1. Department of Earth and Atmospheric SciencesUniversity of Nebraska‐Lincoln Lincoln Nebraska
2. Department of EnvironmentalAgricultural & Occupational Health, University of Nebraska Medical Center Omaha Nebraska
3. Laboratorio de Física de la AtmósferaInstituto de Investigaciones Físicas, Universidad Mayor de San Andrés La Paz Bolivia
4. Department of Atmospheric and Oceanic ScienceUniversity of Maryland College Park Maryland