Basaltic pahoehoe lava-fed deltas: large-scale characteristics, clast generation, emplacement processes and environmental discrimination

Abstract. We examine 14 cases of an interesting type of extremely high latitude aurora as identified in the precipitating particles measured by the DMSP F13 satellite. In particular we investigate structures within large-scale arcs for which the particle signatures are made up of a group of multiple distinct thin arcs. These cases are chosen without regard to IMF orientation and are part of a group of 87 events where DMSP F13 SSJ/4 measures emissions which occur near the noon-midnight meridian and are spatially separated from both the dawnside and duskside auroral ovals by wide regions with precipitating particles typical of the polar cap. For 73 of these events the high-latitude aurora consists of a continuous region of precipitating particles. We focus on the remaining 14 of these events where the particle signatures show multiple distinct thin arcs. These events occur during northward or weakly southward IMF conditions and follow a change in IMF By. Correlations are seen between the field-aligned currents and plasma flows associated with the arcs, implying local closure of the FACs. Strong correlations are seen only in the sunlit hemisphere. The convection associated with the multiple thin arcs is localized and has little influence on the large-scale convection. This also implies that the sunward flow along the arcs is unrelated to the overall ionospheric convection.

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Introduction to special section on Large-Scale Characteristics of the Sea Ice Cover from AMSR-E and Other Satellite Sensors

Journal of Geophysical Research Atmospheres ◽

10.1029/2007jc004442 ◽

2008 ◽

Vol 113 (C2) ◽

Cited By ~ 2

Author(s):

Josefino C. Comiso ◽

Konrad Steffen

Keyword(s):

Sea Ice ◽

Large Scale ◽

Special Section ◽

Ice Cover ◽

Satellite Sensors ◽

Scale Characteristics

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Convectively Coupled Kelvin Waves: From Linear Theory to Global Models

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-15-0153.1 ◽

2015 ◽

Vol 73 (1) ◽

pp. 407-428 ◽

Cited By ~ 12

Author(s):

Michael J. Herman ◽

Zeljka Fuchs ◽

David J. Raymond ◽

Peter Bechtold

Keyword(s):

Composite Structures ◽

Large Scale ◽

Kelvin Waves ◽

Radiosonde Data ◽

3D Analysis ◽

Kelvin Wave ◽

Scale Characteristics ◽

Precipitation Anomalies ◽

Convective Inhibition ◽

Ecmwf Model

Abstract The authors analyze composite structures of tropical convectively coupled Kelvin waves (CCKWs) in terms of the theory of Raymond and Fuchs using radiosonde data, 3D analysis and reanalysis model output, and annual integrations with the ECMWF model on the full planet and on an aquaplanet. Precipitation anomalies are estimated using the NOAA interpolated OLR and TRMM 3B42 datasets, as well as using model OLR and rainfall diagnostics. Derived variables from these datasets are used to examine assumptions of the theory. Large-scale characteristics of wave phenomena are robust in all datasets and models where Kelvin wave variance is large. Indices from the theory representing column moisture and convective inhibition are also robust. The results suggest that the CCKW is highly dependent on convective inhibition, while column moisture does not play an important role.

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