摘要:

An approximate analytic model of ozone photochemistry including reactions with hydrogen compounds is developed for the atmospheric region between 15 and 60 km. The reaction scheme is a simplified version of that used by B. G. Hunt. The model is used to study time‐dependent processes, the sensitivity of the equilibrium‐concentration values to uncertainties in reaction rates, and the variations in the equilibrium ozone concentration with latitude and season. There are five main results. (1) Ozone loss in the model depends on the ratio of the rate of production of O(1D) and the rate of dissociation of H2O by O(1D), but the loss rate and equilibrium ozone concentration are not very sensitive to this ratio. (2) Below 40 km the model is quite sensitive to the rates of reaction of O3with OH and HO2; these unknown reaction rates are the weakest link in the theory. (3) Above 40 km the relevant reaction rates are comparatively certain and the ozone concentration is very likely to be controlled by reactions of atomic oxygen with OH and HO2. (4) As a consequence of (3), the ozone concentration near the stratopause is probably not sensitive to temperature, and the dynamical damping sometimes attributed to this temperature sensitivity is likely to be unimportant. (5) If the model is correct, the photochemical time scale for ozone is much less than it would be if only oxygen reactions control ozone; consequently, in low latitudes, ozone may be subject to significant photochemical influence down to as low as 15

ISSN:0148-0227    

DOI:10.1029/JB074i002p00417

年代:1969

数据来源: WILEY

摘要:

Wind data from the upper mesosphere over Fort Greely, Alaska, and Thule Air Base, Greenland, are presented. The data were gathered with small meteorological rockets and radar reflective chaff in July 1967. These data show increasing easterly winds with height throughout the mesophere at high latitudes in summer with maximum speeds up to 92 m/sec and mean speeds near 50 m/sec in the 75‐ to 80‐km region. Diurnal and semidiurnal oscillations are resolved and compared with current theoretical values for atmospheric thermal ti

ISSN:0148-0227    

DOI:10.1029/JB074i002p00427

年代:1969

数据来源: WILEY

摘要:

Atmospheric CO2, water vapor, net oxidant, and suspended particulate matter were measured at the Blue glacier field station, Mount Olympus, Washington, during the summer of 1966. Diurnal variations of CO2, net oxidant, and water vapor are related to mountain and valley wind transport. Diurnal variations of CO2and net oxidant have a phase nearly opposite to the typical diurnal variations in the rural lowlands. Concentrations of suspended particulate matter are lower than the concentrations of the urban and industrial areas of the Puget Sound region but generally follow the fluctuations of lowland concentrations.

ISSN:0148-0227    

DOI:10.1029/JB074i002p00435

年代:1969

数据来源: WILEY

摘要:

Based on the compiled data of thirty independent oceanic observations, this article systematically presents the wind‐stress coefficient, the surface roughness, and the boundary layer flow regime at the air‐sea interface under various wind conditions. The air flow near the water surface is shown to be aerodynamically rough or in the transition region except at a very low wind velocity (U10<3 m/sec). Both the wind‐stress coefficient and the surface roughness are found to increase with the wind velocity whenU10is less than 15 m/sec and to reach a saturated value forU10greater than 15 m/sec. From the oceanic wave observations, the presence of this discontinuity atU10= 15 m/sec is found to be due to an increase in the wind velocity (measured at the significant wave amplitude above the mean water level) beyond the average wave phase velocity. This finding provides a well‐defined separation for the often quoted terms ‘light’ and ‘strong’ winds. The compiled data also show that the surface roughness is governed by the amplitude of the short gravity waves. Charnock's relationship is shown to be applicable to most of the oceanic data and Charnock's proportionality constant is determined, η/(u*2/g) = 0.0156. Finally, two approximate formulas for the windstress coefficientC10= 0.5 ×U101/2× 10−3for light wind andC10= 2.6 × 10−3for strong wind are suggested f

ISSN:0148-0227    

DOI:10.1029/JB074i002p00444

年代:1969

数据来源: WILEY

摘要:

The rate of dissolved C14O2depletion from a thermally regulated water tank situated in a controlled‐speed wind tunnel was monitored to determine the rate constant for interphase CO2exchange as a function of air speed and solutionpH. The results appear to support the long proposed concept of a layer of laminar (nonturbulent) flow on the surface of bodies of water exposed to wind stress. The CO2exchange rate for a solutionpH in the 6.5 region (where CO2can react with water and hydroxyl ions to a significant extent) was found to be greater than the rate in thepH<4 region (where CO2effectively acts as an inert gas) by an amount that closely matched theoretical expectations based on the stable‐layer diffusion model. When the surface layer was thicker than 0.20 mm (which corresponded to air speeds under 4 m/sac) and the solution pH was greater than 6.0, there was evidence that a net bicarbonate‐CO2conversion, caused by the molecular CO2diffusion gradient, took place in the layer and that this conversion was responsible for an increase in the rate of carbon dioxide exchange. Under certain conditions, this unique surface layer reactivity may allow carbon dioxide to be exchanged between the atmosphere and hydrosphere more rapidly than if it were a nonreactiv

ISSN:0148-0227    

DOI:10.1029/JB074i002p00456

年代:1969

数据来源: WILEY

摘要:

Sediments from the continental slope in the western Gulf of Mexico were tested to determine the shear strength, stability, and consolidation characteristics. Although the topography of parts of the continental slope has been attributed to local slumping of unconsolidated and unstable marine sediments, no evidence was found to indicate instability of the sediments in the present environment. Continental slope sediments tested exhibit apparent overconsolidation and possess relatively high values of shear strength. This stability is assumed to be the result of low deposition rates and incipient cementation of mineral grains. Carbonate content and volcanic debris may also affect shear strength. Paleontological evidence indicates that some of the sediments in the Campeche canyon were deposited as the result of slumping and turbidity currents during the Pleistocene. The test results show, however, that these sediments are also stable in the present environment.

ISSN:0148-0227    

DOI:10.1029/JB074i002p00465

年代:1969

数据来源: WILEY

摘要:

Oceanic refraction surveys are interpreted almost exclusively on a time basis yielding layered crustal models. This study utilizes more of the observed information by requiring the model to produce similar waveforms as well as travel times. Theoretical seismograms based on possible travel time models are compared with the first few seconds of observed recording. Closely spaced comparisons are made along a 120‐km profile located north of the Hawaiian Islands. The final model indicates: (1) a high positive velocity gradient in the upper layers above the main oceanic layer. (2) a relatively homogeneous oceanic layer with a sharp velocity discontinuity at the crust‐mantle interface. (3) a small positive velocity gradient in the upper man

ISSN:0148-0227    

DOI:10.1029/JB074i002p00483

年代:1969

数据来源: WILEY

摘要:

This paper is a theoretical investigation of the implications for the origin of the earth's continents and ocean basins of three possible chemical compositions for the lunar highlands: ultrabasic, basic, and intermediate to acidic. Ultrabasic or basic lunar highlands would imply that the existence of sialic crust on the earth is due to some major difference between the earth and the moon; the three most likely differences are presence of an atmosphere, presence of a core, and size. The theory that continents are essentially geosynclinal accretions is shown by recent geological investigations to have numerous weaknesses and may imply an age for the earth of over 5 b.y. A proposed alternative is that large, thick primordial continents were formed by high‐pressure magmatic processes caused by early segregation of the core, with later continental evolution being essentially subordinate accretion to and reworking of these protocontinents. A basic composition for the lunar highlands would imply that the basic crustal layers of the earth are the remnants of a primordial basaltic crust. Sialic lunar highlands would imply that the earth's continents are essentially igneous, and were derived from the mantle early in geologic time. Furthermore, the nearly global extent of the lunar highlands suggests that the earth's crust has evolved by the growth of ocean basins rather than the growth of continents, perhaps by foundering of continental segments under flood basalts as proposed by Beloussov. A geochemical probe of Venus is recommended as an approach to further study of continent formation, because the nearly identical size and density of Venus would eliminate the variables of mass and core formation complicating the earth‐moon compari

ISSN:0148-0227    

DOI:10.1029/JB074i002p00495

年代:1969

数据来源: WILEY

摘要:

The analysis of a variety of geologic and geophysical data indicates that significant lateral variations in crustal structure exist across the large aperture seismic array (LASA). This structural complexity is inferred from observation of Rayleigh‐wave dispersion, body‐wave spectral ratios,P‐wave amplitude and travel‐time anomalies, seismic refraction profiles, and gravity and magnetic anomalies. To explain these results, we divide LASA into an eastern and a western sector. An attempt is then made to explain the observations in each sector in terms of crustal models consisting of three to five distinct layers. The observations show that the maximum lateral change in structure across LASA takes place in a NE‐SW

ISSN:0148-0227    

DOI:10.1029/JB074i002p00505

年代:1969

数据来源: WILEY

摘要:

Diurnal cycles of soil temperature and heat flux measured on the Pampa de La Joya, Peru are analyzed harmonically. A theory of thermal diffusion put forth by H. H. Lettau (1962) is used to determine the relative calibration of the soil heat flux plates and the relative depth intervals between the flux plates in comparison with the soil temperature profile. The absolute value of the soil heat flux is based on an allowed range of values for the density of the soil.

ISSN:0148-0227    

DOI:10.1029/JB074i002p00532

年代:1969

数据来源: WILEY