Abstract. This study investigates the influence of the 2015 Calbuco eruption (41.2° S, 72.4° W; Chile) on the total columnar aerosol optical properties over the Southern Hemisphere. The well-known technic of sunphotometry was applied for investigation of the transport and the spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sunphotometer measurements performed at 6 South American and 3 African sites were statistically analyzed. This study involves the use of the satellite observations and a back-trajectory model. The passage of the Calbuco plume is statistically detectable on the aerosol optical depth (AOD) observations obtained from sunphotometers and MODIS. This statistical detection confirms that the majority of the plume was transported over the northeastern parts of South America and reached the South African region one week following the eruption. The plume has impacted to a lesser extent the southern parts of South America. The highest AOD anomalies were observed over the northeastern parts of the South America. Over the South African sites, the AOD anomalies induced by the spread of the plume were quite homogeneously distributed between the east and west coast. The optical characteristics of the plume near source region was consistent with a bearing-ash plume. Conversely, the remote sites to the Calbuco volcano were influenced by ash-free plume. The optical properties discuss on this paper will be used as inputs for numerical models for further investigation on the ageing of the Calbuco plume in a forthcoming study.
Tailoring the structure, composition, optical properties and catalytic activity of Ag–Au nanoparticles by the galvanic replacement reaction
