Auroral recombination of N and O: A possible source for emission in the γ and δ bands of NO

Radiative recombination of N and O provides a significant source for auroral emission in the γ and δ bands of NO with selective population of vibrational levels in the A²Σ⁺ and C²Π states. This mechanism may account for emissions detected near 2150 Å. Models are derived for the auroral ionosphere and include estimates for the concentrations of N and NO. The concentration of NO is estimated to have a value of about 10⁸ cm^?1 near 140 km in an IBC III aurora. The corresponding density for N is about 5 × 10⁷cm^?3 and the concentration ratio $\text{NO}{}^{\mathrm{+}}\text{O}{}_2{}^{\mathrm{+}}$ has a value of about 5.5.     

Ion-ion recombination rates in the earth's atmosphere

The temperature dependence of the binary recombination coefficient, α₂, for the reaction NO⁺+NO₂^? → products has been obtained over the range 185–530 K. It is found that the corresponding mean cross section $\text{σ}$ is described by the power law $\text{σ}\text{? A · T}{}^{\mathrm{?0.9}}$, and that α₂ ? B · T^?0.4. Data has also been obtained for two cluster ion recombination reactions which indicate that their recombination cross sections are only about 40% larger than for the parent ions at a given temperature, the cross sections for these reactions also apparently increasing with decreasing temperature. In the light of this data and by considering the most probable positive and negative ions existing at various altitudes up to 90km in the atmosphere, the most appropriate ionic recombination coefficients in various altitude ranges are deduced. Thus, between 30 and 90 km, where the recombination process is two-body, the coefficient varies over the narrow range 5–9 × 10^?8 cm³s^?1, while below 30 km the process is predominantly three-body with an effective two-body rate increasing rapidly to a maximum value ≈3 × 10^?6 cm³s^?1 in the troposphere, these deductions being based on published laboratory determinations of three-body recombination coefficients.     

Mars: Photodesorption from mineral surfaces and its effects on atmospheric stability

A mechanism has been proposed for uv-accelerated desorption from Fe²⁺ sites on mineral surfaces that satisfies kinetic constraints determined in the laboratory by Huguenin. The process is an integral step of the photochemical weathering mechanism for producing dust on Mars, and it now appears that it may play primary roles in stabilizing CO₂ against dissociation by sunlight and in controlling the oxidation state of the atmosphere. We propose that adsorption occurs at octahedrally coordinated Fe²⁺ surface sites to form seven-coordinate transition-state complexes. These complexes acquire 16–18 kcal mole^?1 of ligand field stabilization energy. During illumination (λ ≤ 0.35 μm), electrons are photoemitted from the surfaced Fe²⁺, temporarily oxidizing them to Fe³⁺. Fe³⁺ has no ligand field stabilization energy, and the complexes lose 16–18 kcal mole^?1 of stabilization energy. This is a large fraction of the 19- to 28-kcal mole^?1 activation energy for dissociating the complexes, and desorption should proceed spontaneously. The gases that were observed to undergo adsorption-photodesorption include O₂, CO₂, CO, H₂O, N₂, and Ar. Photodesorption can drive several catalytic reactions, one of which is the oxidation of CO to CO₂. The rate of this reaction should be limited by the supply of CO and O₂ to the surface to ～2 × 10¹² cm^?2 sec^?1 (column photodissociation rate of CO₂). By including this surface reaction in models of Martian atmospheric CO₂ chemistry, CO₂ can be stabilized against photodissociation with eddy diffusion coefficients of only 3 × 10⁵?1 × 10⁷ cm² sec^?1 below 40 km, raising to ～ 10⁹ cm² sec^?1 at 140 km. Odd hydrogen is not needed to catalyze the oxidation of CO below 40 km, and odd hydrogen mixing ratios need only to be $\text{f}{}_{\mathrm{<mtext>H</mtext>}}\text{? 10}{}^{\mathrm{?10}}$ to depress ozone concentrations below the observed upper limit in equatorial regions. Another catalytic reaction that should be driven by photodesorption on Mars is $\text{20}\text{H}{}^{\mathrm{?}}{}_{\mathrm{<mtext>(</mtext><mtext>ads</mtext><mtext>)</mtext>}}\text{→}\text{H}{}_2\text{O}\text{+}\text{1}\text{2}\text{O}{}_{\mathrm{2(g)}}\text{+ 2e}{}^{\mathrm{?}}{}_{\mathrm{<mtext>crystal</mtext>}}$. This is an important source of atmospheric O₂, amounting to 7 × 10¹³?2 × 10¹⁷ O₂ molecules cm^?2 yr^?1, and it could have a significant effect on atmospheric oxidation state.     

Further quantification of the sources and sinks of thermospheric O1D) atoms

In this paper we confirm an earlier finding that the reaction

constitutes a major source of OI 6300 Å dayglow. The rate coefficient for this reaction is found to be consistent with an auroral result, namely k₁ ≈ 6 × 10^?12cm³s^?1. We correct an error in an earlier publication and demonstrate that reaction (1) is consistent with the laboratory determined quenching rate for the reaction

where $\text{k}{}_2\text{= 2.3 × 10}{}^{\mathrm{?11}}\text{cm}{}^3\text{s}{}^{\mathrm{?1}}$. Dissociative recombination of O⁺₂ with electrons is found to be a major daytime source in summer above ～220 km.     

A self-consistent evaluation of the rate constants for the production of the OI 6300 Å airglow

The quenching rate k_N2 of $\text{O(}{}^1\text{D)}$ by N₂ and the specific recombination rate α_1D of O₂⁺ leading to $\text{O(}{}^1\text{D)}$ are re-examined in light of available laboratory and satellite data. Use of recent experimental values for the $\text{O(}{}^1\text{D)}$ transition probabilities in a re-analysis of AE-C satellite 6300 Å airglow data results in a value for k_N2 of 2.3 × 10^?11 cm³s^?1 at thermospheric temperatures, in excellent agreement with the laboratory measurements. This implies a value of J_O2 = 1.5 × 10^?6s^?1 for the O₂ photodissociation rate in the Schumann-Runge continuum. The specific recombination coefficient α_1D = 2.1 × 10^?7cm³s^?1 is also in agreement with the laboratory value. Implications for the suggested $\text{N}\text{(}{}^2\text{D) + O}{}_2\text{→ O(}{}^1\text{D) + NO}$ reaction are discussed.     

Small-scale turbulence in the atmosphere of Venus

Previous studies based on radio scintillation measurements of the atmosphere of Venus have identified two regions of small-scale temperature fluctuations located in the vicinity of 45 and 60 km. A global study of the fluctuations near 60 km, which are consistent with wind-shear-generated turbulence, was conducted using the Pioneer Venus measurements. The structure constants of refractive index fluctuations c_n² and temperature fluctuations c_T² increase poleward, peak near 70° latitude, and decrease over the pole; c_n² varies from 2 × 10^?15 to 1.5 × 10^?14m^{$\text{2}\text{3}$} and c_T² from 4 × 10^?3 to 7 × 10^?2°K²m^{$\text{?2}\text{3}$}. These results indicate greater turbulent activity at the higher latitudes. In the region near 45 km the refractive index fluctuations and the corresponding temperature fluctuations are substantially lower. Based on the analysis of one representative occultation measurement, $\text{c}{}_{\mathrm{<mtext>n</mtext>}}{}^2\text{= 2 × 10}{}^{\mathrm{?16}}\text{m}{}^{\mathrm{<mtext>?2</mtext><mtext>3</mtext>}}\text{and}\text{c}{}_{\mathrm{<mtext>T</mtext>}}{}^2\text{= 7.3 × 10}{}^{\mathrm{?4}}\text{°}\text{K}{}^2\text{m}{}^{\mathrm{<mtext>?2</mtext><mtext>3</mtext>}}$ in the 45-km region. The fluctuations in this region also appear to be consistent with wind-shear-generated turbulence. The turbulence level is considerably weaker than that at 60 km; the energy dissipation rate ε is 4.9 × 10^?5m²sec^?3 and the small-scale eddy diffusion coefficient K is 2 × 10³ cm² sec^?1.     

Charge exchange of metastable D oxygen ions with N2 in the thermosphere

Measurements of N₂⁺ and supporting data made on the Atmosphere Explorer-C satellite in the ionosphere are used to study the charge exchange process

$\text{O}{}^{\mathrm{+}}\text{(}{}^2\text{D}\text{)+}\text{N}{}_2\text{→}\text{k}\text{N}{}^{\mathrm{+}}{}_2\text{+}\text{O}$

The equality k = (5 ± 1.7) × 10^?10cm³s^?1. This value lies close to the lower limit of experimental uncertainty of the rate coefficient determined in the laboratory. We have also investigated atomic oxygen quenching of O⁺(²D) and find that the rate coefficient is 2 × 10^?11 cm³s^?1 to within approximately a factor of two.     

A dynamical effect in the ionospheric f1 layer

Incoherent scatter observations of the ionospheric F₁ layer above Saint-Santin (44.6°N) are analyzed after correction of a systematic error at 165 and 180 km altitude. The daytime valley observed around 200 km during summer for low solar activity conditions is explained in terms of a downward ionization drift which reaches ?30 m s^?1 around 180 km. Experimental determinations of the ion drift confirm the theoretical characteristics required for the summer daytime valley as well as for the winter behaviour without a valley. The computations require an effective dissociative recombination rate of $\text{2.3 × 10}{}^{\mathrm{?7}}\text{(}\text{300/}\text{T}{}_{\mathrm{e}}\text{)}{}^{0.7}\text{(}\text{cm}{}^3\text{s}{}^{\mathrm{?1}}\text{)}$ and ionizing fluxes compatible with solar activity conditions at the time when the valley is observed.     

On the photodissociation of water vapour in the mesosphere

The photodissociation of water vapour in the mesosphere depends on the absorption of solar radiation in the region (175–200 nm) of the O₂ Schumann-Runge band system and also at H-Lyman alpha. The photodissociation products are OH + H, OH + H, O + 2H and H₂ + O at Lyman alpha; the percentages for these four channels are 70, 8, 12 and 10%, respectively, but OH + H is the only channel between 175 and 200 nm. Such proportions lead to a production of H atoms corresponding to practically the total photodissociation of H₂O, while the production of H₂ molecules is only 10% of the H₂O photodissociation by Lyman alpha.The photodissociation frequency (s^?1) at Lyman alpha can be expressed by a simple formula

$\text{J}{}_{\mathrm{<mtext>Ly</mtext><mtext>\alpha </mtext>}}\text{H}{}_2\text{O=4.5 ×10}{}^{\mathrm{?6}}\text{1+0.2}\text{F}{}_{10.7}\text{?65}\text{100}\text{exp}\text{[?4.4 ×10}{}^{\mathrm{?19}}\text{N}{}^{0.917}\text{]}$

where F_{10.7 cm} is the solar radioflux at 10.7 cm and N the total number of O₂ molecules (cm^?2), and when the following conventional value is accepted for the Lyman alpha solar irradiance at the top of the Earth's atmosphere ($\text{Δλ = 3.5}\text{A}\text{?}$) q_Lyα,∞ = 3 × 10¹¹ photons cm^?2 s^1?.The photodissociation frequency for the Schumann-Runge band region is also given for mesospheric conditions by a simple formula

$\text{J}{}_{\mathrm{<mtext>SRB</mtext>}}\text{(}\text{H}{}_2\text{O}\text{) = J}{}_{\mathrm{<mtext>SRB</mtext><mtext>,\infty </mtext>}}\text{(}\text{H}{}_2\text{O}\text{) exp [?10}{}^{\mathrm{?7}}\text{N}{}^{0.35}\text{]}$

where J_SRB,∞(H₂O) = 1.2 × 10^?6 and 1.4 × 10^?6 s^?1 for quiet and active sun conditions, respectively.The precision of both formulae is good, with an uncertainty less than 10%, but their accuracy depends on the accuracy of observational and experimental parameters such as the absolute solar irradiances, the variable transmittance of O₂ and the H₂O effective absorption cross sections. The various uncertainties are discussed. As an example, the absolute values deduced from the above formulae could be decreased by about 25-20% if the possible minimum values of the solar irradiances were used.     

Ion composition in the E- and lower F- region above kiruna during sunset and sunrise

A magnetic type mass spectrometer has been flown on two ESRO sounding rockets from ESRANGE (Kiruna 68°N) on February 25 and 26, 1970. The first launch was at sunset (16:33 UT) and the second the next morning, during sunrise (04:47 UT). For both flights the solar zenith angle was approximately 98°. The instrument was measuring simultaneously the neutral gas and positive ion composition and the total ion density. In this paper the results of the ion composition measurements are presented. For both flights the main ion constituents measured between approximately 110–220 km were O⁺, NO⁺ and O₂⁺. Only at sunset were N⁺ and N₂⁺ detected above 200 km. In spite of the identical solar UV-radiation, pronounced sunset/sunrise variations in the positive ion composition were found. The total ion densities at sunrise were between 5×10³ and 5 × 10⁴ ions cm^?3 and therefore too high to be explained without a night-time ionization by precipitated particles. At sunrise the NO⁺ and O₂⁺ profiles show a correlated wavelike structure with three pronounced almost equally spaced layers in the E-region. Only the highest layer is present in the O⁺ profile. Locally enhanced field aligned ionization originated by particle precipitation and an E × B instability are the most likely source for this structure. In the E- and lower F-regions the $\text{NO}{}^{\mathrm{+}}\text{O}{}_2{}^{\mathrm{+}}$ ration increased overnight from values around 7 at sunset to 15 at sunrise, correlated with an increase of the local magnetic activity index K from 0⁺ to 2°. This could be explained if the NO density and magnetic activity are correlated.     

Estimates of quasipolar absorption by methane in the atmosphere of Titan

The basis for “quasipolar” absorption (QPA) by CH₄ is the existence of a small electric dipole moment in its ground state. The integrated intensity α_QPA at a temperature of 90K is calculated to be between 4.8 × 10^?5 and 1.9 × 10^?2 cm^?2 atm^?1. With an assumed mean pressure of 0.1 atm and a relative abundance of $\text{[}\text{CH}{}_4\text{]}\text{[}\text{H}{}_2\text{]}\text{= 1}$, it is estimated that the ratio of quasipolar to pressure-induced absorption (PIA) is 0.05 ? α_QPA/α_PIA ? 18 for the spectral range from 0 to 300 cm^?1. This result suggests that quasipolar absorption may contribute to a weak, CH₄-induced greenhouse in the atmosphere of Titan.     

Titan: Far-infrared and microwave remote sensing of methane clouds and organic haze

It is shown that Titan's surface and plausible atmospheric thermal opacity sources—gaseous N₂, CH₄, and H₂, CH₄ cloud, and organic haze—are sufficient to match available Earth-based and Voyager observations of Titan's thermal emission spectrum. Dominant sources of thermal emission are the surface for wavelenghts λ ? 1 cm, atmospheric N₂ for 1 cm ? λ ? 200 μm,, condensed and gaseous CH₄ for 200 μm ? λ ? 20 μm, and molecular bands and organic haze for λ ? 20 μm. Matching computed spectra to the observed Voyager IRIS spectra at 7.3 and 52.7° emission angles yields the following abundances and locations of opacity sources: CH₄ clouds: 0.1 g cm^? at a planetocentric radius of 2610–2625 km, 0.3 g cm^?2 at 2590–2610 km, total 0.4 ± 0.1 g cm^–2 above 2590 km; organic haze: $\text{4 ± 2 × 10}{}^{\mathrm{?6}}\text{,}\text{g cm}\text{,}{}^{\mathrm{?2}}$ above 2750 km; tropospheric H₂: 0.3 ± 0.1 mol%. This is the first quantitative estimate of the column density of condensed methane (or CH₄/C₂H₆) on Titan. Maximum transparency in the middle to far IR occurs at 19 μm where the atmospheric vertical absorption optical depth is $\text{?0.6}$ A particle radius $\text{r}\text{? 2 μ}\text{m}$ in the upper portion of the CH₄ cloud is indicated by the apparent absence of scattering effects.     

Simultaneous measurements of No and No2 in the stratosphere

Simultaneous measurements of NO and NO₂ in the stratosphere leading to an NO_x determination have been performed by means of i.r. absorption spectrometry using the Sun as a source in the 5·2 μm band of NO and in the 6·2 μm band of NO₂. The observed abundance of NO_P peaks at 26 km where it is equal to (4·2 ± 1) × 10⁹ cm^?3. The volume mixing ratio of NO_p was observed to vary from 1·3 × 10^?9 at 20 km to 1·3 × 10^?8 at 34 km.     

A global study of O2(1Δg) airglow: Day and twilight

Aircraft measurements of $\text{O}{}_2\text{(}{}^1\text{Δ}{}_{\mathrm{g}}\text{)}$ emission made over a 10-yr period provide information on the variation of ozone with latitude and season in the altitude region 50–90 km. Between 50 and 70 km there appears to be little variation (< ± 25%) whereas the abundance between 80 and 90 km exhibits a large seasonal change north of 30°N and much less at lower latitude. At mid and high latitude the column abundance above ～ 80 km changes from ? 1 × 10¹⁴ cm^?2 in summer to about 3 × 10¹⁴ cm^?2 in winter. There are occasional enhancements in both the day and twilight airglow which almost always occur in association with auroral activity or, at least, where such activity is statistically most likely. These enhancements appear to reflect a corresponding increase in the ozone mixing ratio in the upper stratosphere. While the gradient in ozone mixing ratio with latitude is generally small at altitudes between 50 and 90km there are occasions when a temporary latitude structure can be seen, particularly above 80 km.     

Stratospheric in situ measurements of H2SO4 and HSO3 vapors during a volcanically active period

In situ measurements of stratospheric H₂SO₄ and HSO₃vapors using passive chemical ionization mass spectrometry were made in October 1982 after the eruption of volcano El Chichon. Data were obtained between about 20 and 41 km showing [H₂SO₄ + HSO₃] sum concentrations between about 10⁴ and 2 × 10⁵ cm^?3 below 29 km and a steep rise above this altitude. Maximum [H₂SO₄ + HSO₃] values of about 3 × 10⁶ cm^?3 are reached above 35 km.Partial [HSO₃] concentrations increase above 34 km reaching about $\text{4 × 10}{}^5\text{cm}{}^{\mathrm{?3}}$ around 40 km. From the measurements it is concluded that H₂SO₄ and probably HSO₃photolysis have an important influence above 34 km leading to the observed increase of [HSO₃] and a depletion of H₂SO₄vapor.It also seems that the data support the view of heterogeneous HSO₃ removal. If correct, this would imply that stratospheric aerosols are formed primarily from HSO₃ rather than H₂SO₄vapor.     

Direct measurement of conjugate photoelectrons and predawn 630 nm airglow

A sounding rocket was flown during the predawn on 17 January, 1976 from Uchinoura, Japan, to measure directly the behaviour of the conjugate photoelectrons at magnetically low latitudes. On board the rocket were an electron energy analyzer, 630 nm airglow photometer, and plasma probes to measure electron density and temperature. The incoming flux of the photoelectrons was measured in the altitude range between 210 and 340 km. The differential flux at the top of the atmosphere was determined to be $\text{F = (1.3 ± 0.4) × 10}{}^{11}\text{exp}\text{[?}\text{E(}\text{eV}\text{)}\text{12}\text{]}$ electron · m^?2 · sr^?1 · s^?1 in the energy range 10 ? E ? 50 eV. The emission rate of the 630 nm airglow was observed in the altitude range between 90 and 360 km. The apparent emission rate observed at 80 km was 32 ± 5 R. From a theoretical calculation of the optical excitation rate using the observed electron flux data along with a model distribution of atomic oxygen, it was estimated that more than 65% of the emission could be produced by direct impact of the photoelectrons with atomic oxygen in the thermosphere between 200 and 360 km. Using the observed electron density and the model distribution of oxygen molecules the residual of the emission was ascribed to the excitation of O(¹D) through dissociative recombination, $\text{O}{}_2{}^{\mathrm{+}}\text{+}\text{e}\text{→}\text{O}{}^1\text{+}\text{O}{}^7$. The direct collisional excitation by ambient electrons is estimated to be negligibly small at the level of observed electron temperature.     

Io: Observational constraints on internal energy and thermophysics of the surface

Infrared observations of the Io eclipse of 12 April 1980 in five broad bands from 3 to 30 μm define the thermal emission spectrum both during and after eclipse. A substantial fraction of the emitted radiation during eclipse arises from hot spots; the equivalent global average heat flow is 1.5 ± 0.3 W m^?2, corresponding to an internal source of (6 ± 1) × 10¹³ W. The hot spot spectra can be matched by components with color temperatures of 200–600°K covering 1–2% of the surface. Comparison with observations over the past 8 years suggests that, while the flux at the hottest temperatures may be highly variable, there is no evidence for major changes in the total heat flow, which is emitted primarily in the spectral region 10–20 μm. The heating curves of the surface were observed at 10 and 20 μm; when corrected for the hot spot contribution they indicate a typical global thermal inertia for Io of $\text{(0.2 ± 0.1) × 10}{}^{\mathrm{?3}}\text{cal cm}{}^{\mathrm{?2}}\text{sec}\text{?}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{K}{}^{\mathrm{?1}}$, similar to that of the other Galilean satellites.     

Residual mass from atmospheric ablation of small meteoroids

Numerical solutions of the equations of meteor ablation in the Earth's atmosphere have been obtained using a variable step size Runge-Kutta technique in order to determine the size of the residual mass resulting from atmospheric flight. The equations used include effects of meteoroid heat capacity and thermal radiation, and a realistic atmospheric density profile. Results were obtained for initial masses in the range 10^?7–10^?2 g, and for initial velocities less than 24 km s^?1 (results indicated no appreciable residual mass for meteors with velocities above 24 km s^?1 in this mass range). The following function has been obtained to provide the logarithm of the ratio of the residual mass following atmospheric ablation to the original preatmospheric mass

$\text{log r = 4.7 ?0.33v}{}_{\mathrm{\infty }}\text{?0.013v}{}_{\mathrm{\infty }}{}^2\text{+ 1.2 log m}{}_{\mathrm{\infty }}\text{+ 0.08 log}{}^2\text{m}{}_{\mathrm{\infty }}\text{?0.083v}{}_{\mathrm{\infty }}\text{log m}{}_{\mathrm{\infty }}\text{M}$

The pre-atmospheric mass and velocity are represented by m_∞ and v_∞.When the results are expressed in terms of the size of the residual mass following atmospheric ablation as a function of the initial mass and velocity, it is found that the final residual mass is almost independent of the original mass of the meteoroid, but very strongly dependent on the original velocity. For example, the residual mass is very nearly 10^?7 g for a meteoroid with velocity 18 kms^?1 for initial masses from 10^?7 to 10^?3 g. On the other hand, a slight change in the initial velocity to 20 km s^?1 will shift the residual mass to approx. 10^?8 g. This strong velocity dependence coupled with the weak dependence on the original mass has important consequences for the sampling of ablation product micrometeorites.     

On fourier-analysis of geomagnetic pulsations pc-1, “two-fold” and “three-fold” pulsations pc-1 and fundamental frequencies of the magnetospheric cavity—I

The paper gives the results of detailed studies of the frequency spectra $\text{S}{}_{\mathrm{s}}\text{(?)}$ of the chain of the wave packets F_s(t) of geomagnetic pulsations PC-1 recorded at the Novolazarevskaya station. The bulk of the energy of F_s(t) is concentrated in the vicinity of the central frequencies $\text{?}{}_{\mathrm{s0}}$ of spectra—the carrier frequencies of the signals. The velocity $\text{V}{}_0\text{≌ 6.10}{}^3\text{km s}{}^{\mathrm{?1}}$ of the flux of protons generating these signals correspond to them. The spectra of the signals have oscillations—“satellites” irregularly distributed in frequency. These satellites, as the authors believe, testify to the presence of the individual groups of protons of low concentration whose velocities vary within 10³–10⁴ km s^?1.Their energy is only of the order of 10^?2–10^?3 of the energy of the main proton flux. Clearly pronounced maxima on double and triple frequencies $\text{? = 2?}{}_{\mathrm{s0}}\text{and}\text{3?}{}_{\mathrm{s0}}$ are detected. They show that the generation of pulsations PC-1 is accompanied by the generation on the overtones of wave packets called in this paper “two-fold” and “three-fold” pulsations PC-1. Intensive symmetrical satellites of a modulation character have been discovered on frequencies $\text{?}{}^{\mathrm{\pm }}{}_{\mathrm{sK}}$. Frequency differences $\text{Δ?}{}_{\mathrm{sK}}{}^{\mathrm{\pm }}\text{=}\text{¦?}{}_{\mathrm{s0}}\text{? ?}{}_{\mathrm{sK}}{}^{\mathrm{\pm }}\text{¦}\text{= (0.011,0.022}\text{and}\text{0.035)}\text{Hz}$ correspond to them. The authors believe that the values of Δ?^±_sK are resonance frequencies of the magnetospheric cavity in which geomagnetic pulsations PC-1 are generated. It is established that the values of Δ?^±_sK coincide closely with the carrier frequencies of geomagnetic pulsations PC-3 and PC-4 generated in the magnetosphere. This leads to the conclusion that the resonance oscillations of the magnetospheric cavity are their source. Thus, the generation of geomagnetic pulsations of different types and resonance oscillations in the magnetosphere are integrated into a unified process. The importance of the results obtained and the necessity to check further their trustworthiness and universality, using experimental data gathered in different conditions, is stressed.