NASA Scientific and Technical Aerospace Reports

temperature and relative humidity measurements. The archived data are available at:http: //croc.gsfc.nasa.gov/shadoz. In
Thompson et al., accuracies and imprecisions in the SHADOZ 1998- 2000 dataset were examined using ground-based
instruments and the TOMS total ozone measurement (version 7) as references. Small variations in ozonesonde technique
introduced possible biases from station-to-station. SHADOZ total ozone column amounts are now compared to version 8
TOMS; discrepancies between the two datasets are reduced 2\% on average. An evaluation of ozone variations among the
stations is made using the results of a series of chamber simulations of ozone launches (JOSIE-2000, Juelich Ozonesonde
Intercomparison Experiment) in which a standard reference ozone instrument was employed with the various sonde techniques
used in SHADOZ. A number of variations in SHADOZ ozone data are explained when differences in solution strength, data
processing and instrument type (manufacturer) are taken into account.
Author
Atmospheric Composition; Atmospheric Temperature; Data Processing; Ozone; Pressure Measurement; Total Ozone Mapping
Spectrometer; Troposphere; Stratosphere
20040070945 NASA Marshall Space Flight Center, Huntsville, AL, USA
Differential Velocity between Solar Wind Protons and Alpha Particles in Pressure Balance Structures
Yamauchi, Yohei; Suess, Steven T.; Steinberg, John T.; Sakurai, Takashi; Journal of Geophysical Research; 2004; ISSN
0148-0227; Volume 109; 1 pp.; In English; Ulysses Science Working Team Meeting, 22-23 Apr. 2004, Noordwijk,
Netherlands; No Copyright; Avail: Other Sources; Abstract Only
Pressure balance structures (PBSs) are a common high-plasma beta feature in high-latitude, high-speed solar wind. They
have been proposed as remnants of coronal plumes. If true, they should reflect the observation that plumes are rooted in
unipolar magnetic flux concentrations in the photosphere and are heated as oppositely directed flux is advected into and
reconnects with the flux concentration. A minimum variance analysis (MVA) of magnetic discontinuities in PBSs showed there
is a larger proportion of tangential discontinuities than in the surrounding high-speed wind, supporting the hypothesis that
plasmoids or extended current sheets are formed during reconnection at the base of plumes. To further evaluate the character
of magnetic field discontinuities in PBSs, differential streaming between alpha particles and protons is analyzed here for the
same sample of PBSs used in the MVA. Alpha particles in high-speed wind generally have a higher radial flow speed than
protons. However, if the magnetic field is folded back on itself, as in a large-amplitude Alfven wave, alpha particles will
locally have a radial flow speed less than protons. This characteristic is used here to distinguish between folded back magnetic
fields (which would contain rotational discontinuities) and tangential discontinuities using Ulysses high-latitude, high-speed
solar wind data. The analysis indicates that almost all reversals in the radial magnetic field in PBSs are folded back field lines.
This is found to also be true outside PBSs, supporting existing results for typical high-speed, high-latitude wind. There remains
a small number of cases that appear not to be folds in the magnetic field and which may be flux tubes with both ends rooted
in the Sun. The distinct difference in MVA results inside and outside PBSs remains unexplained.
Author
Alpha Particles; Protons; Solar Wind; Pressure
20040073558 Naval Research Lab., Washington, DC
Atmospheric Photo Ionization of Argon with a Short Pulse Laser
Manheimer, Wallace; Mar. 28, 2004; 17 pp.; In English
Report No.(s): AD-A422355; NRL/MR/6707--04-8751; No Copyright; Avail: CASI; A03, Hardcopy
One of the goals of the NRL laser-atmospheric propagation program is to produce a plasma spot, at a controlled range
with a combination of longitudinal compression of a laser pulse over long distance, followed by transverse self focusing over
short distance. The ease by which one can accomplish this depends, at least in part, on the ionization mechanism. This report
suggests that photo ionization of the argon component, via a four photon resonant excitation, followed by ionization of the
highly excited state could be easier to accomplish than ionization of the oxygen by a direct four photon process, a seemingly
more obvious choice. The reason is that the former is a resonant process, while the latter is not. While detailed calculations
are not performed, initial crude calculations indicate that the rate via the argon channel could exceed the rate via the oxygen
channel by several orders of magnitude.
DTIC
Argon; Atmospheric Circulation; Atmospheric Ionization; Gas Ionization; Pulsed Lasers
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