A transatlantic flight is the flight of an aircraft across the Atlantic Ocean, from Europe, Africa or the Middle East to North America, Central America South America, or vice versa. Such flights have been made by fixed-wing aircraft, airships, balloons and other devices. In 2016 Dr Paul Williams of the University of Reading published a scientific study showing that transatlantic flight times are expected to change as the North Atlantic jet stream responds to global warming, with eastbound flights speeding up and westbound flights slowing down.