scholarly journals Preliminary findings of surface fair-weather electric field trends over small tropical island station, Suva, Fiji

2007 ◽  
Vol 25 (1) ◽  
pp. 70
Author(s):  
V. Ramachandran ◽  
V. Kumar ◽  
J.N. Prakash ◽  
S. Kumar
Keyword(s):  
Electric Field ◽  
Fair Weather ◽  
Tropical Island ◽  
Island Station

scholarly journals Surface fair-weather potential gradient measurements from a small tropical island station Suva, Fiji

2009 ◽  
Vol 61 (6) ◽  
pp. 747-753 ◽  
Author(s):  
Vickal V. Kumar ◽  
V. Ramachandran ◽  
V. Buadromo ◽  
J. Prakash
Keyword(s):  
Potential Gradient ◽  
Fair Weather ◽  
Tropical Island ◽  
Island Station ◽  
Gradient Measurements

scholarly journals Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

2012 ◽  
Vol 30 (1) ◽  
pp. 49-56 ◽  
Author(s):  
M. Yamauchi ◽  
M. Takeda ◽  
M. Makino ◽  
T. Owada ◽  
I. Miyagi
Keyword(s):  
Electric Field ◽  
Nuclear Power ◽  
Potential Gradient ◽  
Radioactive Material ◽  
Strong Wind ◽  
Fair Weather ◽  
Large Area ◽  
Radiation Dose Rate ◽  
Radioactive Dust ◽  
Cloudy Weather

Abstract. Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14–15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50 V m−1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16–20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20–22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface.

scholarly journals Atmospheric electric field in the Atlantic marine boundary layer: first results from the SAIL project

2020 ◽  
Author(s):  
Susana Barbosa ◽  
Mauricio Camilo ◽  
Carlos Almeida ◽  
José Almeida ◽  
Guilherme Amaral ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Electric Field ◽  
Marine Boundary Layer ◽  
Weather Conditions ◽  
Cape Verde ◽  
The Other ◽  
Atmospheric Electric Field ◽  
Fair Weather ◽  
Near Surface ◽  
First Results

<p><span>The study of the electrical properties of the atmospheric marine boundary layer is important as the effect of natural radioactivity in driving near surface ionisation is significantly reduced over the ocean, and the concentration of aerosols is also typically lower than over continental areas, allowing a clearer examination of space-atmosphere interactions. Furthermore, cloud cover over the ocean is dominated by low-level clouds and most of the atmospheric charge lies near the earth surface, at low altitude cloud tops. </span></p><p><span>The relevance of electric field observations in the marine boundary layer is enhanced by the the fact that the electrical conductivity of the ocean air is clearly linked to global atmospheric pollution and aerosol content. The increase in aerosol pollution since the original observations made in the early 20th century by the survey ship Carnegie is a pressing and timely motivation for modern measurements of the atmospheric electric field in the marine boundary layer. Project SAIL (Space-Atmosphere-Ocean Interactions in the marine boundary Layer) addresses this challenge by means of an unique monitoring campaign on board the ship-rigged sailing ship NRP Sagres during its 2020 circumnavigation expedition. </span></p><p><span>The Portuguese Navy ship NRP Sagres departed from Lisbon on January 5th in a journey around the globe that will take 371 days. Two identical field mill sensors (CS110, Campbell Scientific) are installed </span><span>o</span><span>n the mizzen mast, one at a height of 22 m, and the other at a height of 5 meters. </span><span>A visibility sensor (SWS050, Biral) was also set-up on the same mast in order to have measurements of the extinction coefficient of the atmosphere and assess fair-weather conditions.</span><span> Further observations include gamma radiation measured with a NaI(Tl) scintillator from 475 keV to 3 MeV, cosmic radiation up to 17 MeV, and atmospheric ionisation from a cluster ion counter (Airel). The</span><span> 1 Hz measurements of the atmospheric electric field</span><span> and from all the other sensors</span><span> are </span><span>linked to the same rigorous temporal reference frame and precise positioning through kinematic GNSS observations. </span></p><p><span>Here the first results of the SAIL project will be presented, focusing on fair-weather electric field over the Atlantic. The observations obtained in the first three sections of the circumnavigation journey, including Lisbon (Portugal) - Tenerife (Spain), from 5 to 10 January, Tenerife - Praia (Cape Verde) from 13 to 19 January, and across the Atlantic from Cape Verde to Rio de Janeiro (Brasil), from January 22nd to February 14th, will be presented and discussed.</span></p>

Atmospheric electric field measurements in the central United Arab Emirates

2020 ◽  
Author(s):  
Keri Nicoll ◽  
R. Giles Harrison ◽  
Graeme Marlton ◽  
Martin Airey
Keyword(s):  
Electric Field ◽  
United Arab Emirates ◽  
Daily Variation ◽  
Sea Breeze ◽  
Abu Dhabi ◽  
Atmospheric Electric Field ◽  
Fair Weather ◽  
Al Ain ◽  
Dust Charging ◽  
Convection Dominated

<p>Measurements of the atmospheric electric field (or Potential Gradient, PG) in arid, desert regions are few in comparison to those in more wet/mid latitude regions, despite the fact that such measurements can provide important insights into dust charging processes. Dust charging is emerging as potentially important in sustaining the long range transport of particles, for which new charge and field data are essential. Here we present new PG data from an electric field mill at Al Ain international airport in the eastern part of the Abu Dhabi Emirate in the United Arab Emirates (UAE).  Measurements were made alongside a visibility sensor and ceilometer to provide information on the background meteorological conditions.  At Al Ain, the conditions are generally fair weather in mid-latitude terms (predominantly no clouds or precipitation), with very occasional fog or thunderstorms, but the PG still demonstrates considerable variability associated with local factors such as dust and aerosol content.  Throughout the data series, the PG is almost entirely positive, with the only negative values occurring during thunderstorms and violent dust storms.  The desert climate of the UAE lead to widespread uplift of dust on a regular basis, as evidenced by the generally low visibility measured at the airport (mean visibility = 9km).  The PG at Al Ain was found to be generally much larger than typical fair weather values at other sites, with a mean of 116 V/m, with 2 kV/m exceeded regularly.  The local influences on the PG at Al Ain are strongly apparent and the daily variation in PG was found to fall into two main categories: 1) convection dominated, 2) sea breeze dominated.   On the convection dominated days the PG followed the daily variation in temperature and wind speed closely, with very large maximum values of PG up to 4 kV/m in the mid afternoon.  The other regular daily feature in Al Ain PG was a sharp positive increase in PG up to several kV/m around 1800-1900 local time.  This feature is associated with the arrival of a sea breeze front, which originates more than 150 km away on the Abu Dhabi coastline.  The extremely large change in PG over a very short time scale (tens of minutes) is thought to be due to the action of dust pickup within the sea breeze front as it travels substantial distances over the flat arid landscape.  Overall, the electrical environment at Al Ain is found to be generally very highly charged and so the local effects (primarily from dust and aerosol) mask Global Electric Circuit influences in the surface data.</p><p> </p><p> </p><p> </p>

Short-period fluctuations in the fair-weather electric field

1974 ◽  
Vol 79 (15) ◽  
pp. 2177-2184 ◽  
Author(s):  
Donald G. Yerg ◽  
K. Ross Johnson
Keyword(s):  
Electric Field ◽  
Fair Weather ◽  
Short Period

Deploying vertical wires with drones to study wind turbine electrification under fair weather

2021 ◽  
Author(s):  
Pol Fontanes Molina ◽  
Marcelo Arcanjo ◽  
Joan Montanyà Puig ◽  
Carmen Guerra-Garcia
Keyword(s):  
Electric Field ◽  
Wind Turbine ◽  
Corona Discharge ◽  
Turbine Blades ◽  
Induced Current ◽  
Fair Weather ◽  
Wind Turbine Blades ◽  
Vertical Speed ◽  
Induced Currents ◽  
The Wire

<p>The response of tall structures such as towers to the electrical atmosphere is well known, but much has to be learned about how the rotation of wind turbine blades affects the electrical response of wind turbines. To better understand current induction and the appearance of point/corona discharge from wind turbine blades, a series of experiments lifting vertical wires with drones under fair weather conditions have been conducted. During the experiments, the length of the wire (vertical) and its vertical velocity were recorded using the drone’s telemetry. Additionally, the wire was grounded through a pico-ammeter to measure current induction and a corona discharge detector, based on a wideband current measurement coil, was placed close to the tip of the lifting wire to detect possible point/corona discharge appearance at the wire tip.</p><p>Preliminary tests included testing the sensor in the laboratory by measuring artificially generated corona pulses, to verify that pulses from this sensor registered on the field could be attributed to point/corona discharge phenomena. Measured amplitude for this induced current was on the order of hundreds of nano-amps.</p><p>For these experiments, an insulated copper wire with  0.14Ω/m resistance and with the top tip exposed to the environment was deployed using two different tips, a rounded tip of 1mm radius and a sharp needle tip of 0.1mm radius. The electric field at the ground level was measured using an electric field mill. All flights were performed during the morning and the ground electric field amplitude ranged from 50V/m to 200V/m.</p><p>When using rounded tips, corona discharge was not detected by the coil, but an induced current proportional to the vertical speed of the wire was measured. This component of the current is interpreted as a change of potential in time, and the amplitude of these induced currents is on the order of tens of nano-amps.</p><p>Results when using the sharp tip showed two clear sources of induced currents on the wire, vertical speed (as in the rounded case) and corona discharge. When using the sharp tip, corona discharge was detected when the wire reached around 50 m and induced current amplitude increased with altitude. A pulsating current was measured by the coil sensor indicating the existence of corona discharge on the wire.</p><p>The rate of decrease of the measured currents after reaching steady positions of the wires might be attributed to the screening effect of the released charge.</p><p>These experiments proved that key factors for the current induction on wind turbine blades include the change in height at a certain speed, along with the occurrence of point/corona discharges with the radius of curvature of the blade tips. Under the effects of electrified thunderclouds, the magnitudes of the currents could reach several orders of magnitude.</p><p> </p>

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