Autores: Andrea Patricia Cuesta-Mosquera, MatthewWahl, Jansen GabrielAcosta-López, José Agustín García-Reynoso*, Beatriz Helena Aristizábal-Zuluaga
* Ciencias Ambientales | Fisicoquímica de la Atmósfera
istinct times of sulfur dioxide concentration (SO2) were observed in the main square of a tropical Andean city, revealing strong meteorological control of SO2. Concentrations were measured by UV fluorescence at 5-minute intervals, and compared to local meteorological forcing. A consistent morning peak of SO2 (4.32 μg∙m⁻³ at 7:40 AM) was concurrent with peak traffic, and occurred 10 minutes into an 80-minute period of calm (wind velocities ˂ 0.3 m s⁻1). Instead of accumulating, SO2 decreased 54%, due an expanding mixing layer. Peak evening SO2 (5.2 μg∙m⁻³ at 8:15 PM) was observed 2:15 hours after flow reversal, and consistent with travel-times of an air parcel descending from industrial facilities. The consistent anthropogenic emissions formed a pattern of daily SO2 concentration that aided in identifying more random volcanic SO2. Manizales (pop. 400000) is located on the western slope of the Cordillera Central in proximity to the Nevado del Ruiz volcano. The complex trajectory necessary for volcanic SO2 to arrive in the main square was simulated for the highest observed concentration (114 μg•m⁻³), using Hysplit and Aura-OMI information. This type of analysis can be applied to urban planning – from locating industrial zones to managing transportation – particularly in tropical montane cities.