The last week a large part of the Europe has been smashed by a wave of cold siberian weather carried by the Burian. Burian is a strong wind of cold air and it is indeed characteristic of the steppes located to the west of the Urals. The extremely cold air carried by Burian leds to blizzards, storms and winds full of ice and snow, just like is indeed happened in the Eastern Europe up to the overall Italian peninsula starting from the last sunday. Copernicus Sentinel-3A satellite captured Burian in some of its critical step of its journey through the Europe and thanks to the infrared bands of SLSTR instrument shows the storm thermal map, progression and snow detection on the ground.
This first shot has been observed in the late morning of monday 26th of February, just after the heavy snowfall hit Rome and the central part of Italy. The thermal channels of SLSTR clearly show the extremely cold temperature at the cloud top of the storm and highlight Burian approaching the southern part of Italy, regions that will be hit by its cold winds in the evening until the morning of the day after. This evidence is enhanced also thanks to the following comparison between a false colour RGB and thermal map showed above, both processed from the same scene.
Considering a visible RGB inspection could be hard to identify and separate the snow from the clouds, appearing both in white. Thankfully they have a different emission in the infrared and thus the snow detection could be easily performed with the proper methods. From this perspective the infrared channels of SLSTR allow to detect the snow on the ground and avoid to confuse it with clouds. In the slide below the image on the right has been processed in order to highlight the snow spectral response tin the near infrared, pictured in cyan, whereas the clouds appear in their classic white outfit. The image on the left is instead a classic visible RGB composition.
Snow detection with Sentinel-3A SLSTR
Burian has raged over the peninsula up to the end of the week, when flashes of spring have been felt thanks to the increasing temperatures. Burian is a distant memory but its legacy has been anyway still present for few days: this image of Mount Vesuvius, captured by Sentinel-2 constellation after the storm hit Naples few days ago, shows indeed the volcano completely covered by the snow.
Contains modified Copernicus Sentinel data 2018.