摘要:

Total solar irradiance was observed outside the earth's atmosphere by three types of absolute cavity pyrheliometer in a June 1976 sounding rocket experiment. The 1367 W/m2average solar ‘constant’ result is uncertain by less than ±0.5%, the most accurate determination to date. Nearly simultaneous observations by the Nimbus 6 earth radiation budget total irradiance detector of 1389 W/m2exceeded the rocket result by 1.6%. These recent results are discussed in the context of a summary of solar constant determinations made above the troposphere by cavity pyrheliome

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04003

年代:1978

数据来源: WILEY

摘要:

Airborne measurements of particle and gas emissions have been obtained in paroxysmal, intraeruptive, posteruptive, and extraeruptive emissions from six volcanoes. The paroxysmal and intraeruptive emissions contained relatively few small particles (<0.1 μm in size) and little gaseous sulfur in comparison to the posteruptive and extraeruptive emissions. The majority of the SO2injected in the atmosphere (≃0.1 Tg) by the 1976 eruption of Saint Augustine probably occurred during the intraeruptive and posteruptive stages. The paroxysmal eruptions of Saint Augustine produced about 6 Tg of particles of 0.01–66 μm in size and about 0.2 Tg of particles 0.01–5 μm in size. An additional 0.05 Tg of 0.01‐ to 5‐μm sized particles were emitted during the posteruptive and intraeruptive periods. Estimated emission rates from the six volcanoes ranged from 3 × 102to 5 × 10−4kg s−1(SO2), 4 × 10−1to 2 × 10−4kg s−1(H2S), 1 × 105to 1 × 101kg s−1(water vapor), 6 × 105to 2 × 10−5kg s−1(particulate mass), 6 × 1019to 3 × 1014s−1(condensation or Aitken nuclei), and 2 × 1018to 1 × 1016s−1(cloud condensation nuclei). The impacts of these new measurements on previous estimates of worldwide particle a

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04009

年代:1978

数据来源: WILEY

摘要:

We analyze data (Telegadas, 1974, 1976) on the transport of95Zr from five Chinese 3‐Mt thermonuclear explosions which deposited their debris clouds at approximately 18‐km altitude and location (40°N, 90°E) in terms of one‐dimensional diffusive transport into the troposphere. The motivation for the work is that the dynamics of oxides of nitrogen and other materials injected into the lower stratosphere by supersonic transport aircraft in the general region of 15‐ to 18‐km altitude, 40°–60°N latitude, is not well known, and different parameterizations of the transport by different authors vary substantially. A technique is developed here that allows data from pulsed sources at different seasons to be used to parameterize stratospheric motions in terms of a mean stratospheric eddy diffusivityand a mean tropopause heightz0(which characterizes an effective height of injection above the local tropopause) and thus to estimate the atmospheric residence time (equal to burden divided by flux) and also the ‘injection coefficient’ of McElroy et al. (1974) for continuous sources. A correction is made for the sedimentation of the parti

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04019

年代:1978

数据来源: WILEY

摘要:

The process by which odd nitrogen species (atomic nitrogen and nitric oxide) are formed during atmospheric entry of meteoroids is analyzed theoretically. An ablating meteoroid is assumed to be a point source of mass with a continuum regime evolving in its wake. The amounts of odd nitrogen species, produced by high‐temperature reactions of air in the continuum wake, are calculated by numerical integration of chemical rate equations. Flow properties are assumed to be uniform across the wake, and 29 reactions involving five neutral species and five singly ionized species are considered, as well as vibrational and electron temperature nonequilibrium phenomena. The results, when they are summed over the observed mass, velocity, and entry angle distribution of meteoroids, provide odd nitrogen species annual global production rates as functions of altitude. The peak production of nitric oxide is found to occur at an altitude of about 85 km; atomic nitrogen production peaks at about 95 km. The total annual rate for nitric oxide is 4 × 107kg; for atomic nitrogen it is 1.7 × 10

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04029

年代:1978

数据来源: WILEY

摘要:

The reactions of O2+· O2ions with the minor stratospheric neutrals CO2, O3, and CH4have been studied in a variable temperature flowing afterglow to test whether they represent reaction paths that can compete with the one leading to H3O+·nH2O ions and hence can offer the possibility of different terminal ions. The reaction of O2+· O2with CH4was found to be too slow to be competitive. The measured equilibrium constants of the reactions with CO2and O3indicated that only the latter, which had an O2+· O3product, could play a stratospheric role. The O2+· O3ion chemistry was also examined. It was found that the reaction with CH4was immeasurably slow but that the reaction with H2O was fast, yielding O2+· H2O ions. Since this product ion is part of the sequence of reactions that lead to the H3O+·nH2O ions, it is concluded that CO2, O3, and CH4do not afford alternative reaction paths that could rationalize the recent in situ observation of non‐H3O+·nH2O ions in the lower str

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04036

年代:1978

数据来源: WILEY

摘要:

Measurements of tropospheric ozone have been made in the southern and middle California regions and over the Pacific Ocean during two series of flights in February and May 1977. The data were obtained by using a laser absorption spectrometer, a nadir‐viewing instrument which remotely measures the ozone column abundance between ground level and aircraft altitude by interacting with ozone at specific wavelengths near 9.5 μm. The measurements indicate significantly lower ozone abundances above the Mojave Desert region as compared with farm, forest, and urban areas. The average tropospheric column density was found to be 2.7 × 10−3atm cm/km over the California region and 3.5 × 10−3atm cm/km over the Pacific Ocean region 1000–2000 km west of the coast

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04039

年代:1978

数据来源: WILEY

摘要:

The use of ammonia as an actinometer for measurement of the solar flux in the region 1950–2150 Å is presented. The solar flux was found to be 2.7 × 108photons/cm2s at ground level in this wavelength interval in an area with minimum overhead ozone concentration. The advantages of this method over previously used methods are discussed, and the results are related to the present estimates of the tropospheric photodissociation rates for the freons CFCl3and CF2Cl2by radiation in this wavelength reg

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04044

年代:1978

数据来源: WILEY

摘要:

Estimates of the atmospheric210Pb flux can be made from old (∼ 100 years) soil profiles because of the strong retention of this nuclide in the organic rich surface layers. Correction for radon loss can be made by modeling the observed210Pb and226Ra profiles. This is shown to have only a small effect for most of the soils studied. Comparison of soil‐based210Pb fluxes with other estimates indicates good agreement except in the forested montane region of eastern New Mexico; the high210Pb content of soils there remains to be explai

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04047

年代:1978

数据来源: WILEY

摘要:

The distributions of the concentrations of methane, ethene, ethane, propene, and propane in twelve 1‐to 2‐m‐long gravity cores for two transects from nearshore to midslope off the southwest Texas Gulf Coast are reported. Methane profiles exhibit maxima in the top 40 cm of sediment on the shelf, in contrast to downward increasing gradients in the slope region. Nearshore surface methane concentrations ranging from 50 to 400 μl (normal temperature and pressure) per liter pore water are apparently due to microbial production in sulfate‐free microenvironments such as fecal pellets in a near‐seawater sulfate environment. A decrease in sediment methane levels to less than 5 μl/l pore water in downslope sediments is attributed to reduced microbial activity due to lower organic contents and temperatures. Profiles of the saturated and unsaturated C2and C3hydrocarbons suggest that these gases are also microbial

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04053

年代:1978

数据来源: WILEY

摘要:

Acoustic data, transmissometer data, and calculations are presented which indicate that high‐frequency acoustic backscattering systems can become a valuable tool in the remote monitoring of suspended particle distributions and active resuspension areas. Data are also presented which show that acoustic backscattering systems can be used to remotely detect slope/shelf water frontal zones. Towed acoustic systems should be able to map the extent of the frontal zone and add significantly to the understanding of frontal zone processe

ISSN:0148-0227    

DOI:10.1029/JC083iC08p04062

年代:1978

数据来源: WILEY