Dr. Ariel Stein is Acting Director of the Global Monitoring Laboratory. Dr. Stein was previously the Deputy Director of NOAA's Air Resources Laboratory (ARL). He has ample experience working with transport, dispersion, and photochemical models. He has an in-depth understanding of hybrid dispersion modeling techniques including ARL’s HYSPLIT model. His research interests cover a wide range of topics dealing with atmospheric transport and dispersion modeling including the simulation of atmospheric tracer release experiments, radionuclides, smoke originated from wild fires, volcanic ash, and wind-blown dust. He has several peer-reviewed papers in these topics in prestigious international journals. He holds a B.Sc. in Chemistry from the University of Cordoba, Argentina, a M.Sc. in Environmental Pollution Control and PhD in Meteorology from Penn State University.