Impact Of Storms Research Articles

Estimating mangrove above-ground biomass at Maowei Sea, Beibu Gulf of China using machine learning algorithm with Sentinel-1 and Sentinel-2 data

Blue carbon ecosystems such as mangroves are natural barriers to resisting and alleviating the impact of storm surges and extreme catastrophic weather. Accurate and efficient determination of the aboveground biomass of mangroves is of great importance for the protection and restoration of blue carbon ecosystems and their response to climate change. This study proposes a light gradient boosting model (LGBM) based on particle swarm optimization (PSO) algorithm for feature selection. We constructed and verified the proposed model using 227 quadrat datasets from a field survey and Sentinel-1 and Sentinel-2 data. The determination coefficient (R 2) and root-mean-square error (RMSE) were used to evaluate the performance of the model. Compared with random forest(RF), K-nearest neighbourhood regression(KNNR), extreme gradient boosting(XGBR), LGBM, and other machine learning algorithms, the LGBM-PSO model achieves better results (R 2 = 0.7807, RMSE = 24.6864 Mg·ha−1), The predicted range of mangrove biomass is 4.623–206.975 Mg·ha−1. Therefore, the use of multisource remote sensing data combined with the LGBM-PSO model can provide better prediction results of aboveground biomass of mangroves, thereby providing a new method for estimating the aboveground biomass of large-scale mangroves.

Tropical storms and the U.S. natural gas demand: how have hurricanes impacted natural gas consumption?

ABSTRACT Studies of the impact of tropical storms on various economic activities including energy production are on the rise given higher frequencies of tropical storms and the increasingly large and negative impact in more recent years. However, we found no academic study of tropical storms on natural gas consumption. This paper provides such a study. In carrying out the empirical investigation, we created a dataset that includes the detailed path of the storms and the cities and states impacted. We estimated the storms’ impact on temperature and also the temperature’s impact on consumption to gauge the specific impact of tropical storms by state and by end use. We found significant storm impact on natural gas consumption, especially consumption of gas to produce power. However, the impact of a typical storm on gas consumption was relatively small on a monthly basis even though it could have a large impact on storm days. This study provides an important empirical result to better understand natural gas price dynamics in the presence of a tropical storm.

The Unique Ability of Fine Roots to Reduce Vegetated Coastal Dune Erosion During Wave Collision

Vegetated coastal sand dunes can be vital components of flood risk reduction schemes due to their ability to act as an erosive buffer during storm surge and wave attack. However, the effects of plant morphotypes on the wave-induced erosion process are hard to quantify, in part due to the complexity of the coupled hydrodynamic, morphodynamic, and biological processes involved. In this study the effects of four vegetation types on the dune erosion process under wave action was investigated in a wave flume experiment. Sand dune profiles containing real plant arrangements at different growth stages were exposed to irregular waves at water levels producing a collision regime to simulate storm impact. Stepwise multivariate statistical analysis was carried out to determine the relationship of above- and below-ground plant variables to the physical response. Plant variables included, among others, fine root biomass, coarse root biomass, above-ground surface area, stem rotational stiffness, and mycorrhizal colonization. Morphologic variables, among others, included eroded sediment volume, cross-shore area centroid shift, and scarp retreat rate. Results showed that vegetation was able to reduce erosion during a collision regime by up to 37%. Although this reduction was found to be related to both above- and belowground plant structures and their effect on hydrodynamic processes, it was primarily accounted for by the presence of fine root biomass. Fine roots increased the shear strength of the sediment and thus lowered erosional volumes and scarp retreat rates. For each additional 100 mg/L of fine roots (dry) added to the sediment, the erosional volume was reduced by 6.6% and the scarp retreat rate was slowed by 4.6%. Coarse roots and plant-mediated mycorrhizal colonization did not significantly alter these outcomes, nor did the apparent enhancement of wave reflection caused by the fine roots. In summary, fine roots provided a unique ability to bind sediment leading to reduced dune erosion.

A study on the wave reflection coefficient near berthing facilities

Introduction. The article deals with the experimental studies on values of the wave reflection coefficient near the structures of berthing facilities with a front vertical wall. The authors present the findings of experimental studies conducted in the form of physical modeling.
 Materials and methods. The method of physical modeling was employed to conduct the experimental studies. These studies are an integral part of the research project that benefits all modern large marine cargo facilities being designed. The method of physical modeling, applied to port facilities, allows obtaining a model wave, identical to that of a full-scale object, and studying interaction between waves and designed hydraulic engineering structures within a pre-set time range. Experiments were conducted in a wave flume of the Hydraulic Engineering Centre for Research and Experiments at NRU MGSU. The most advanced measuring equipment, produced by Wallingford (UK), was used in the experiment.
 Results. As a result of the experiment, the authors obtained values of the coefficient of reflection of waves near a berthing facility with a vertical front wall (the bulwark type of the berthing structure), subjected to the impact of a standard storm. The main Russian regulatory document, SP (Construction regulations) 38.13330.2018 doesn’t have information about the definition of the wave reflection coefficient for all types of hydraulic structures, and the information available there is not exhaustive. The availability of information about the exact values of the wave reflection coefficient for various types of hydraulic structures, such as berthing facilities, can reasonably reduce their elevation, that will ultimately lead to a substantial reduction in construction costs and time.
 Conclusions. The results of these scientific studies will ensure the successful implementation of the most recent designs of seaports, terminals and cargo complexes in unfavourable natural environments, including the harsh climate of Arctic latitudes, regions where raw hydrocarbons and liquefied natural gas are intensively extracted. This will help to solve the priority task of our time: construction of new transshipment facilities along the Northern Sea Route.

Solar Wind Speed Prediction via Graph Attention Network

AbstractThe solar wind is a plasma flow formed by the expansion of the high‐temperature corona and propagates in the interplanetary space with speeds between 200 km/s and 900 km/s. Accurate solar wind speed prediction and longer lead time will help mitigate the impact of solar storms on aerospace equipment and the Earth's magnetic field. Recently, most approaches do not explicitly capture the relationships between different solar wind features, and the prediction accuracy of 96‐hr is still not good enough. This paper elaborately designs an end‐to‐end model: Graph‐Temporal‐AR model (GTA) for solar wind speed prediction. First, our framework considers each feature as the node to construct the graph structure and adopts the graph attention module to learn the complex dependencies among features. Second, our approach employs the dilated causal convolution to extend the receptive field and prolong the prediction time. Furthermore, we leverage the autoregressive model to solve the scale insensitive problem of the neural network, making our model more robust. Specifically, we combine the OMNI data measured at Lagrangian Point 1 (L1) with the extreme ultraviolet images observed by the Solar Dynamics Observatory satellite to predict the solar wind speed at L1. Compared with the baseline models, GTA obtains significant performance improvements. Through visualization, we find GTA excavates the relationships between multiply variables without domain prior knowledge, which may help us find other unknown associations in heliophysics data sets. The data and code are available from https://github.com/syrGitHub/GTA.

On the impact of meridional wind circulation changes in the electron density distribution over the Indian equatorial and low latitude ionospheric region during a severe geomagnetic storm

Using a suite of instruments, which included a chain of ground-based dual-frequency GPS receivers, and magnetometers, we have studied the importance of thermospheric meridional wind circulation in controlling the distribution of plasma over the Indian low latitude ionospheric regions during the period of a severe geomagnetic storm. The storm on 15 May 2005, which had its onset coinciding with the local noon time sector for the Indian ionospheric zone, was a severe geomagnetic storm with symH ∼ - 305 nT. A steep increase in the Total Electron Content (TEC) of the ionosphere over the entire Indian ionospheric region was observed on May 15. The enhancement in the TEC was well correlated with the increase in ΔH at the dip-equator due to the prompt penetration of the convection electric field associated with the storm. However, contrary to the previous studies on the storm impact over low latitude regions, a clear signature of disturbance dynamo was absent on the day after the storm. Enhancements in the TEC were observed on May 16, a day after the storm, as well, though the ΔH at the dip-equator was quite below the quite-time mean. The TEC remained well above its monthly mean over the entire Indian ionospheric region during the storm recovery period. We suggest that the TEC enhancement on May 16, even though it looked like due to a prompt penetration effect, was directly related to the compositional disturbances as given by the O/N2 ratio. We conclude that the meridional wind circulation plays an important role in the distribution of electron density over the equatorial and low latitudinal region during the period of a geomagnetic storm.

沙尘暴对火星表面探测器的影响<bold>: </bold>回顾与展望

沙尘暴会对火星表面探测器带来发电量减少、环境温度降低、通信不稳定和仪器污染等方面的影响。为保障我国祝融号火星车的安全运行及未来火星表面探测任务的顺利开展，亟需评估沙尘暴对火星表面探测器的影响。通过系统性地回顾1997-2018年间火星表面探测器（包括着陆器与火星车）对沙尘的响应，初步认清了沙尘对火星表面探测器的影响规律——探测器太阳能电池阵列表面的尘埃以比较稳定的速率积累，而尘埃的沉积速率在沙尘暴期间，尤其是全球性沙尘暴期间会大大加快；同时，受多方面影响，电池阵列表面也会发生具有季节性模式的除尘事件。为规避沙尘暴带来的风险，美国洞察号着陆器（InSight）在设计阶段就全面评估了沙尘暴对其着陆硬件系统及太阳能电池阵列的影响，并采取了一系列应对措施。洞察号应对沙尘暴的举措为我国未来的火星采样返回任务提供了重要启迪——前瞻性的科学指导是保障工程任务成功实施的关键。通过分析我国火星采样返回任务的初步轨道设计方案，建议未来火星探测器发射的最优窗口为2028年1月左右，以合理规避沙尘暴带来的风险。

Increase in Suspended Sediment Contents by a Storm Surge in Southern Bohai Sea, China

Most of the existing results were related to the impact of land storms on sediment, and few explained the impact of storms on sediment movement and its formation law from the mechanism. At present, the research on the impact of storm on sediment suspension on the North Bank of Longkou City in the south of Bohai Sea was not clear. Therefore, this study aimed to explore the formation and mechanism of storm on suspended sediment from the perspective of hydrodynamic characteristics and sediment distribution by monitoring the impact of storm on sediment suspension in the south of Bohai Sea. A storm with wind speeds of 4.5–13.5 m/s occurred in the coastal area of the north side of Longkou City located in Southern Bohai Sea in April, 2015. Suspended sediment samples were obtained using automatic samplers, and the results showed that the suspended sediment content was 7.8 mg/L under normal weather conditions, which reached 121.2 mg/L at the highest during the storm event. Waves and tides were synchronously observed by acoustic Doppler current meter. Wave height was more closely correlated with wind speed when the wind veered to north, and the maximum wave height was 243 cm. The reciprocating motion of the current at the sampling site was strong, with the maximum current speed of 43.8 cm/s and a water depth of 10 m. The results of laser analysis showed that the bottom sediments were composed of 92% sand and 8% silt, with a medium diameter of 0.102 mm. From the experimental observation and result analysis, it was known that the strong dynamic process during storm surge led to the movement of sediment surface and the resuspension of sediment.

Estimation of Affected Customers and Load Loss Under Wind Storms in the Caribbean Region

The disruption of extreme weather events can significantly impact the operation of nation’s critical infrastructures. With the growing trend of extreme weather events in the Caribbean region, evaluating hazard effects of wind storms on power distribution systems becomes increasingly important for disaster preparedness and fast responses in utilities. These catastrophic events disable critical paths of electricity overhead infrastructure, resulting in extended power outages and loss of critical services. In this article, probabilistic wind storm models for the study region have been built by mining the 169-year storm events recorded in the Hurricane Database from the National Hurricane Center of the National Oceanic and Atmospheric Administration. In addition, a simulation approach is presented to evaluate the impacts of wind storms over the power distribution system under different levels of hazards using a random storm trajectory generator and geographic information system data. Extensive studies for the Puerto Rico’s electrical distribution system indicate that our models and procedure effectively estimate the number of affected customers and load loss due to a wind storm impact.

Cyclone Impacts on Coral Reef Communities in Southwest Madagascar

Tropical cyclones can cause severe destruction of coral reefs with ecological consequences for reef fish communities. Ocean warming is predicted to shorten the return interval for strong tropical cyclones. Understanding the consequences of cyclone impacts on coral reefs is critical to inform local-scale management to support reef resilience and the livelihood security of small-scale fishing communities. Here, we present the first analysis of a tropical cyclone disturbance on coral reefs in Madagascar. We investigate the impact of Cyclone Haruna (category 3 Saffir-Simpson scale) in February 2013 on coral communities, both adults and recruits, and explore the relationship between the severity of cyclone impact with cyclone parameters (wind speed, duration of storm impact and distance from cyclone track) and environmental variables (reef type and reef depth). We use survey data collected as part of a long-term citizen science monitoring programme at 21 coral reef sites between 2012 and 2015 in the Velondriake Locally Managed Marine Area along Madagascar’s southwest coast. Coral cover declined at 19 sites, however damage was spatially heterogeneous ranging from a decrease in coral cover of 1.4% to 45.8%. We found the severity of cyclone damage related to: distance from the cyclone track, duration of cyclone impact and reef depth. The taxonomic and morphological composition of coral communities was significantly different after the cyclone. Notably, there was a decrease in the dominance of branching morphologies, and an increase in the relative abundance of encrusting and massive morphologies. Two years after Cyclone Haruna, mean coral cover had increased and the density of coral recruits increased to above pre-cyclone levels indicating the potential recovery of coral populations. However, recovery to pre-disturbance community composition will likely be hindered by the increasing occurrence of acute and chronic disturbance events.

COMBINED FLOODING AND WATER QUALITY MONITORING DURING SHORT EXTREME EVENTS USING SENTINEL 2: THE CASE STUDY OF GLORIA STORM IN EBRO DELTA

Abstract. Short extreme events have significant impact on landscape and ecosystems in low-lying and exposed areas such as deltaic systems. In this context, this paper proposes a combined methodology for the mapping and monitoring of the flooding and water quality dynamics of coastal areas under extreme storms from Sentinel 2 imagery. The proposed methodology has been applied in a coastal bay of the Ebro Delta (Catalonia, NE Spain) to evaluate jointly the impact of Gloria storm (January 2020) in land-flooding and water quality. The experimental results show that the Gloria storm had a strong morphological impact and altered the water quality (chl-a) dynamics. The results show a recovery in terms of water quality after some weeks but in contrast the coastal morphology did not show the same degree of resilience. This paper is the first step of an overall goal that is to set the bases in a long term, for a workflow for rapid response and continuous monitoring of storm effects in coastal areas and/or highly valuable ecosystems such as the Ebro Delta.

OPTIONS FOR ADAPTATION OF URBANIZED AREAS TO CLIMATE CHANGE INDUCED EXTREME RAINFALLS

Abstract. The impacts of the climate change progress in a form of heavy cloudbursts, have been being reported over the course of last decade from many world cities. The consequences of this phenomenon are causing damages to urban infrastructure and private properties, and they affect urban transport as well as other primary city functions. In this respect we should ask question, if and to which extent can our society be protected against these extreme hydrological processes. The paper focuses on current adaptation possibilities of cities and settlements to mitigate the impact of extreme heavy storms resulting in sudden flash floods, regardless of the location and elevation of the particular place. The impact of such cloudbursts on urban drainage performance in the city of Prague is analysed by means of coupled 1D and 2D simulation model supported by DEM and GIS technology as well as services of Google Maps. The influence of climate change in terms of growing rainfall intensities is assessed by an indicator called „Climate Factor“. The authors present that the only way of adapting cities to these rainfall extremes is based on a proper management of rainfall water outflow on the catchment surface.

An extensive dust storm impact on air quality on 22 November 2018 in Sydney, Australia, using satellite remote sensing and ground data

Recurrent dust storms represent a significant concern in Australia because of their related hazards and damages since particulate matter (PM) has harmful impacts on the environmental, health and economic sectors. The particulate matter may be released from natural sources and human activities. The major part of natural particulate matter is emitted into the air by wind erosion processes from desert and semi-desert areas at the world scale. A huge dust storm crossed over several areas of New South Wales (NSW), Australia, including the Sydney region on 21–22 November 2018 and decreased the horizontal visibility to less than 1 km for 22 h. This study examined the synoptic weather conditions, and assessed the air quality and identified the source and transport trajectory of the dust storm over Sydney using ground and satellite remote sensing data. PM10 (< 10 μm) concentrations were obtained from selected air quality monitoring sites operated by the Environmental Protection Agency in NSW. The highest hourly concentration of PM10 (578.7 μg/m3) was recorded at Singleton in the Hunter Valley, while concentrations in Sydney ranged from 480 to 385 μg/m3, well above the standard air quality level in Australia (50 μg/m3 per 24 h). The HYSPLIT back trajectories of air parcels suggest that the potential sources of the dust episode originated from the Lake Eyre Basin and northeast South Australia, the Mundi Mundi plains west of Broken Hill, Cobar and the grazing lands and the red sandplains in northwestern NSW. It then travelled towards the east coast. These long-range airflows transported suspended dust particles, raising air quality to hazardous levels (elevated PM10 levels) over most areas of NSW. The results from the HYSPLIT model for dust movement are confirmed by MODIS satellite images. Many areas of NSW experienced this intense dust storm due to northwest wind generated by the low-pressure systems and cold fronts over South Australia and many parts of western NSW as it moved eastward.

Estimating the Different Return Periods of Storm Impact Regimes on Beach and Foredune Systems Based in Hindcast Data: Applications to Exposed and Sheltered Beaches of Santa Catarina Island, Brazil

Prado, M.F.V.; Dalinghaus, C.; Gomes da Silva, P.; Weschenfelder, J., and Klein, A.H.F., 2022. Estimating the different return periods of storm impact regimes on beach and foredune systems based in hindcast data: Applications to exposed and sheltered beaches of Santa Catarina Island, Brazil. Journal of Coastal Research, 38(4), 844–859. Coconut Creek (Florida), ISSN 0749-0208. This paper presents an adapted methodology to estimate the different return periods of storm-induced impacts on beaches and foredune systems based on hindcast data, with examples of applications in areas exposed to and sheltered from the wave action. The methodology consists of using wave, tide, and surge reanalysis data to obtain large series of total water level, which are used to estimate the values related to different return periods (5,10, 25, and 50 years). Those levels are summed to the corresponding projection of sea level rise from the worst-case scenario projections. The final values are used to classify the beaches according to the coastal storm impact regime as (1) swash, (2) collision, (3) overwash, and (4) inundation. Finally, the limit between each regime is established based on the relation among dynamical and geomorphological parameters. The methodology was applied to the east (exposed beaches) and north (sheltered beaches) coasts of Santa Catarina Island (Florianópolis, Southern Brazil), a zone constantly submitted to extreme storm events and where large series of measured data are commonly missing. The results for Santa Catarina Island indicate that the storm impact regime in most of the exposed beaches is similar for different return periods (most of them classified as collision regime). Overwash regime is predominant on sheltered beaches. Sectors with an intense urban occupation are classified as under inundation regime for all return periods, while zones with well-developed foredune are classified as the collision regime. Some of those results could be qualitatively verified with observations from recent storm events, highlighting the value of this kind of methodology to estimate the impact of coastal storms in zones with an important lack of measurements.

Microbially induced sedimentary structures (MISS) generated by episodic storm surges in a temperate coast

This study recognizes the creation of primary sedimentary structures in a modern environment that reports valuable insights into the role of microbiota in sculpting sedimentary structures, and it may explain many previously confusing sedimentary structures in the rock record. The research considered the frequent flooding events on a coastal sedimentary flat colonized by microbial mats and the effect produced by severe storm surge events. Large-scale microbially induced sedimentary structures (MISS) were created; thus, the interaction between meteorologic, oceanographic, and geomorphologic conditions necessary to form them was analysed. The study was developed in Paso Seco, Argentina (40°38′31” S - 62°12′54” W), a sedimentary flat behind a sand spit, coated by thick microbial mats recurrently affected by storm events. Water level measurements were recorded continuously for five years (measurement interval 10 min). The seawater inundations were related to synoptic weather maps and oceanographic parameters (wave height, period, and tides) to analyse the cause of storm surges. Two situations of severe storms were studied in 2018 and 2019. The inundation of the study area occurs when a cold front in association with a low-pressure centre in the Atlantic Ocean, moving in an SW-NE direction, produces strong SW winds higher than 45 km h−1 and wave height higher than 2 m. Strong winds and storm duration (two or three days) in co-occurrence with spring tides create an extreme erosional event that affects the sedimentary microbial flat. In sum, the interaction between storm surge, high tide, wave setups and wave heights in Paso Seco produces coastal hinterland flooding that creates meter-sized MISS such as roll-ups, erosional pockets, and remnants mats structures. The impact of storm surges on the coast is common and catastrophic in modern times but is challenging to identify in the sedimentary record. Therefore, the microbial structures presented here could help interpret high-energy events occurrence, favourable to assessing past environmental conditions.

Climatic Controls on the Spring Phytoplankton Growing Season in a Temperate Shelf Sea

AbstractThe Northwest European Shelf is positioned directly beneath the North Atlantic Storm Track, within which the frequency and intensity of transient storms are modulated by large‐scale climatic oscillations. In temperate shelf seas, the impact of storms on the physical environment has received considerable attention, but the effect on biogeochemistry is less studied. Here, we use output from a multidecadal (1982–2015) coupled physical‐biogeochemical model supported by observations from ocean gliders to investigate phytoplankton growth throughout the winter‐spring transition. We define two separate phytoplankton growth events: the spring bloom, defined as the exponential growth following seasonal stratification, and the prebloom, occurring before stratification, and accounting for up to 22% of the total spring growth. Our results support the paradigm that light is a first‐order control, with the spring bloom initiating up to 22 days after stratification onset should light levels be too low to trigger the bloom. The prebloom is heavily influenced by the phase of the Atlantic Multidecadal Oscillation (AMO), demonstrated by an acceleration in the rate of increase of total chlorophyll concentrations (±90% confidence limit) from 7.6 ± 2.8 mg m−2 d−1 (during a positive AMO) to 13.1 ± 4.3 mg m−2 d−1 (negative AMO), due to modulation of periods of ephemeral stratification that occur between successive storms. We propose that phytoplankton growth in prebloom events might help buffer the lag between phytoplankton supply and larval recruitment, particularly during years when the spring bloom is delayed.

Impacts of Hurricane Matthew on adjacent developed and undeveloped barrier islands in southeastern North Carolina

High-magnitude storms such as hurricanes can cause significant and potentially long-lasting morphological coastal change, particularly along low-lying barrier islands. This study investigated the impacts of Hurricane Matthew (2016) on neighboring undeveloped Masonboro Island reserve and engineered/nourished Wrightsville Beach barrier islands, located in southeast North Carolina. Using a combination of high-resolution pre- and post-storm RTK–GPS beach surveys, coupled with direct observations, storm surge and wave runup calculations and aerial imagery, a range of contrasting storm-induced coastal changes and impact regimes were identified across the two adjacent barriers. Storm impacts were especially pronounced across low-lying undeveloped central/southern Masonboro Island, which was dominated by significant overwash processes, leading to landward directed barrier crest migration. In contrast, only short-lived and minor collision with the dune base was observed at Wrightsville Beach, were storm impacts were dominated by a swash storm regime resulting in significant beach erosion. Field- and aerial based observations match well with modeled extreme water level estimates. This study offers a real-time example of how geomorphologically different neighboring islands respond to specific storm events, and how storm impact regime type and duration helps explain differences in barrier responses. Similar storm impacts are likely at other locations with comparable barrier island settings and differing coastal management approaches.

Investigation of June 2020 giant Saharan dust storm using remote sensing observations and model reanalysis

This paper investigates the characteristics and impact of a major Saharan dust storm during June 14th–19th 2020 on atmospheric radiative and thermodynamics properties over the Atlantic Ocean. The event witnessed the highest ever aerosol optical depth for June since 2002. The satellites and high-resolution model reanalysis products well captured the origin and spread of the dust storm. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) measured total attenuated backscatter and aerosol subtype profiles, lower angstrom exponent values (~ 0.12) from Modern-Era Retrospective Analysis for Research and Application—version 2 (MERRA-2) and higher aerosol index value from Ozone monitoring instrument (> 4) tracked the presence of elevated dust. It was found that the dust AOD was as much as 250–300% higher than their climatology resulting in an atmospheric radiative forcing ~ 200% larger. As a result, elevated warming (8–16%) was observed, followed by a drop in relative humidity (2–4%) in the atmospheric column, as evidenced by both in-situ and satellite measurements. Quantifications such as these for extreme dust events provide significant insights that may help in understanding their climate effects, including improvements to dust simulations using chemistry-climate models.

Primary Outcomes for Adults Receiving the Unified Protocol after Hurricane Harvey in an Integrated Healthcare Setting.

The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP) has demonstrated efficacy for treating anxiety and depression. However, there are limited effectiveness data when conducted in real-world settings with diverse populations, including those with trauma. We evaluated treatment outcomes in a naturalistic, community setting among 279 adults who received UP following Hurricane Harvey. We examined change in overall clinical severity, depression and anxiety symptoms, functional impairment, and baseline outcome predictors (i.e., demographic characteristics, impact from Hurricane Harvey, co-occurrence of depression and anxiety symptoms). Global clinical severity, depression and anxiety symptoms, and functional impairment decreased by end-of-treatment. Participants experienced global symptom improvement to a lesser degree than demonstrated in efficacy trials. Participants who experienced greater storm impact reported larger reductions in anxiety symptoms than those less impacted by Harvey. Further studies evaluating the effectiveness of the UP post-disaster and with diverse samples are needed.

Chemical characteristics and source apportionment of particulate matter (PM2.5) in Dammam, Saudi Arabia: Impact of dust storms

Atmospheric particulate matter (PM) is known to be harmful to human and environmental health, with factors including particle size and composition thought to be key drivers of toxicity. Understanding the composition and hence sources of PM is critical to distinguish between anthropogenic and natural impacts, and develop the most efficient air pollution mitigation policies. This distinction is particularly important in areas affected by dust storm activity from nearby arid regions, which may dominate long-term PM mass concentrations. In this work, 24-hour PM 2.5 samples were collected from two locations in Dammam city, Saudi Arabia during the winter and summer of 2018, and subjected to detailed analysis to assess the PM characteristics and sources. Offline chemical analysis of the samples utilied ICP/MS, ion chromatography and thermal decomposition for measurement of trace metals, ions and OC/EC concentrations, respectively. Positive Matrix Factorization (PMF) analyses were used to identify sources of PM 2.5 in Dammam. The mean PM 2.5 mass concentration in the summer was twice that in the winter at both locations, and crustal and secondary inorganic aerosol components dominated over other species in determining PM 2.5 mass concentrations at both seasons and locations. The PMF analysis identified six source factors, including crustal, nitrate-rich, sea salt, sulfate-rich, biomass burning and traffic sources. In addition, the impact of dust storms on PM 2.5 concentrations was analysed. Dust storms increased the 24-hour average concentration of PM 2.5 by three-fold, and that of crustal elements by five-fold while the impact of dust storms on components identified as anthropogenic in origin was limited. Overall, dust-storm activity accounted for 42% of PM 2.5 mass concentration; after accounting for this aspect, secondary inorganic components derived largely from primary pollutant emissions dominated the remaining PM 2.5 mass. • Comprehensive assessment of PM 2.5 composition and sources in Dammam, Saudi Arabia. • Average 24-hour PM 2.5 mass concentrations ranged from 54 to 121 ug/m 3 . • Dominant components found to be crustal elements, metals, organic and inorganic carbon. • Anthropogenic sources accounted for 40% of PM 2.5 mass, rising to 58% if dust storm periods were excluded. • These results highlight emissions control priorities to improve air quality in Saudi Arabia.