Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Seasonal Cycle of Gravity Wave Potential Energy Density from Lidar and
  Satellite Observations at $54^{\circ}$N and $69^{\circ}$N
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph