Bulletin of the American Meteorological Society, Vol. 37, No. 6 (June, 1956), pp. 251-262 (12 pages) The study of tropospheric refractive index distributions which began in 1951 using an airborne ...

ABSTRACT Recent advances have made ground‐based relative astrometry accurate to 100 microarcseconds (μas) or better a possibility. An important systematic effect on such measurements is the refraction ...

Researchers have developed a dielectric film that has optical and electrical properties similar to air, but is strong enough to be incorporated into electronic and photonic devices -- making them both ...

Smoke from wildfires in Canada has drifted into the U.S., prompting air quality alerts for Americans as it continues to spread. But when officials and forecasters classify a city's air as "unhealthy" ...

Editor’s Note: CNN has an agreement with Copernicus to provide air quality data. The content below is provided by Copernicus, but CNN’s weather team has verified the information and methodology. The ...