Neutral air waves in the thermosphere

Neutral air waves in thermosphere - eigenvalues of characteristic wave

The thermospheric tides as an oscillator circuit system

Approximative derivation of diurnal tidal density wave in thermosphere as oscillatory circui

Note on the semi-annual effect in the thermosphere

The semi-annual variation in the thermospheric density is discussed in terms of the spatial and temporal variations in the solar heat input. Two heat sources are considered: the solar heat input associated with the semi-annual migration of the sun, and the auroral heat associated with the semi-annual component in magnetic storms. It is shown that the relatively large global component in the semi-annual effect of the total mass density can be explained by the lack of advective loss which otherwise damps the latitude dependent components in the annual and semi-annual variations, and the significant latitude dependence in the semi-annual variations of composition and temperature can be tied to the diffusion process which is induced by the thermospheric circulation

Theoretical model for the latitude dependence of the thermospheric annual and semiannual variations

A three-dimensional model for the annual and semiannual variations of the thermosphere is presented in which energy and diffusive mass transport associated with the global circulation are considered in a self-consistent form. It is shown that these processes play a major role in the thermosphere dynamics and account for a number of temperature and compositional phenomena

A numerical study of a three dimensional spherical thermospheric density and wind model

Numerical calculations of the generation and propagation of the two important fundamental symmetric tidal wave modes - the diurnal mode (1, 1, 1,) and the semidiurnal mode (2, 2, 2) - were performed applying a realistic model thermosphere and taking into account heat conduction and the temporally and spatially varying ion-neutral collision number. Both wave modes are predominantly generated by the solar EUV heat input. It is shown that the latitude structure of the (1, 1, 1)-mode which is identical with the Hough function(1, -1) within the lower non-dissipative atmosphere degenerates into the spherical function P sub 1, 1 at thermospheric heights. The pressure field of this mode constitutes the observed pressure bulge of the thermosphere, the diurnal component of which peaks at 15 h L. T. The electric polarization field of the geomagnetic Sq current generates a significant fraction of this wave mode at F layer heights. This wave component shifts the total horizontal wind system to earlier times by about 1 hour in agreement with ionospheric observations. The latitude structure of the (2, 2, 2) mode is identical with the Hough function (2, 2) within the lower non-dissipative atmosphere. It degenerates to the spherical function P sub 2, 2 at thermospheric heights

A model of the magnetospheric temperature distribution

Turbulent heat transfer and heat conductivity effects on magnetospheric temperature distributio

Theory of the phase anomaly in the thermosphere

The temperature-density phase anomaly is discussed on the basis of a quasi-three-dimensional model in which the thermosphere dynamics (including energy advection and diffusion associated with wind circulation) is considered in a self consistent form. Included in this analysis are the first three harmonics with nonlinear coupling between diurnal and semi-diurnal tides

Helios-1 Faraday rotation experiment: results and interpretations of the Solar occultations in 1975

The polarization angle of the HELIOS-1 downlink signal has been monitored during two solar occultations in 1975 at two widely separated ground stations. Significant Faraday rotation of the signal occurs whenever the signal ray path passes through the solar corona near superior conjunction. Large-scale variations in the data arise both from rotation of the solar corona and from the slowly changing solar offset (point of smallest heliocentric distance along ray path). A simplified model of the solar corona has been developed to simulate the results of the Faraday rotation measurements. In this model the known polarity of the large-scale interplanetary magnetic field is employed as an aid in determination of the product N · B (electron density x magnetic field) as a function of heliographic longitude and heliocentric distance r within 2-10 R☉ . In this distance range N · B is proportional to r-5.5. If the magnetic field can be assumed to follow an inverse square law over this range, the electron density is found to be decreasing as r-3.5, in good agreement with previous results. The derived longitudinal structure for the corona during both occultations is consistent with synoptic coronal white light observations.           ARK: https://n2t.net/ark:/88439/y065590 Permalink: https://geophysicsjournal.com/article/112 &nbsp

Characterization of Botulinum Neurotoxin Type A Neutralizing Monoclonal Antibodies and Influence of Their Half-Lives on Therapeutic Activity

Botulinum toxins, i.e. BoNT/A to/G, include the most toxic substances known. Since botulism is a potentially fatal neuroparalytic disease with possible use as a biowarfare weapon (Centers for Disease Control and Prevention category A bioterrorism agent), intensive efforts are being made to develop vaccines or neutralizing antibodies. The use of active fragments from non-human immunoglobulins (F(ab')2, Fab', scFv), chemically modified or not, may avoid side effects, but also largely modify the in vivo half-life and effectiveness of these reagents. We evaluated the neutralizing activity of several monoclonal anti-BoNT/A antibodies (mAbs). F(ab')2 fragments, native or treated with polyethyleneglycol (PEG), were prepared from selected mAbs to determine their half-life and neutralizing activity as compared with the initial mAbs. We compared the protective efficiency of the different biochemical forms of anti-toxin mAbs providing the same neutralizing activity. Among fourteen tested mAbs, twelve exhibited neutralizing activity. Fragments from two of the best mAbs (TA12 and TA17), recognizing different epitopes, were produced. These two mAbs neutralized the A1 subtype of the toxin more efficiently than the A2 or A3 subtypes. Since mAb TA12 and its fragments both exhibited the greatest neutralizing activity, they were further evaluated in the therapeutic experiments. These showed that, in a mouse model, a 2- to 4-h interval between toxin and antitoxin injection allows the treatment to remain effective, but also suggested an absence of correlation between the half-life of the antitoxins and the length of time before treatment after botulinum toxin A contamination. These experiments demonstrate that PEG treatment has a strong impact on the half-life of the fragments, without affecting the effectiveness of neutralization, which was maintained after preparation of the fragments. These reagents may be useful for rapid treatment after botulinum toxin A contamination