These data are subsequently validated and certified in accordance with the procedures defined in the MCCP QA Plan. This database is exercised by a series of report generation software programs to yield the desired frequency distribution graphic reports and other statistical reports required by MCCP scientists or by the forest research community. The following segments summarize the 1986-87 results. Various techniques for monitoring the presence of clouds have been studied and tested during the 1986-87 field seasons and have been summarized in a MCCP interim technical report. For the 1988 field season, a uniform cloud detection technique has been implemented network- wide using an optical cloud detection instrument developed originally by the Netherlands Research Foundation.
All concentrations are in micromoles per liter.
There is a considerable interannual and intersite variation in cloud water ion concentration, reflecting the different weather patterns and meteorological conditions that give rise to clouds at the MCCP sites. There is no clear pattern evident of cloud frequency as a function of latitude or elevation. Current studies are focusing on the monitoring of cloud exposure at several mountain sub-sites to determine relationships with elevation, slope and aspect. At Whiteface Mountain for example, the mean SO2 concentration in 1987 was 1.3 ppb and 65 percent of the time the values were below the detection level of the instrument, i.e., 0.5 ppb. Ozone, hydrogen peroxide and sulfur dioxide show almost no diurnal variation in concentration at high elevation sites.