Sentinel-3 OLCI True Colour 8 August 2021

Smoke and burned areas from Greek fires

8 August 2021 08:25-10:25 UTC

Sentinel-3 OLCI True Colour 8 August 2021
Sentinel-3 OLCI True Colour 8 August 2021

Widespread smoke and large burned area scars from the wildfires across in Greece in August 2021 shown in satellite imagery.

Last Updated

04 May 2023

Published on

23 August 2021

By HansPeter Roesli (Switzerland), Federico Fierli (EUMETSAT) and Sancha Lancaster (Pactum)

A large number of wildfires developed in the eastern Mediterranean between late July and early August 2021. The largest wildfires were in Attica, Olympia, Messenia, and Greece's second largest island, Evia (also known as Euboea). The event in Evia is visible in Figure 1 as intense values of Fire Radiative Power, it had a particularly destructive impact with at least two people reported to have died and 125,000 hectares of land destroyed.

Sentinel-3 SLSTR FRP 8 August 2021
Figure 1: Sentinel-3 SLSTR Fire Radiative Power, 8 August.

The wide extent of the damage caused by the fires on Evia and north of Athens can be clearly seen by comparing 2020 and 2021 imagery from Sentinel-3A (Figure 2).

Sentinel-3 NCOL 8 Aug 2021 v 15 Aug 2020
Figure 2: Sentinel-3A SLSTR Natural Colour 15 August 2020 (left) v 8 August 2021. Red arrows indicate burned areas.

Also seen on the zoomed in Sentinel-3B Natural Colour image from 08:25 UTC on 8 August (Figure 3).

Sentinel-3B Natural Colour RGB, 8 Aug 08:25 UTC
Figure 3: The burned areas are the darker brown areas in the Sentinel-3B Natural Colour RGB, 8 August 08:25 UTC.

On the comparison of the Sentinel-3 Natural Colour and Fire Temperature images at 09:05 UTC on 8 August (Figure 4), the bright yellow spots show the location of the fires at that time were at the northern tip of the island, while the very faint yellow hue over the burned scars indicates slightly higher land surface temperature.

Sentinel-3A NCOL v Fire temp 8 Aug 2021
Figure 4: Sentinel-3A Natural Colour RGB (left) and Fire Temperature, 8 August 09:05 UTC. The Fire Temperature RGB (called fire01 here) uses the NOAA/NASA GOES-R recipe, partially re-tuned: Red: S7 373K..333K, gamma=0.4, Blue: S6 0..100, gamma=0.33, Green:: S5 0..100, gamma=0.33

Extensive smoke from the fires on the same day could also be seen in both Sentinel-3 OLCI True Colour and MODIS imagery (Figures 5 and 6).

Sentinel-3 OLCI True Colour 8 August 2021
Figure 5: Sentinel-3 OLCI True Colour RGB, 8 August 10:20 UTC
MODIS 8 August 2021
Figure 6: MODIS composite, 8 August. Source: DLR

Additional content

Fire Consumes Large Swaths of Greece (NASA Earth Observatory)
Greece wildfires: Evia island residents forced to evacuate (BBC News)
Greece wildfires: Multinational force works to tame flare-ups on Evia and in Peloponnese (euronews)
Over 100,000 hectares burnt in two weeks (