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Full-Text Articles in Physical Sciences and Mathematics

Undulations In A Confined Lamellar System With Surface Anchoring, T. Ishikawa, Oleg Lavrentovich Oct 2013

Undulations In A Confined Lamellar System With Surface Anchoring, T. Ishikawa, Oleg Lavrentovich

Oleg Lavrentovich

We visualize undulations in layered systems using a cholesteric stripe phase with a macroscopic supramicron periodicity. The wave vector of stripe pattern is in the cell's plane. The-undulation is induced by an in-plane magnetic field normal to the stripes. The observed displacement of layers is much larger than the value predicted by the Helfrich-Hurault classic theory. We propose a model of undulations that explains the data by finite surface anchoring of layers.


Observations Of Overturning In The Upper Mesosphere And Lower Thermosphere, M. F. Larsen, Alan Z. Liu, C. S. Gardner, M. C. Kelley, S. Collins, J. Friedman, J. H. Hecht Oct 2013

Observations Of Overturning In The Upper Mesosphere And Lower Thermosphere, M. F. Larsen, Alan Z. Liu, C. S. Gardner, M. C. Kelley, S. Collins, J. Friedman, J. H. Hecht

Alan Z Liu

A number of observations of the sodium density primarily in the mesosphere and lower thermosphere (but also of the electron density structure) have shown what appears to be overturning or convective roll cells near the transition from the mesosphere to the lower thermosphere. The cells are found in the region between 95 and 105 km and occur near the boundary between the region of lower stability in the mesosphere and the region of higher stability in the lower thermosphere. The vertical scale for the rolls is ~5–6 km, and the timescale is ~1–3 hours. The rolls occur in a region …


Kelvin-Helmholtz Instability Of The Cme Reconnection Outflow Layer In The Low Corona, Claire Foullon, Erwin Verwichte, Katariina Nykyri, Markus J. Aschwanden, Iain G. Hannah Apr 2013

Kelvin-Helmholtz Instability Of The Cme Reconnection Outflow Layer In The Low Corona, Claire Foullon, Erwin Verwichte, Katariina Nykyri, Markus J. Aschwanden, Iain G. Hannah

Publications

New capabilities for studying the Sun allow us to image for the first time the magnetic Kelvin–Helmholtz (KH) instability developing at the surface of a fast coronal mass ejecta (CME) less than 150 Mm above the solar surface. We conduct a detailed observational investigation of this phenomenon, observed off the east solar limb on 2010 November 3, in the EUV with SDO/AIA. In conjunction with STEREO-B/EUVI, we derive the CME source surface position. We ascertain the timing and early evolution of the CME outflow leading to the instability onset. We perform image and spectral analysis, exploring the CME plasma structuring …