Atmospheric precipitation

Over the period of service the P-scan unit has proved to be a reliable system, operating in a stable manner under the conditions of strong electrical interference, natural atmospheric precipitation. The mechanical scanner of the system adapts quite... 

In the atmosphere, precipitation is the most important means to remove the NHJ and ions. These ions are produced by reactions such as the following ... 

A small flux is shown between the land and atmosphere. This represents the transport of dust particles to the atmosphere (F28) and the deposition of these particles back on land either as dry deposition or associated with atmospheric precipitation (F82). Similarly, fluxes that represent the transport of seasalt from the surface ocean to the atmosphere (Fss) and the deposition of soluble (F85) and insoluble (F81) atmospheric forms are also shown. As already discussed for the river fluxes, the insoluble particulate flux is represented as a direct transport of P to the sediment reservoir. 

Endrin may also be found in atmospheric precipitation. In an analysis of pesticides in rainfall from four stations in Canada in 1984, detectable concentrations of endrin were found at each site (Strachan 1988). There was a noticeable pattern of decline in detections within the summer season (May-August). In more recent studies in the Great Lakes area, endrin was found in 5% of 450 wet deposition (rain/snow) samples collected between 1986 and 1991, at volume weighted mean concentrations ranging from 0.02 to 0.98 ng/L (ppt) (Chan et al. 1994). 

Chan CH, Perkins LH. 1989. Monitoring of trace organic contaminants in atmospheric precipitation. Journal of Great Lakes Research 15(3) 465-475. 

Geochemical mass balance studies (also known as input-output budgets) invoke a simple conservation-of-mass principle. If the flux of any element leaving a watershed (e.g., via streams), and the flux of that element into the watershed (e.g., via atmospheric precipitation) are known, the difference between the two can be calculated, and this difference must be due to the sum of all reactions and transformations involving that element which took place within the watershed. Pioneering mass balance studies on weathering profiles and/or small watersheds include those of Garrels and Mackenzie (,51, 52) and Cleaves and Bricker and their... 

Lazrus, A. L., G. L. Kok, S. N. Gitlin, and J. A. Lind, Automated Fluorometric Method for Hydrogen Peroxide in Atmospheric Precipitation, Anal. Chem., 57, 9f7-922 (f985). 

Radionuclides with half-lives of minutes to hours would be useful in studying atmospheric precipitation scavenging mechanisms since their half-lives are of the same order of magnitude as the time scale on which... 

Influence of Atmospheric Precipitation on the Operation of a Natural Draught Indirect-Contact Cooling Tower... 

Neumman, G. H., S. Fonselius, and I. Wahlman. 1959. Measurements on the content of nonvolatile organic material in atmospheric precipitation. International Journal of Air Pollution 2 132-141. 

Timperley, M. H. R., J. V. Timperley, M. Kawashima, and M. Ishigami. 1985. Organic nitrogen compounds in atmospheric precipitation Their chemistry and availability to phytoplankton. Canadian Journal of Fisheries and Aquatic Sciences 42 1171—1177. 

Ukraine has good prospects to revive highly efficient agriculture, which is able to satisfy domestic needs in foodstuff and feedstock and also produce products for export. The big part of the territory is steppe. It is characterized by low atmospheric precipitation, frequent draughts, and other unfavorable phenomena. Due to that yields of the main crops are not stable. Potential yield of straw and stems may come to 35 mill t/year. Demand of agriculture is 13 mill t of straw a year, the surplus - about 20 mill t/year that is equivalent to 82 TWh - can be used for other purposes including energy production. 

Atmospheric Precipitation in Ontario Study, Ontario Ministry of Environment, Annual statistics of concentration cumulative ambient air monitoring network, 1985, APIQS-002-87. Ontario Ministry of Environment, 1987. 

Timperley, M.H., Vigor-Brown, R.J., Kawashima, M., and Ishigamo, M. (1985) Organic nitrogen compounds in atmospheric precipitation their chemistry and availability to phytoplankton. Can. J. Fish. Aquat. Sci. 42, 1171-1177. 

River, stream, and lake water groundwater as well as atmospheric precipitation are commonly analyzed by using ICP-MS [303], Often the samples can be run directly or after simple filtration or centrifugation to remove suspended particulates [304]. Typically samples can be preserved by the addition of 1% to 2% concentrated nitric acid by volume [305]. Nitric acid is preferable to hydrochloric or sulfuric acid because of the lack of molecular ion spectral overlaps from nitric acid or its reaction products in the ICP, as discussed earlier. In most cases preconcentration or separation is unnecessary. In some cases preconcentration and removal of chlorides from the sample are advantageous and can be done by using a simple flow injection approach [306]. 

The water balance of the Sea of Azov consists of the following components the incoming part contains the riverine runoff and the atmospheric precipitation, while the outgoing part includes evaporation. The water exchange via the Kerch Strait should also be taken into account. According to the data averaged over 1923 to 1985, the riverine runoff, precipitation, and evaporation comprised 38.6, 15.5, and 34.6 km3/year, respectively. The annual inflow of the Black Sea waters via the Kerch Strait was 36-38 km3/year, while the outflow of the Azov waters comprised 53-55 km3/year this provided a value of the resulting water removal from the Sea of Azov of about 17 km3/year. 

Atmospheric precipitation. Atmospheric precipitation over the Black Sea is mostly related to the cyclonic activity. The convective process plays a noticeable role only it near-shore band and on the coasts. An additional influence is provided by the topography of the coastal zone. Throughout the year, the precipitation amount grows from the northwest (380-420 mm/ year) to the southeast, where the Caucasian ridges approach the coastline and are oriented across the principal moisture-bearing airflows (up to 1500-2500 mm/year) (Fig. 8). The greatest number of days with precipita-... 

The receipt part of the water balance of the Black Sea consists of the riverine runoff, atmospheric precipitation, and marine water supply via the Bosporus and Kerch Straits. A small contribution is also provided by the ground water delivery. The expenditure part of the balance includes evaporation from the water surface and the removal of the Black Sea waters via the Bosporus and Kerch Straits. The mean annual value of these components of the balance (under certain assumptions) comprises about 816 km3/year, that is, only 0.15% of the total volume of the Black Sea waters. Approximately 354 km3 of riverine waters is annually supplied to the sea of them, up to 200 km3 is contributed by the Danube River. The atmosphere precipitation in the form of rain and snow provides 237 km3 of water. The lower current via the Bosporus Strait annually delivers about 175 km3 of saline waters of the Sea of Marmara, while the Kerch Strait supplies approximately 50 km3 from the Sea of Azov. The mean annual water expenditure for evaporation comprises up to 396 km3 the upper current in the Bosporus Strait removes about 385 km3 of the Black Sea water to the Sea of Marmara, and the water removal via the Kerch Strait to the Sea of Azov makes up to 35 km3. Thus, the receipt part of the balance mostly consists of riverine waters, which comprise about 40% of all the water supplied. This component is characterized by a strong variability. The expenditure part of the balance consists of evaporation and water removal via the Bosporus. Meanwhile, evaporation features a low variability and thus has no significant effect on the variations in the water regime. 

A decrease in SST by 3.5 °C with respect to the adjacent waters may also take place at the centers of anticyclonic eddies (see Ginzburg AI, Zatsepin AG, Kostianoy AG, Sheremet NA Mesoscale Water Dynamics , in this volume). Local changes in SST are sometimes related to the increased suspended matter content (mainly in near-mouth regions), to the atmospheric precipitation, and to the presence of oil films at the water surface [20]. 

Wine is a widely consumed beverage worldwide, with thousands of years of tradition and a remarkable commercial and social value. The evaluation of the quality of wine is a permanent concern for manufactures, merchants, and consumers. The presence of potentially toxic elements in wines is associated with soil contamination and also related to atmospheric precipitation, pesticides, and materials used in production, transportation, and storage. Although at the end of alcoholic fermentation there is a significant reduction of the mineral content, this may not be enough to prevent some problems related to wine stability, namely,... 

Introduction to Derivatization For many years derivatization by alkylation -especially as ethylation, but also as propylation - has been applied to transform Hg species into volatile Hg species before measurement with hyphenated techniques [2, 50, 52]. Sodium tetraphenylborate (NaBPh4) was also used for derivatization prior to measurement with GC-MIP-AED [53], Studies of possible species transformation, for example, during the analytical procedure, have been carried out with isotope-specific determination methods. The results showed that a direct ethylation of Me-Hg in an atmospheric precipitation sample by NaBEt4 produced no significant amount of artifactual Me-Hg [54]. Others investigated the species transformation processes in synthetic solutions to simulate environmental matrices. From the experiments it could be concluded that the species conversion, for example, of Me-Hg into zerovalent Hg, depends on the concentration levels of the halide [2]. Furthermore, the procedural order is of great importance, for example, ethylation should be done after addition of the organic phase to avoid species transformation [55]. 

Dissociation of the polysulfides yields an alkaline solution which, together with dissolved Ca(OH)2, increases the pH of the surrounding medium to the point where incoming polysulfide anions can remain in solution. If the system is closed or under an inert atmosphere, precipitation will cease, and the concentration of polysulfides in the surrounding liquid will gradually increase as sulfur is removed from the concrete. 

Typical values of scavenging ratio lie within the range 300-2000. Scavenging ratios are rather variable, dependent upon the ehemieal nature of the trace substance (particle or gas, soluble or insoluble, etc) and the type of atmospheric precipitation. Incorporation of gases and particles into rain can occur both by in-cloud scavenging (also termed rainout) and below-cloud scavenging (termed washout). 

Under the pseudo-dry storage one understands the presence of water in unsealed shrouds due to either insufficient unwatering of storage pools or atmospheric precipitations. In case of considerable deviations of the storing-medium quality from the established corrosive-admixture-concentration standards rather active fuel corrosion is possible. 

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