scholarly journals Spectral characteristics of atmospheric pressure and electric field variations under severe weather conditions at high latitudes

2006 ◽  
Vol 6 (4) ◽  
pp. 6613-6626 ◽  
Author(s):  
E. A. Kasatkina ◽  
O. I. Shumilov ◽  
Y. A. Vinogradov ◽  
A. N. Vasilyev
Keyword(s):  
Electric Field ◽  
Atmospheric Pressure ◽  
Surface Ozone ◽  
Spectral Characteristics ◽  
Data Gathering ◽  
Vertical Component ◽  
Weather Conditions ◽  
Severe Weather ◽  
Time Dependent ◽  
Computer Aided

Abstract. The time-dependent relationships between atmospheric parameters (electric field, positive and negative conductivity, variations of atmospheric pressure) and different meteorological phenomena (rain, fogs, snowstorms, thunderstorms) were investigated through spectral analysis. These parameters were measured with help of a high-latitude computer-aided complex installed at Apatity (66.5 N, 33.4 E). The complex consists of three spaced microbarographs for measurements of atmospheric pressure variations in the range of periods from 1 s to 40 min, an instrument measuring the vertical component of the electric field, and instrument used for measurements of air conductivity and surface ozone. A computer-aided data-gathering system makes it possible to obtain information in the frequency range between 1 and 0.0001 Hz. The time-dependent frequency analysis showed that the spectral characteristics of both electric field and atmospheric pressure variations changed synchronously during severe weather conditions.

scholarly journals Modelling the trajectory of the corpses of mountaineers who disappeared in 1926 on Aletschgletscher, Switzerland

2014 ◽  
Vol 60 (220) ◽  
pp. 255-261 ◽  
Author(s):  
Guillaume Jouvet ◽  
Martin Funk
Keyword(s):  
Velocity Field ◽  
Weather Conditions ◽  
Space Time ◽  
Severe Weather ◽  
Time Dependent ◽  
Glacier Area ◽  
Glacier Surface ◽  
Space And Time ◽  
End Point

AbstractIn this paper we reconstruct the space–time trajectory beneath the surface of Aletschgletscher, Switzerland, of the corpses of three mountaineers that disappeared in March 1926 and reappeared at the glacier surface in June 2012. Our method integrates the time-dependent velocity field of an existing full-Stokes glacier model, starting at the point where the corpses were found at the glacier surface. Our main result is that we were able to localize the immersion location where the brothers presumably died. As a second result, the upstream end point of the computed trajectory emerges very close to the glacier surface in 1926, giving a new and global validation of the glacier model in space and time. Testing the sensitivity of the immersion location obtained with respect to the model and other uncertainties indicates an area of 0.6% of the entire glacier area where the accident could have occurred. Our result suggests that death was not caused by an avalanche or a fall into a crevasse; instead, it is likely that the mountaineers became disoriented in prolonged severe weather conditions and froze to death.

Spectral Characteristics of Daily to Seasonal Ground Motion at the Piñon Flats Observatory from Coherence of Seismic Data

2019 ◽  
Vol 109 (5) ◽  
pp. 1948-1967 ◽  
Author(s):  
Lei Qin ◽  
Frank L. Vernon ◽  
Christopher W. Johnson ◽  
Yehuda Ben‐Zion
Keyword(s):  
Seasonal Variations ◽  
Seismic Data ◽  
Atmospheric Pressure ◽  
Anthropogenic Activities ◽  
Spectral Characteristics ◽  
Vertical Component ◽  
Atmospheric Effects ◽  
Deep Borehole ◽  
Near Surface ◽  
Frequency Bands

Abstract We investigate coherences of seismic data recorded during three years (2015–2017) at the Piñon Flats Observatory (PY) array and a collocated 148 m deep borehole station B084, along with oceanic data from a buoy southwest of the PY array. Seismic and barometric recordings at PY stations are analyzed with a multitaper spectral technique. The coherence of signals from seismic sources is >0.6 at 0.05–8 Hz between closely spaced (<65  m) surface stations and decreases to ∼0.2 in frequency bands in which the wavelengths are smaller than interstation distances. There are several local coherence increases at 1–8 Hz between nearby (<65  m) surface stations, whereas large coherence values between a surface and 148 m deep borehole stations are only present at the secondary microseism (∼0.14  Hz). These points to significant modification of seismic recordings in the top crust, and those continual near‐surface failures might produce shallow rapidly attenuating signals at surface stations. Incoherent local atmospheric effects induce incoherent seismic signals in low‐ and high‐frequency ranges through different coupling mechanisms. Between 0.003 and 0.05 Hz, atmospheric loadings generate ground tilts that contaminate the two horizontal seismic recordings and decrease their coherence, whereas the vertical component is less affected. At 1–8 Hz, coupling of atmospheric pressure with surface structures transmits incoherent signals into the ground, degrading the seismic coherence in all three components. The two horizontal coherences show seasonal variations with extended coherent frequency bands in winter and spring, likely to be produced by seasonal variations in microseisms and local ground tilts. The coherences also contain high anomalies between 2 and 4 Hz resulting from anthropogenic activities. The results provide useful information on instrument characteristics and variations in the shallow crustal response to earthquakes, seasonal and ambient sources of seismic energy, along with atmospheric pressure–temperature changes and anthropogenic activities.

scholarly journals AnANN Model Trained on Regional Data in the Prediction of Particular Weather Conditions

2021 ◽  
Vol 11 (11) ◽  
pp. 4757
Author(s):  
Aleksandra Bączkiewicz ◽  
Jarosław Wątróbski ◽  
Wojciech Sałabun ◽  
Joanna Kołodziejczyk
Keyword(s):  
Atmospheric Pressure ◽  
Real Life ◽  
Real Data ◽  
Weather Conditions ◽  
Maximum Temperature ◽  
Air Masses ◽  
Weather Forecasts ◽  
Life Problems ◽  
The World ◽  
The City

Artificial Neural Networks (ANNs) have proven to be a powerful tool for solving a wide variety of real-life problems. The possibility of using them for forecasting phenomena occurring in nature, especially weather indicators, has been widely discussed. However, the various areas of the world differ in terms of their difficulty and ability in preparing accurate weather forecasts. Poland lies in a zone with a moderate transition climate, which is characterized by seasonality and the inflow of many types of air masses from different directions, which, combined with the compound terrain, causes climate variability and makes it difficult to accurately predict the weather. For this reason, it is necessary to adapt the model to the prediction of weather conditions and verify its effectiveness on real data. The principal aim of this study is to present the use of a regressive model based on a unidirectional multilayer neural network, also called a Multilayer Perceptron (MLP), to predict selected weather indicators for the city of Szczecin in Poland. The forecast of the model we implemented was effective in determining the daily parameters at 96% compliance with the actual measurements for the prediction of the minimum and maximum temperature for the next day and 83.27% for the prediction of atmospheric pressure.

scholarly journals Vacuum radiation induced by time dependent electric field

2017 ◽  
Vol 767 ◽  
pp. 431-436 ◽  
Author(s):  
Bo Zhang ◽  
Zhi-meng Zhang ◽  
Wei Hong ◽  
Shu-Kai He ◽  
Jian Teng ◽  
...  
Keyword(s):  
Electric Field ◽  
Time Dependent ◽  
Radiation Induced ◽  
Vacuum Radiation

Effect of Time Dependent Excitation Signals on Gating in Nanofluidic Channels

2015 ◽  
Author(s):  
C. Boone ◽  
M. Fuest ◽  
K. Wellmerling ◽  
S. Prakash
Keyword(s):  
Electric Field ◽  
Ionic Transport ◽  
Local Variation ◽  
Time Dependent ◽  
Local Perturbation ◽  
Gate Electrode ◽  
Nanofluidic Channels ◽  
Field Effect Devices ◽  
Dc Excitation ◽  
Dependent Signal

Nanofluidic field effect devices feature a gate electrode embedded in the nanochannel wall. The gate electrode creates local variation in the electric field allowing active, tunable control of ionic transport. Tunable control over ionic transport through nanofluidic networks is essential for applications including artificial ion channels, ion pumps, ion separation, and biosensing. Using DC excitation at the gate, experiments have demonstrated multiple current states in the nanochannel, including the ability to switch off the measured current; however, experimental evaluation of transient signals at the gate electrode has not been explored. Modeling results have shown ion transport at the nanoscale has known time scales for diffusion, electromigration, and convection. This supports the evidence detailed here that use of a time-dependent signal to create local perturbation in the electric field can be used for systematic manipulation of ionic transport in nanochannels. In this report, sinusoidal waveforms of various frequencies were compared against DC excitation on the gate electrode. The ionic transport was quantified by measuring the current through the nanochannels as a function of applied axial and gate potentials. It was found that time varying signals have a higher degree of modulation than a VRMS matched DC signal.

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