scholarly journals A high-altitude balloon experiment to probe stratospheric electric fields from low latitudes

2017 ◽  
Vol 35 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Subramanian Gurubaran ◽  
Manu Shanmugam ◽  
Kaliappan Jawahar ◽  
Kaliappan Emperumal ◽  
Prasanna Mahavarkar ◽  
...  
Keyword(s):  
Electric Fields ◽  
Middle Atmosphere ◽  
Electric Circuit ◽  
Field Measurements ◽  
Electrical Circuit ◽  
Lower Atmosphere ◽  
Near Space ◽  
Low Latitudes ◽  
Small Fields ◽  
Balloon Experiment

Abstract. The Earth's electrical environment hosts a giant electrical circuit, often referred to as the global electric circuit (GEC), linking the various sources of electrical generators located in the lower atmosphere, the ionosphere and the magnetosphere. The middle atmosphere (stratosphere and mesosphere) has been traditionally believed to be passively transmitting electric fields generated elsewhere. Some observations have reported anomalously large electric fields at these altitudes, and the scientific community has had to revisit the earlier hypothesis time and again. At stratospheric altitudes and especially at low latitudes, horizontal electric fields are believed to be of ionospheric origin. Though measurements of these fields from a balloon platform are challenging because of their small magnitudes (around a few mV m−1), a suitably designed long-duration balloon experiment capable of detecting such small fields can provide useful information on the time evolution of ionospheric electric fields, which is otherwise possible only using radar or satellite in situ measurements. We present herein details of one such experiment, BEENS (Balloon Experiment on the Electrodynamics of Near Space), carried out from a low-latitude site in India. The instrument package for this experiment is comprised of four deployable booms for measurements of horizontal electric fields and one inclined boom for vertical electric field measurements, all equipped with conducting spheres at the tip. The experiment was conducted from Hyderabad (17.5° N, 78.6° E) during the post-midnight hours on 14 December 2013. In spite of a few shortcomings we report herein, a noticeable feature of the observations has been the detection of horizontal electric fields of ∼ 5 mV m−1 at the stratospheric altitudes of ∼ 35 km.

The effects of solar activity on the Global Atmospheric Electrical Circuit

2020 ◽  
Author(s):  
Marzieh Khansari ◽  
Eija Tanskanen ◽  
Shabnam Nikbakhsh
Keyword(s):  
Solar Activity ◽  
Electric Circuit ◽  
Electrical Circuit ◽  
Thunderstorm Activity ◽  
Lightning Activity ◽  
Lower Atmosphere ◽  
Radiation Budget ◽  
Global Electric Circuit ◽  
Aerosol Loading ◽  
The Earth

<p>The global electric circuit (GEC) links the electric field and current flowing in the lower atmosphere, ionosphere and magnetosphere forming a giant spherical condenser, which is charged by the thunderstorms to a potential of several hundred thousand volts (Roble and Tzur, 1986) and drives vertical current through the atmosphere’s columnar resistance. Monitoring and researching the global electric circuit (GEC) are crucially important due to its links with climate change. Those two phenomena are connected by lightning activity, which itself is a measure of the GEC. It is known that space weather affects the Earth’s lightning activity, therefore the GEC might prove to be a critical tool in examining changing climate in terms of solar and lightning activity.</p><p>The possible relation between solar activity and lightning activity has been studied for a long period of time. The relation between sunspot number and lightning activity has been investigated, although the results still remain inconclusive across regions and time. At some regions a positive correlation is found, at others a negative one. Thus, it is important to explore other solar-geomagnetic variables possibly influencing lightning activity, such as geomagnetic index or fast solar wind streams, which were found to correlate well with lightning activity (Scott et al, 2014). Another increasingly important question is whether or not aerosols will contribute significantly to the Earth’s radiation budget, whether it be cooling or warming the climate. In a warming climate aerosol loading could alter and increase lightning activity, which in turn can lead to a positive feedback due to generation of NOx and thus O3 in the troposphere, a potent greenhouse gas.</p><p>In this project we will look at the connection between solar activity, aerosol loading, and thunderstorm activity in different types of regions such as coastal, boreal forest and urban area first in Finland and later on globally.</p><p> </p><ol><li>Aniol, R., 1952. Schwankungen der Gewitterha</li></ol>

scholarly journals Time-Domain Analysis of Fractional Electrical Circuit Containing Two Ladder Elements

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 475
Author(s):  
Ewa Piotrowska ◽  
Krzysztof Rogowski
Keyword(s):  
Fractional Derivative ◽  
Fractional Derivatives ◽  
Electric Circuit ◽  
Theoretical Models ◽  
Time Domain Analysis ◽  
Electrical Circuit ◽  
State Variable ◽  
State Space System ◽  
Derivatives Of ◽  
Different Order

The paper is devoted to the theoretical and experimental analysis of an electric circuit consisting of two elements that are described by fractional derivatives of different orders. These elements are designed and performed as RC ladders with properly selected values of resistances and capacitances. Different orders of differentiation lead to the state-space system model, in which each state variable has a different order of fractional derivative. Solutions for such models are presented for three cases of derivative operators: Classical (first-order differentiation), Caputo definition, and Conformable Fractional Derivative (CFD). Using theoretical models, the step responses of the fractional electrical circuit were computed and compared with the measurements of a real electrical system.

Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument

2020 ◽  
Vol 9 (5) ◽  
pp. 305-312
Author(s):  
Ryan Cardman ◽  
Luís F. Gonçalves ◽  
Rachel E. Sapiro ◽  
Georg Raithel ◽  
David A. Anderson
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurement ◽  
Near Field ◽  
Measurement Instrument ◽  
Rydberg Atom ◽  
Field Measurements ◽  
Atom Probe ◽  
Electric Field Measurement ◽  
Measurement Uncertainties

AbstractWe present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution of ${\lambda }_{RF}/2$ with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.

Aerosol Properties and Processes: A Path from Field and Laboratory Measurements to Global Climate Models

2007 ◽  
Vol 88 (7) ◽  
pp. 1059-1084 ◽  
Author(s):  
Steven J. Ghan ◽  
Stephen E. Schwartz
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Field Measurements ◽  
Substantial Improvement ◽  
Global Climate Models ◽  
Department Of Energy ◽  
Lower Atmosphere ◽  
Laboratory Measurements ◽  
Successive Generations ◽  
Aerosol Properties

Aerosol particles in the lower atmosphere exert a substantial influence on climate and climate change through a variety of complex mechanisms. Consequently, there is a need to represent these influences in global climate models, and models have begun to include representations of these influences. However, the present treatment of aerosols in global climate models is highly simplified, omitting many processes and feedbacks that are thought to be climatically important. Thus, there is need for substantial improvement. Here we describe the strategy of the U.S. Department of Energy for improving representation of the properties, processes, and effects of tropospheric aerosols in global climate models. The strategy begins with a foundation of field and laboratory measurements that provide the basis for modules describing specific aerosol properties and processes. These modules are then integrated into regional aerosol models, which are evaluated by comparison with field measurements. Issues of scale are then addressed so that the modules can be applied to global aerosol models, which are evaluated by comparison with satellite retrievals and other observations. Finally, the validated set of modules is applied in global climate models for multicentury simulations. This strategy is expected to be applied to successive generations of global climate models.

Formation of the double stratopause and elevated stratopause associated with the major stratospheric sudden warming in 2018/19

2021 ◽  
Author(s):  
Haruka Okui ◽  
Kaoru Sato ◽  
Dai Koshin ◽  
Shingo Watanabe
Keyword(s):  
General Circulation ◽  
Middle Atmosphere ◽  
Baroclinic Instability ◽  
Lower Thermosphere ◽  
Circulation Model ◽  
Lower Atmosphere ◽  
Temperature Structure ◽  
Residual Circulation ◽  
Stratospheric Sudden Warming

<p>After several recent stratospheric sudden warming (SSW) events, the stratopause disappeared and reformed at a higher altitude, forming an elevated stratopause (ES). The relative roles of atmospheric waves in the mechanism of ES formation are still not fully understood. We performed a hindcast of the 2018/19 SSW event using a gravity-wave (GW) permitting general circulation model containing the mesosphere and lower thermosphere (MLT), and analyzed dynamical phenomena throughout the entire middle atmosphere. An ES formed after the major warming on 1 January 2019. There was a marked temperature maximum in the polar upper mesosphere around 28 December 2018 prior to the disappearance of the descending stratopause associated with the SSW. This temperature structure with two maxima in the vertical is referred to as a double stratopause (DS). We showed that adiabatic heating from the residual circulation driven by GW forcing (GWF) causes barotropic and/or baroclinic instability before DS formation, causing in situ generation of planetary waves (PWs). These PWs propagate into the MLT and exert negative forcing, which contributes to DS formation. Both negative GWF and PWF above the recovered eastward jet play crucial roles in ES formation. The altitude of the recovered eastward jet, which regulates GWF and PWF height, is likely affected by the DS structure. Simple vertical propagation from the lower atmosphere is insufficient to explain the presence of the GWs observed in this event.</p>

scholarly journals Seasonal variation of vertical eddy diffusivity in the troposphere, lower stratosphere and mesosphere over a tropical station

2001 ◽  
Vol 19 (8) ◽  
pp. 975-984 ◽  
Author(s):  
D. Narayana Rao ◽  
M. V. Ratnam ◽  
T. N. Rao ◽  
S. V. B. Rao
Keyword(s):  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
Beam Width ◽  
Eddy Diffusivity ◽  
Lower Atmosphere ◽  
Spectral Parameters ◽  
Vhf Radar ◽  
June July ◽  
Vertical Eddy Diffusivity ◽  
Vertical Eddy

Abstract. Long-term VHF radar (53 MHz with 3° beam-width) observations at Gadanki (13.5° N, 79.2° E), India, during the period from September 1995 to August 1999 are used to study monthly, seasonal and annual medians of vertical eddy diffusivity, K in the troposphere, lower stratosphere and mesosphere. First, the spectral width contribution due to non-turbulent effects has been removed for further analysis and the monthly, seasonal medians of K are calculated. The monthly median of K in the troposphere shows maximum and minimum in June-July and November-December, respectively. In general, large values of K are seen up to 10 km and then decrease with height. Larger values of K are observed during monsoon and post-monsoon than in winter and summer. In general, the maximum and minimum values of the annual median of K (in logarithmic values) in the troposphere are found to be 0.25 and - 1.3 m2 s-1 respectively. In the mesosphere, the monthly median of K shows maximum and minimum during June-July and November-December, respectively, similar to the lower atmosphere. The value of K in the mesosphere becomes larger and it increases with height up to 75 km and again decreases above that height. The maximum values are seen during the summer, followed by equinoxes and a minimum during the winter. In general, the maximum and minimum values of K (in logarithmic values) are found to be 0.7 and 0.3 m2 s-1, respectively, in the mesosphere. A comparison of Doppler spectral parameters in different beam directions shows anisotropy in both signal-to- noise ratio (SNR) and spectral widths in the mesosphere, whereas it shows isotropy in SNR and anisotropy in the spectral widths in troposphere and lower stratosphere.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; turbulence; waves and tides)

scholarly journals Recent Dynamic Studies on the Middle Atmosphere at Mid- and Low-Latitudes Using Rayleigh Lidar and Other Technologies

2018 ◽  
pp. 757-776
Author(s):  
Alain Hauchecorne ◽  
Sergey Khaykin ◽  
Philippe Keckhut ◽  
Nahoudha Mzé ◽  
Guillaume Angot ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Dynamic Studies ◽  
Low Latitudes ◽  
Rayleigh Lidar

scholarly journals The Global Electric Circuit and Global Seismicity

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 491
Author(s):  
Sergey Pulinets ◽  
Galina Khachikyan
Keyword(s):  
Electric Fields ◽  
Ground Surface ◽  
Electric Circuit ◽  
Thunderstorm Activity ◽  
Radon Emanation ◽  
Global Electric Circuit ◽  
Important Conclusion ◽  
Earthquake Preparation ◽  
Deep Focus ◽  
Ionospheric Potential

Basing on the catalogue of earthquakes with a magnitude of M ≥ 4.5 for the period 1973–2017, a UT variation with an amplitude of ~10% in the number of earthquakes is revealed and compared with a UT variation in the ionospheric potential (IP) with an amplitude of ~18%. We demonstrate that the amplitude of the UT variation in the number of deep-focus earthquakes is greater compared with that of crustal earthquakes, reaching 19%. The UT of the primary maxima of both the IP (according to modern calculations) and of earthquake incidence coincides (near 17:00 UT) and is, by 2 h, ahead of the classical Carnegie curve representing the UT variation in the atmospheric electric field on the ground surface. The linear regression equation between these UT variations in the number of deep-focus earthquakes and the ionospheric potential is obtained, with a correlation coefficient of R = 0.97. The results support the idea that the processes of earthquake preparation are coupled to the functional processes of the global electric circuit and the generation of atmospheric electric fields. In particular, the observed increase in thunderstorm activity over earthquake preparation areas, provided by air ionization due to radon emanation, yields a clue as to why the global thunderstorm distribution is primarily continental. Another important conclusion is that, in observing the longitudinal distributions of earthquakes against the IP distribution, we automatically observe that all such events occur in local nighttime hours. Considering that the majority of earthquake precursors have their maximums at local night and demonstrating the positive deviation from the undisturbed value, we obtain a clue as to its positive correlation with variations in the ionospheric potential.

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