Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Testing and forecasting the time series of the solar activity by
  singular spectrum analysis   To study and forecast the solar activity data a quite perspective method of
singular spectrum analysis (SSA) is proposed. As known, data of the solar
activity are usually presented via the Wolf numbers associated with the
effective amount of the sunspots. The advantages and disadvantages of SSA are
described by its application to the series of the Wolf numbers. It is shown
that the SSA method provides a sufficiently high reliability in the description
of the 11-year solar cycle. Moreover, this method is appropriate for revealing
more long cycles and forecasting the further solar activity during one and a
half of 11-year cycle.

12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio