Fog deposition

Patterson s friend Edward D. Goldberg at the Scripps Institution of Oceanography in La Jolla, California, had tipped him off that one of the best records of the world s climate is embedded in thin layers of glacial ice at high altitudes or near the poles. Snow, dust, and fog deposit chemicals from the atmosphere onto the ice, where they remain undisturbed for thousands of years. As Patterson quickly realized, Only the quiescent ice sheets in the arid, perpetually frozen polar regions of the Earth provide annual layers of precipitation that are undisturbed by percolation and mechanical mixing, that are relatively free of dusts and salts, and also are thin enough to be accessible even when centuries old. ... 

Solid Snow, haU, ice, snow pellets, frost pellets, hoar frost, rime Liquid Rain, drizzle, fog deposition... 

However, fog can also contribute to precipitation. This so-called fog deposition occurs as a result of drifting fog and clouds, whereby the volume of precipitation is... 

Locally, fog deposition can account for a significant proportion of the total volume of precipitation (e.g. [23, 24]). Yet a high local variability in fog deposition characteristics must be assumed, particularly in the alpine region. Hence the water balance in larger alpine catchments is only slightly distorted if fog deposition is not taken into consideration [5]. 

Seiber, J. N., B. W. Wilson, and M. M. McChesney, Air and Fog Deposition Residues of Four Organophosphate Insecticides Used on Dormant Orchards in the San Joaquin Valley, California, Environ. Sci. Technol., 27, 2236-2243 (1993). 

Slides coated with fused zinc stearate were exposed with the cages to furnish records of the fog deposits, which might be correlated with the kills. 

Seiber JN, Wilson BW, McChesney MM. 1993. Air and fog deposition residues of four organophosphate insecticides used on dormant orchards in the San Joaquin Valley, California. Environ Sci Tecnol 27(10) 2236-2243. 

In addition to wet and dry deposition, many high-elevation sites may receive substantial inputs of N from clouds or fog (15-17). Few quantitative estimates of cloud deposition are available, but results from one site on Whiteface Mountain in the Adirondacks indicate that clouds and fog can contribute up to 40% of total deposition (18). Rates of wet and dry deposition at Whiteface Mountain were comparable to the Adirondack values given in Table I ( 740 equiv/ha), but total deposition rates (including cloud and fog deposition) averaged 1170 equiv/ha. 

Deposition during fog episodes can make a significant contribution to the overall flux of pollutants in certain ecosystems. Furthermore, when atmospheric stagnation prevents normal ventilation in a region, fog deposition may become the main route of pollutant removal. Fogs can consequently exert dominant control over pollutant levels in certain environments. 

Hence, the total and fog deposition rates, respectively, can be expressed ... 

Deposition from the atmosphere to the ground, vegetation or water surface can occur via three deposition processes. The direct interaction of a material with the surface is called dry deposition and occurs continuously. The second process is called wet deposition and includes the removal of material from the atmosphere in any falling hydrometeors, such as raindrops, snowflakes or hailstones. The third process includes deposition in fog droplets which do not readily fall under gravity due to size limitations. Fog deposition is a process which falls midway between dry and wet deposition and includes mechanisms which are important in both the wet and dry removal processes. 

Zimmermann, L, Zimraermann, F. 2002. Fog deposition to Norway spruce stands at high elevation sites in the Eastern Erzgebirge (Germany). J. Hydrology 256 166-175. 

Fog deposition, that is, the removal of material by settling fog droplets... 

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