Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution of the inner core of the earth: consequences for geodynamo   Using models of the Earth's core evolution and the length of the day
observations the change of the dimensionless geodynamo parameters is
considered. The evolutionary model includes cooling of the liquid adiabatic
core, growing solid core, and the region in the outer part of the core with a
subadiabatic temperature gradient. The model covers time period 4.5Ga in the
past till 1.5Gy to the future, and produce evolution of the energy sources of
the thermal and compositional convection, spatial scales of the convective
zone. These quantities are used for Ekman, Rayleigh and Rossby numbers
estimates. So far these numbers determine regime of the geomagnetic field
generation, we discuss evolution of the geomagnetic field over Earth's
evolution.

12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin