled with the same analysis unit and climate indices. Our results indicated marked spatial areas with significant trends in occurrence and intensity. Additionally, there was evidence of linear changes in the number of major hurricanes and an increase in the maximum annual speed of +1.61 m s−1 in the North Atlantic basin and +1.75 m·s−1 in the Northeast Pacific, reported for a 10-year period. In terms of occurrence, there were increases of 19% and 5%, respectively, which may be related to ocean warming and natural variability associated with oceanic and atmospheric circulation.

Fast Flood Extent Monitoring With SAR Change Detection Using Google Earth Engine

Flooding is one of the most frequent and disastrous natural hazards triggered by extreme precipitation, high river runoff, hurricane storm surges, and the compounding effects of various flood drivers. This study introduces a new multisource remote sensing approach that leverages both multispectral optical imagery and the weather- and illumination-independent characteristics of synthetic aperture radar (SAR) data to streamline, automate, and map geographically reliable flood inundation extents. Utilizing the near real-time and cloud computing capabilities of Google Earth Engine (GEE), this process facilitates data acquisition and enables large-scale flood monitoring in an expeditious manner. Two major hurricanes along the U.S. Gulf Coast were evaluated: 1) the 2021 Hurricane Ida to the south of New Orleans, LA, USA, and 2) the 2017 Hurricane Harvey to the east of Houston, TX, USA. We devised a change detection and thresholding framework using multitemporal SAR imagery and validated the results with flood extent maps derived from Landsat 8 and Sentinel-2 optical imagery. We demonstrate that constant threshold values for flood extraction from SAR change detection indices are not ubiquitously suitable for all geographies; thus, we outline a heuristic that can be used to select thresholds suitable for specific sites through a fully automated sensitivity analysis. The results indicated high agreement between the SAR and optical imagery (77%–80%), with SAR providing the benefit of under-cloud detection. Furthermore, our results contribute to scaling the SAR approach to produce rapid and accurate information for decision-makers and emergency responders during time-sensitive flood events.