Changes In Barometric Pressure Research Articles

Study of Methane Outgassing and Mitigation in Longwall Coal Mines

Historically, there have been many occurrences of mine fires and explosions recorded in the United States and other countries that have demonstrated the existence of explosive methane–air mixtures, herein referred to as explosive gas zones (EGZs). The risk of mine explosions can increase if the EGZs migrate out from the gob into the surrounding mine entries. Fluctuating barometric pressure is the common cause for EGZs outflowing or outgassing from the gob. Numerical analysis using a 3D computational fluid dynamics method was developed to fully understand the outgassing phenomenon. A number of simulations using various magnitudes and periods of barometric pressure changes indicated that the EGZ outgassing potentially occurs due to lags in pressure, which are strongly influenced by mine conditions and ventilation systems. An early warning system with a real-time pressure monitoring and the application of gob ventilation boreholes are recommended to detect and mitigate explosion hazards from gob outgassing.

Membranous or Hypermobile Stapes Footplate: A New Anatomic Site Resulting in Third Window Syndrome.

Objectives: To describe a potentially underappreciated pathology for post-traumatic persistent intractable dizziness and third window syndrome as well as the methods to diagnose and surgically manage this disorder.Study Design: Observational analytic case studies review at a tertiary care medical center.Methods: Patients suffering persistent dizziness following head trauma and demonstrating Tullio phenomena or Hennebert signs are included. All had reportedly normal otic capsules on high resolution temporal bone CT scans (CT). The gray-scale invert function was used to visualize the stapes footplate, which helped determine the diagnosis. Gray-scale inversion can be used to improve visualization of temporal bone anatomy and pathologic changes when diagnoses are in doubt. A search to check for the presence of perilymph leakage was performed in all cases. This was accomplished using intraoperative Valsalva maneuvers. Fat grafting of round and oval windows was performed.Results: Over an 11-year period between January 2009 and December 2019, 28 patients (33 ears) were treated. Follow-up with balance testing and audiograms were performed 6–8 weeks following surgery. Follow-up ranged from 6 months to 7 years. Prior to surgery all patients reported dizziness in response to loud sounds and/or barometric pressure changes. Seven out of 33 ears had demonstrable perilymph leakage into the middle ear; the rest (26 ears) appeared to have membranous or hypermobile stapes footplates. Membranous stapes footplates were better visualized using the invert function on CT. Thirteen patients had a fistula sign positive bilaterally while 15 had unilateral pathology. Twenty-four of the 28 patients (85.7%) showed both subjective and objective improvement following surgery. No patients suffered from a deterioration in hearing.Conclusions: A previously underappreciated membranous or hypermobile stapes footplate can occur following head trauma and can cause intractable dizziness typical of third window syndrome (TWS). Durable long term success can be achieved by utilizing fat graft patching of the round and oval windows. High resolution temporal bone CT scans using the gray-scale inversion (invert) function can assist in preoperative diagnosis.

Relationship between synoptic weather type and emergency department visits for different types of pain across the Triangle region of North Carolina.

Many people around the world are impacted by some form of bodily pain. Outside factors, such as weather, are thought to help trigger pain, especially in those who have pain-related conditions. When it comes to human health and comfort, understanding the potential external factors that aide in triggering pain is essential. Identifying such factors makes prevention and treatment of pain more feasible. This study focused on how those who suffer from various pain-related conditions (fibromyalgia, rheumatoid arthritis, osteoarthritis, and general back pain) are impacted by different synoptic weather types (i.e., air masses). Synoptic weather types and emergency department (ED) visits for pain in select central North Carolina counties were collected over a seven-year period to determine a potential relationship. Bootstrapped confidence intervals revealed that moist tropical weather types resulted in the highest number of ED visits for each of the conditions examined, while moist polar weather types often resulted in the fewest. The barometric pressure changes associated with transitional weather types, which are often associated with fronts, did not have any significant relationships with pain.

Beyond Barnwell: Applying lessons learned from the Barnwell site to other historic underground nuclear tests at Pahute Mesa to understand radioactive gas-seepage observations

An underground nuclear explosion (UNE) generates radioactive gases that can be transported through fractures to the ground surface over timescales of hours to months. If detected, the presence of particular short-lived radionuclides in the gas can provide strong evidence that a recent UNE has occurred. By drawing comparisons between sixteen similar historical U.S. UNEs where radioactive gas was or was not detected, we identified factors that control the occurrence and timing of breakthrough at the ground surface. The factors that we evaluated include the post-test atmospheric conditions, local geology, and surface geology at the UNE sites. The UNEs, all located on Pahute Mesa on the Nevada National Security Site (NNSS), had the same announced yield range (20–150 kt), similar burial depths in the unsaturated zone, and were designed and performed by the same organization during the mid-to-late 1980s. Results of the analysis indicate that breakthrough at the ground surface is largely controlled by a combination of the post-UNE barometric pressure changes in the months following the UNE, and the volume of air-filled pore space above the UNE. Conceptually simplified numerical models of each of the 16 historical UNEs that include these factors successfully predict the occurrence (5 of the UNEs) or lack of occurrence (remaining 11 UNEs) of post-UNE gas seepage to the ground surface. However, the data analysis and modeling indicates that estimates of the meteorological conditions and of the post-UNE, site-specific subsurface environment including air-filled porosity, in combination, may be necessary to successfully predict late-time detectable gas breakthrough for a suspected UNE site.

Adverse weather conditions impede odor-guided foraging of parasitoids and reduce their host-finding success

Biological pest control depends on the ability of natural enemies to find herbivore-infested plants, which is often guided by herbivore-induced plant volatiles (HIPVs). While foraging behavior of natural enemies has been extensively studied under controlled conditions, little is known on how odor-guided foraging behavior is influenced by fluctuating weather conditions in the field.Here we investigated how HIPV-guided foraging of Cotesia glomerata parasitoids is influenced by prevailing weather conditions in the field. C. glomerata females were released in 5 m radius circles of cabbage plants infested with Pieris brassicae caterpillars, and host finding success and direction of foraging activity was assessed by recapturing parasitoids on the host-infested plants. Wind speed and direction, humidity, barometric pressure and temperature was recorded and related to parasitoid foraging activity. Parasitoid foraging behavior was studied in more detail by observing individually released parasitoids in 0.5 m circles with host-infested cabbages.Recapture rates and movement direction of parasitoids was influenced by an interaction between humidity, wind speed, temperature and change in barometric pressure. High humidity and low wind speed was generally positively associated with host finding success. Direct observations of parasitoid flight behavior confirmed the influence of humidity and wind speed. Successful host finding in upwind direction was only observed at wind speeds below 3 m/s.Our study highlights the complex ways in which weather variables moderate parasitoid foraging behavior under field conditions. Since unfavorable weather conditions result in a strong reduction in parasitoid foraging efficiency, weather conditions are an important factor in the effectiveness of parasitoids as biocontrol agents.

An information fusion approach for conflating labeled point-based time-series data

In geographic data analysis, it is often the case that multiple aspects of a single phenomenon are captured by different sources of data. For instance, a storm can be identified based on its precipitation, as well as windspeed, and changes in barometric pressure. It proves beneficial in specific domains to be able to use all available sources of data, and some method must be used to integrate all of these sources of data into a singular decision, often in the form of a classification. This paper proposes the general form of what has been termed the Class Label Conflation Problem – the problem of taking a number of distinct and possibly conflicting sources in the form of spatially-located time series, and using this historical dataset to determine a class label at a new location. In addition to this formalization, this paper details an algorithm (called ACCL) to solve the general case of the problem. This algorithm has its foundations in information theory (specifically Dempster-Shafer Theory), supervised classification, and data fusion. An analysis of the algorithm demonstrates its effectiveness using synthetic datasets as well as the US Drought Monitor as a case study.

Time response characteristics of a highly sensitive barometric pressure change sensor based on MEMS piezoresistive cantilevers

This paper describes the frequency characteristics of a highly sensitive barometric pressure change sensor. Here, we propose a method to measure pressure changes based on microelectromechanical systems piezoresistive cantilevers and an air chamber. The proposed sensor structure realizes a mechanical high pass filter to eliminate the influence of the barometric pressure change due to meteorological variations. The experimental frequency characteristics indicate that the proposed sensor unit with a high resolution of less than 0.1 Pa from 0.1 to 10 Hz responds to pressure changes with a high pass filter property according to the chamber volume size.

Premature Rupture of Membranes and Severe Weather Systems.

There has long been anecdotal evidence of early labor and delivery in severe weather events leading to preterm birth. In particular, significant barometric pressure changes are associated with hurricanes and bomb cyclones. Some authors have related these low pressure weather events to premature rupture of fetal membranes, hypothesizing that the membranes act as an inflated balloon and respond directly to pressure changes. In this article, the key literature including data supporting this hypothesis is reviewed. A simple numerical model, based on a competition between the driving and resisting forces for fetal membrane rupture, is presented. This model provides a quantitative mechanism for membrane failure in the context of storms with low atmospheric pressure. Other sequelae of severe storms that are unrelated to fetal membrane rupture are also discussed. Labor and delivery in the context of major weather events should be understood in a holistic framework that includes both exogenous and endogenous factors relevant to the pregnant patient.

PND55 IMPACT OF BAROMETRIC PRESSURE CHANGES AND PROPHYLACTIC MIGRAINE MEDICATION USE ON THE OCCURRENCE OF SEVERE MIGRAINES: A CASE-CROSSOVER STUDY USING LINKED WEATHER AND CLAIMS DATA

Severe migraine patients may use prophylactic medications to reduce the number or severity of their headaches. Patients often experience a migraine after a meteorological change, and the association between these events and occurrence of severe migraines for patients with and without prophylactic use was examined. A case-crossover design was implemented utilizing the IBM® MarketScan Weather Database, which links weather data with administrative claims data using metropolitan statistical area (MSA)-specific daily weather data and the patients’ MSA from administrative claims. Patients with ≥1 severe migraine (a migraine-related inpatient or emergency room visit) between 2015 and 2017 were selected. The date of the first severe migraine was the ‘case date.’ Patients were stratified by whether or not they had a pharmacy claim for medication commonly used for migraine prophylaxis between 180 days before and 7 days after the case date. Three control dates were selected for comparison: 7 days before, 28 days before, and 7 days after the case date. Weather conditions on the case date versus control dates were compared via conditional logistic regression model to determine if weather conditions were predictive of a severe migraine for patients with or without prophylactic. The study included 34,776 patients who met the inclusion criteria. Of these, 17,508 patients used a prophylactic, while 17,268 did not. The conditional logistic regression model revealed that for each 1 inHg increase in daily maximum barometric pressure, the odds of severe migraine increased by 9% (OR: 1.09; p=0.025) for patients with prophylactic, and by 56% (OR: 1.56; p<0.001) for those without, controlling for other weather conditions. This study utilized a novel linked weather and administrative claims database to provide real-world evidence of the impact of prophylactic medication use on severe migraine events after changes in barometric pressure.

Association Between Spontaneous Cervical Artery Dissection and Changes in Barometric Pressure (2144)

Association Between Spontaneous Cervical Artery Dissection and Changes in Barometric Pressure (2144)

Using water-level fluctuations in response to Earth-tide and barometric-pressure changes to measure the in-situ hydrogeological properties of an overburden aquifer in a coalfield

For the quantitative evaluation of the impact of mining on a groundwater system, it is necessary to constrain the hydrogeological and mechanical properties. However, the in situ estimation of the mechanical properties of rock such as compressibility and porosity, is often difficult. Additionally, determining the hydraulic properties such as hydraulic conductivity, of rock by conventional methods is often expensive. The response of the groundwater level to external loading such as Earth tides and barometric pressure, couples the hydrogeological and mechanical processes of rocks, thus providing a way to infer these properties in the field. This study compared aquifer parameters inferred from tidal and barometric responses with those inferred from conventional hydraulic tests and rock mechanics tests in three groundwater monitoring wells at a site in China. The results show that the hydraulic conductivity inferred from a tidal response is similar to that of a pumping test. The compressibility values calculated for the three wells are all higher than those determined by experiment, and the porosity values calculated are all lower than those determined by experiment, but the differences between the calculated and experimentally measured values are lower than one order of magnitude. Considering the costs and convenience of the water-level response method, this method is a good choice for obtaining the properties of an aquifer, especially those in areas of tectonic activity and those affected by anthropogenic perturbations.

The effect of atmospheric pressure on oxygen saturation and dyspnea: the Troms\xf8 study

A drop in atmospheric pressure, as observed at high altitudes, leads to decreased oxygen saturation. The effect of regular changes in barometric pressure at sea level has never been studied in a general population. A cohort of adults aged 40 years were examined with pulse oximetry at two separate visits, and the local barometric pressure was available from the local weather station. The study aimed at determining the effect of atmospheric pressure on oxygen saturation also called SpO2, as well as on shortness of breath. Based on spirometry, the participants were divided into two groups, with normal and decreased lung function. Decreased lung function was defined as forced expiratory volume in 1 s (FEV1) below lower limit or normal (LLN) or FEV1/FVC (FVC, forced vital capacity) below LLN, with GLI 2012 reference values. The statistical analysis included uni/multivariable linear and logistic regression. A total of 7439 participants of the Tromsø 7 cohort study were included. There was a significant association between barometric pressure and SpO2 < 96%, and we found that a reduction of 166.67 hPa was needed to get a 1% reduction in SpO2. The change in atmospheric pressure was not significantly associated with shortness of breath, also not in subjects with reduced lung function.

Influence of Meteorological Conditions on the Incidence of Chronic Subdural Haematoma, Subarachnoid and Intracerebral Haemorrhages - the "Bleeding Weather Hypothesis".

To elucidate possible causal relationships on climate change and intracranial haematomas. In a retrospective study we examined all patients (N=1169) treated for subarachnoid haemorrhage (SAH; n=484), intracerebral haemorrhage (ICH; n=417) or chronic subdural haematoma (CSDH; n=268) in our department over a 7-yearperiod between 1st June 2005 until 31th May 2012. The date of admission was correlated with the corresponding meteorological parameters which included; mean daily temperature (°C), relative humidity (%), vapor pressure (hPa), barometric pressure (hPa), cloud amount (/8), and wind speed (m/s). Incidence of SAH tended to increase in April, ICH in January and CSDH in July, respectively, but ?² test did not reveal any statistical significance in seasonality for the three bleeding pathologies. Comparing the arithmetic average of meteorological key parameters of uneventful and eventful days by using student?s t-test within the three groups (SAH, ICH, CSDH) we could not demonstrate any statistical significance (p > 0.05). For SAH, logistic regression analyses revealed an increased risk associated with a decrease of barometric pressure (p=0.021). Although our data suggest seasonal variabilities of SAH, ICH and CSDH, the single weather parameters do not demonstrate causal relationships with the incidence of cerebrovascular events. However, incidence of SAH tended to increase with changes of barometric pressure which confirms previously published results and might indicate a possible underlying relationship.

Heterogeneous Permeability Changes along a Fault Zone Caused by the Xingwen M5.7 Earthquake in SW China

AbstractEarthquakes can change permeability. Continuous monitoring of the response of water level to solid Earth tides or changes in barometric pressure provides an opportunity to document how earthquakes influence permeability. Here we document spatial variations in changes in a fault zone in SW China. The response of the water level to barometric pressure and the Earth tide in four observation wells was used to calculate the relative changes in permeability at different locations on the fault before and after the Xingwen M5.7 earthquake. The results revealed that the earthquake resulted in a spatial heterogeneity in permeability changes along the Huarongshan fault. Moreover, permeability changes in the horizontal and vertical directions differed from one another at the same well location; that is, there was anisotropy at each location. These findings will help to enhance the understanding of earthquake‐induced changes of permeable fault structure and fault segment deformation.

Headache and Barometric Pressure: a Narrative Review.

Alterations in atmospheric pressure have been long associated with headaches. The purpose of this review article is to investigate the association of barometric pressure with headache, classifying into two broad categories primary headache disorders (barometric pressure triggering migraine or tension-type headache) and secondary headache disorders (barometric pressure triggering high-altitude headache and headache attributed to airplane travel), discussing the pathophysiology and possible treatments. Multiple studies have been performed with inconsistent results regarding the directionality of the association between atmospheric pressure changes and triggering of primary headache disorders, chiefly headaches. Atmospheric pressure is also a trigger of two secondary headache disorders, i.e., high-altitude headache and headache attributed to airplane travel. Hypothesized mechanisms include excitation of neurons in trigeminal nucleus, central and peripheral vasoconstriction, barotrauma, and hypoxia. There are no randomized clinical trials regarding effective acute or preventive treatments. Greater understanding of pathophysiology may enable both acute and preventive treatments for headaches triggered by changes in barometric pressure. Further studies on the subject are needed.

Tropical cyclones alter short-term activity patterns of a coastal seabird

BackgroundMobile organisms in marine environments are expected to modify their behavior in response to external stressors. Among environmental drivers of animal movement are long-term climatic indices influencing organism distribution and short-term meteorological events anticipated to alter acute movement behavior. However, few studies exist documenting the response of vagile species to meteorological anomalies in coastal and marine systems.MethodsHere we examined the movements of Eastern brown pelicans (Pelecanus occidentalis carolinensis) in the South Atlantic Bight in response to the passage of three separate hurricane events in 2 years. Pelicans (n = 32) were tracked with GPS satellite transmitters from four colonies in coastal South Carolina, USA, for the entirety of at least one storm event. An Expectation Maximization binary Clustering algorithm was used to discretize pelican behavioral states, which were pooled into ‘active’ versus ‘inactive’ states. Multinomial logistic regression was used to assess behavioral state probabilities in relation to changes in barometric pressure and wind velocity.ResultsIndividual pelicans were more likely to remain inactive during tropical cyclone passage compared to baseline conditions generally, although responses varied by hurricane. When inactive, pelicans tended to seek shelter using local geomorphological features along the coastline such as barrier islands and estuarine systems.ConclusionsOur telemetry data showed that large subtropical seabirds such as pelicans may mitigate risk associated with spatially-extensive meteorological events by decreasing daily movements. Sheltering may be related to changes in barometric pressure and wind velocity, and represents a strategy common to several other classes of marine vertebrate predators for increasing survival probabilities.

Foraging activity of leaf‐cutter ants is affected by barometric pressure

AbstractAmong all activities displayed by ant colonies, searching for food is essential for all individuals survival. However, many external activities are hazardous or restrictive for the entire society. Even though leaf‐cutter ants are highly successful insects, they are subject to extreme aspects of foraging, as raindrops and wind. Although recruitment and food exploitation are known to change with temperature and humidity, barometric pressure changes and how they affect ant behavior remain unknown. We aimed to determine how an increase or decrease in barometric pressure might modify foraging strategies of the leaf‐cutter ant Atta sexdens compared to steady pressure. The first modification observed in the workers behavior was the scouts greater promptness in leaving the nest when the barometric pressure decreased. Regard to the foragers, there was no difference in the number of individuals recruited for collecting leaves. However, it was cut and brought into the nest 1.5 and 2 times more leaves during the pressure drop, respectively. The reason for this foraging efficiency as a whole was ultimately the sum of the efficiency of each forager. The shifts in behavior, therefore, could be related to the indirect consequences of a pressure decrease, such as rainfall and strong winds, both strong constraints on ants on a trail. This is the first report of barometric pressure affecting the behavior of a social insect under controlled conditions.

Barometric-pumping controls fugitive gas emissions from a vadose zone natural gas release

Subsurface natural gas release from leaking oil and gas wells is a major environmental concern. Gas migration can cause aquifer contamination, explosive conditions in soil gas, and greenhouse gas emissions. Gas migration is controlled by complex interacting processes, thus constraining the distribution and magnitude of “fugitive gas” emissions remains a challenge. We simulated wellbore leakage in the vadose zone through a controlled release experiment and demonstrate that fugitive gas emissions can be directly influenced by barometric pressure changes. Decreases in barometric-pressure led to surface gas breakthroughs (>20-fold increase in <24 hours), even in the presence of low-permeability surficial soils. Current monitoring strategies do not consider the effect of barometric pressure changes on gas migration and may not provide adequate estimates of fugitive gas emissions. Frequent or continuous monitoring is needed to accurately detect and quantify fugitive gas emissions at oil and gas sites with a deep water table.

Tackling the Tibetan Plateau in a down suit: insights into thermoregulation by bar-headed geese during migration.

Birds migrating through extreme environments can experience a range of challenges while meeting the demands of flight, including highly variable ambient temperatures, humidity and oxygen levels. However, there has been limited research into avian thermoregulation during migration in extreme environments. This study aimed to investigate the effect of flight performance and high altitude on body temperature (Tb) of free-flying bar-headed geese (Anser indicus), a species that completes a high-altitude trans-Himalayan migration through very cold, hypoxic environments. We measured abdominal Tb, along with altitude (via changes in barometric pressure), heart rate and body acceleration of bar-headed geese during their migration across the Tibetan Plateau. Bar-headed geese vary the circadian rhythm of Tb in response to migration, with peak daily Tb during daytime hours outside of migration but early in the morning or overnight during migration, reflecting changes in body acceleration. However, during flight, changes in Tb were not consistent with changes in flight performance (as measured by heart rate or rate of ascent) or altitude. Overall, our results suggest that bar-headed geese are able to thermoregulate during high-altitude migration, maintaining Tb within a relatively narrow range despite appreciable variation in flight intensity and environmental conditions.

Going Downriver: Patterns and Cues in Hurricane-Driven Movements of Common Snook in a Subtropical Coastal River

Extreme climate events such as hurricanes can influence the movement and distribution of fish and other aquatic vertebrates. However, our understanding of the scale of movement responses and how they vary across taxa and ecosystems remains incomplete. In this study, we used acoustic telemetry data to investigate the movement patterns of common snook (Centropomus undecimalis) in the Florida Coastal Everglades during Hurricane Irma, which made landfall on the southwest Florida coast as a Category 3 storm on 10 September 2017 after passing in close proximity to our study site. We hypothesized that the hurricane resulted in shifts in distribution and that these movements may have been driven by environmental cues stemming from changes in barometric pressure associated with hurricane conditions, fluctuations in water levels (stage) characterizing altered riverine conditions, or a combination of both hurricane and riverine drivers. The data revealed large-scale movements of common snook in the time period surrounding hurricane passage, with 73% of fish detected moving from the upper river into downriver habitats, and some individuals potentially exiting the river. Furthermore, regression model selection indicated that these movements were correlated to both hurricane and riverine conditions, showing increased common snook movement at higher river stage and lower barometric pressure, and stage explaining a larger proportion of model deviance. Animal movement has widespread and diverse ecological implications, and by better understanding the factors that drive movement, we may anticipate how future extreme climate events could affect fish populations in impact-prone regions.