Mexico City Air, Clear, Smog (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption A clear day and a smoggy day, as seen from the MILAGRO Campaign's T0 test site on the roof of the Mexican Institute of Petroleum in northern Mexico City. Credit Photos by Mary Gilles Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.