1. Department of Earth and Planetary Sciences; McGill University; Montreal Quebec Canada
2. Observatorio Vulcanológico y Sismológico de Costa Rica, Universidad Nacional; Heredia Costa Rica
3. Atmospheric Chemistry, Bayreuth Center of Ecology and Environmental Research; University of Bayreuth; Bayreuth Germany
4. Escuela de Física, GasLab, CICANUM; Universidad de Costa Rica; San José Costa Rica
5. Istituto Nazionale di Geofisica e Vulcanologia; Palermo Italy