Natural phenomena

Dolphin megapod spotted off California coast swimming alongside boat
Onlookers watched as a huge pod of dolphins - known as a super- or megapod - swam alongside them.
Massive dust storm engulfs Australian city
The storm swept over Mildura in Australia with wind gusts reaching up to 87km/h (54mph).
How the cherry blossom season boosts Japan's economy
Japan's "hanami" or "flower viewing" season boosted the economy by about $2.7bn, recent statistics show.