Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gravity currents in a porous medium at an inclined plane   We consider the release from a point source of relatively heavy fluid into a
porous saturated medium above an impermeable slope. We consider the case where
the volume of the resulting gravity current increases with time like $t^\alpha$
and show that for $\alpha<3$, at short times the current spreads
axisymmetrically, with radius $r\sim t^{(\alpha+1)/4}$, while at long times it
spreads predominantly downslope. In particular, for long times the downslope
position of the current scales like $t$ while the current extends a distance
$t^{\alpha/3}$ across the slope. For $\alpha>3$, this situation is reversed
with spreading occurring predominantly downslope for short times. The governing
equations admit similarity solutions whose scaling behaviour we determine, with
the full similarity form being evaluated by numerical computations of the
governing partial differential equation. We find that the results of these
analyses are in good quantitative agreement with a series of laboratory
experiments. Finally, we briefly discuss the implications of our work for the
sequestration of carbon dioxide in aquifers with a sloping, impermeable cap.

9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org