New York City 9/11 Memorial lamps could overwhelm migrating birds during ceremony

On Thursday, a new bird migration prediction system issued its first forecasts, calling for favourable migration conditions in New York City this week including during Tuesday night's 9/11 memorial 'Tribute in Light' ceremony.

BirdCast began issuing forecasts as of September 3rd. The project is run by researchers at Cornell University, Oregon State University, the University of Massachusetts, Microsoft, and the U.S. National Weather Service, who combine weather forecasts with empirical knowledge of bird migration patterns and feedback from radar to show current flock locations to produce weekly forecasts. Forecasts are updated as needed and include focused forecasts for specific geographic areas and migration routes.

Their first forecasts took into account the strong line of storms that passed through the northeast on Saturday and the associated cold front that passed through on Sunday night. With the warmer weather, scattered showers and generally southerly winds, flocks of birds would remain grounded until after the front has passed. The northerly and northwesterly winds behind the front, along with generally calmer weather as high pressure moved over the northeast offers much more favourable conditions as the birds fly south.

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With favourable migration conditions on Tuesday night, Andrew Farnsworth, a research associate from the Cornell Lab of Ornithology, along with members of the New York City Audubon Society, will be on hand at the 9/11 ceremony to observe any effects it has on the birds' migration.

The ceremony uses two 7000-watt lamps to project twin columns of light into the night sky, in a memorial to the twin towers of the World Trade Center. These bright lights can overwhelm the normal ways the birds use to navigate at night, such as by the Earth's magnetic field and the positions of the stars.

Foggy or overcast conditions are the worst for the birds on the night of the ceremony. The twin columns of light get trapped in the fog or clouds traps the light from the columns.

"But thankfully, it looks like it will be very clear, so the effects of the bright lights will not be as extreme," said Farnsworth.

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