Complex Terrain Modeling Still Woefully Short of Goals

After many years of over predictions of concentrations on the sides or tops of hills or ridges from stacks below the hilltops, the state-of -the art is apparently no better than it was two decades ago. US EPA still prefers the CTDMplus methodology for all permits and SIP plans. To decribe the problem which we call "complex terrian" there are new examples which show the over prediction is still rampant and still needs correction. Because of the lack of further field experiments and lack of interest in the regulatory and academic communities, modelers are stuck with antiquated tools and clients are stuck with over predictions.