Ash from a Chilean volcano is continuing to cause disruption to air traffic in Australia and overseas.
UN chief Ban Ki Moon was forced onto an overnight bus to meet Argentine leaders.
Ban did not have time to change his arrangements after his flight was diverted to Cordoba and he had to slog it 700 kilometers (440 miles) overnight to Buenos Aires in a bus.
"He and his delegation went to the capital by bus through the night," said UN spokesman Martin Nesirky.
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In Australia, Qantas announced flights to and from Adelaide have been suspended until 10 am Tuesday.
Airlines are racing to clear a massive backlog as flights resumed in to and out of Melbourne.
And the situation could become even worse, as another plume of ash heads our way.
More than 60,000 travellers had their plans disrupted by the ash plume from Chile's Puyehue volcano that spread across three oceans and over Victoria and Tasmania on Sunday and Monday.
Qantas was set to schedule extra services on Monday night and Tuesday to start moving stranded passengers out of Melbourne, with more than 20,000 of the national carrier's customers affected by 110 cancellations.
The situation could become even worse as a second ash plume spreads from the volcano.
"It could take a number of days (to clear the backlog) depending on when airspace in Tasmania and New Zealand opens up," a spokeswoman for the airline told AAP.
Services to Tasmania and New Zealand remain suspended. Virgin Australia resumed flights to and from Hobart about 11am (AEST) on Monday, with up to 14,000 passengers affected by 34 cancellations.
Traveller Patrick Korghian, of Sydney, vented his frustration in the Qantas domestic terminal at Melbourne Airport when it was announced hundreds of passengers with flights booked between 6am and midday on Monday should go home and contact the customer service centre to rebook. "What if you don't live here?" he yelled.
The president of the Tasmanian Legislative Council, Sue Smith, had been in Melbourne for the long weekend with her daughter to see Andrew Lloyd Webber's new production, Love Never Dies.
After several cancellations, she now has a seat on a Thursday Qantas flight but hoped to get an earlier service. She made three calls to the airline's customer service number, waiting more than two hours each time. Ms Smith said passengers agreed that safety had to come first.
"None of us want to fly if it's not safe, and nobody knows that better than Tasmanians," Ms Smith told AAP.
The atmosphere at the airport since she arrived at 7.15am had been calm, she said.
"It's really that Australianism of all people just accepting the inevitable." Tiger Airways cancelled all Australian flights until 5pm on Monday, while Jetstar cancelled 82 flights.
CLOUD DISSIPATES
Late Monday afternoon, Bryan Nicholson from Airservices Australia said the ash cloud had begun to dissipate and was moving north.
Supervising meteorologist at the Volcanic Ash Advisory Centre in Darwin, Gordon Jackson, said the body was monitoring a second ash plume hovering over the ocean south of Australia. "It depends on how the wind is moving.
It may actually be brought up over Tasmania and Victoria in 48 hours," he said. Flights that had resumed would be flying under the ash cloud, which is 8.5 kilometres high, Mr Jackson said.
The flight cancellations also forced politicians and sports people to make other travel arrangements.
The air force flew Tasmanian federal politicians from Hobart to Canberra aboard a special VIP plane so they could attend parliament on Tuesday.
Referees for Monday night's NRL clash between the Melbourne Storm and Sydney Roosters at AAMI Park had to fly from Sydney to Albury before driving the remaining 320km to Melbourne in time for the 7pm start. Some members of the Australian netball team had also secured flights out of Auckland, following their loss to New Zealand on Sunday night.
In AFL, the Bombers were delayed in returning to Melbourne from Perth and the Tigers from Sydney.
Essendon are expected to arrive back in Melbourne on Monday, while Richmond, who have only a six-day turnaround before their next match, gave up on getting a flight and travelled from Sydney to Melbourne via bus.
