Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling transverse dunes   Transverse dunes appear in regions of mainly unidirectional wind and high
sand availability. A dune model is extended to two dimensional calculation of
the shear stress. It is applied to simulate dynamics and morphology of
transverse dunes which seem to reach translational invariance and do not stop
growing. Hence, simulations of two dimensional dune fields have been performed.
Characteristic laws were found for the time evolution of transverse dunes.
Bagnold's law of the dune velocity is modified and reproduced. The interaction
between transverse dunes led to interesting results which conclude that small
dunes can pass through bigger ones.

2
The categories of this paper are: math
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph