scholarly journals Investigation on the Distinct Nocturnal Secondary Sodium Layer Behavior Above 95 km in Winter and Summer Over Logan, UT (41.7°N, 112°W) and Arecibo Observatory, PR (18.3°N, 67°W)

2019 ◽  
Vol 124 (11) ◽  
pp. 9610-9625 ◽  
Author(s):  
Xuguang Cai ◽  
Tao Yuan ◽  
J. Vincent Eccles ◽  
Shika Raizada
Keyword(s):  
Sodium Layer ◽  
Layer Behavior ◽  
Arecibo Observatory

Arecibo Observatory: another great lost in 2020

Nature ◽  
2020 ◽  
Vol 588 (7839) ◽  
pp. 539-539
Author(s):  
Abel Méndez
Keyword(s):  
Arecibo Observatory

Daytime observation of the sodium layer with a Fabry-Perot spectrometer at Mawson, Antarctica

1989 ◽  
Vol 16 (8) ◽  
pp. 871-874 ◽  
Author(s):  
P. Greet ◽  
M. Conde ◽  
F. Jacka
Keyword(s):  
Sodium Layer ◽  
Fabry Perot

scholarly journals Pulsar Discovery by Global Volunteer Computing: Fig. 1

Science ◽  
2010 ◽  
Vol 329 (5997) ◽  
pp. 1305-1305 ◽  
Author(s):  
B. Knispel ◽  
B. Allen ◽  
J. M. Cordes ◽  
J. S. Deneva ◽  
D. Anderson ◽  
...  
Keyword(s):  
Survey Data ◽  
Large Data ◽  
Large Data Sets ◽  
Volunteer Computing ◽  
Data Sets ◽  
Pulse Profile ◽  
Computing Power ◽  
Spin Period ◽  
Arecibo Observatory ◽  
Computer Power

Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 192 countries to mine large data sets. It has now found a 40.8-hertz isolated pulsar in radio survey data from the Arecibo Observatory taken in February 2007. Additional timing observations indicate that this pulsar is likely a disrupted recycled pulsar. PSR J2007+2722’s pulse profile is remarkably wide with emission over almost the entire spin period; the pulsar likely has closely aligned magnetic and spin axes. The massive computing power provided by volunteers should enable many more such discoveries.

scholarly journals Radiant measurement accuracy of micrometeors detected by the Arecibo 430 MHz Dual-Beam Radar

2004 ◽  
Vol 4 (3) ◽  
pp. 621-626 ◽  
Author(s):  
D. Janches ◽  
M. C. Nolan ◽  
M. Sulzer
Keyword(s):  
Measurement Accuracy ◽  
Signal To Noise Ratio ◽  
Side Lobe ◽  
Beam Axis ◽  
Main Beam ◽  
High Signal ◽  
Precise Knowledge ◽  
Dual Beam ◽  
Arecibo Observatory ◽  
Meteoric Material

Abstract. Precise knowledge of the angle between the meteor vector velocity and the radar beam axis is one of the largest source of errors in the Arecibo Observatory (AO) micrometeor observations. In this paper we study ~250 high signal-to-noise ratio (SNR) meteor head-echoes obtained using the dual-beam 430 MHz AO Radar in Puerto Rico, in order to reveal the distribution of this angle. All of these meteors have been detected first by the radar first side lobe, then by the main beam and finally seen in the side lobe again. Using geometrical arguments to calculate the meteor velocity in the plane perpendicular to the beam axis, we find that most of the meteors are travelling within ~15° with respect to the beam axis, in excellent agreement with previous estimates. These results suggest that meteoroids entering the atmosphere at greater angles may deposit their meteoric material at higher altitudes explaining at some level the missing mass inconsistency raised by the comparisson of meteor fluxes derived from satellite and traditional meteor radar observations. They also may be the source of the observed high altitude ions and metalic layers observed by radars and lidars respectively.

The bistatic LGS scheme for sodium layer height characterization (based on the Teide Observatory experimental setup)

2008 ◽  
Author(s):  
Julio A. Castro-Almazán ◽  
Jesús J. Fuensalida ◽  
Ángel Alonso ◽  
Sergio Chueca
Keyword(s):  
Experimental Setup ◽  
Layer Height ◽  
Sodium Layer

scholarly journals Survey of electron density changes in the daytime ionosphere over the Arecibo observatory due to lightning and solar flares

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caitano L. da Silva ◽  
Sophia D. Salazar ◽  
Christiano G. M. Brum ◽  
Pedrina Terra
Keyword(s):  
Electron Density ◽  
Solar Flares ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Weather Conditions ◽  
Optical Observations ◽  
Radio Waves ◽  
D Region ◽  
E Region ◽  
Arecibo Observatory

AbstractOptical observations of transient luminous events and remote-sensing of the lower ionosphere with low-frequency radio waves have demonstrated that thunderstorms and lightning can have substantial impacts in the nighttime ionospheric D region. However, it remains a challenge to quantify such effects in the daytime lower ionosphere. The wealth of electron density data acquired over the years by the Arecibo Observatory incoherent scatter radar (ISR) with high vertical spatial resolution (300-m in the present study), combined with its tropical location in a region of high lightning activity, indicate a potentially transformative pathway to address this issue. Through a systematic survey, we show that daytime sudden electron density changes registered by Arecibo’s ISR during thunderstorm times are on average different than the ones happening during fair weather conditions (driven by other external factors). These changes typically correspond to electron density depletions in the D and E region. The survey also shows that these disturbances are different than the ones associated with solar flares, which tend to have longer duration and most often correspond to an increase in the local electron density content.

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