The hole that opens in the ozone layer over Antarcticaeach southern spring formed earlier and grew bigger this year than at any time since satelliteshave been monitoring the polar atmosphere, scientists have reported. In early September, several weeks before it normally reaches its peak, the hole expanded to a record 17.1 million square miles, an expanse larger than North America, according to the National Oceanic and Atmospheric Administration. By comparison, in 1981, according to the atmospheric agency, it covered just 900,000 square miles.