Since the saltiness of ocean surface waters is a key variable in the climate system, understanding how this changes is important to understanding climate change. 

This week, the UN World Meteorological Organization announced that concentrations of greenhouse gases in the atmosphere have reached yet another high. This ongoing trend is not only heating up the planet, but also affecting the chemical composition of our oceans. Until recently, it has been difficult to monitor 'ocean acidification', but scientists are exploring new ways to combine information from different sources, including from ESA's SMOS mission, to shed new light on this major environmental concern.

Strange ribbons of purple light that appeared in the sky – known as Steve – became the subject of debate in 2017, as their origins were unbeknown to scientists. Now, photographs of this remarkable phenomena have been studied to understand their exact position in the night sky.

ESA's ESTEC Test Centre in the Netherlands has completed its initial test campaign for the future of European weather forecasting – MetOp Second Generation.

Torrential downpours have battered many parts of Italy this month, with extreme flooding wreaking havoc across northern Italy. The province of Alessandria is said to be one of the worst-affected areas according to Italian media, with around 200 people evacuated and 600 said to be left stranded.

The Copernicus Sentinel-2 mission captured the plumes of smoke from the bushfires in Australia. The recent blazes triggered a ‘hazardous' air quality warning for Sydney – the highest level on Australia's Air Quality Index.

This week, southeast France was hit by a magnitude 5 earthquake with tremors felt between Lyon and Montélimar. The Copernicus Sentinel-1 radar mission has been used to map the way the ground shifted as a result of the quake.

Media representatives and mission partners gathered today in Germany to see a new satellite, which will take the lead in charting sea-level change, before it undergoes final testing and is packed up for shipment to the US for lift-off next year.

The Copernicus Sentinel-3 mission captured the multiple bushfires burning across Australia's east coast. Around 150 fires are still burning in New South Wales and Queensland, with hot and dry conditions accompanied with strong winds, said to be spreading the fires.

Tests carried out show that new wind profile observations from ESA's Aeolus satellite significantly improve weather forecasts – particularly in the southern hemisphere and the tropics.