Dr. John D. Wilson



bLS measurements of ammonia emission by Wisconsin dairy farm (2007)

The laser gas detector measures the line-averaged concentration of ammonia on a path of some 300 m extent (the retro-refledtor is at the far edge of the field) downwind of dairy barns.

Dr. Tom Flesch used the backward Lagrangian stochastic model (as implemented in Brian Crenna's GIS-like software WindTrax) to compute the paths of fluid elements upwind from the laser beam to the sources.

"On a per-animal basis, the yearly average emission rates from the three dairies were estimated to be 55, 51, and 55 g-NH3 animal-1 d-1."

"Summertime rates were roughly ten times those of the winter, mid-day rates approximately three times those at night." (Flesch et al., submitted to Trans. ASABE)



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Last Modified: 25 Sept., 2008