This paper uses the sea ice data during 1973- 1988,and divides the South Ocean into fiveregions: 20￣ 88°E, 90￣ 158°E, 160°E￣ 132°W,130￣ 62°W and 60°W￣ 18°E, to analyse the spatial distribution of the Antarctic sea ice extent and its time variation.
The paper studies generic commutative and anticommutative algebras of a fixed dimension, their invariants, covariants and algebraic properties (e.g., the structure of subalgebras).
We show that wonderful varieties are necessarily spherical (i.e., they are almost homogeneous under any Borel subgroup ofG).
Along the way, we recover theorems of Steinberg  and E.
This paper is devoted to a systematic study of quantum completely integrable systems (i.e., complete systems of commuting differential operators) from the point of view of algebraic geometry.
This implies that a system is algebraically integrable (i.e., its eigenvalue problem is explicitly solvable in quadratures) if and only if the differential Galois group is commutative for generic eigenvalues.