Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modeling D-Region Ionospheric Response of the Great American TSE of
  August 21, 2017 from VLF signal perturbation   Solar eclipse is an unique opportunity to study the lower ionospheric
variabilities under a controlled perturbation when the solar ultraviolet and
X-ray are temporally occulted by the lunar disk. Sub-ionospheric Very Low
Frequency (VLF) radio signal displays the ionospheric response of solar eclipse
by modulating its amplitude and phase. During the Total Solar Eclipse (TSE) on
August 21, 2017 in North America, data was recorded by a number of receivers as
presented in public archive. Out of these, two receiving stations YADA in
McBaine and K5TD in Tulsa could procure a reasonable quality of noise free data
where the signal amplitude was clearly modulated due to the eclipse. During the
lunar occultation, a C3.0 solar flare occurred and the signal received from
Tulsa manifested the effect of sudden ionization due to the flare. The VLF
amplitude in Tulsa shows the effect which is generally understood by
superimposing effects of both the solar eclipse and flare. However, the signal
by YADA did not perturb by the solar flare, as the flaring region was totally
behind the lunar disk for the entire period. We numerically reproduced the
observed signal amplitude variation at both the receiving locations by using
Wait's two component D-region ionospheric model and the well-known Long
Wavelength Propagation Capability (LWPC) code. The perturbed electron density
for both the cases is computed which matches satisfactorily with the true
ionospheric conditions.

34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs