Selected Whiteface Mountain cloud water concentrations summers 1981 and 1982

Abstract

A statistical analysis was made of source trajectory air mass regions versus receptor in cloud water at Whiteface Mountain, Wilmington, New York for the summers of 1981 and 1982. Also tested was the assumption that in 1982 sulfate concentrations should decrease in the cloud water when associated with a trajectory from the west northwest. This assumption was based on the fact that Canadian smelters were idle during August 1982 which resulted in a reduction of SO 2 emissions by approximately 75%.The trajectory analysis was done using the NOAA/ARL transport model and anion-cation analysis of cloud water was performed using ion chromatography. The Canadian emission data were provided by the Air Resources Branch, Ministry of the Environment. Student's Test was used to test the null hypothesis that no [SO4 2] differences existed in the cloud water collected during 1981 and 1982.The results were suggestive of the following conclusions:(1) There is so much inherent noise in the data due to meteorological variability that the hypothesized decrease in [SO4 -2] from the smelting operation could not be detected.(2) The trajectory analysis is not precise enough, due to the frequency of soundings and station spacing, to indicate the correct source-receptor for Whiteface Mountain; and a careful analysis of cloud water samples associated with fast moving cold fronts from the Sudbury region might detect an effect on sulfate production.(3) The available meteorology does not seem sufficient to explain the variation seen at the Whiteface Mountain field station.

Chemical Dynamics of Clouds at Mt. Mitchell, North Carolina

“…The results of cloud water acidity data and LWC data analyses revealed an increase of cloud acidity from mixed cloud events (pH 3.57 to pH ~4.05) to short cloud events (pH 3.03 to pH ~3.23) as the LWC increases from short cloud events (0.15 -0.24 g nr 3 ) to mixed cloud events (0.32 -0.71 g nr 3 ). This increase in LWC may be explained as follows: in general, the short cloud events are associated with stratus (St) and stratocumulus (Sc) cloud types, in which the cloud droplets are a very concentrated solution of soluble cloud condensation nuclei.…”

“…During the field seasons, average LWC values ranged from 0.15 to 0.24 g nr 3 for the short cloud events, 0.22 to 0.54 g nr 3 for the long cloud events', and from 0.32 to 0.71 g nr 3 for the mixed cloud events. The results of cloud water acidity data and LWC data analyses revealed an increase of cloud acidity from mixed cloud events (pH 3.57 to pH ~4.05) to short cloud events (pH 3.03 to pH ~3.23) as the LWC increases from short cloud events (0.15 -0.24 g nr 3 ) to mixed cloud events (0.32 -0.71 g nr 3 ).…”

“…Contribution diagrams for long events during 1987 and 1988 field seasons are missing because no chemical analysis were performed on the samples during those years. Figure 6 shows that the mass contribution of the four principal ionic species (SO 4 2 ", NO 3 , H + , and NH 4 + ) in long and short events are above 95 percent for 1989 field seasons. However, those chemical species in mixed events contribute less to total concentration (~74 percent), while the rest of chemical species in mixed events are much more (five to ten times) than in cloud only events.…”

“…Formic acid may be produced because of the reaction of HCHO (aq) with OH (aq) in cloud water 23 and (2) there were errors in one or more species' measurements. 3 From Table 5 bacterial production from agricultural activities and hydrolysis of urea, and partly to man-made pollutants, and is thought to neutralize the cloud water acidity. Sulfate and nitrate are mainly derived from anthropogenic sources, and are mainly thought to acidify the cloud water.…”

Acidic deposition to forests: The 1985 chemistry of high elevation fog (CHEF) project

“…(1983) Dollardetal. (1983) Castillo et al (1983) Castillo andJiusto (1984) Fuzzietal. (1985) Waldmanetal.…”