In Partnership with the Joint Institute for the Study of the Atmosphere and Ocean
Scientists use a hand-held sun photometer to measure the brightness of the sun at the earth’s surface under non-cloudy conditions. Reduction in clear-sky solar brightness is due to tiny particles, known as aerosols, in the atmosphere which reflect a small fraction of the sun’s rays back to space. These data, not routinely collected at sea, will be compared to NASA’s satellite-based measurements and supplement NASA’s ground-based photometer network.
Aerosols come from both man-made and natural sources. They reduce the amount of solar radiation (energy) reaching the earth’s surface, thus reducing temperature and partially counteracting global warming from greenhouse gases. However, any aerosol counteraction of greenhouse warming is short term and localized.