Bibliography

Notice:

Clicking on the title will open a new window with all details of the bibliographic entry.
Clicking on the DOI link will open a new window with the original bibliographic entry from the publisher.
Clicking on a single author will show all publications by the selected author.
Clicking on a single keyword, will show all publications by the selected keyword.

Found 10 entries in the Bibliography.

Showing entries from 1 through 10

2014

Hemispheric distributions and interannual variability of NO _y produced by energetic particle precipitation in 2002-2012

We investigate the interannual variability and hemispheric differences of reactive odd nitrogen produced by energetic particle precipitation (EPP-NO_y) and transported into the stratosphere and lower mesosphere during polar winters in 2002\textendash2012. For this purpose, EPP-NO_y amounts derived from observations of the Michelson Interferometer for Passive Atmospheric Sounding by means of a tracer correlation method have been used. Southern hemispheric (SH) seasonal maximum EPP-NO_y amounts transported below the 0.02 hPa level range from 0.5GM to 2.5GM in the 2009 and 2003 winters, respectively. Northern hemispheric (NH) amounts were typically 2\textendash5 times smaller, with the exception of the 2003/2004 winter. This interhemispheric asymmetry is primarily caused by a reduction of the mesospheric descent rates in NH midwinter, as opposed to the SH. Hemispherically integrated NO_y fluxes through given pressure levels reach up to 0.07GM/day at 0.1 hPa. A multilinear regression of the EPP-NO_y evolution to the A_p index of the preceding months indicates that a large fraction of the SH interannual variability of EPP-NO_y (excluding direct contributions by solar protons) can be linked to geomagnetic activity variations. This relationship holds throughout the winter and at all vertical levels where EPP-NO_y is present. In the NH, a similar correlation is found until midwinter, however, breaking down afterward above 2 hPa in years with elevated stratopause occurrence. As an exception, EPP-NO_y amounts in the Arctic winter 2004/2005 were much higher than in other NH winters with similar geomagnetic activity. We attribute this behavior to the unusually stable polar vortex in that winter, otherwise typical for the SH.

Funke, B.; opez-Puertas, M.; Holt, L.; Randall, C.; Stiller, G.; von Clarmann, T.;

Published by: Journal of Geophysical Research: Atmospheres Published on: 11/2014

YEAR: 2014 DOI: 10.1002/2014JD022423

2009

Influence of solar-geomagnetic disturbances on SABER measurements of 4.3 Micrometer emission and the retrieval of kinetic temperature and carbon dioxide

Thermospheric infrared radiance at 4.3 μm is susceptible to the influence of solar-geomagnetic disturbances. Ionization processes followed by ion-neutral chemical reactions lead to vibrationally excited NO+ (i.e., NO+(v)) and subsequent 4.3 μm emission in the ionospheric E-region. Large enhancements of nighttime 4.3 μm emission were observed by the TIMED/SABER instrument during the April 2002 and October\textendashNovember 2003 solar storms. Global measurements of infrared 4.3 μm emission provide an excellent proxy to observe the nighttime E-region response to auroral dosing and to conduct a detailed study of E-region ion-neutral chemistry and energy transfer mechanisms. Furthermore, we find that photoionization processes followed by ion-neutral reactions during quiescent, daytime conditions increase the NO+ concentration enough to introduce biases in the TIMED/SABER operational processing of kinetic temperature and CO2 data, with the largest effect at summer solstice. In this paper, we discuss solar storm enhancements of 4.3 μm emission observed from SABER and assess the impact of NO+(v) 4.3 μm emission on quiescent, daytime retrievals of Tk/CO2 from the SABER instrument.

Mertens, Christopher; Winick, Jeremy; Picard, Richard; Evans, David; opez-Puertas, Manuel; Wintersteiner, Peter; Xu, Xiaojing; Mlynczak, Martin; Russell, James;

Published by: Advances in Space Research Published on:

YEAR: 2009 DOI: 10.1016/j.asr.2008.10.029

2005

Energy transport in the thermosphere during the solar storms of April 2002

Mlynczak, Martin; Martin-Torres, Javier; Crowley, Geoff; Kratz, David; Funke, Bernd; Lu, Gang; Lopez-Puertas, Manuel; Russell, James; Kozyra, Janet; Mertens, Chris; Sharma, Ramesh; Gordley, Larry; Picard, Richard; Winick, Jeremy; Paxton, L.;

Published by: Journal of Geophysical Research Published on: Jan-01-2005

YEAR: 2005 DOI: 10.1029/2005JA011141

2004

Thermospheric infrared radiance response to the April 2002 geomagnetic storm from SABER infrared and GUVI ultraviolet limb data

The SABER instrument on TIMED continuously measures certain infrared limb radiance profiles with unprecedented sensitivity. Among these are emissions of CO₂ ν₃ at 4.3 μm, routinely recorded to tangent heights of ~140-150 km, and NO at 5.3 μm, seen to above ~200 km and ~300 km, respectively. We use these infrared channels of SABER and coincident far ultraviolet (FUV) measurements from GUVI on TIMED, to study the geometric storm of April 2002. These all give a consistent measure of auroral energy input into the lower thermosphere at high latitudes. Emission in yet another SABER channel, near 2.0 μm, correlates well with enhanced electron energy deposition. We also have, in the 5.3-μm emissions from the long-lived population of aurorally produced NO, a tracer of how this energy is transported equator-ward and released over an extended period of time, a few days. In this paper, we discuss the global patterns of energy deposition into the expanded auroral oval, its transport to lower latitudes, and its loss as revealed by the NO 5.3-μm emissions.

Winick, Jeremy; Mlynczak, Martin; Wintersteiner, Peter; Martin-Torres, Francisco; Picard, Richard; Paxton, L.; Lopez-Puertas, Manuel; Russell, James; Christensen, Andrew; Gordley, Larry;

Published by: Published on:

YEAR: 2004 DOI: 10.1117/12.515982

2003

The natural thermostat of nitric oxide emission at 5.3 μm in the thermosphere observed during the solar storms of April 2002

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on the Thermosphere-Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite observed the infrared radiative response of the thermosphere to the solar storm events of April 2002. Large radiance enhancements were observed at 5.3 μm, which are due to emission from the vibration-rotation bands of nitric oxide (NO). The emission by NO is indicative of the conversion of solar energy to infrared radiation within the atmosphere and represents a \textquotedblleftnatural thermostat\textquotedblright by which heat and energy are efficiently lost from the thermosphere to space and to the lower atmosphere. We describe the SABER observations at 5.3 μm and their interpretation in terms of energy loss. The infrared enhancements remain only for a few days, indicating that such perturbations to the thermospheric state, while dramatic, are short-lived.

Mlynczak, Marty; Martin-Torres, F.; Russell, J.; Beaumont, K.; Jacobson, S.; Kozyra, J.; opez-Puertas, M.; Funke, B.; Mertens, C.; Gordley, L.; Picard, R.; Winick, J.; Wintersteiner, P.; Paxton, L.;