Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The effect of stream interaction regions on ICME structures observed in
  longitudinal conjunction   We study two interplanetary coronal mass ejections (ICMEs) observed at
Mercury and 1 AU by spacecraft in longitudinal conjunction, investigating the
question: what causes the drastic alterations observed in some ICMEs during
propagation, while other ICMEs remain relatively unchanged? Of the two ICMEs,
the first one propagated relatively self-similarly, while the second one
underwent significant changes in its properties. We focus on the presence or
absence of large-scale corotating structures in the ICME propagation space
between Mercury and 1 AU, that have been shown to influence the orientation of
ICME magnetic structures and the properties of ICME sheaths. We determine the
flux rope orientation at the two locations using force-free flux rope fits as
well as the classification by Nieves-Chinchilla et al. (2019). We also use
measurements of plasma properties at 1 AU, the size evolution of the sheaths
and ME with heliocentric distance, and identification of structures in the
propagation space based on in situ data, remote-sensing observations, and
simulations of the steady-state solar wind, to complement our analysis. Results
indicate that the changes observed in one ICME were likely caused by a stream
interaction region, while the ICME exhibiting little change did not interact
with any transients between Mercury and 1 AU. This work provides an example of
how interactions with corotating structures in the solar wind can induce
fundamental changes in ICMEs. Our findings can help lay the foundation for
improved predictions of ICME properties at 1 AU.

22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
16
The categories of this paper are: stat