NASA is set to launch satellite Glory early Wednesday. It will measure incoming sunlight and atmospheric particles, both key to crafting better climate models.
In the dark of night, scientists expect to launch a satellite they hope will provide new insights into the energy the sun provides for Earth's climate in the light of day.
At 2:09 a.m. Pacific Standard Time Wednesday, NASA is launching Glory on a mission that will give the most accurate measurements yet of incoming sunlight, as well as highly accurate measurements of the size, distribution, and effects of tiny particles in the atmosphere known as aerosols, planners say.
The satellite's data should help atmospheric scientists improve climate models. Better models not only would increase scientists' knowledge of how the climate system operates, but also would help them make more accurate projections of the effects of global warming – even as atmospheric concentrations of greenhouse gases continue to rise, as a result of burning fossil fuels and land-use changes.
Direct and indirect effects of aerosols and black-carbon soot represent "the greatest uncertainty in our ability to predict climate," says Hal Maring, the Glory program scientist at NASA headquarters in Washington.
Aerosols reflect sunlight or absorb it, cooling or heating the atmosphere depending on the particles' size and composition.
Aerosols also can have indirect effects on climate by serving as tiny platforms on which atmospheric water vapor can condense to form cloud droplets.
These tiny particles can vary widely in size, composition, and sources. Aerosols in the atmosphere have natural sources, such as volcanic eruptions, or can result from human activities, such as burning fossils fuels or using wood for cooking and heating. Aerosols from different sources and with different compositions can occupy the same parcel of air.