News•February 26, 2015

NASA Satellites Show Rain In Detail Like Never Before

Few things on our planet connect us like precipitation. The storm that drops snow in the mountains of Tennessee one day can bring rain to the plains of Spain a week later.

Yet there hasn't been a way to effectively monitor all the precipitation across the globe at once, let alone create a vertical profile from the clouds to the ground. All that changed last year, though, when NASA and the Japan Aerospace Exploration Agency launched the last piece of the Global Precipitation Measurement (GPM) mission, a constellation of at least 12 satellites that give an unprecedented view of global precipitation available in near real time. And on Thursday, NASA released its first map produced by those satellites.

It shows the ripples and eddies of small rain and snowstorms crossing the planet on a daily basis, from data captured every 30 minutes. Large storms race across the Southern Ocean, where no land is there to impede them. The rain from tropical cyclones such as Hurricane Arthur, which tracked across the Atlantic in early July, and Typhoon Rammasun, which moved across the Pacific before striking the Philippines in the middle of the month, are also readily visible.

“In the U.K., they experience mostly light rain,” Gail Skofronick-Jackson, GPM project scientist, said. “In India they experience monsoons. In other regions, there's snow. GPM can measure it all.”

While the light rain is certainly of interest, information on the monsoon and tropical storms is where GPM could have its greatest immediate impact. The data from GPM is publicly available, and NASA is already working with emergency managers to figure out how the near real-time view of precipitation can be used to improve emergency management.

Beyond the immediate disaster preparedness uses, the data from GPM could also help inform climate and weather models because it provides a three dimensional view of precipitation.

“The data that we’re collecting has a 3-D structure to it. Weather forecast models and climate change models have a very simplistic way of representing snow and ice and water in vertical resolution so it can help improve those models,” Skofronick-Jackson said.

Heavy rainfall events are on the rise across the U.S., a pattern that's expected to continue due in part to climate change. Data from GPM could help scientists get a better estimate of just how these events are likely to change in the future and forecast them better when they do occur.

NASA has had a busy year upgrading its eyes in the sky. In 2014, the agency launched four Earth-monitoring missions and added a fifth earlier this month, completing its busiest science mission launch schedule in a decade. The new mix of satellites and sensors aboard the International Space Station provide a flurry of information on carbon dioxide, winds, soil moisture and clouds in addition to the upgraded look at precipitation GPM provides.

“We're really looking forward to contributions these new projects will make for science and life on Earth,” Peg Luce, deputy director of the NASA's Earth Science Division, said.