Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On stratification, barotropic tides, and secular changes in surface
  tidal elevations: Two-layer analytical model
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph