摘要:

Recently atomic nitrogen densities of ∼106cm−3were measured at 400 km by the open source mass spectrometer on the Atmosphere Explorer‐C satellite (AE‐C). Daytime N densities ∼5 × 107cm−3at 160 km have also been inferred from airglow and other measurements on AE‐C. We show that atomic nitrogen densities of this magnitude result in significantly lower values for the O2+concentration than those measured on AE‐C over the altitude range to 160 to 200 km, because of the removal process O2++ N k3→ NO++ O. We show that the discrepancy can be explained in terms of latitudinal variations in both the N and O2densities. We also present evidence which indicates that k3could be as low as 1 × 10−10cm−3at i

ISSN:0094-8276    

DOI:10.1029/GL003i001p00001

年代:1976

数据来源: WILEY

摘要:

Night airglow emissions near 6230A, as observed from the Ogo 4 spacecraft in 1967‐8, show enhancements at polar latitudes by more than a factor of ten over mid and low latitude values. The enhancements are generally not symmetrical with either the north pole or the auroral oval. They are attributed in part to increases in the Meinel band emissions of OH, particularly as associated with a stratospheric warming event, and in part to increases in nitric oxide densities in the lower thermospher

ISSN:0094-8276    

DOI:10.1029/GL003i001p00005

年代:1976

数据来源: WILEY

摘要:

Emission of the NO γ(1,0) band at 2150 A has been observed by a rocket‐borne spectrophotometer in an IBC II+aurora. The v'=0 progression of the γ‐system does not appear in the spectrum. The observed emission rate of the 2150 A feature increases relative to N2+first negative band emission with increasing altitude. We suggest radiative recombination of NO+ions with electrons as a possible excitation mechanism compatible with the

ISSN:0094-8276    

DOI:10.1029/GL003i001p00009

年代:1976

数据来源: WILEY

摘要:

HCl has been observed in both the troposphere and stratosphere from ground‐based and airborne spectroscopic measurements of the 1‐0 band at 3 microns wavelength. The results, which are specific to the HCl molecule in the gas phase, show a decreasing mixing ratio with altitude in the lower stratosphere. The stratospheric layer, which commences at about 15 km, reaches its maximum concentration at an altitude above 21 km (the limiting height of the observations to date). The local value for the volume mixing ratio at 21 km is 7 ± 1 × 10−10. However, the zenith column abundance observed above 21 km (6.3 × 1014mols. cm−2) implies that the mixing ratios at greater altitudes are unlikely to reach values much in excess of the local valu

ISSN:0094-8276    

DOI:10.1029/GL003i001p00013

年代:1976

数据来源: WILEY

摘要:

In‐situ GC analysis of SF6and halofluorocarbons in the atmosphere was achieved by sampling a measured volume of ambient air through a short adsorption tube, or precolumn, from which the collected vapours were released by heating and then transferred directly by the carrier stream to the analytical column. The collection, transfer and analysis operations were performed in the one instrument with the aid of gas sampling valves, thereby minimizing the risk of loss or contamination associated with other sample storage and removal procedures. Field trials using CBr2F2and SF6as tracers have demonstrated the efficacy of the technique for the quantitative measurement of such gases in the atmosphere. The detection limit attained in this work is estimated to be about 5 × 10−1

ISSN:0094-8276    

DOI:10.1029/GL003i001p00017

年代:1976

数据来源: WILEY

摘要:

Formulae are suggested for the approximate description of below‐ and in‐cloud precipitation scavenging of monodisperse aerosol partic

ISSN:0094-8276    

DOI:10.1029/GL003i001p00021

年代:1976

数据来源: WILEY

摘要:

A technique for estimating water contents within the root zones of crops from measurements of midday leaf‐air temperature differentials is developed. Pertinent data used in the analysis were obtained from a cotton crop and two sorghum crops grown on an Avondale loam at Phoenix, Arizona. Since air temperature is the most commonly measured meteorological parameter on earth, and since crop canopy temperatures can be obtained by radiometric means, the technique appears to point the way toward the eventual development of a procedure for the estimation of crop yields via remote sensin

ISSN:0094-8276    

DOI:10.1029/GL003i001p00023

年代:1976

数据来源: WILEY

摘要:

A thermal model of the Earth's surface has been developed and used to determine the thermal inertia of a test site in the Mojave Desert, California. The model, which includes meteorological heating terms as well as radiation and conduction heating terms, is used with remotely sensed surface temperature and reflectance data to determine the thermal inertia of the surface materials at the test site. The thermal inertia is displayed in image form, and can aid in the differentiation of the various lithologic materials in the test site. Since this thermal property is representative of the upper several cm of the surface, it complements visible and reflected near‐IR image dat

ISSN:0094-8276    

DOI:10.1029/GL003i001p00026

年代:1976

数据来源: WILEY

摘要:

Explorer 45 satellite observations of medium energy electrons and ELF waves (100‐1000 hz) have been analysed during a modest isolated substorm which occurred at about 0430 UT on Feb. 13, 1972. Approximately 50 minutes before the sharp rise in AE the electron flux (E ∼ 30 ‐ 240 KeV) measured within the plasmapause near dusk at L = 5 dropped below the normal quiet time level. Simultaneously the intensity of plasmaspheric hiss emissions fell to background levels. Following the substorm activity the electron flux recovered and plasmaspheric emissions first reappeared when the electron flux (E>30 KeV) attained a value comparable to the Kennel‐Petschek stably trapped level required for cyclotron resonant instability. The substorm associated electron flux reduction is explained as a modification in the drift orbits of geomagnetically trapped electrons caused by the onset of a large scale convection electric field. The simultaneous wave and particle observations are consistent with electron cyclotron resonant generation for plasmaspheric hiss emissions. During this relatively quiet period the source location appears to be restricted to the outer plasmasphere

ISSN:0094-8276    

DOI:10.1029/GL003i001p00029

年代:1976

数据来源: WILEY

摘要:

Analysis of data from the Pioneer 10 flyby discloses that pitch angle scattering plays an important part in determining the distribution of energetic electrons in the inner magnetosphere of Jupiter. Angular distributions measured by the UCSD Cerenkov detector reveal that redistribution takes place in pitch angle. Additionally, the radial profile of phase space density along the equator demands simultaneous particle losses. The loss rates are too high to be accounted for by synchrotron radiation loss, but are reasonably attributed to pitch angle scattering into the planetary loss cone.

ISSN:0094-8276    

DOI:10.1029/GL003i001p00033

年代:1976

数据来源: WILEY