摘要:

It is well known that the microwave thermal emission from the atmosphere as observed at the ground is related to the vertical temperature profile of the atmosphere by a quasi‐linear integral equation. We have measured the spectrum of the microwave emission at the zenith in the 5–6‐mm band of atmospheric oxygen during December 1967 and August 1968. From these measurements we have obtained temperature profiles for the first 10 km of the troposphere using the statistical estimation technique of Westwater and Strand (1967). We treat the nonlinearity in the integral equation due to the temperature dependence of the oxygen absorption coefficient by iteration. The inferred profiles compare favorably with concurrently obtained radiosonde profiles. The absolute accuracy of the microwave radiometric measurements is 1°–2°K, and the rms agreement between the inferred profiles and concomitant radiosonde profiles is with

ISSN:0148-0227    

DOI:10.1029/JC077i006p00975

年代:1972

数据来源: WILEY

摘要:

We have examined the zonal harmonic waves in the southern hemisphere by means of longterm average heights of constant‐pressure surfaces from sea level to 100 mb and by daily 500‐mb heights, and found that waves 1, 2, and 3 have significant standing components. Wave 1 at extratropical latitudes has one peak in the subpolar regions and another in the subtropics. The ridge of the subpolar region is in the Pacific and the ridge of the subtropical region is in the Atlantic Ocean. The phase changes near 40°S where the amplitude tends toward nought. In summer the wave is biggest near the tropopause but in winter it continues to grow into the stratosphere over the area where the temperature drops poleward. Wave 2 has a large standing component over Antarctica with its ridges over the highest parts of west and east Antarctica. There is a well‐defined wave 3 between 25° and 60°S in all months, with ridges near the three lower‐latitude continents. In addition the wave has a marked peak in the upper tropical troposphere in summer, which is in phase with that at higher

ISSN:0148-0227    

DOI:10.1029/JC077i006p00992

年代:1972

数据来源: WILEY

摘要:

Radioactivity concentrations and activity ratios in air sampled at ground‐level locations are useful in correlating the latitudinal spread of nuclear debris with a tropospheric or stratospheric source. In late 1968 and again in late 1969, China detonated a high‐yield nuclear device in the northern hemisphere (40°N), and France conducted a nuclear test series (22°S) in mid‐1968 and in mid‐1970. An examination of the Zr‐95 concentrations and Zr‐95 to Ce‐144 activity ratios indicates several time and space regions with similar radioactivity characteristics that can be related to one of these specific so

ISSN:0148-0227    

DOI:10.1029/JC077i006p01004

年代:1972

数据来源: WILEY

摘要:

Measurements of the concentrations of short‐lived fission products,140Ba and95Zr, from the French tests in Polynesia, which were carried out during 1968, 1970, and 1971, are presented. The data show that the debris reached the west coast of India in 15–22 days after the burst date for the three test series, which strikingly confirms all our previous findings based on the 1968 and earlier test debris. A comparative study of the levels of short‐lived fission products at various stations in the northern and southern hemispheres following the French tests is also presented. The results of this comparison shows that the rapid transport of air masses across the equator by the southerly jet results in levels in India (west coast) that are up to an order of magnitude higher compared to levels at the same latitude in other meridians. The above radioactive data are consistent with recent meteorological studies on the magnitude of interhemispheric exchange in the west Indian

ISSN:0148-0227    

DOI:10.1029/JC077i006p01012

年代:1972

数据来源: WILEY

摘要:

Transmission spectra of natural aerosol substances have been obtained from λ2.5 to 15 μm (4000 to 666 cm−1) by the potassium bromide pellet technique; and the spectral variation of the absorption coefficient and the imaginary part of the refractive index of typical aerosol fractions, which includes sea salt and ammonium sulfate, is presented. Some data for the visual range are discussed. The aerosol fractions, i.e., dry water solubles (evaporation residues), dust (minerals), soot, and benzene solubles, have been obtained primarily from rain and snow water. The structured spectra of water solubles from tropical and mid‐latitude rains (and aerosol filters) and their concentration are generally similar though more variable in snow, especially in the arctic and in arctic glacier ice. Absorption by dust and soot is less dependent on wavelength, and the influence of soot percentage and water content oniraerosol absorption has been calculated. Problems ofirspectroscopy, such as the dependence of absorption coefficients on concentration in the KBr technique, and mixing effects, are also mentioned. Concentration and absorption spectra of alcohol and benzene extract of dry water solubles indicate that hydrocarbons play a more important role in air chemistry, especially in arctic regions, than previously as

ISSN:0148-0227    

DOI:10.1029/JC077i006p01017

年代:1972

数据来源: WILEY

摘要:

Direct‐current measurements during March and April 1970, in the four major passages through the Lesser Antilles show a westward transport of about 26 × 106m3sec−1. This transport is divided between the Grenada, St. Vincent, and St. Lucia passages with, respectively, 10, 10, and 6 × 106m3sec−1flowing to the west. The transport through Dominica passage was less than 2 × 106m3sec−1during these measurements. This flow pattern is consistent with the distribution of variables as shown by data from hydrographic stations to the east and west of each passage. On the basis of the temperature‐oxygen relationship, water that enters the Caribbean with a temperature between 16°–23°C comes from a broad band of water found

ISSN:0148-0227    

DOI:10.1029/JC077i006p01032

年代:1972

数据来源: WILEY

摘要:

Two numerical experiments that test the feasibility of a modified sigma equations' approach to resolve large‐scale topographical and baroclinic effects are undertaken for Lake Huron. The application of a realistic bottom topography (and zero stratification) produces significant flow modification only where the depth change is large (at least for the grid resolution employed); in particular, a co‐oscillation of Saginaw Bay with the remainder of the Lake Huron basin is observed. The inclusion of baroclinicity (and constant depth) permits internal waves to form with density oscillations of about a 17‐hour period (the mean inertial period of Lake Huron is approximately 17.2 hours). A third case, in which baroclinicity and variable depth are included together, showed some evidence of numerical instability and is therefore not discussed

ISSN:0148-0227    

DOI:10.1029/JC077i006p01050

年代:1972

数据来源: WILEY

摘要:

Concentrations of7Be,95ZrNb,106Ru, and144Ce were determined in surface water and vertical profiles in the North Pacific Ocean. Latitudinal distribution of radionuclides in equatorial waters differed from previous patterns of both terrestrial and oceanic fallout of long‐lived fission products. Fallout rates were quite uniform across narrow latitude belts, with constant amounts of radionuclides occurring both vertically and horizontally in the water mass. The short‐lived radionuclides were uniformly distributed in the mixed layer, but decreased in concentration as the thermocline was penetrated. Vertical eddy diffusion coefficients, calculated from7Be and95ZrNb data, were 0.5–0.7 cm2/sec within the upper boundary of the main oceanic thermo

ISSN:0148-0227    

DOI:10.1029/JC077i006p01061

年代:1972

数据来源: WILEY

摘要:

Oxygen and carbon‐isotope analyses of carbonate and carbon‐isotope analyses of organic matter from a 6‐meter core suggest that the Black Sea was fresh or brackish between 17,000 and 9000 years ago. In the lower parts of the core the fraction of redeposited carbonate may be as high as 80%. It is possible that postdepositional exchange of oxygen isotopes in the extremely fine‐grained carbonate below 1.5 meters in the core has occurred. First signs of increasing salinity in the basin can be detected in the oxygen isotopes of the carbonate that was deposited about 1500 to 2000 years prior to the onset of sapropel deposition. This interval appears to be the one between the first influx of saline Mediterranean water after the last glacial maximum and the establishment of anoxic bottom conditions in the Black Sea. The isotope data indicate a gradual rise of salinity until about 3000 years ago when the present level appears to have been

ISSN:0148-0227    

DOI:10.1029/JC077i006p01071

年代:1972

数据来源: WILEY

摘要:

Extrapolations of recent work of ground‐based measurements of atmospheric water‐vapor profiles show that a measurement of stratospheric water‐vapor content is fea

ISSN:0148-0227    

DOI:10.1029/JC077i006p01078

年代:1972

数据来源: WILEY