1,302 research outputs found
The Glacier Complexes of the Mountain Massifs of the North-West of Inner Asia and their Dynamics
The subject of this paper is
the glaciation of the mountain massifs
Mongun-Taiga, Tavan-Boghd-Ola, Turgeni-
Nuru, and Harhira-Nuru. The glaciation is
represented mostly by small forms that
sometimes form a single complex of domeshaped
peaks. According to the authors,
the modern glaciated area of the mountain
massifs is 21.2 km2 (Tavan-Boghd-Ola),
20.3 km2 (Mongun-Taiga), 42 km2 (Turgeni-
Nuru), and 33.1 km2 (Harhira-Nuru).
The area of the glaciers has been shrinking
since the mid 1960’s. In 1995–2008, the rate
of reduction of the glaciers’ area has grown
considerably: valley glaciers were rapidly
degrading and splitting; accumulation
of morainic material in the lower parts
of the glaciers accelerated. Small glaciers
transformed into snowfields and rock
glaciers. There has been also a degradation
of the highest parts of the glaciers and the
collapse of the glacial complexes with a
single zone of accumulation into isolated
from each other glaciers. Reduced snow
cover area has led to a rise in the firn
line and the disintegration of a common
accumulation area of the glacial complex.
In the of the Mongun-Taiga massif, in 1995–
2008, the firn line rose by 200–300 m. The
reduction of the glaciers significantly lagged
behind the change in the position of the
accumulation area boundary. In the past two
years, there has been a significant recovery
of the glaciers that could eventually lead to
their slower degradation or stabilization of
the glaciers in the study area
Photon splitting and Compton scattering in strongly magnetized hot plasma
The process of photon splitting is investigated in the presence of strongly
magnetized electron-positron plasma. The amplitude of the process is calculated
in general case of plasma with nonzero chemical potential and temperature. The
polarization selection rules and corresponding partial amplitudes for allowed
splitting channels are obtained in the case of charge-symmetric plasma. It is
found that the new splitting channel forbidden in magnetized vacuum becomes
allowed. The absorption rates of the photon splitting are calculated with
taking into account of the photon dispersion and wave function renormalization.
In addition, the comparison of photon splitting and Compton scattering process
is made. The influence of the reactions under consideration on the radiation
transfer in the framework of magnetar model of SGR burst is discussed.Comment: 17 pages, 17 figures. v2: minor changes, typos corrected, to be
published in Phys.Rev.
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