A cloud stretches over the northern hemisphere for several thousands of kilometres. Raikoke volcano, one of Russia's Kuril Islands, hurled a massive plume of gases and ash more than 10 km up into the atmosphere when it erupted on 22 June.
Sentinel-5 Precursor, a European satellite, records the sulphur dioxide it contains and thus provides important information for the science community as well as the air traffic sector. The data, acquired and processed by DLR at EOC, so far comprise over one million data packets.
The precise spatial and temporal spread of the gas plume and its disruption by atmospheric turbulence from a cyclone can be closely followed in the high-resolution data. Another eruption on the Pacific Ring of Fire, that of Ulawun volcano on Papua New Guinea on 26 June, is also clearly visible. The Sentinel-5 Precursor atmosphere mission supplies global daily measurements at the uniquely high resolution of 7 x 3.5 km of various atmospheric trace gases like ozone, sulphur dioxide, nitrogen dioxide and formaldehyde, as well as aerosol and cloud properties.
Sentinel-5 Precursor began routine operations barely one year ago. Nonetheless, almost simultaneously with the Raikoke eruption the number of processed data products passed the one million mark. DLR's Earth Observation Center (EOC) executes on behalf of ESA and in cooperation with international partners the entire value adding chain for the mission's payload ground segment. This includes acquisition of the satellite data, its processing, and the handling, supply and long-term archiving of a total of 14 distinct data products.
Some of these products need to be made available within just three hours of acquisition. Rapid delivery is crucial for the operation and development of timely service applications because of the high dynamics of the atmosphere. At the same time, long-term archiving and continuous provision of the data is essential for scientists. Only access to lengthy time series makes it possibly to reliably identify and statistically confirm trends in atmospheric processes.
Since the mission began, about 830 terabytes of Sentinel-5 Precursor data have already been incorporated in the German Satellite Data Archive (D-SDA). It is estimated that by August this data flow will have increased by about one quarter. At that time the resolution of data from the Tropomi instrument is scheduled to increase from presently 7 x 3.5 km to 5.5 x 3.5 km in order to provide users with even more precise data on our planet's atmosphere. In addition to the Sentinel-5 Precursor payload ground segment EOC also operates processing and archiving centres for the Sentinel-1 and Sentinel-3 Copernicus missions.