Showing papers on "Haze published in 1985"
TL;DR: In this article, the authors pointed out possible pitfalls and errors in the measurement of haze by ASTM Method D 1003 and discussed the advantages of obtaining both spectrophotometric and goniophotometric data for the characterization and interpretation of haze.
Abstract: Possible pitfalls and errors in the measurement of haze by ASTM Method D 1003 are pointed out and discussed. This property is an important measure of the optical clarity of plastic films and sheets. Although special hazemeters are usually used for the measurement, it is demonstrated that accurate haze measurements can be performed by using widely available integrating-sphere spectrophotometers. Additional advantages of obtaining both spectrophotometric and goniophotometric data for the characterization and interpretation of haze are pointed out.
141 citations
TL;DR: The synoptic conditions over the Alaskan Arctic during the Arctic Gas and Aerosol Sampling Program (AGASP) of March 1983 are described in this paper.
25 citations
TL;DR: In this paper, a combined ground-based and aircraft campaign was conducted in the Svalbard (Spitsbergen) area, where the concentration of soot particles and its vertical variation were determined for different synoptic conditions by passive sampling with the aircraft and subsequent laboratory analysis.
24 citations
TL;DR: Arctic haze observed during polar flights from Anchorage, Alaska, to Thule, Greenland, and Thule to Bodo, Norway, during March 1983, was widespread over the entire Arctic region flown as mentioned in this paper.
21 citations
TL;DR: In this paper, it was shown that the 11-18 March 1983 Arctic haze episode observed at Barrow, Alaska, was caused by air pollutants being rapidly transported from Eurasia industrial sources across the Arctic.
18 citations
TL;DR: In this article, a box model calculation is used to make preliminary estimates of the springtime fluxes of carbon and sulfur particles into the Arctic troposphere, which can only be accounted for by major sulfur and soot sources.
16 citations
TL;DR: In this article, the authors present evidence of horizontal variations of aerosol black carbon concentration during the AGASP 1983 sampling experiment, showing that some of these variations correlate with meteorological parameters, but also observed horizontal inhomogeneities with a characteristic scale of 50-100 km occurring in the absence of meteorological activity.
16 citations
TL;DR: In this paper, the effect of the dust haze prevalent at this time is evaluated and the predicted solar radiation, using the above relationship, compares well with measured values with an error of 0.07.
12 citations
TL;DR: In this article, changes in visibility and the occurrence of smoke or haze during the last three decades are identified for eight locations in and around Illinois using individual daily data and are performed on both seasonal and annual bases.
Abstract: Changes in visibility and the occurrence of smoke or haze during the last three decades are identified for eight locations in and around Illinois. The analyses utilize individual daily data and are performed on both seasonal and annual bases. Visibility variation is investigated using cumulative percentiles and mean ridits. Summer is the season that experienced the greatest 1950–80 visibility change. Except at Chicago, this was dominated by a pronounced overall decline that coincided with a marked increase in the frequency of smoke/haze. Superimposed on these trends are 1) a strong early-1960s visibility maximum and smoke/haze minimum for Indianapolis and the northern half of Illinois and 2) particularly pronounced visibility degradation and increased smoke/haze occurrence during the late 1960s at most stations. The 1950–80 summer visibility decline at Chicago was much smaller than elsewhere and coincided with a marked downward smoke/hue frequency trend. The extra-Chicago visibility results for s...
11 citations
TL;DR: In this article, exact formal solutions are obtained for the single scattered component of the reflection of light from an optically thick spherical atmosphere, in which the scatterers are distributed exponentially with a scale height that is small by comparison to the radius of the planet.
9 citations
01 Dec 1985
TL;DR: In this paper, the absorption of solar radiation by the Arctic haze indicate atmospheric heating rates of 0.15 to 0.25/Kday at latitudes between 72.6 and 74.0 N during early spring.
Abstract: Airborne measurements of the absorption of solar radiation by the Arctic haze indicate atmospheric heating rates of 0.15 to 0.25/Kday at latitudes between 72.6 and 74.0 N during the early spring. The haze interaction with solar radiation alters the radiative balance of the atmosphere-surface system. Generally, this interaction results in an increase of the solar energy absorbed by the atmosphere and in a decrease of the radiation absorbed by the ground. The cumulative deposition of black carbon over the surface produces a change in the optical properties of the ice which may results in an accelerating rate of ice melt. Experimental evidence of the magnitude of this effect is necessary to properly evaluate its consequences. An extended monitoring program is suggested.
01 Jul 1985
TL;DR: The observed photometric, spectral, and polarization properties of the polar regions of Jupiter and Saturn are due primarily to the presence of aerosols above the main cloud deck as mentioned in this paper, which remains even in the ultraviolet.
Abstract: The observed photometric, spectral, and polarization properties of the polar regions of Jupiter and Saturn are due primarily to the presence of aerosols above the main cloud deck. The polar regions differ from the other regions in the limb darkening coefficient and its wavelength dependence, the color properties, the degree of polarization, and the magnitude and variations of molecular absorbtion. On Jupiter, the aerosol haze with an optical depth of 0.2 - 0.3 is responsible for the limb darkening at the polar regions, which remains even in the ultraviolet. Moreover, an altitude-limited layer of very fine particles whose optical depth also does not exceed 0.2 - 0.3, must exist at the 30-mbar level near the poles. The aerosol distribution is not the same in the north and south polar regions of Jupiter. On Saturn the aerosol haze above the polar regions, also with strong ultraviolet absorption, must have a greater optical depth than on Jupiter, but there is evidently no isolated high-altitude layer.
01 Jan 1985
01 Feb 1985
TL;DR: In this article, a new method of measuring haze in installed aircraft transparencies is developed and explained using data obtained with the new method, equations were derived to help predict target detection performance as it is affected by windscreen haze, windscreen transmissivity, ambient illumination, mean target luminance, target contrast and target size.
Abstract: : A new method of measuring haze in installed aircraft transparencies is developed and explained. Using data obtained with the new method, equations were derived to help predict target detection performance as it is affected by windscreen haze, windscreen transmissivity, ambient illumination, mean target luminance, target contrast and target size. The equations may be applied to many transparency types and configurations. Graphs are provided to show the effects of another of typical visibility conditions. No similar relationships were found for older methods of measuring haze. Keywords: Optical quality; Vision; Glare; Human engineering; Visual perception; and Halation.
TL;DR: The optical properties of the Arctic haze are known only roughly, but seem to be bracketed in the following ranges: optical depth, 0.1 to 0.5; haze asymmetry factor, 0,6 to 0,7; albedo of single scattering, 0.,8,0.98 as mentioned in this paper.
Abstract: Optical properties of Arctic Haze are known only roughly, but seem to be bracketed in the following ranges: optical depth, 0.1 to 0.5; haze asymmetry factor, 0.6 to 0.7; albedo of single scattering, 0.8 to 0.98. On the basis of these numbers, simple static energy balance considerations suggest that the light-absorbing haze over the northern reflecting ice cap creates an earthatmosphere warming of 0.1 to l.O°C in comparison to a hypothetical haze-free Arctic. Before elaborate climatic models can be run with such meaning, the optical properties of the Arctic Haze, its geographical extent and seasonal variation have to be determined more accurately. DOI: 10.1111/j.1600-0889.1985.tb00046.x
Journal Article•
TL;DR: In this paper, a single-parameter statistical model of directed light-scattering coefficients of coastal haze is suggested. And the physical reasons for the observed statistical relationships are briefly discussed. But this model assumes that the scattering coefficient for λ = 0.55 μm is the input parameter of the model.
Abstract: A single-parameter statistical model of directed light-scattering coefficients of coastal haze is suggested. The scattering coefficient for λ = 0.55 μm is the input parameter of the model. The accuracy of restoration of directed light-scattering coefficients for the scattering angles of 15–160° has been determined to be no worse than 20–25%. The increase in values of the restoration errors for the scattering angles for the near-forward and -backward directions is mentioned. The physical reasons for the observed statistical relationships are briefly discussed.
01 Jan 1985
TL;DR: Visibility in the Great Smoky Mountains National Park (GSMNP) is poor during the summer months when the greatest tourism occurs as discussed by the authors, and the summertime median visibility is less than one-half this value at 24 km.
Abstract: Results of visibility monitoring indicate that visibility in the Great Smoky Mountains National Park (GSMNP) is poorest during the summer months when, coincidentally, the greatest tourism occurs. While the annual median visibility as inferred from nephelometry measurements is about 65 kilometers (km); the summertime median visibility is less than one-half this value at 24 km. Visibility at the GSMNP is poor when compared with federal land-use areas in the western United States where median annual visibilities are more than 150 km. Regional haze is the most frequent cause of visibility impairment in the Park, especially during the summer months. Annually, haze is the principal obscuring phenomenon 65% of the time, but during the summer months, haze occurs about 85% of the time. During the summers of 1980 and 1983, periods which, because of extensive air stagnation and generally hot and dry weather, were especially conducive to the formation of photochemical air pollution, ozone levels greater than the National Ambient Air Quality Standard (NAAQS) were recorded on 23 days. Poor regional visibility also occurred on many of these days. 35 refs., 8 figs., 5 tabs. (ACR)
TL;DR: In this article, a single particle scintillation counter-analyser mounted in a light aircraft was used to obtain information on the Na and K content of the particulates in the atmosphere of Sydney, Australia.
01 Apr 1985
TL;DR: A presentation of climatological information for the Central American region from Guatemala and Belize southward through Panama includes narrative descriptions of Central American climate and weather, to include major synoptic features, precipitation, psychrometrics, cloudiness, visibility, surface winds, thunderstorms, fog, and haze as mentioned in this paper.
Abstract: : A presentation of climatological information for the Central American region from Guatemala and Belize southward through Panama Includes narrative descriptions of Central American climate and weather, to include major synoptic features, precipitation, psychrometrics, cloudiness, visibility, surface winds, thunderstorms, fog, and haze Also includes astronomical, tidal, and seismic data Includes contoured climatological charts and climatological data tables Primarily addresses surface weather data, but includes some upper atmospheric data
TL;DR: Brown et al. as discussed by the authors presented a comprehensive, interactive, time-dependent model of the coupled atmospheric planetary boundary-upper soil (water) layers, specifically formulated to include such radiative parameters.
Abstract: The optical properties of two ‘haze’ conditions prevalent during well-observed occasions in the central U.S.A. were estimated by Ball and Robinson (1982). A comprehensive, interactive, time-dependent model of the coupled atmospheric planetary boundary-upper soil (water) layers, specifically formulated to include such radiative parameters, is described in Brown et al. (1982) and earlier papers. A version of that model, including the Robinson and Ball radiative parameters, is applied with detailed micrometeorological measurements tabulated in Lettau and Davidson (1957), to obtain some quantitative estimates of the effects of haze on near-surface air and soil temperatures in agriculturally important regions of the central U.S.A.