Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Biological Impact of Ozone Depletion at the End-Permian: A modeling
  study   The end-Permian mass extinction is the most severe known from the fossil
record. The most likely cause is massive volcanic activity associated with the
formation of the Permo-Triassic Siberian flood basalts. A proposed mechanism
for extinction due to this volcanic activity is depletion of stratospheric
ozone, leading to increased penetration of biologically damaging Solar
ultraviolet-B (UVB) radiation to Earth's surface. Previous work has modeled the
atmospheric chemistry effects of volcanic emission at the end-Permian. Here we
use those results as input for detailed radiative transfer simulations to
investigate changes in surface-level Solar irradiance in the ultraviolet-B,
ultraviolet-A and photosynthetically available (visible light) wave bands. We
then evaluate the potential biological effects using biological weighting
functions. In addition to changes in ozone column density we also include
gaseous sulfur dioxide (SO2) and sulfate aerosols. Ours is the first such study
to include these factors and we find they have a significant impact on
transmission of Solar radiation through the atmosphere. Inclusion of SO2 and
aerosols greatly reduces the transmission of radiation across the ultraviolet
and visible wavelengths, with subsequent reduction in biological impacts by
UVB. We conclude that claims of a UVB mechanism for this extinction are likely
overstated.

27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc