Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Properties of stream interaction regions at Earth and Mars during the
  declining phase of SC 24   We inspect the evolution of SIRs from Earth to Mars (distance range 1-1.5 AU)
over the declining phase of solar cycle 24 (2014-2018). So far, studies only
analyzed SIRs measured at Earth and Mars at different times. We compare
existing catalogs for both heliospheric distances and arrive at a clean dataset
for the identical time range. This allows a well-sampled statistical analysis
and for the opposition phases of the planets an in-depth analysis of SIRs as
they evolve with distance. We use in-situ solar wind data from OMNI and the
MAVEN spacecraft as well as remote sensing data from SDO. A superposed epoch
analysis is performed for bulk speed, proton density, temperature, magnetic
field magnitude and total perpendicular pressure. Additionally, a study of
events during the two opposition phases of Earth and Mars in the years 2016 and
2018 is conducted. SIR related coronal holes with their area as well as their
latitudinal and longitudinal extent are extracted and correlated to the maximum
bulk speed and duration of the corresponding high speed solar wind streams
following the stream interaction regions. We find that while the entire solar
wind HSS shows no expansion as it evolves from Earth to Mars, the crest of the
HSS profile broadens by about 17%, and the magnetic field and total pressure by
about 45% around the stream interface. The difference between the maximum and
minimum values in the normalized superposed profiles increases slightly or
stagnates from 1-1.5 AU for all parameters, except for the temperature. A sharp
drop at zero epoch time is observed in the superposed profiles for the magnetic
field strength at both heliospheric distances. Maximum solar wind speed has a
stronger dependence on the latitudinal extent of the respective coronal hole
than on its longitudinal extent. We arrive at an occurrence rate of fast
forward shocks three times as high at Mars than at Earth.

24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph