Effect Of Barometric Pressure Research Articles

Improving the water table fluctuation method to estimate groundwater recharge below thick vadose zones

ABSTRACT The water table fluctuation (WTF) method is popular for groundwater recharge (GR) estimation, but its accuracy is challenged when applied in areas with thick vadose zones because of the signal lag and attenuation with depth and uncertainties from barometric pressure effect and lateral flow. Improvement of the WTF method used the linear regression method and Darcy’s law, and has been assessed to give satisfactory results. In particular, the improved method presented lower GR (20–34%) relative to the conventional method. GR decreased from the centre to the edge of the tableland. The regional average GR was 63–81 mm year−1, equivalent to 11–14% of annual average rainfall. Lag times between recharge and rainfall ranged from 1 to 9 months. Rainfall and vegetation dominated the spatiotemporal variability of GR. Our study provides reference and technical support for GR estimation with the WTF method in regions with a thick vadose zone.

Barometric pressure variation alters electrical resistivity during water infiltration in the vadose zone

To reveal the mechanism of the water–gas two-phase repulsion during water infiltration and its barometric pressure change and resistivity response in the vadose zone while it provides the basic theory for water resources evaluation and groundwater pollution, also provides technical support for the accurate interpretation of electrical resistivity tomography (ERT) application. Therefore, a research system based on laboratory experiments, numerical simulations, and ERT was established to determine the moisture transport pattern and the quantitative relationships between barometric pressure and resistivity. The results show that the intensity of the water infiltration process in the vadose zone meets the percolation theory. The barometric pressure will go through three stages when the infiltration intensity is higher than the critical value. The critical time of the barometric pressure variation shortens gradually with the infiltration intensity and medium permeability increase. In contrast, the maximum barometric pressure increases gradually with the rise in infiltration intensity and medium porosity. The layered-heterogeneous structure's effect depends on the underlying medium's properties. The trivial variation of resistivity responds to the barometric pressure variation. The quantitative relationship between the resistivity and the barometric pressure in the vadose zone is established by the difference between the measured value and the calculated value by improving Archie's formula. The resistivity reduction due to increasing barometric pressure can account for over 10.9% of the moisture effect. These insights provide technical support for ERT applications to eliminate barometric pressure's effect on resistivity and accurately identify the target medium.

Effect of barometric pressure on single-breath carbon monoxide diffusing capacity

BackgroundSingle-breath diffusing capacity for carbon monoxide (DLCO) quantifies gas transfer in the lungs. DLCO measurement is affected by barometric pressure (Pb) and alveolar partial pressure of oxygen (PAO2). The current equations for adjusting DLCO for Pb and PAO2 may not be accurate given advances in test performance and technology. We quantify changes in DLCO with alterations in Pb in normal and COPD subjects, determine the accuracy of the current Pb and PAO2 adjustment equations and develop updated adjustment equations. MethodsWe measured DLCO in 13 normal and 10 COPD subjects at 1330 m altitude and in a hypobaric/hyperbaric chamber at altitudes of sea-level and 2500 m; six normal subjects were tested at 3600 m. We determined if there were significant differences in DLCO between altitudes. We developed an equation for adjusting DLCO for changes in Pb from sea-level. We compared this equation with the existing Pb adjustment equation in normal and COPD subjects. We determined the accuracy of the current PAO2 adjustment equation and developed a new PAO2 adjustment equation. ResultsDLCO significantly increased with decreasing Pb. We developed a Pb adjustment equation that adjusts DLCO measured at altitudes between 1330 m and 3600 m to sea-level values. This Pb adjustment equation yields DLCO results that are not significantly different than the currently recommended equation. We developed a more accurate PAO2 adjustment equation. ConclusionDLCO measurement is significantly affected by altitude. We developed equations that accurately adjust DLCO for changes in Pb and PAO2 in normal and COPD subjects.

FACIAL VACUUM MASSAGE IS AN EFFECTIVE COMPONENT OF THE COMPLEX MANAGEMENT OF PATIENTS WITH SEBORRHEA

Introduction. Vacuum massage is a popular procedure of hardware cosmetology, which brings not only pleasure but visible results too. This technique is the dosed effect of negative barometric pressure on a particular body's parts. As a result, blood circulation and lymphatic drainage in the tissues intensify, muscle tone increases, and favorable conditions for tissue trophies creates.

Temperature and barometric pressure affect the activity intensity and movement of an endangered thermoconforming lizard

AbstractGlobal warming is expected to affect movement‐related thermoregulation in ectotherms, but the likely effects on thermoconforming lizards, which spend little energy in thermoregulation behavior, are unclear. We used the Guatemalan beaded lizard (Heloderma charlesbogerti) as a model thermoconforming species to investigate the effects of ambient temperature and barometric pressure (a cue for rain in the study area) on activity intensity and the structure of movement paths. We tracked 12 individuals over a total of 148 animal days during the wet season of 2019 using Global Positioning System tags and triaxial accelerometry. We found a clear positive effect of ambient temperature on activity (using vectorial dynamic body acceleration [VeDBA]) and step length of lizard movements. The movement also became more directional (longer step lengths and smaller turning angles) with increasing ambient temperatures. There was a small negative effect of barometric pressure on VeDBA. We propose that our patterns are indicative of internal state changes in the animals, as they move from a state of hunger, eliciting foraging, which is enhanced by lower temperatures and rainfall to a thermally stressed state, which initiates shelter‐seeking. Our findings highlight the sensitivity of this species to temperature change, show that not all thermoconforming lizards are thermal generalists, and indicate that predicted regional increases in temperature and reduction in rainfall are likely to negatively impact this species by reducing the width of their operational thermal window.

Mechanistic movement models identify continuously updated autumn migration cues in Arctic caribou

BackgroundMigrations in temperate systems typically have two migratory phases, spring and autumn, and many migratory ungulates track the pulse of spring vegetation growth during a synchronized spring migration. In contrast, autumn migrations are generally less synchronous and the cues driving them remain understudied. Our goal was to identify the cues that migrants use in deciding when to initiate migration and how this is updated while en route.MethodsWe analyzed autumn migrations of Arctic barren-ground caribou (Rangifer tarandus) as a series of persistent and directional movements and assessed the influence of a suite of environmental factors. We fitted a dynamic-parameter movement model at the individual-level and estimated annual population-level parameters for weather covariates on 389 individual-seasons across 9 years.ResultsOur results revealed strong, consistent effects of decreasing temperature and increasing snow depth on migratory movements, indicating that caribou continuously update their migratory decision based on dynamic environmental conditions. This suggests that individuals pace migration along gradients of these environmental variables. Whereas temperature and snow appeared to be the most consistent cues for migration, we also found interannual variability in the effect of wind, NDVI, and barometric pressure. The dispersed distribution of individuals in autumn resulted in diverse environmental conditions experienced by individual caribou and thus pronounced variability in migratory patterns.ConclusionsBy analyzing autumn migration as a continuous process across the entire migration period, we found that caribou migration was largely related to temperature and snow conditions experienced throughout the journey. This mechanism of pacing autumn migration based on indicators of the approaching winter is analogous to the more widely researched mechanism of spring migration, when many migrants pace migration with a resource wave. Such a similarity in mechanisms highlights the different environmental stimuli to which migrants have adapted their movements throughout their annual cycle. These insights have implications for how long-distance migratory patterns may change as the Arctic climate continues to warm.

Astronomical Tide and Storm Surge Signals Observed in an Isolated Inland Maar Lake Near the Coast

Aimed at the explanation of clear tidal signal and storm surge signals in a closed inland lake near the coast (the Huguangyan Lake), this work uses a combined approach with observations and model experiments. Huguangyan Lake is a closed inland freshwater coneless volcanic crater lake near the coast in tropical southern China, less than 5 km from an estuary. It has a diameter of about 1.5 km and relatively deep water of up to 20 m. Bottom pressure was measured from an acoustic Doppler current profiler (ADCP) for 10 days in September 2018 and 10 days in January 2019. The observations encompass the period of Typhoon Mangkhut, which passed the region when it made its landfall. The time series demonstrate clear tidal and subtidal signals. The tidal signal remains even if we exclude the barometric pressure effect. Interestingly, the lake has no surface connection with the ocean. The astronomical tide has an amplitude of about 2 cm. The major tidal signals include the principal solar semidiurnal (S2) and lunisolar (K1) constituents. During the passage of Typhoon Mangkhut, the water level variability inside the lake increased by an order of magnitude (>0.3 m). To examine whether the lake water level change was due to the natural oscillations inside the lake (or seiche), a numerical wind-driven hydrodynamics model was designed using the 3-D Finite Volume Community Ocean Model (FVCOM). The results show that a small first-order seiche can be generated, but only with a time scale of minutes and with a magnitude much smaller than the observed surface elevation changes. This excludes any measurable seiche and the observed surface elevation change inside the lake cannot be wind-driven. Moreover, tides inside the lake are not generated by tidal potential, as the lake is too small for having a locally generated tide. The main result of our study has therefore excluded the local tidal-generating force, wind-driven seiche, and barometric effect, as possible causes of the lake oscillation which has tidal and subtidal signals. The subtidal variation is at least one order of magnitude greater than tides inside the lake and is caused by weather-induced overall coastal ocean water level oscillations transmitted into the lake through groundwater connection. All these lead to the major conclusion that the lake is connected to the coastal ocean through groundwater.

Parametric influence study of cryogenic hydrogen dispersion on theoretical aspect

In this paper, we proposed a theoretical model to study the dispersion of hydrogen. The model given a correlation between the concentration and temperature for cryogenic gases. The model based on adiabatic mixing hypothesis and neglected exterior heat sources, and thought the gas mixture was always at quasi-steady state. Real-gas law was adopted, and thermal physical properties of the gases are obtained from NIST REFPROP database. The concentration curve approximately appears a decreasing straight line, and turns on dew point and ice point, since heat released from water vapor phase change. Compared with liquid hydrogen and liquid natural gas spill experimental data, the model obtained well agreement solutions.Effects of three typical weather conditions (atmospheric temperature, relative humidity and barometric pressure) on hydrogen dispersion were quantitatively studied. It is confirmed that the dispersion is excited in summer, and is depressed in winter and transition seasons with increased ambient temperature. With increased ambient temperature, the effect of increased enthalpy reduction of the dry air components and the effect of the water latent heat are respectively dominate in the 268.15–293.15 K and 293.15–308.15 K ranges. Compared to ambient temperature and barometric pressure, relative humidity has the strongest positive effect on hydrogen dispersion, and the slight dampening effect of barometric pressure could be neglected.

Outage Performances of 5G Channel Model Influenced by Barometric Pressure Effects in Yogyakarta

The need of using telecommunications networks is driving develop to increasing a cellular technology. Cellular technology has reached the fifth-generation (5G) which is expected to be launched in 2020. 5G technology is predicted to use high frequencies, where high frequencies present a new challenge namely wave propagation attenuation problems that are affected by natural conditions such as barometric pressure, rain rate, humadity, and vegetation density. Differences from the shape of the earth's contours and natural conditions in each region require research to find the most appropriate channel model to be used in the region.The channel model is obtained based on the representative value of Power Delay Profile (PDP) simulation resul ts using the NYUSIM channel simulator. The frequency used is 28 GHz with a scenario under the influence of minimum and maximum barometric using environment parameters based on the city of Yogyakarta. PDP value is used to calculate the outage probability of channel capacity (C) is smaller than the coding rate (R) so that it indicates a failure of detection at the receiver based on the shannon theory. Outage probability is obtained by the cumulative distribution function of the capacity evaluated against the coding rate. Outage probability result in both scenarios are able to reach a point of 10-4, for coding rate ½ it needs 17.649883 dB, for coding rate ¾ it needs 20.020953 dB, dan coding rate 1 it needs 22 dB. This shows that barometric does not significantly influence the performance of the 5G communication system.

Impact of stressors in the aviation environment on xenobiotic dosimetry in humans: physiologically based prediction of the effect of barometric pressure or altitude

ABSTRACT Standard health risks from volatile organic compounds (VOCs) are generally interpreted at ambient environmental conditions. The aim of this study was to develop a strategy for using physiologically based pharmacokinetic (PBPK) modeling to compare known risks in the general population to calculated risks in pilots experiencing pressure-based stressors. PBPK models facilitate these comparisons by prediction of how target-tissue specific doses are altered when a stressor, such as high altitude, produces changes in physiological parameters. Cardiac output, regional blood flow, and alveolar ventilation rate following acute exposure to altitude ranging from moderate to extremely high were estimated from published data from 52 groups of human subjects. Scenarios where pilots might inhale toluene, 1,2,4-trimethylbenzene (1,2,4-TMB), or cyclohexane during routine military flight training were simulated. At the recommended Threshold Limit Values (TLV), arterial blood concentrations were predicted to be higher for exposure at 15000 ft (4572 m) than at sea level. The differences were greater for toluene and TMB, which have higher blood: air and fat: blood partition coefficients than less lipophilic cyclohexane. In summary, quantitative approaches to internal dosimetry prediction that take advantage of existing knowledge of physiological changes induced by occupational stressors possess potential as tools in performing a human health risk assessment.

CrossTalk opposing view: Barometric pressure, independent of , is not the forgotten parameter in altitude physiology and mountain medicine.

CrossTalk opposing view: Barometric pressure, independent of , is not the forgotten parameter in altitude physiology and mountain medicine.

Investigation of effect of barometric pressure on gas emission in longwall mining by monitoring and CFD modelling

Methane emission fluctuations are strongly related to the barometric pressure changes. Variations of barometric pressure increase the occurrence of fires and explosions of underground mines. As part of the project supported by the Australian Government Coal Mining Abatement Technology Support Package (CMATSP), the methane concentration at tailgate return and the barometric pressure in the longwall panel were monitored and analysed. It was found from the monitoring that when the amplitude of barometric pressure change reaches +/− 0.5%, the emission methane concentration measured changed from the minimum value of 1% to 1.5%. In order to understand better the mechanism behind the phenomena, a 3D computational fluid dynamics (CFD) model developed during the project is used to investigate the effect of barometric pressure on methane emission. Intensive studies on the effect of different parameters on the fluctuation amplitude of methane emission are conducted including the period of barometric pressure variations, the size of the longwall goaf. It is found that the longwall goaf formed during the longwall mining performs like an air accumulator in storing and releasing methane. Barometric pressure changes with smaller period causes larger changes of methane concentration at the return, and larger goaf in size causes larger variation amplitude of methane concentration. Concentrations of methane drawn from vertical boreholes are also affected by the barometric pressure changes.

Well Water Level Analysis Based on Barometric Pressure Effects and Earth Tides

Barometric pressure coefficient and tidal factor are used to study the porosity, the solid skeleton volume compressibility coefficient and the water volume compressibility coefficient of the Dahuichang well, Banqiao well, Huanghua well, Dadianzi well, Fengzhen well and Sanhaodi well in the northern region of North China under undrained condition. The results show that there is power function relation between the porosity and the volume compressibility coefficient(the solid skeleton and the water)in the aquifer. In the first quadrant, the solid skeleton volume compressibility coefficient of each well increases with the increase of the porosity, the volume compressibility coefficient of the water decreases with the increase of porosity. Between the volume compressibility coefficient of the solid skeleton and the water exist unary quadratic polynomial relationship, and the volume compressibility coefficient of water is larger than that of solid skeleton, the water is easier to compress. In addition, according to the step barometric pressure response function in the regression deconvolution method, the groundwater type identifying results of the six wells aquifer system are shown that there is an e based exponential function between the lag time and the step barometric pressure response function of each well water level to barometric pressure. The coefficient before the base e is positive or negative to determine the groundwater type of the well aquifer system. For confined wells, the step barometric pressure response function increases with lag time of well water level to barometric pressure, while the unconfined wells and semi-confined wells are opposite.

Investigation of the relationship between rock strain and radon concentration in the tidal frequency-range

Changes in the radon gas concentration can precede geodynamic processes associated with tectonic, volcanic activities and earthquakes. For this reason the relationship between rock strain and radon concentration is an important scientific issue to be answered. According to the complexity of the radon emanation process influenced by environmental effects, the interpretation of radon concentration variation as a possible precursor of geodynamic processes is not yet resolved unambiguously. The Sopronbánfalva Geodynamic Observatory in Hungary is one of the few places where radon concentration and rock strain variations are simultaneously monitored. The object of this study is to investigate the connection between indoor radon concentration and rock strain in the tidal frequency-range on the basis of seven-year long data series measured in years from 2009 till 2015. The relationship between rock deformation and radon concentration was investigated together with the temperature and barometric pressure effects. It was found that the strain induced radon concentration variations are in the order of 10–100 Bq nstr−1, while the concentration variations bear more considerable similarity and relation to the temperature and barometric variations. The theoretical tide at the location of the measurement site and tidal components computed from strain, radon concentration, barometric pressure and temperature data were compared with each other. Spectral and tidal analysis of data demonstrated that only the thermally induced solar components S1 and S2 are present in the radon concentration but their amplitudes hardly exceed the spectral noise level. The principal lunar semidiurnal M2 and diurnal O1 tidal waves cause the largest rock strain variations. The lack of the O1 and M2 constituents in the radon concentration confirms the fact that the detected S1 and S2 tidal components appear due to the barometric tide and the daily variations of the temperature and barometric pressure.

Review: Moisture loading—the hidden information in groundwater observation well records

Changes of total moisture mass above an aquifer such as snow accumulation, soil moisture, and storage at the water table, represent changes of mechanical load acting on the aquifer. The resulting moisture-loading effects occur in all observation well records for confined aquifers. Deep observation wells therefore act as large-scale geological weighing lysimeters, referred to as “geolysimeters”. Barometric pressure effects on groundwater levels are a similar response to surface loading and are familiar to every hydrogeologist dealing with the “barometric efficiency” of observation wells. Moisture-loading effects are small and generally not recognized because they are obscured by hydraulic head fluctuations due to other causes, primarily barometric pressure changes. For semiconfined aquifers, long-term moisture-loading effects may be dissipated and obscured by transient flow through overlying aquitards. Removal of barometric and earth tide effects from observation well records allows identification of moisture loading and comparison with hydrological observations, and also comparison with the results of numerical models that can account for transient groundwater flow.

Response to: "Snowfall and myocardial infarction. What is the effect of barometric pressure?"

In a recent letter to CMAJ , Hernandez-Garduno raised the possibility that barometric pressure contributes to the association between snowfall and myocardial infarction (MI).[1][1] We confirm that in sensitivity analyses, adjustment for barometric pressure (kPa) had no impact on the association

The major influence of the atmosphere on intracranial pressure: an observational study.

The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6hPa (95% CI 1004.5 to 1008.8hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9hPa (95% CI 1006.3 to 1009.6hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r=0.87, p<0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8%). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

Effects of weather conditions on emergency ambulance calls for acute coronary syndromes.

The aim of this study was to evaluate the relationship between weather conditions and daily emergency ambulance calls for acute coronary syndromes (ACS). The study included data on 3631 patients who called the ambulance for chest pain and were admitted to the department of cardiology as patients with ACS. We investigated the effect of daily air temperature (T), barometric pressure (BP), relative humidity, and wind speed (WS) to detect the risk areas for low and high daily volume (DV) of emergency calls. We used the classification and regression tree method as well as cluster analysis. The clusters were created by applying the k-means cluster algorithm using the standardized daily weather variables. The analysis was performed separately during cold (October-April) and warm (May-September) seasons. During the cold period, the greatest DV was observed on days of low T during the 3-day sequence, on cold and windy days, and on days of low BP and high WS during the 3-day sequence; low DV was associated with high BP and decreased WS on the previous day. During June-September, a lower DV was associated with low BP, windless days, and high BP and low WS during the 3-day sequence. During the warm period, the greatest DV was associated with increased BP and changing WS during the 3-day sequence. These results suggest that daily T, BP, and WS on the day of the ambulance call and on the two previous days may be prognostic variables for the risk of ACS.

Weather, Mood, and Stock Market Expectations: When Does Mood Affect Investor Sentiment?

Using survey-based explicit investor sentiment measures, this paper analyzes when investors' stock market expectations are a ffected by weather-induced mood. This study provides new insights into mood and decision making by directly comparing private and institutional investors. This paper shows that while private investors' stock market expectations are biased through weather conditions, expectations of institutional investors are not biased. Private investors' biases are longer-term. There is a signi fficant positive eff ect of barometric pressure on investors' 6-months expectations. Short-term investor sentiment, however, is not aff ected. I conclude that higher stock returns on days when the weather is pleasant are due to longer-term induced optimism, not due to short-term optimism.

Removing barometric pressure effects from groundwater level and identifying main influential constituents

Changes in barometric pressure can affect the micro-dynamic state of groundwater level. The groundwater level data carry a lot of important information of tectonic activity and earthquakes. It is very significant to eliminate the barometric pressure effects from the groundwater level data in order to recognize seismic anomalies effectively. With the analysis of the main influential constituents of barometric pressure and their changes, we can have a better understanding of the changes of the aquifer medium, which can provide useful information for earthquake prediction. Taking the May 12, 2008 Wenchuan earthquake as an example, this paper deals with the influence of barometric pressure on groundwater level based on observational data from Nanxi, Qionglai and Chaohu wells. The methods of the linear regression and the deconvolution regression were employed to remove the barometric pressure from the groundwater level data. The harmonic analysis and the spectral analysis were used to recognize the main influential waves of barometric pressure effect. A comparison was conducted on the main influential waves before and after the earthquake. The results showed that the main influential waves of barometric pressure effect changed and the amplitudes of all constituents also changed. This phenomenon may result from the characteristics of the influential constituents of pressure, or from the changes of the aquifer medium, which were caused by the earthquake.