The same optical principles responsible for the NASA blue hue of the sky and the creation of rainbows are integral to unraveling mysteries surrounding cloud formation and the impact of minute airborne particles on our atmosphere. NASA’s upcoming PACE mission is poised to provide crucial insights into aerosols, encompassing sea salt, smoke, pollutants, and dust, by examining their interaction with light. The mission, set to launch in early 2024, will employ advanced polarimeters to scrutinize Earth, elucidating the chemical composition, movement, and interplay of aerosols and clouds.
While human eyes perceive certain light properties like color, polarization, an imperceptible characteristic, plays a pivotal role in scientific investigations. Polarization, invisible to the human eye but detectable by specialized sensors, alters light behavior when interacting with elements such as clouds or aerosol particles. The two polarimeters on PACE, namely HARP2 and SPEXone, operate synergistically, measuring different aspects of light to provide an unprecedentedly detailed picture of Earth’s atmosphere.
NASA
Polarimeters, like those aboard PACE, gauge the angle of polarized light, unveiling specific traits of the objects it bounced off. This data allows scientists to deduce the size, composition, abundance, and other features of particles in the atmosphere. PACE’s instruments, HARP2 and SPEXone, constructed at the University of Maryland, Baltimore County, and the Netherlands Institute for Space Research (SRON) respectively, complement each other, offering a comprehensive view of Earth’s atmosphere.
The PACE mission, scanning Earth every two days post-launch, aims to gather extensive data on aerosols and clouds. This data will not only enhance our understanding of climate change but will also contribute to real-time insights on air pollution. By deciphering the complex relationships between aerosols, clouds, and climate, PACE’s polarimetry data will aid in refining climate models and reducing uncertainties, ultimately paving the way for more accurate climate predictions in the coming decades and centuries.
