Ice fog

Supercooled fog is fog having a temperature less than (1C. It consists of small droplets at temperatures less than freezing which can exist as liquid down to approximately - 40 C. Below this temperature, ice crystals tend to form automatically and the fog changes to ice fog. 

Grosjean D, Wright B. 1983. Carbonyls in urban fog, ice fog, cloudwater and rainwater. Atmos Environ 17 2093-2096. 

What additional environmental conditions, specifically for times of delivery, may be considered (e.g., ice, fog, low spots) ... 

Chernyak SM, Rice CP, McConnell LL (1996) Evidence of currently-used pesticides in air, ice, fog, seawater and surface microlayer in the Bering and Chukchi Seas. Mar Pollut Bull 32 410-419... 

The atmosphere becomes milky through light scattering on particles in the size range between 50 and 200 nm. WMO uses for atmospheric obscuration the following terms Fog, Ice fog. Steam fog. Mist, Haze, Smoke, Volcanic ash. Dust, Sand, and Snow. With the exception of smoke, volcanic ash, dust and sand (all these are... 

Environmental Situational Awareness (e.g. weather formations and movement temperature icing fog turbulence winds sun IFR/VFR conditions areas to avoid etc.)... 

Patel, S. M., Bhugra, C., Pikal, M. J., 2009. Reduced pressure ice fog technique for controlled ice nucleation during freeze-drying. AAPS PharmSciTech 10(4) 1406-1411. 

When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating carbon dioxide produces a dense fog often used to create special effects. In a simple dry ice fog machine, dry ice is added to warm water in a Styrofoam cooler. The dry ice produces fog until it evaporates away, or until the water gets too cold to sublime the dry ice quickly enough. Suppose that a small Styrofoam cooler holds 15.0 liters of water heated to 85 °C. Use standard enthalpies of formation to calculate the change in enthalpy for dry ice sublimation, and calculate the mass of dry ice that should be added to the water so that the dry ice completely sublimes away when the water reaches 25 C. Assume no heat loss to the surroundings. [The AHf for C02(5) is -127.4 kJ/moL]... 

Cloud Seeding. In 1947, it was demonstrated that silver iodide could initiate ice crystal formation because, in the [ -crystalline form, it is isomorphic with ice crystals. As a result, cloud seeding with silver iodide has been used in weather modifications attempts such as increases and decreases in precipitation (rain or snow) and the dissipation of fog. Optimum conditions for cloud seeding are present when precipitation is possible but the nuclei for the crystalliza tion of water are lacking. 

Not only may the cooling-tower plume be a source of fog, which in some weather conditions can ice roadways, but the plume also carries salts from the cooling water itself. These salts may come from salinity in the water, or may be added by the cooling-tower operator to prevent corrosion and biological attack in the column. 

Fog A mist formed where the ambient air cannot absorb all the plume s moisture. The intensity of the fog is a function of the heat rise of air passing through the tower and the temperature and humidity of the ambient air. Fog plumes are normally permissible since there are no droplets of water raining out of the discharge area however, fog may cause icing of nearby roads and may restrict visibility. 

Condensation occurs when air temperatures cool. The cooling occurs in one of two ways. Either the air vapor cools as it rises and expands or as it comes into contact with a cool object such as a cold landmass or an ice-covered area. Air rises for several reasons. It can be forced up as it encounters a cooler, denser body of air, or when it meets mountains or other raised land masses. It can rise as it meets a very warm surface, like a desert, and become more buoyant than the surrounding air. Air also can be forced to rise by storms—during tornadoes particles of air circling to the center of a cyclone collide and are forced up. When the water vapor collides with a cold object, it can become fog, dew, or frost as it condenses. The vapor cools as it rises into the atmosphere and condenses to form clouds and, sometimes, rain. 

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. ... 

Over the polar regions of the north, snow, fog and dust precipitated out the lead. Unknown to mankind, the lead lay there, encased in Greenland s glacial ice cap, for 2500 years. 

In the Nordic creation myth, which can be found at the beginning of the Edda, we encounter Ginnungagap, a timeless, yawning void. It contains a type of supreme god, Fimbultyr, who willed the formation of Niflheim in the north, a cold, inhospitable land of fog, ice and darkness, and in the south Muspelheim (with light and fire). Sparks from Muspelheim flew onto the ice of Niflheim. This caused life to emerge, and the ice giant Ymir and the huge cow Audhumbla were formed. 

Leave a full ice cube tray in your freezer for a very long time and you ll notice the ice cubes will shrink and eventually disappear.This is because the ice is sublimating, or going directly to a gas.You may have seen sublimation on Halloween. Dry ice, which is frozen carbon dioxide, sublimates to a gas, forming a spooky-looking fog. 

The environmental conditions present at the time can be particularly significant. Those may include time of day, temperature, lighting, and weather conditions such as rain, fog, ice, snow, or wind conditions. 

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

Commercial airports have been cleared of supercooled fog for many years by dry ice seeding as a standard practice. Military airfields have been cleared by use of bolh propane and dry ice methods,... 

Three types of instruments have received wide acceptance in dew point measurements tllthe saturated salt dew point sensor 121 the condensation-type hygrometer and t.lt the aluminum oxide sensor. Many other instruments are used in specialized applications, including pressure tatio dev ices, dewcups. and fog chambers. The luttei ate manually operated... 

In places in which ground fog is undesirable, the dry-wet mechanical-draft cooling tower is the best solution. It will have its wet peaking tower out of service during the cooler months of the year, thereby substantially eliminating the fog problem and totally eliminating the icing problems of wet towers. 

Under certain conditions, the exhaust air of conventional mechanical draft cooling towers may form a fog plume, causing visibility and icing problems to highways and equipment. In cases where this cannot be tolerated, a combination wet/dry cooling tower is shown to be effective fog plume control method. The paper describes the basic phenomena of cooling tower fog formation. The operation and performance characteristics of the wet/dry tower are discussed as well as a method of select wet/dry design criteria. 11 refs, cited. 

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