摘要:

The infrared interferometer spectrometer carried on the Nimbus 4 meteorological satellite measures the infrared spectrum of the earth and atmosphere between 400 and 1600 cm−1. The instrument is similar to one flown on Nimbus 3, but a number of improvements have been implemented, including higher spectral resolution (2.8 cm−1), higher spatial resolution (5 degree field of view), and a lower noise equivalent radiance (0.5 to 1.0 erg‐sec−1‐cm−2‐ster−1/cm−1). In an effort to obtain spectra with high absolute accuracy, it was necessary to incorporate many factors into the calibration, including small departures from unity in the emissivity of the on‐board calibration source, imbalance between cold and warm calibration ports, and effects due to orbital variations in instrument temperature. The inclusion of such higher order corrections, along with careful data screening processes, has ensured a high quality data set that can be used in a variety of geophysical and meteorological investigations. This set is available to qualified investigators. Representative samples of data are presented that illustrate the behavior of the thermal emission spectra under a variety of conditions encountered in a typical orbit, including extremes in temperature, surface reststrahlen effects, and various types of cloud conditions. The data are being used currently in a number of investigations that include a study of radiative transfer processes in the atmosphere, examinations of vertical sounding techniques, studies of the statistical properties of the spectra, and the study of global fields of te

ISSN:0148-0227    

DOI:10.1029/JC077i015p02629

年代:1972

数据来源: WILEY

摘要:

On the basis of an earlier calculation (Hill, 1971) of the heating of a lightning‐stroke channel, the absorptions of line radiations emitted by lightning have now been computed. It is found that absorption is not sufficiently negligible that the assumption of an optically thin channel can be wholly accepte

ISSN:0148-0227    

DOI:10.1029/JC077i015p02642

年代:1972

数据来源: WILEY

摘要:

The short‐lived daughters of radon 222 existing as ions in laboratory air are deposited by an electric field on a foil acting as the central electrode in a cylindrical capacitor. The experiments show that the time dependence of the alpha activity from214Po, which is determined by the relative concentrations of the daughter ions in the air, depends on the critical mobility used in the collecting system. For high critical mobilities (kc>10−5m2v−1sec−1) one characteristic decay curve was always obtained, indicating relative concentrations of218Po,214Pb, and214Bi ions in the ratio 1:1.5:0.2. Experiments with critical mobilities about 10−6m2v−1sec−1gave a second characteristic decay curve, indicating relative concentrations of218Po,214Pb, and214Bi ions in the

ISSN:0148-0227    

DOI:10.1029/JC077i015p02648

年代:1972

数据来源: WILEY

摘要:

Hourly average radon‐gas concentrations have been measured at elevations of 6.1, 61, 174, and 271 meters on a continuous basis for over 1 year. A search through 5 months of data revealed 383 hours of data that satisfy a steady‐state criteria. The steady‐state radon profiles correlate with atmospheric stability through a stability ratio and are naturally divided into four categories. The turbulent transfer is parameterized in terms of a radon diffusivityKthat is related to general meteorological conditions. An independent specification ofKis made based on dimensional reasoning and empirical turbulence statistics in an extension of work by Hanna (1968). A two‐layer domain for diffusivity is used in a computational model in which the upper‐layerKis independent of height but varies with meteorological conditions; and in the surface layer below 100 metersKis given asK(Z) =K(Z0

ISSN:0148-0227    

DOI:10.1029/JC077i015p02654

年代:1972

数据来源: WILEY

摘要:

Earlier models of the electrical behavior of the boundary layer (Hoppel, 1967, 1969; Hoppel and Gathman, 1971a; Law, 1963) have suffered from the disadvantage of assumption of steady‐state conditions for their solution. In this paper, we present results of applying a time‐dependent primitive equation model to the problem of electrical behavior of the electrode effect and the atmospheric boundary layer over the sea. From the results of this model, we conclude that the electrode effect has a relaxation time of the order of 15 min. In addition, it is shown that the presence of a concentrated layer of neutral particles is sufficient to separate cha

ISSN:0148-0227    

DOI:10.1029/JC077i015p02669

年代:1972

数据来源: WILEY

摘要:

A set of differential equations is derived to relate the light field and its derivative to the inherent optical properties of sea water (volume‐scattering function and beam‐attenuation coefficient) when the light field is axially symmetric. From these equations, the volume‐scattering function and the beam‐attenuation coefficient can be calculated if the light field and its derivative with depth are known. The equations are then used to provide an alternate proof for the asymptotic light field hypothesis. The shape of the asymptotic light field is derived as a function of the inherent optical properties and the asymptotic decay constant. It is finally shown that if the shape of the asymptotic light field and the asymptotic decay constant are known, the inherent optical properties can be cal

ISSN:0148-0227    

DOI:10.1029/JC077i015p02677

年代:1972

数据来源: WILEY

摘要:

A nonlinear finite‐difference model has been used to investigate the creation of unstable regions in the atmosphere by internal gravity waves. These waves grow exponentially with height, so that an upward‐propagating wave that is not reflected or absorbed will eventually cause nonlinear interactions or regions of instability or both. In this model the unstable regions are produced at roughly the height predicted from the linear theory if the transients produced by the source are considered. Simultaneously with the development of the instability, a jet develops in the originally at‐rest atmosphere. Very shortly after the first instabilities appear, this jet becomes large enough to possess a critical level, so the problem of turbulence generation in the stratosphere by internal gravity waves is complicated by the nonturbulent wave interaction in a sheared region containing a critical level and by the nonlinear interaction of the wave with the turbulence it is gener

ISSN:0148-0227    

DOI:10.1029/JC077i015p02681

年代:1972

数据来源: WILEY

摘要:

Significant changes occur in the sea‐surface spectrum as it propagates from deep to shallow water. These changes are a combined result of nondissipative forces (refraction, shoaling) and dissipative‐generative forces (bottom friction, wind generation, wave breaking). In this study two prediction schemes for these changes are developed. Numerical predictions of spectral changes in shoaling water are made and compared with observed d

ISSN:0148-0227    

DOI:10.1029/JC077i015p02693

年代:1972

数据来源: WILEY

摘要:

Detailed wind and temperature profiles up to a height of 4 meters have been obtained at 30‐sec intervals for a period of 20 days in March 1970 from an ice field drifting in the Gulf of St. Lawrence in Canada. Wind speeds were measured with fast‐response cup anemometers at heights of 37.5, 50, 100, 200, and 400 cm, and temperatures were measured with shielded copper constantan thermopiles at heights of 12.5, 25, 50, 100, 200, and 400 cm above the ice surface. Some 250 values of roughness lengthz0have been calculated from wind profiles averaged over periods of 15 min when conditions of dynamic near‐neutral stability were observed (i.e., the Richardson number at a height of 1.22 meters was less than 0.03). The roughness length was found to be a sensitive function of surface conditions. Changes were caused by rain and snow and by fluctuations of near‐surface temperature through 0°C. During the first week, March 7–14, the median value ofz0was 0.084 cm, and the probability that 0.002 cm

ISSN:0148-0227    

DOI:10.1029/JC077i015p02708

年代:1972

数据来源: WILEY

摘要:

The steady‐state wind‐driven currents in Lake Erie are investigated. A numerical solution for the mass‐transport stream function and the three‐dimensional velocities as a function of depth and horizontal position is obtained and compared with measurements. The agreement is good. This report shows that the currents depend strongly on bottom topography and boundary g

ISSN:0148-0227    

DOI:10.1029/JC077i015p02714

年代:1972

数据来源: WILEY