摘要:

The thermodynamic stability of the mesosphere and lower thermosphere requires that there be a downward transport of heat associated with any turbulent mixing. The maximum amount of heat that is available for transportation downward through any level by eddy conduction can be determined from the absorption of solar energy above that level; any heat losses by infrared radiation or large‐scale circulation can only reduce the available heat. This evaluation of the available heat can be used to place an upper limit on the vertical eddy diffusivity, and this limit is substantially below values frequently quoted on the basis of vapor or meteor trail studies. The upper limit is about 106cm2/sec above 80 km and about 4×105cm2/sec from 50 to 70 km. The fact that diffusive equilibrium distributions of atmospheric constituents prevail no lower than 105 km, where the molecular diffusion coefficient is 106cm2/sec, indicates that the eddy coefficient at that altitude has the limiting value obtained from thermal consideratio

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01281

年代:1965

数据来源: WILEY

摘要:

Narrow‐band interference filters having a bandpass centered atHα (λ = 6563 A) have been used successfully in photographing lightning discharges in daylight and in the design of an improved lightning flash counter. Preliminary results are presented along with a discussion of design principles and possible further applications of the techniq

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01285

年代:1965

数据来源: WILEY

摘要:

It is shown that the EM radiation frequencies from external sources required to form ball lightning (according to the Kapitza theory) are emitted during the collision of charged water drops. Calculations show that a reasonable volume of nominally charged droplets will provide the energy necessary for the lightning ball, but a prohibitively large volume of ordinary rain drops is required. It is hypothesized that shock from ordinary bolt lightning may provide the requisite droplet‐charging energy, either through liquid breakup in a polarizing field or by gas friction. Interactions or convergence of the EM radiation may be of importance in producing the required localized energy densitie

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01291

年代:1965

数据来源: WILEY

摘要:

In an attempt to resolve contradictory conclusions based on meteorological considerations, we present radiochemical data bearing on the origin of the unusually high radioactive fallout over southeastern United States during the period September 17–22, 1961. The isotopic composition of the escaping cloud from the vented Antler underground shot affords an explanation for the marked enrichment of Ce141relative to Ce144in Washington, D.C., fallout samples. The appreciable enrichment of Ce141, Ba140, and Sr90relative to Ce144in the fallout over southeastern United States on September 18 and thereafter seems explainable only by the contribution of fractionated debris from the vented underground Antler shot. The radiochemical data are inadequate for an assessment of the relative proportion of Antler shot debris and Soviet atmospheric test debris in the fallout mixtur

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01295

年代:1965

数据来源: WILEY

摘要:

The condensation of one of the components in a gas flow mixture is shown to increase significantly the amount of current blown past a negative point‐ring corona discharge. Using a nozzle configuration, the power required to form and charge the aerosol can be shown to originate from the mechanical energy of the flow and not from the power supply feeding the corona discharge. At constant velocity and pressure the amount of current available from the point is not affected by gas composition and does not vary significantly with particle size if a minimum size is exceeded. The highly charged aerosol cloud has a space charge density such that it invokes a positive corona discharge from a grounded point in its vicinity. This discharge effectively neutralizes the cloud charge. In consequence, this method indicates attractive possibilities for experimentation in the production and interaction of positively and negatively charged miniature cloud masses and electrical discharges between the

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01303

年代:1965

数据来源: WILEY

摘要:

The chemical analysis of surfaces using α‐particle interactions has been investigated. Simple instruments incorporating Cm242α sources and semiconductor silicon detectors are described. The characteristic energy spectrums of α particles scattered at large angles from thick targets of different elements have been determined. The relative intensities of scattering by different elements have been established. They show large enhancement due to nuclear effects over Rutherford scattering for elements lighter than sodium. The production of protons from (α,p) reactions in certain elements increases the sensitivity of the method for these elements. The theoretical basis for the quantitative interpretation of scattering spectrums from complex materials is developed. The technique appears to be suitable for instrumented space mis

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01311

年代:1965

数据来源: WILEY

摘要:

Infrared signals received in the 8‐ to 12‐μ window by weather satellites and aircraft are dependent on surface temperature (Ts), surface emissivity (ε), and atmospheric interference. It seems that nowhere can variations of ε be neglected in order to evaluateTsdata correctly. Methods of determining ε of typical surface materials are presented. They are: (1) determinations from reflection data obtained from polished rock samples run on a spectrophotometer; (2) a fieldworthy device constructed by the authors, called the emissivity box; and (3) ε as inferred from Tiros data. Over the Sahara, emissivity of SiO2‐containing surfaces is frequently below 0.95. Emissivity of water and oil on water are shown

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01329

年代:1965

数据来源: WILEY

摘要:

The positions and bathymetric profiles of three distinct knolls on the Sigsbee abyssal plain and seven knoll‐like structures to the south‐southwest on the continental rise are presented. These knolls, some with total surface relief of over 400 m, extend the region of reported knolls some 200 km farther to the south‐southwest. The positions of all knolls reported to date are seen to trend approximately along an azimuth 15°. The occurrence of discrete ooids and oolitically coated pellets in the sediments obtained from an interknoll position on the continental rise is offered as proof of the occurrence of submarine slumping from the Campeche shelf. Chemical work performed on small black particles obtained in one core from a knoll indicated that these materials were of high molecular weight (>500) and dominantly aliphatic hydrocarbons. The sediment veneer on the flanks and tops of the knolls differs from that of the abyssal plain; the former contains a much thicker interval of grayish‐orange foraminifera

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01339

年代:1965

数据来源: WILEY

摘要:

Temperature logging of boreholes as a continuous function of depth yields more information than measurements made at discrete depths and requires no more time. Continuous‐logging equipment is described that has a resolution of about 0.01°C and is suitable for use to depths of at least 3 km. A balanced Wheatstone bridge, strip chart recorder, and thermistor are used to measure temperature. The depth indicator and recorder chart are driven through selsyns by the cab

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01349

年代:1965

数据来源: WILEY

摘要:

Temperatures were measured at twelve levels in the Nundydroog mine of the Kolar gold field (12°55′N, 78°15′E) using a thermistor and a dc Wheatstone bridge. The mean gradient is 10.4°C/km, at depths between 230 and 1640 meters below the surface. The mean thermal conductivity in the vertical direction of hornblende schists collected from various levels in the mine is 6.3±0.7 mcal/cm sec °C. The heat flow is 0.66±0.1 μcal/cm2sec. The observed heat flow is lower than the average value for the continents and supports the world pattern of low heat flow values from Precambri

ISSN:0148-0227    

DOI:10.1029/JZ070i006p01353

年代:1965

数据来源: WILEY