In the evening of 22 May 2021 the volcano, Nyiragongo started to erupt, threatening life and property, in particular in the nearby town of Goma in the Democratic Republic of the Congo. Thousands of people fled their home after the mass evacuation of Goma. According to reports, more than 30 people have died – mainly due to traffic accidents during the evacuation.
While the eruption was a calamity for the local people, its view from space was not very impressive. Due to the local climate, heavy clouds shrouded the area most of the time. Nevertheless, in the Ash and SO2 RGBs from Meteosat-11, signals of Sulfur Dioxide SO2 (green) first, then ash (red) and finally an SO2 ash mix (orange) were observed among the clouds.
The Meteosat-11 imagery (Figure 1) shows these episodes at 18:30 UTC (SO2) on 22 May, and at 07:15 UTC (ash) and 17:00 UTC (ash and SO2 mix) on 23 May. The Meteosat-11 loop (Figure 2) shows the evolution through these phases.
Figure 2: Meteosat-11 ASh & SO2 RGB, 22 May 18:00-23 May 17:15 UTC
In the Meteosat-8 and Sentinel-3 imagery in Figure 3, the middle panel zooms in on the eruption using a Sentinel-3a OLCI True Colour RGB on 23 May at 07:32 UTC. Although there are no clear signs of the eruption, the brown-grey hues north of the white cloud mass might indicate the presence of an ash veil. The Meteosat-8 Ash and SO2 RGB in the right panel confirm this, where a red ash plume extends towards the northwest flanked by green SO2. However, on the Meteosat-8 Natural Colour RGB in the left panel, no signs are visible
figure 4 is a combination of the Suomi-NPP VIIRS Day-Night band on 22 May at 22:47 UTC in black-and-white and the temperature in false colours measured in NIR3.7 band. It shows the glare from lava flows (light grey) on the flanks of Nyiragongo and the hot spot over its peak (yellow, temperature >350 K).