How Smoke From Canada's , Wildfires Has Transformed , Skies in the U.S.br 'The New York Times' reports that atmospheric scattering br is why skies across the northeastern United States have br turned orange amid heavy smoke from Canadian wildfires.br On a normal day with a blue sky, sunlight bounces off br of molecules of air in the atmosphere, scattering high br energy colors with shorter wavelengths into blue light.br Larger smoke particles scatter br the orange and red colors br in the light from the sun.br The resulting surreal haze br is also closely related to how br the sky appears at sunset.br As the sun travels closer to the horizon, only longer br wavelengths can travel through the atmosphere to br be perceived as the reddish hues visible at sunset.br 'NYT' reports that hundreds of fires continue to burn across br Eastern Canada, spreading clouds of hazardous air br pollution across a large swath of the eastern U.S.br Air quality warnings have been br issued for areas spanning br from New York to the Carolinas.br Air quality warnings have been br issued for areas spanning br from New York to the Carolinas.br On June 7, major cities experienced unhealthy br levels of air pollution, including br Philadelphia, Washington and New York.br 'NYT' reports that while air quality is expected to improve in parts of the Northeast, smoke from the ongoing fires continues to spread across the U.S.br On June 8, Canadian authorities said that approximately br 250 wildfires were burning out of control in the eastern part of the br country. Some of those fires have already burned for weeks.