摘要:

Previous studies of the photodissociation of water vapor and the resulting evolution of oxygen in the earth's atmosphere have led to the conclusion that, over most of geologic time, the atmospheric oxygen abundance has been ≲10−3times the present atmospheric level. There appear, however, to be several objectionable features in these studies (i.e. the neglect of both the path length dependence of the effective absorption coefficient in the O2Schumann‐Runge bands and the importance of H2O dissociation when H2O is a minor absorber). New calculations have been performed in which these deficiencies are rectified. It now appears that the O2level could have reached an appreciable fraction of the present amount in the absence of biological act

ISSN:0148-0227    

DOI:10.1029/JC074i023p05355

年代:1969

数据来源: WILEY

摘要:

The variation of the infrared solar spectrum in the region around 6.3 μ during sunset over New Mexico was observed by a balloon‐borne spectrometer system. Analysis of the variation of the water vapor absorption lines in this region with the increased high‐altitude optical path has shown that the water vapor mixing ratio in the region from 25 to 30 km is between 2.5×10−6and 3.0

ISSN:0148-0227    

DOI:10.1029/JC074i023p05369

年代:1969

数据来源: WILEY

摘要:

A specially constructed apparatus was used to compare the ice‐nucleating properties of dust particles collected above 80 km with those of soil and Agi particles. The dust particles were found to be relatively inactive in ice nucleation when compared with Agi and soil particles of terrestrial origi

ISSN:0148-0227    

DOI:10.1029/JC074i023p05374

年代:1969

数据来源: WILEY

摘要:

The sound pulse produced by the electrostatic stress of the cylindrical charge distribution of a lightning Stepped leader (the predischarge, large‐radius, nonequilibrium, electrostatic breakdown leader) has been calculated with a numerical computational program. The radial diffusion of the charge (ionic mobility) in the electrostatic field occurs simultaneously with the radial propagation of the sound pulse. The magnitude of the resulting sound pulse is approximately 300 dynes/cm2after propagating 5 times the original stepped leader radius. The shock and sound pulse originating from the Subsequent main stroke hot air channel has been similarly calculated and duplicates previous results of G. G. Goyer and M. N. Plooster (1968) except for a variable γ‐law equation of state of air. The electrostatic sound pulse is roughly 1/300 of the subsequent main stroke, but, since it occurs earlier in time (10 to 100 msec), it should be detectable. The dominant frequency is roughly the same for the two sound pu

ISSN:0148-0227    

DOI:10.1029/JC074i023p05379

年代:1969

数据来源: WILEY

摘要:

Vertical dipole charge configurations placed in an atmosphere where the conductivity increases exponentially with altitude have been calculated. The problem is divided into cases involving fast and slow time variations, so that quasi‐stationary situations can be compared with the fast changes of lightning discharges. The calculations are presented in the form of graphs in such a way that they can be used for dipoles of all magnitudes. The calculations indicate possible convective motions that can regenerate the dipole charge configurations, and they also show that the potential difference between the ionosphere and the earth can be maintained by thunderstorms only by the pumping action produced by lightning discharges to the eart

ISSN:0148-0227    

DOI:10.1029/JC074i023p05390

年代:1969

数据来源: WILEY

摘要:

A theoretical analysis of atmospheric thermal radiation reveals that previous formulas relating this parameter to screen‐level air temperature have lacked universal applicability. New considerations indicate that the effective emittance of the atmosphere is a minimum at 273°K and that it increases symmetrically to approach unity exponentially at higher and lower temperatures. A formula is developed that meets these standards and fits experimental data from Alaska, Arizona, Australia, and the Indian Ocean with a correlation coefficient of 0.992. The atmospheric radiationRintegrated over all wavelengths, is specified solely in terms of the screen‐level air temperatureTasR= σT4{1 ‐ c exp [−d (273 ‐T)2]}, wherecanddare constants having values of 0.261 and 7.77×10−4, respectively. It appears that the formula may be valid at all latitud

ISSN:0148-0227    

DOI:10.1029/JC074i023p05397

年代:1969

数据来源: WILEY

摘要:

Measurements of reflected solar energy obtained from NASA's ATS satellites offer new possibilities for meteorological research. For the first time, both relative and absolute values of reflected radiance are available on a nearly continuous basis during the daytime over a large region of the earth's surface. Examples of these applications emphasize the high areal resolution and wide dynamic range of the satellite‐borne camera

ISSN:0148-0227    

DOI:10.1029/JC074i023p05404

年代:1969

数据来源: WILEY

摘要:

Observation of infrasonic waves at Bombay (18°57′N, 72°55′E) on the magnetically disturbed days during the period July 9–14, 1968, are reported. Variation of microbarographic activity with the three‐hour range of geomagnetic activity indicesKphas been studied during the disturbed period. It is observed that microbarographic activity has a tendency to increase rapidly following a sharp rise in the magnetic

ISSN:0148-0227    

DOI:10.1029/JC074i023p05413

年代:1969

数据来源: WILEY

摘要:

A theory for resonance amplification of standing interfacial gravity waves in viscous fluids is applied to obtain a prediction of the wavelengths for bow waves observed in some satellite photographs of orographic clouds. A second theory, predicting the rate of viscous attenuation of such waves, yields reasonable lengths for the branches of the bow waves whenever the predicted wavelengths are used along with an effective eddy viscosity of 106cm2/sec for the inversion layer and 107cm2/sec below the inversion. The latter value is consistent with that required for the occurrence of Karman vortex trails in the wake of obstacles.

ISSN:0148-0227    

DOI:10.1029/JC074i023p05418

年代:1969

数据来源: WILEY

摘要:

Two techniques have been developed for obtaining high‐resolution vertical profiles of oceanographic variables. The methods increase the spatial resolution of lowered sensors by removing the influence of vertical ship motions. Both telemetry and retrieval are accomplished easily. Used with theSTDrecorder, the methods allow the resolution of features whose vertical extent is a few decimeters. This permits smaller, laterally homogeneous layers to be distinguished and contrasted with morphological features intersecting isopycnal and isothermal surfaces and will make possible more comprehensive surveys of physical microstructur

ISSN:0148-0227    

DOI:10.1029/JC074i023p05425

年代:1969

数据来源: WILEY