​​Temperature Inversions and Off-Target Movement of Herbicides

March 2019 | 22 min., 12 sec.
by Richard H. Grant
Purdue University

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​Much of recent off-target dicamba damage is blamed on volatilization, transport and deposition during temperature inversions. Unfortunately it is not possible to easily know if inversion conditions are present. As a result the USEPA has restricted guidelines designed to prevent application during inversions based on winds and time-of-day. Characteristics of inversions in northern Mississippi were explored through an analysis of five years of National Reference Climate Network measurements at Holly Springs, MS. This presentation addresses to answer a set of questions: ‘Do low wind speeds (<1 mph) indicate an inversion?’, ‘Does fog indicate an inversion?’, ‘Does dew indicate and inversion?’, ‘Do inversions form only after sunset?’, and lastly ‘If I do not have an inversion over my field, does my neighbor?’​

About the Presenter

Richard H. GrantRichard H. Grant completed his undergraduate degree with distinction at Duke University (1977), received a Masters of Forest Science at Yale University (1979), and his PhD at State University of New York College of Environmental Sciences and Forestry (1982). Dr. Grant’s research focuses on the physical and chemical interactions betw​een the atmospheric surface boundary layer and biological systems. His work has included extensive studies in the emission, transport and deposition of trace gases and particulates in agricultural operations.

Contact Information:
Email: rgrant@purdue.edu


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