Large smoke plumes from fires over Bolivia

By HansPeter Roesli (EUMETSAT)

South America's annual fire season was well underway when, in the second part of August 2010, EUMETSAT's MSG (Meteosat-9) satellite captured spectacular images of large smoke plumes from fires over Bolivia (Figures 1 and 2). Extended smoke veils covered the skies and some plumes were blown a long way over the Southern Atlantic. According to CNN, the smoke closed 28 of Bolivia's 39 airports on 19 August.

According to NASA Earth Observatory, while some fires do occur naturally in Bolivia, most of these fires were probably set deliberately to clear land for crops or pasture. August is the height of the dry fire season in the region. In 2010, however, unusually dry weather and winds allowed many land management fires to expand into dangerous large wildfires.

An MSG image mosaic (Figure 3) covers the nine days from 21 to 29 August, one image per day close to local noon. The mosaic is focusing on the situation over the Atlantic where the smoke plumes are visible in blue hues on most of the days together with major cloud systems.

A detailed view over the continent is depicted in an animated image sequence (19 Aug 11:00 UTC–25 Aug 21:00 UTC). The smoke screen stands out most prominently before sunset, when the blue hue is swamping other details in the images, due to increased forward-scattering of the sunlight by the smoke particles. Note the similarity of these evening scenes to the morning ones of smoke spreading over the Indian Ocean (1 September 2008) where forward scattering happens at sunrise.

Compared to MSG imagery, AVHRR images from the mid-morning Metop orbit (Figure 5) are less performant in smoke detection due to the unfavourable Sun-satellite orientation. Only over the dark background of the Atlantic is the blue-coloured smoke clearly detectable whereas over the continent it is visible only with hindsight.