Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Edge States in the Climate System: Exploring Global Instabilities and
  Critical Transitions   Multistability is a ubiquitous feature in systems of geophysical relevance
and provides key challenges for our ability to predict a system's response to
perturbations. Near critical transitions small causes can lead to large effects
and - for all practical purposes - irreversible changes in the properties of
the system. The Earth climate is multistable: present astronomical and
astrophysical conditions support two stable regimes, the warm climate we live
in, and a snowball climate, characterized by global glaciation. We first
provide an overview of methods and ideas relevant for studying the climate
response to forcings and focus on the properties of critical transitions.
Following an idea developed by Eckhardt and co. for the investigation of
multistable turbulent flows, we study the global instability giving rise to the
snowball/warm multistability in the climate system by identifying the climatic
edge state, a saddle embedded in the boundary between the two basins of
attraction of the stable climates. The edge state attracts initial conditions
belonging to such a boundary and is the gate facilitating noise-induced
transitions between competing attractors. We use a simplified yet Earth-like
climate model constructed by coupling a primitive equations model of the
atmosphere with a simple diffusive ocean. We refer to the climatic edge states
as Melancholia states. We study their dynamics, their symmetry properties, and
we follow a complex set of bifurcations. We find situations where the
Melancholia state has chaotic dynamics. In these cases, the basin boundary
between the two basins of attraction is a strange geometric set with a nearly
zero codimension, and relate this feature to the time scale separation between
instabilities occurring on weather and climatic time scales. We also discover a
new stable climatic state characterized by non-trivial symmetry properties.

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The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an