Diurnal variations in the atmospheric electric field on the South Polar ice-cap

1981 ◽  
Vol 43 (2) ◽  
pp. 171-177 ◽  
Author(s):  
M.S. Muir ◽  
C.A. Smart
2019 ◽  
Vol 46 (13) ◽  
pp. 7268-7277 ◽  
Author(s):  
Patricio Becerra ◽  
Michael M. Sori ◽  
Nicolas Thomas ◽  
Antoine Pommerol ◽  
Emanuele Simioni ◽  
...  

Polar Record ◽  
2019 ◽  
Vol 55 (6) ◽  
pp. 392-401
Author(s):  
Rip Bulkeley

AbstractThere has been some uncertainty as to which of the two southerly probes, during which Bellingshausen passed latitude 69°S in early 1820, achieved the first sighting of an ice coast of Dronning Maud Land in Eastern Antarctica. The author criticizes Frank Debenham’s English translation of Bellingshausen’s narrative before presenting and discussing new translations of Bellingshausen’s descriptions of those events, with relevant sections of his track chart, plus a third passage from the book which interpreted what was seen. He concludes that the Russians first sighted an ice coast in mid-February, rather than late January as has been widely claimed.


2021 ◽  
Author(s):  
Giacomo Di Silvestro ◽  
Roberto Orosei ◽  
Luca Guallini ◽  
Andrea Morelli

<p>The ESA Mars Express mission was launched in June 2003 and reached Martian orbit in December of the same year. Among the instruments onboard, the Italian-American radar MARSIS has retrieved valuable data, therefore contributing many discoveries related to the Red Planet, such as the evidence of sub-glacial water lakes beneath the South Pole of Mars. The technique used by this antenna is the radar echo sounding which, thanks to the electromagnetic waves emitted at frequencies in the HF range – in four separate bands centered at 1.8, 3, 4, and 5 MHz - has the ability to penetrate the ice masses, allowing the study of the internal properties and structures of glaciers and the regolith underneath.<br>Based on selected MARSIS radargrams, the main purpose of our analysis is to define the topography and main morphologies of the bedrock beneath Ultimi Lobe, part of the South Polar Ice Cap. Geologically speaking, this region is characterized by the South Polar Layered Deposits unit, widely showing complex layering and locally broad deformational structures (i.e., faults and folds). In particular, through the use of a georeferenced model of the bedrock surface, we focused on the search for low-topographies possibly consistent with basins able to contain the subglacial water reservoirs inferred by Orosei et al. (2018) and Lauro et al. (2020). Furthermore, we are implementing an algorithm focused on semi-automatic surface delineation using radar echo observations. Through the implementation of this script and retrieved data/images, we suggest that the machine-learning algorithm could be trained for further analysis.</p>


2021 ◽  
Author(s):  
Susana Barbosa ◽  
Mauricio Camilo ◽  
Carlos Almeida ◽  
Guilherme Amaral ◽  
Nuno Dias ◽  
...  

<p>The marine boundary layer offers a unique opportunity to investigate the electrical properties of the atmosphere, as the effect of natural radioactivity in driving near surface ionization is significantly reduced over the ocean, and the concentration of aerosols is also typically lower than over land. This work addresses the temporal variability of the atmospheric electric field in the South Atlantic marine boundary layer based on measurements from the SAIL (Space-Atmosphere-Ocean Interactions in the marine boundary Layer) project. The SAIL monitoring campaign took place on board the Portuguese navy tall ship NRP Sagres during its circumnavigation expedition in 2020.  Two identical field mills (CS110, Campbell Scientific) were installed on the same mast but at different heights (about 5 and 22 meters), recording the atmospheric electric field every 1-second. Hourly averages of the atmospheric electric field are analyzed for the ship’s leg from 3<sup>rd</sup> to 25<sup>th</sup> March, between Buenos Aires (South America) and Cape Town (South Africa). The median daily curve of the electric field has a shape compatible with the Carnegie curve, but significant variability is found in the daily pattern of individual days, with only about 30% of the days exhibiting a diurnal pattern consistent with the Carnegie curve.</p>


2005 ◽  
Vol 51 (173) ◽  
pp. 231-238 ◽  
Author(s):  
S. Barwick ◽  
D. Besson ◽  
P. Gorham ◽  
D. Saltzberg

AbstractWe have determined the in situ electric field attenuation length Lα (defined as the length over which the signal amplitude diminishes by a factor 1/e) for radio-frequency signals broadcast vertically through South Polar ice and reflected off the underlying bed. Conservatively assuming a bedrock field reflectivity for f = 380 MHz, and T = –50°C; the errors incorporate uncertainties in R. This value is consistent with previous estimates that the radiofrequency attenuation length exceeds the attenuation length at optical frequencies by an order of magnitude.


2006 ◽  
Vol 21 (supp01) ◽  
pp. 221-226 ◽  
Author(s):  
◽  
SEBASTIAN BÖSER ◽  
S. BÖSER ◽  
C. BOHM ◽  
S. HUNDERTMARK ◽  
...  

Due to its large Greeneisen coefficient ice is of special interest for the acoustic detection of ultra-high energetic neutrino-induced cascades. The abundant homogeneous volume and an existing neutrino observatory make the south polar ice cap a favourable location for this purpose. Theoretical calculations yield absorption lengths of ~ 10 km, but no measurements at all are available in the frequency range of interest. We present an experimental setup to measure the key parameters of the antarctic glacial ice.


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