A differential GPS system provides precise wind readings, which is vital for quantifying sources of greenhouse gases, including methane.

The most recent flight was Dec. 23, when Conley recorded approximately 30 tons, or 60,000 pounds, of methane per hour.

Background

Methane is a powerful greenhouse gas and roughly 25 times more potent than carbon dioxide. Porter Ranch residents downwind from the plume have complained of headaches, nausea, dizziness and nosebleeds.

Southern California Gas Co., which owns the Aliso Canyon storage facility, announced in late December that it does not expect crews to plug the leak until at least late February or March.

The Aliso Canyon facility is the largest underground methane storage facility in the western United States.This article is more than 6 years old

This article is more than 6 years old

Outside the headquarters of the Aam Admi (Common Man) party in central Delhi on Sunday night, hawkers sold poppadoms, bored police watched from squad cars and a crowd of excited young people sang songs dating back to the days of India's independence movement.

"This is what we do best in this country: non-violent revolution," said Shehshan Partak, a 25-year-old engineer and activist for Aam Admi (AAP). "And this is a revolution."

The claim is exaggerated but perhaps not entirely unjustified. The results of recent elections in Delhi and three other Indian states, released on Sunday, indicate that change is imminent in the in the world's biggest democracy. A general election is less than six months away.

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