The science behind a baby’s smile - University of Miami News

The joint European-Chinese Smile satellite officially began its science operations this week by sharing a ghostly image of Earth's sunlit North Pole ringed by auroras.

On 23 September, the European-Chinese Smile mission was declared ready to start revealing how Earth responds to the wind of charged particles from the Sun. This follows a busy in-space commissioning period since the spacecraft launched on 19 May and reached its target orbit for science operations on 20 June. A spacecraft never quite behaves the same in space as it does on the ground. Between 20 June and now, European and Chinese teams have been getting Smile ready – including deploying mechanisms, switching on units, checking all communications between the spacecraft and the ground, and fixing any issues that came up.

Mud from a fjord shows an Atlantic air pattern brought wetter, colder spells to southern Greenland, a clue to how its ice may fare. Greenland’s ice is shrinking as the planet warms. But in the island’s southwest, rainfall and snowfall have been influenced by the same North Atlantic air-pressure pattern for at least 5,000 years. When that pattern tipped one way, the region turned wetter and colder. The record comes from mud on the floor of a Greenland fjord, and it suggests snowfall, not only temperature, shaped how the area’s ice grew and shrank. It doesn’t yet show how glaciers there will respond to the warming ahead. Johan Faust, a researcher at MARUM, the Center for Marine Environmental Sciences at the University of Bremen in Germany, led the work with colleagues in Germany, Norway, Denmark and Canada. A seesaw in the airThe pattern is called the North Atlantic Oscillation. It’s the difference in air pressure between a low that sits near Iceland and a high near the Azores, and it’s strongest in winter. When that difference is large, the pattern is in its positive phase. Northwestern Europe and southwestern Greenland both get more rain and snow.