Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Prediction of Geomagnetic Storm Strength from Inner Heliospheric In Situ
  Observations   Prediction of the effects of coronal mass ejections (CMEs) on Earth strongly
depends on knowledge of the interplanetary magnetic field southward component,
Bz. Predicting the strength and duration of Bz inside a CME with sufficient
accuracy is currently impossible, which forms the so-called Bz problem. Here,
we provide a proof-of-concept of a new method for predicting the CME arrival
time, speed, Bz and the resulting Dst index at Earth based only on magnetic
field data, measured in situ in the inner heliosphere (< 1AU). On 2012 June
12-16, three approximately Earthward-directed and interacting CMEs were
observed the by the STEREO imagers, and by Venus Express (VEX) in situ at 0.72
AU, 6 degree away from the Sun Earth line. The CME kinematics are calculated
using the drag-based and WSA-Enlil models, constrained by the arrival time at
VEX, resulting in the CME arrival time and speed at Earth. The CME magnetic
field strength is scaled with a power law from VEX to Wind. Our investigation
shows promising results for the Dst forecast (predicted: -96 and -114 nT (from
2 Dst models), observed: -71 nT), for the arrival speed (predicted: 531 +- 23
km s-1, observed: 488 +- 30 km s-1) and timing (6 +- 1 hours after actual
arrival time). The prediction lead time is 21 hours. The method may be applied
to vector magnetic field data from a spacecraft at an artificial Lagrange point
between the Sun and Earth, or to data taken by any spacecraft temporarily
crossing the Sun--Earth line.

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The categories of this paper are: math
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th