Air sampling tubes protrude from the side of a Coast Guard HC-130 Hercules airplane in Kodiak, Alaska, Tuesday, July 16, 2013. The sampling gear is hooked up to electronic equipment and a computer from NOAA's Global Monitoring Division to detect and log the concentration of certain gases in the air at different altitudes throughout northern Alaska. (U.S. Coast Guard photo by Petty Officer 1st Class Sara Mooers)