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Selected Career Accomplishments for Ronald L. Miller
 
As a graduate student, I developed a new approach (Miller and Winefordner, 1971) for computing the amount of excess air in combustion processes such as those in municipal incinerators or jet engines.  My approach is independent of fuel composition unlike previously published methods.
 
I developed equations and computer algorithms to relate major ion concentrations to specific conductance (Miller et al, 1988). These algorithms were used by Norman E. Peters while on detail to the Office of Water Quality to resolve data problems in the USGS acid precipitation program during the 1980's. This and other work on the natural relationships between major ions (Miller and Sutcliffe, 1984. p. 32-34) allow more rigorous chemical logic checks of major ion data than previously was possible. These tools also allow computer review of major ion data in large computer databases.
 
I verified that high radium-226 in ground water of southwestern Florida occurs when high-conductance water contacts phosphatic deposits as the result of ion-exchange reactions on clays. Clays will scavenge radium-226 when low-conductance water is present. Charlotte Harbor, Florida, has radium-226 radioactivities that are an order of magnitude higher than many estuaries in the US. I have verified that most of the radium-226 in Charlotte Harbor enters in ground water (Miller and Sutcliffe, 1985, and
Miller et al, 1990).
 
I developed an approach for estimating the rate of sinkhole formation from water-quality data and estimates of the rate of recharge to an aquifer (Sinclair et al, 1985)
 
I developed (Miller and McPherson, 1991) a novel approach to estimating residence times of estuarine water by relating salinity to fresh-water inflow at fixed sampling sites in the estuary using a newly derived equation. The salinity and fresh-water flow are related using the least-squares equation of a simple mixing equation and requires only one fitted parameter (Qg) that is the upestuary pseudoflow of oceanic water. The basic concept may apply to most estuaries with significant river inflows and relatively simple geometries. The utility of the model is enhanced because the data requirements are modest and can be easily obtained for many estuaries. The value of Qg appears to be related to the fundamental properties of estuarine geometry and tidal mixing. I have received reprint requests for this article from a number of foreign countries. Researchers from the University of Southwestern Louisiana (Robert Twilley et al) have used this model for ecosystem modeling in southern Florida (http://www.ucs.louisiana.edu/~rrt4630/mangrove-restudy.htm). This work was foundational for later work by Sheldon and Alber of the University of Georgia in their article on residence times in the Altamaha River Estuary that was published in Estuaries (v. 25, No. 6, pp. 1304-1317).
 
I developed laboratory (McPherson and Miller, 1987) and statistical (McPherson and Miller, 1994) techniques for determining the partial attenuation coefficients for nonchlorophyll suspended matter (NSM) and for dissolved organic matter (color) in water. These techniques permit better determination of the causes of light attenuation and better assessment of approaches for improving water clarity. This aspect of light attenuation is currently of great interest in Tampa Bay because seagrasses have not responded, as hoped, to reductions in nitrogen loading during recent decades and NSM is possibly one of the causes of stable or declining seagrass coverage.
 
I designed methods (Miller and McPherson, 1995) for computing the loss of light at the air-water interface and the vertical attenuation coefficient for scalar irradiance using data from two spherical (4p) quantum sensors floated at fixed depths below the water surface plus one in-air sensor. I developed theory and a computer model of light behavior that uses incident light data to predict the intensity of photosynthetically active radiation (PAR) in water and the length of time during a day that a threshold PAR irradiance is exceeded at a given depth. This light versus depth information combined with the average bottom slope of an estuary can be used to predict the area of seagrass recolonization following improvements in water clarity. The model includes the effects of the loss of PAR at the air-water interface and the effects of solar elevation angle (sun angle) and cloudiness on the vertical attenuation coefficient for scalar irradiance. This work is a major theoretical breakthrough in understanding and working with the loss of light at the air-water interface and for understanding the influence of seasons and time of day on the vertical attenuation coefficient and the amount of light available in water. The air-water interface has a significant effect that in Tampa Bay averages on an annual basis to an approximate loss of 1/2 of the in-air 4p PAR at the interface. To my knowledge, this is the first theoretical and practical model of the behavior of light at the air-water interface. Classical texts on light in the aquatic environment, such as those by Jerlov or Kirk, did not adequately address this topic. This article has been used by professor Peter Sheng of the University of Florida in his graduate course on estuarine modeling.