Major Storm Research Articles

Orbital forcing of late Early Devonian storm events on a mixed carbonate-siliciclastic shelf, Longmenshan area, Sichuan Province, China

AbstractThe Yangmaba Formation of latest Early Devonian age in the Longmenshan area of Sichuan Province, China, is a shelfal facies that consists of four types of carbonate-siliciclastic deposits: clay-rich, siliciclastic sand-rich, carbonate-dominated, and hybrid mixed. Storm deposits vary in their thickness, composition, and abundance-per-meter within these mixed carbonate-siliciclastic deposits. Meter-scale statistics of the relative storm frequency (events-per-meter) and magnitude (bed thickness) were compiled in two coeval sections through each of the hybrid facies in the lower Yangmaba Formation, which spans approximately the entire conodont Polygnathus patulus Zone of the uppermost Emsian Stage. Low-pass filtering, spectral analysis, and Acycle software interpretation of these tempestite statistics yield 3.5 main oscillations in each section, with an average wavelength of ~23 m. These long-wavelength trends are semi-coincident with interpreted long-term variations in sea level, where shallower depths allowed a greater influence by storms. Superimposed on the long-wavelength cycles are medium-wavelength cycles of 5.5–6.3 m. The estimated ~1.5 m.y. time-span of this conodont zone of the lower Yangmaba Formation and the approximate 1:4 ratios of these wavelengths indicate that frequency and intensity of major storms and the recording of tempestites in the sedimentary record were modulated by ~100- and 95-k.y.-short-eccentricity orbital-climate oscillations superimposed on a main 405-k.y.-long-eccentricity cycle. These eccentricity climate cycles governed storm intensity and regional sea level on this margin of the tropical Yangtze Platform of South China.

A Tri-Level Planning Approach to Resilient Expansion and Hardening of Coupled Power Distribution and Transportation Systems

Natural disasters which include major storms, floods, tornados, and hurricanes can seriously threaten the resilience of large and coupled infrastructures such as electric power distribution and transportation systems. This paper proposes a planning (i.e., investment + operation) method for enhancing the resilience of coupled power distribution and transportation systems. The proposed investment method includes capacity expansions of power lines, roads, and charging stations, and the hardening of roads and power lines. A tri-level problem is proposed and formulated to accommodate random natural disasters. The proposed model is solved by applying the Benders decomposition and the column-and-constraint generation (C&CG) algorithms. Benders decomposition will decompose the tri-level coupled problem into a single-level master problem and a bi-level subproblem. However, the latter with binary variables is not a convex problem and cannot be converted to the maximization problem. The C&CG algorithm is applied to solve the bi-level subproblem with binary variables. The proposed resilience enhancement algorithm is tested using a coupled power distribution and transportation system with 21 electric buses and 20 roads and numerical results are analyzed to validate the effectiveness of the proposed planning method.

Using sUAS-Acquired Imagery to Map Landslide Susceptibility along the Lake Michigan Shoreline of Wisconsin

Bluffs along the Wisconsin shoreline of Lake Michigan frequently collapse, and this collapse often occurs due to saturation and weakness in a sand layer present in the bluffs. We used an sUAS to collect visible and thermal imagery of bluffs along Lake Michigan in Kewaunee County, WI. We then proceeded to classify this imagery in ArcGIS Pro to determine whether the program’s classification tools could locate the sand layer. Furthermore, we examined imagery before and after a major storm to determine the storm’s effect on water content in the sand layer. Our results indicate that we can use automated computer programs to classify the sand layer based on a combination of visible and thermal imagery. Additionally, we found that large summer storms do not significantly alter the saturation of the sand layer and infer that their effect on bluff collapse is minimal.

Impact of storms and proximity to entry points on marine litter and wrack accumulation along Mediterranean beaches: Management implications

Beach litter can affect public health and economic activities worldwide forcing local authorities to expensive beach cleaning. Understanding the key mechanisms affecting the accumulation of this waste on beaches, such as sea state and proximity to entry points, is critical to plan effective management strategies. In this one-year study, we estimated the impact of storm events and waterways runoff on litter abundance and local economy using as a model a managed, peri-urban beach facing a north-western sector of the Mediterranean Sea. We also investigated the relationship between litter composition/density and beach proximity to major/closest harbors/rivers at regional scale by combining our data with those on litter density available in literature. Autumn/winter storms caused larger litter depositions than spring/summer ones in the peri-urban beach. No preferential accumulation occurred near to waterway mouths. Litter mainly consisted of plastic, and its composition in terms of micro-categories varied over seasons. In total, 367,070 items were deposited along 4.7 km of beach over one year, and the cost for the removal of this waste amounted to approximately 27,600 euros per km/year. At regional scale, beach litter density was positively correlated to the proximity of major harbors while its composition was related to the proximity to both major harbors and rivers. Results indicate that autumn/winter storms are important drivers of marine litter deposition. They also suggest that beaches in front of the convergence zone of littoral currents and close to major harbors can be particularly subjected to this kind of pollutant. To increase their effectiveness, litter mitigation/cleaning activities should be planned based on predictions of major storm events and performed at spatial scales encompassing at least coastal regional sectors.

Where does the moisture for North Atlantic tropical cyclones come from?

Abstract In this study, we identified the origin of the moisture associated with the tropical cyclones (TCs) precipitation in the North Atlantic Ocean basin during their three well-differentiated life stages between 1980 and 2018. The HURDAT2 database was used to detect the location of 598 TCs during their genesis, maximum intensification peak, and dissipation phases. The global outputs of the Lagrangian FLEXPART model were then used to determine the moisture sources. Using a K-means cluster analysis technique, seven different regions were identified as the most common locations for the genesis and maximum intensity of the TC phases, while six regions were found for the dissipation points. Our results showed that the origin of moisture precipitating was not entirely local over the areas of TC occurrence. The North Atlantic Ocean to the north of the Inter Tropical Convergence Zone at 10°N (NATL) -especially from tropical latitudes, the Caribbean Sea and the Gulf of Mexico- provides most of the moisture for TCs (∼87%). The Atlantic Ocean basin southward the ITCZ (SATL) played a non-negligible role (∼11%), with its contribution being most pronounced during the TC genesis phase, while the eastern tropical Pacific Ocean made the smallest contribution (∼2%). The moisture supported by TCs varied depending on their category, being higher for hurricanes than for major hurricanes or tropical storms. Additionally, the approach permitted to estimate the mean residence time of the water vapour uptake that produce the precipitation during TC activity, which ranged between 2.6 and 2.9 days.

Establishing Stage–Discharge Rating Curves in Developing Countries: Lake Tana Basin, Ethiopia

A significant constraint in water resource development in developing countries is the lack of accurate river discharge data. Stage–discharge measurements are infrequent, and rating curves are not updated after major storms. Therefore, the objective is to develop accurate stage–discharge rating curves with limited measurements. The Lake Tana basin in the upper reaches of the Blue Nile in the Ethiopian Highlands is typical for the lack of reliable streamflow data in Africa. On average, one stage–discharge measurement per year is available for the 21 gaging stations over 60 years or less. To obtain accurate and unique stage–discharge curves, the discharge was expressed as a function of the water level and a time-dependent offset from zero. The offset was expressed as polynomial functions of time (up to order 4). The rating curve constants and the coefficients for the polynomial were found by minimizing the errors between observed and predicted fluxes for the available stage–discharge data. It resulted in unique rating curves with R2 > 0.85 for the four main rivers. One of the river bottoms of the alluvial channels increased in height by up to 3 m in 60 years. In the upland channels, most offsets changed by less than 50 cm. The unique rating curves that account for temporal riverbed changes can aid civil engineers in the design of reservoirs, water managers in improving reservoir management, programmers in calibration and validation of hydrology models and scientists in ecological research.

Exploring Social Contracts of Disaster Risk Through Twitter Narratives During a Major Storm

Exploring Social Contracts of Disaster Risk Through Twitter Narratives During a Major Storm

The Great Aurora of 4 February 1872 observed by Angelo Secchi in Rome

Observation of auroras at low latitudes is an extremely rare event typically associated with major magnetic storms due to intense Earth-directed Coronal Mass Ejections. Since these energetic events represent one of the most important components of space weather, their study is of paramount importance to understand the Sun-Earth connection. Due to the rarity of these events, being able to access all available information for the few cases studied is equally important. Especially if we refer to historical periods in which current accurate observations from ground-based instruments or space were not available. Certainly, among these events, we must include the great aurora of February 4, 1872. An event whose effects have been observed in different regions of the Earth. What we could consider today a global event, especially for its effects on the communication systems of the time, such as the transatlantic cable that allowed a connection between the United States and Europe since 1866. In this paper, we describe the main results of the observations and studies carried out by Angelo Secchi at the Observatory of the Roman College and described in hisMemoria sull’Aurora Elettrica del 4 Febbraio 1872for the Notes of the Pontifical Academy of new Lincei. This note is extremely modern both in its multi-instrumental approach to the study of these phenomena and in its association between solar-terrestrial connection and technological infrastructures on the Earth. The Secchi’s note definitely represents the first example of analysis and study of an event on a global scale, such as the Atlantic cable, affecting the Earth. What we nowadays call an extreme space weather event.

Współczesna dynamika plaż i wydm w środkowej części Mierzei Wiślanej oraz prognoza ich zmian po wykonaniu falochronów kanału = Contemporary dynamics of the beaches and dunes in the central part of the Vistula Sandbar, as well as forecast changes following the construction of canal breakwaters

The aim of the work described here has been to analyse contemporary changes along the shore along the central part of the Vistula Sandbar located on the Baltic’s south coast. There, breakwaters are being installed to protect the canal cut that has been under construction since 2020 (fig.1). Shoreline changes involving both dunes and beaches have been predicted to arise following construction of breakwaters, which will obviously influence the dynamics of the previously natural shore of the Sandbar. Factors exerting done in the 2003‑2020 period. The section of the Sandbar under discussion (the middle part, at km 18‑25, fig. 1, 2) has so far shown only limited accumulation trends. Plate 1 presents different relief of the foredunes caused by storm surges and aeolian processes. The wind regime for 2001‑2017 features the more marked presence of wind from the W and SW sector. Aeolian accumulation caused by such westerly winds is rebuilding the beach and dune in the investigated area (fig. 6‑8). The strongest winds are those from the NW that arise during the autumn-winter period. The orientation of the sandbar coast ensures that erosion in the course of storm surges is different. The middle part of the Vistula Sandbar is only eroded during the highest storm surges (fig. 3). Over the research period, it was possible to observe erosion of various types caused by storm surges recorded in Gdańsk. Since 2003, there have been several storm surges featuring a water level higher than 1.2 m AMSL. Each such surge ensures severe erosion of dunes (as in 2004, 20006, 2007, 2012, 2017 and 2019). Storm erosion is a major factor in dune development: the higher the surge, the higher the levels of water run up and coastal erosion (fig. 4). During the highest surges (featuring water of H>1.2 m AMSL, the run-up is of almost 4 m AMSL. The mean rate of retreat at the base of the foredune is 3‑4 m, while the maximum reaches 7‑8 m. In the periods between storms, the areas at the bases of dunes increases by 0.8 to 1.5 m/y. Reconstruction of the dunes took place up to 2‑3 years after a major storm surge. The sand building foredunes is fine and medium (average 0.20‑0.21 mm). There are fines sands along the whole Vistula Sandbar, while beach dune sand is coarser. The coarsest sand is the type that builds the beach ridge (0.3‑0.4 mm). This type of material comes from the cliffs of the Sambian Peninsula located in the NE part of the Gulf of Gdańsk. Plants scattered across the beach ensure aeolian accumulation on the upper beach. Beach height is often higher than the highest water run-up during storm surges, with this serving to safeguard dunes against erosion. Beach width is almost widest on the investigated part of Sandbar (other than at the mouth of the Vistula delta), exceeding 41 m on average (figs. 1C and 5). The foredune dynamics are not great (figs. 6 and 7). However, there are more major increases in years lacking storm erosion, with the height of foredunes exceeding 4‑5 m. Neighbouring sections of coast lack such foredunes, however – meaning that erosion is more marked there than along the Sandbar’s central stretch. The area under study is one of two accumulating sections of the Vistula (the second being in the Vistula Delta). Analyses show that breakwaters constructed will block sediment transport on both the shore and the beach. All aeolian sediment will accumulate on the western side of the Canal that is to be completed (at km 26‑25). There will be new dune growth and beach widening. Sand will not be transported eastwards (at km 23‑18 and further east to Krynica Morska). Dunes will not develop in this section, and that will ensure the development of erosive tendencies. The erosion of dunes will take place on the eastern side of breakwaters and may exceed 0.5 to 1.2 m/y (fig. 8). Annual rates of erosion will depend on the number of strong storm surges with sea level H > 1 m. Such surges occur more frequently than they did in the 20th century.

Variable-Fidelity Euler–Lagrange Framework for Simulating Particle-Laden High-Speed Flows

The current work presents a simulation framework for modeling high-speed flows with suspended solid particles using the point-particle discrete element method. The dispersed particle phase is treated in a Lagrangian manner, whereas the dynamics of the surrounding carrier fluid are determined by solving the compressible Navier–Stokes equations in the Eulerian frame. Additionally, a variable fidelity paradigm is adopted with the ability to model one-, two-, and four-way coupling between the dispersed and carrier phases depending on the desired levels of physical realism. Particle mesh-localization is performed using mesh-connectivity information, which also simplifies boundary conditions enforcement, parallelization, and the backcoupling of particle-induced source terms to the carrier fluid. A time-driven hard-sphere approach is employed to accelerate calculations for particle–particle collisions. The particle solution methodology in conjunction with the unstructured, finite-volume US3D flow solver is used to simulate a variety of multiphase flows. These include a series of verification tests and the first-of-its-kind numerical investigation into elevated levels of surface heat flux experienced by the Mars 2020 spacecraft if planetary entry through the Martian atmosphere were to occur during a major dust storm.

Escherichia coli levels and microbial source tracking in stormwater retention ponds and detention basins.

Little is known about the spatial and temporal changes that occur with Escherichia coli in urban stormwater systems. The goal of this project was to assess E.coli in urban stormwater detention basins and retention ponds, not connected to the sewer system, to determine temporal and spatial differences and evaluate the sources of E.coli utilizing microbial source tracking (MST). Surface water quality was sampled at three detention basins and five retention ponds during major storm events in the summers of 2018 and 2019. One week after each storm, groundwater and surface water were sampled. The MST samples were taken from storm events and normal flows, for both surface and groundwater. E.coli levels were higher during rain events in both detention basins and retention ponds and infrequently met a recreational standard. E.coli in groundwater was pervasive and infrequently met a recreational standard. The MST analysis found sewage, dog, human, and bird markers during storm events and sewage and bird markers during regular flows. PRACTITIONER POINTS: Rain events had significantly more E.coli than during normal flows in both retention ponds and detention basins. E.coli in groundwater was ubiquitous and fluctuates over time. Microbial source tracking (MST) found bird, dog, human, and sewage markers present during all storm events analyzed.

Nearshore sandbar switching episodes and their relationship with coastal erosion at the Curonian Spit, Baltic Sea

The longshore realignment of nearshore sandbars is a morphodynamic phenomenon of multiple sandbar systems that has been known about for several decades. However, it is unknown how switching-related nearshore changes influence the evolution of subaerial beaches. This study aims to define the relationship between sandbar switching episodes and the dynamic state of the beach-foredune system along the Curonian Spit coast (Baltic Sea) using decadal satellite-derived and beach profiling data. To define this connection, sandbar switching locations, sandbar cross-shore positions, shoreline positions, and sand volume changes in the beach-foredune system were assessed on interannual and storm-related time scales. Twenty-seven sandbar switching episodes were observed with an average duration of 14.3 months. Most of the switching episodes occurred at preferred locations, coinciding with breaking points of different shoreline orientations where oblique waves and longshore currents prevailed. Shoreline retreat at an average rate of –14.2 m was observed within most of the sandbar switching zones. During major storm events, the average rate of erosion within the sandbar switching zones was significantly higher than the rate outside them. On an interannual time scale, a moderate average rate of erosion was observed within the sandbar switching zones compared to a small accretion rate outside them. Additional case studies of coastal evolution within the switching zones indicated well-correlated rates of switching-determined outer sandbar positions, shoreline positions, and sand volume on the beach and foredune during the switching episodes. The results of this study could be important for the identification of erosional hot spots and coastal prediction.

A Detention Reservoir Reduced Combined Sewer Overflows and Bathing Water Contamination Due to Intense Rainfall

Combined sewer overflows (CSOs) close to water bodies are a cause of grave environmental concern. In the past few decades, major storm events have become increasingly common in some regions, and the meteorological scenarios predict a further increase in their frequency. Consequently, CSO control and treatment according to best practices, the adoption of innovative treatment solutions and careful sewer system management are urgently needed. A growing number of publications has been addressing the quality, quantity and types of available water management and treatment options. In this study, we describe the construction of an innovative detention reservoir along the Arzilla River (Fano, Italy) whose function is to store diluted CSO wastewater exceeding the capacity of a combined drain system. River water sampling and testing for microbial contamination downstream of the tank after a heavy rain event found a considerable reduction of fecal coliform concentrations, which would have compounded the impact of stormwater on the bathing site. These preliminary results suggest that the detention tank exerted beneficial environmental effects on bathing water by lowering the microbial load.

Source Locations and Solar-Cycle Distribution of the Major Geomagnetic Storms ($\mathrm{Dst} \le -100$ nT) from 1932 to 2018

Source Locations and Solar-Cycle Distribution of the Major Geomagnetic Storms ($\mathrm{Dst} \le -100$ nT) from 1932 to 2018

Electron Acceleration by Magnetosonic Waves in the Deep Inner Belt (L = 1.5–2) Region During Geomagnetic Storm of August 2018

AbstractThe relativistic electron acceleration in the inner radiation belt have received little attention in the past due to sparse measurements. The 90° minimum pitch angle distributions of electrons in extremely low L‐shells during storms are speculated to be preferentially heated by fast magnetosonic waves. The high‐quality measurements of relativistic electrons by instruments onboard Van Allen Probes and ZH–1 provide a great opportunity to investigate the dynamics of relativistic electrons in the inner radiation belt. At extremely low L‐shells (L 2), a weak flux enhancement (increased by 2–3 times) of 100s keV electrons and the corresponding formation of butterfly PADs are observed during the major geomagnetic storm (minimum Dst ≈ −179 nT) occurred in August 2018. Simultaneously the magnetosonic waves, accompanied with weak hiss waves, were observed also in such low L‐shells. Combining with a numerical simulation of wave and particle interaction model, magnetosonic waves are thought to play an important role in electron acceleration and formation of butterfly PADs during this storm, which is the first direct observation in such low L‐shells.

Improved Neutral Density Predictions Through Machine Learning Enabled Exospheric Temperature Model

AbstractThe community has leveraged satellite accelerometer data sets in previous years to estimate neutral mass density and exospheric temperatures. We utilize derived temperature data and optimize a nonlinear machine‐learned (ML) regression model to improve upon the performance of the linear EXospheric TEMPeratures on a PoLyhedrAl gRid (EXTEMPLAR) model. The newly developed EXTEMPLAR‐ML model allows for exospheric temperature predictions at any location with one model and provides performance improvements over its predecessor. We achieve reductions in mean absolute error of 2 K on an independent test set while providing similar error standard deviation values. Comparing the performance of both EXTEMPLAR models and the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended model (NRLMSISE‐00) across different solar and geomagnetic activity levels shows that EXTEMPLAR‐ML has the lowest mean absolute error across 80% of conditions tested. A study for spatial errors demonstrated that at all grid locations, EXTEMPLAR‐ML has the lowest mean absolute error for over 60% of the polyhedral grid cells on the test set. Like EXTEMPLAR, our model's outputs can be utilized by NRLMSISE‐00 (exclusively) to more closely match satellite accelerometer‐derived densities. We conducted 10 case studies where we compare the accelerometer‐derived temperature and density estimates from four satellites to NRLMSISE‐00, EXTEMPLAR, and EXTEMPALR‐ML during major storm periods. These comparisons show that EXTEMPLAR‐ML generally has the best performance of the three models during storms. We use principal component analysis on EXTEMPLAR‐ML outputs to verify the physical response of the model to its drivers.

Natural vs. trawling-induced water turbidity and suspended sediment transport variability within the Palamós Canyon (NW Mediterranean)

Increases of water turbidity and suspended sediment transport in submarine canyons have been associated with high-energy events such as storms, river floods and dense shelf water cascading (DSWC), and occasionally with bottom trawling along canyon flanks and rims. To assess the variations on the water column turbidity and sediment transport in the Palamós Canyon linked to both natural and trawling-induced processes, an autonomous hydrographic profiler, as well as a near-bottom current meter and a turbidimeter were deployed in the canyon axis (929 m depth) from February to June 2017, covering a trawling closure (February) and trawling activities (March-June). Periods of enhanced water turbidity during the trawling closure were mostly associated with storms and DSWC events, transporting turbid dense waters into the canyon. In absence of such events, the water column displayed low suspended sediment concentrations (~ 0.3 mg L− 1) until the trawling season began, when particulate matter detachments, ranging between > 1 mg L− 1 and 3.8 mg L− 1, were observed at the water depths where the trawling grounds are found. During the trawling closure, high near-bottom suspended sediment fluxes (35–44 g m− 2 s− 1) were sporadically registered at ~ 920 m depth associated with a major storm and DSWC event. Smaller but more frequent increases of near-bottom suspended sediment fluxes (0.1–1.4 g m− 2 s− 1) were recorded during trawling activities. Despite these smaller trawling-induced suspended sediment fluxes, 30 days of continuous bottom trawling activity transported a total amount of 40 kg m− 2, of similar magnitude to that generated by a major DSWC event (50 kg m− 2). Since bottom trawling in Palamós Canyon is practiced on a daily basis throughout the year, a much larger contribution of anthropogenically derived water turbidity and suspended sediment transport can be expected.

Estimation of Return Levels for Extreme Skew Surge Coastal Flooding Events in the Delaware and Chesapeake Bays for 1980–2019

Extreme storm surges can overwhelm many coastal flooding protection measures in place and cause severe damages to private communities, public infrastructure, and natural ecosystems. In the US Mid-Atlantic, a highly developed and commercially active region, coastal flooding is one of the most significant natural hazards and a year-round threat from both tropical and extra-tropical cyclones. Mean sea levels and high-tide flood frequency has increased significantly in recent years, and major storms are projected to increase into the foreseeable future. We estimate extreme surges using hourly water level data and harmonic analysis for 1980–2019 at 12 NOAA tide gauges in and around the Delaware and Chesapeake Bays. Return levels (RLs) are computed for 1.1, 3, 5, 10, 25, 50, and 100-year return periods using stationary extreme value analysis on detrended skew surges. Two traditional approaches are investigated, Block Maxima fit to General Extreme Value distribution and Points-Over-Threshold fit to Generalized Pareto distribution, although with two important enhancements. First, the GEV r-largest order statistics distribution is used; a modified version of the GEV distribution that allows for multiple maximum values per year. Second, a systematic procedure is used to select the optimum value for r (for the BM/GEVr approach) and the threshold (for the POT/GP approach) at each tide gauge separately. RLs have similar magnitudes and spatial patterns from both methods, with BM/GEVr resulting in generally larger 100-year and smaller 1.1-year RLs. Maximum values are found at the Lewes (Delaware Bay) and Sewells Point (Chesapeake Bay) tide gauges, both located in the southwest region of their respective bays. Minimum values are found toward the central bay regions. In the Delaware Bay, the POT/GP approach is consistent and results in narrower uncertainty bands whereas the results are mixed for the Chesapeake. Results from this study aim to increase reliability of projections of extreme water levels due to extreme storms and ultimately help in long-term planning of mitigation and implementation of adaptation measures.

Power outage mediates the associations between major storms and hospital admission of chronic obstructive pulmonary disease

BackgroundChronic obstructive pulmonary disease (COPD) is the third-leading cause of death worldwide with continuous rise. Limited studies indicate that COPD was associated with major storms and related power outages (PO). However, significant gaps remain in understanding what PO’s role is on the pathway of major storms-COPD. This study aimed to examine how PO mediates the major storms-COPD associations.MethodsIn this time-series study, we extracted all hospital admissions with COPD as the principal diagnosis in New York, 2001–2013. Using distributed lag nonlinear models, the hospitalization rate during major storms and PO was compared to non-major storms and non-PO periods to determine the risk ratios (RRs) for COPD at each of 0–6 lag days respectively after controlling for time-varying confounders and concentration of fine particulate matter (PM2.5). We then used Granger mediation analysis for time series to assess the mediation effect of PO on the major storms-COPD associations.ResultsThe RRs of COPD hospitalization following major storms, which mainly included flooding, thunder, hurricane, snow, ice, and wind, were 1.23 to 1.49 across lag 0–6 days. The risk was strongest at lag3 and lasted significantly for 4 days. Compared with non-outage periods, the PO period was associated with 1.23 to 1.61 higher risk of COPD admissions across lag 0–6 days. The risk lasted significantly for 2 days and was strongest at lag2. Snow, hurricane and wind were the top three contributors of PO among the major storms. PO mediated as much as 49.6 to 65.0% of the major storms-COPD associations.ConclusionsBoth major storms and PO were associated with increased hospital admission of COPD. PO mediated almost half of the major storms-COPD hospitalization associations. Preparation of surrogate electric system before major storms is essential to reduce major storms-COPD hospitalization.

Nearshore microfossil assemblages in a Caribbean reef environment show variable rates of recovery following Hurricane Irma

AbstractModern microfossil distributions reflect site‐specific habitats and provide an opportunity to assess sediment transport pathways in the nearshore environment. When applied to overwash deposits in the geological record, they provide insight into sediment provenance and transport, factors important for understanding patterns of frequency and intensity of past storms and tsunamis. Modern distribution studies are rare and often the first established ones occur immediately after an overwash event as part of a post‐event field survey. This is problematic because it is unclear what effect overwash events have on nearshore microfossil assemblages and what time interval is necessary for them to return to pre‐event conditions. This study documents the impacts of Hurricane Irma on nearshore sediments off the coast of Anegada, British Virgin Islands, using distributions of Homotrema rubrum, an encrusting foraminifer with a defined provenance in coral reefs. At four sampling intervals spanning two years, from six months pre‐Hurricane Irma to eighteen months after, surface sediment was collected from three transects on the northern and southern shores of the island. Partitioning Around Medoids cluster analysis revealed that Hurricane Irma introduced an influx of well‐preserved fragments into the reef flat and made the sediments more uniform, limiting the foraminifer’s utility as a known sediment transport indicator. The mixing of sediments along the two northern transects (reef proximal) persisted for seven to eighteen months before returning to near pre‐hurricane conditions. However, the southern transect (absence of reef), where Homotrema rubrum concentrations are significantly less, failed to recover within the time period assessed by this study, indicating a variable recovery period between Atlantic Ocean and Caribbean Sea facing shorelines. Results from this study suggest that a waiting period of at least eighteen months after a major storm is recommended before collecting surface sediment from the nearshore environments of reef‐dominated coastlines.