摘要:

The drag on a storm by environmental winds, which vary with height, is considered by analogy with a hydrodynamic experiment of vortex shedding due to flow past smooth and rough cylinders. The vortex shedding rate for rough cylinders is shown experimentally to be smaller than that for smooth cylinders, and this difference is equivalent to an increase in fluid viscosity. This result is at variance with earlier predictions that roughness‐induced turbulence would destabilize the flow and cause transition to occur at a lower Reynolds number. The eddy viscosity influences the drag on a storm during its growth. If the hydrodynamic analogy between the rough cylinder experiment and the storm cloud is valid, then increased roughness at the storm cloud edge increases the eddy viscosity locally, which would be indicative of increased mixing. The increased mixing at the periphery of the storm between ambient air and storm air causes the storm motion to respond more to the momentum of the flow. The vertical variation in ‘roughness’ of the storm may cause a number of different responses in the direction of m

ISSN:0148-0227    

DOI:10.1029/JC078i006p00913

年代:1973

数据来源: WILEY

摘要:

The earth's daytime horizon was scanned on several occasions between 1963 and 1968. The limb was observed at six wavelengths in the ultraviolet and visible spectrum with a narrow field of view instrument on the X‐15 aircraft. The inversion of such horizon observations to yield atmospheric density and the concentrations of ozone and aerosol extinctions is discussed. The most significant features of the X‐15 data are effects attributed to stratospheric aerosols. Observations of both the 20‐km aerosol layer and a layer at approximately 50 km are inferred from the data. Both layers apparently possess considerable variability. It is pointed out that the existence of substantial aerosol concentrations above 30 km is an important limitation of the nadir technique of determining ozone concentrations in which the earth's radiance is observed at ultraviolet wavelengths from a sate

ISSN:0148-0227    

DOI:10.1029/JC078i006p00920

年代:1973

数据来源: WILEY

摘要:

Intermittent observations of CO2concentrations over 6 years at heights up to 125 meters show that the CO2content of air is extremely variable but that diurnal, seasonal, and annual patterns are conspicuous. The usual diurnal pattern shows largest variation close to the ground. Highest concentrations occur during nocturnal temperature inversions. As might be expected on Long Island, westerly winds tend to have higher CO2contents than easterly winds. The normal seasonal fluctuation is from a high in December and January to a low in September. The difference is about 19 ppm. There is a year‐to‐year increase in CO2content of air that averaged 1.2 ppm/yr over the 6‐year span of the study. Although the variance of CO2measurements is high within the industrialized area of eastern North America, there is a reasonable possibility of examining trends in CO2content of air by sufficiently intensive measure

ISSN:0148-0227    

DOI:10.1029/JC078i006p00932

年代:1973

数据来源: WILEY

摘要:

Rainfall within 55 km of the northwest coast of the United States was measured from a buoy and estimated from weather reports at lightships. Results show that precipitation at sea was only about one half to one third of that found at coastal land stations. Rainfall typically occurs both at sea and on shore on the same days but for fewer hours at sea. The relative amount at sea seems to vary with the type of atmospheric system producing the rainfall.

ISSN:0148-0227    

DOI:10.1029/JC078i006p00941

年代:1973

数据来源: WILEY

摘要:

The chemical changes occurring during the transformation of aerosols to cloud droplets and rain were observed in orographic clouds on the eastern end of the island of Puerto Rico. Comparisons of elemental ratios in particles and rain and of elemental particle size distributions in and out of the clouds demonstrated scavenging efficiencies of>100% for the elements I, Br, and Cl relative to Na and of<25% for the elements Al, Mn, and V relative to Na. These different scavenging efficiencies are consistent with predictions based on existing cloud physics theory and are a reflection of the geochemical properties of the aerosol consisting partly of a hygroscopic sea salt component containing I, Br, Cl, and Na and partly of a soil dust component containing Al, Mn, and possibly V.

ISSN:0148-0227    

DOI:10.1029/JC078i006p00949

年代:1973

数据来源: WILEY

摘要:

Ice crystals etched during exposure to unsaturated air and then replicated with methyl 2‐cyanoacrylate indicate the existence of a mosaic structure. The domains on the basal face have a mean diameter of 3 μ. Enhanced etching at the center of each domain with suppressed etching at the domain boundaries is similar to the observations of Truby (1955) and in agreement with the dislocation theory calculations of Gentile and Drost‐Hansen (1956). Whisker densities observed on the basal faces of ice crystals are of the same magnitude as the domain densities, and the whisker diameters are the same size as the central etch pit and the calculated strain core diame

ISSN:0148-0227    

DOI:10.1029/JC078i006p00958

年代:1973

数据来源: WILEY

摘要:

Recent data on ambient wave generated oceanic bubble spectra (Medwin, 1970) permit the calculation of the influence of bubble solution on air‐sea gas exchange. Schulkin's formula is used to estimate the depth variation of bubbles, and a square law is used to estimate the increase of bubble volume with wind speed. Calculations indicate that bubble solution can be a very significant factor in gas exchange. Bubble solution enhances gas input and retards degassing of the water column. Preliminary data show a lag time of about 5 hours in the response of the water column to an atmospheric pressure chang

ISSN:0148-0227    

DOI:10.1029/JC078i006p00962

年代:1973

数据来源: WILEY

摘要:

This study reports our experimental investigation of various factors affecting the surface properties of the ocean as seen by a passive microwave radiometer operating at 2.66 GHz. The principal uncertainties in the absolute measurements of the thermal emissions from the sea in terms of molecular temperature stem from (1) surface contaminations, such as oil slicks, (2) spray and foam, (3) salinity variation, and (4) surface waves. The results of a variety of experiments conducted so far indicate that the direct contribution of surface films and spray to the thermal emission from the sea is considerably less significant than that of foam and waves. In particular, oil slicks appear to contribute about 1°K/mm thickness to the apparent brightness temperature, exclusive of any wave‐damping effect they may exert, and spray gives a negligible contribution for the droplet concentrations generally expected near the sea surface. Salinity variations can generate a significant uncertainty in radiometric measurements if they are not accounted for. Exploratory observations on the influence of surface waves have suggested that their contribution to the brightness temperature may be substantially higher than would be expected from theory based on the well‐known tangent plane approximation. Limited experiments on the influence of simulated foam by air bubble formation suggest that this effect may be less than that of surface w

ISSN:0148-0227    

DOI:10.1029/JC078i006p00969

年代:1973

数据来源: WILEY

摘要:

Shoaling formula for a spiral wave generated in a basin with circular contours is presented. Differences with rectilinear beaches are pointed out to provide information for the spiral wave generator system recently proposed by Dalrymple and Dean for littoral drift studies.

ISSN:0148-0227    

DOI:10.1029/JC078i006p00977

年代:1973

数据来源: WILEY

摘要:

In this study the downward propagation of temperature waves through the sea floor has been examined. Sediment temperatures from an array of buried thermistors were recorded hourly for more than a year. The measurements were made in a coastal location where temperature changes in the overlying water due to surface heating, internal waves and tides, and upwelling reach to the sea floor. Thermal waves from these changes were found to travel through the sediment in approximately the manner predicted by a mathematical model. The model is based on a solution of Fourier's heat conduction equation.

ISSN:0148-0227    

DOI:10.1029/JC078i006p00981

年代:1973

数据来源: WILEY