Polar mesopheric clouds change based on effects, such as thunderstorms, in areas both far beneath them and even from the pole in the opposite hemisphere.
An extension of a NASA research mission is enabling space scientists to study noctilucent (night-shining) clouds for almost an entire solar cycle. NASA recently extended the Aeronomy of Ice in the Mesosphere (AIM) mission, which originally launched in 2007.
Usually NASA missions led by universities are two-year missions, and researchers can apply for an extended mission, explains ECE's Scott Bailey, deputy principle investigator on the project. NASA has extended the AIM mission three times, with funding through 2018. Bailey explains that since researchers will be able to collect data for 10 of the 11 years of the solar cycle, "this allows us to get observations at all levels of radiation. It's a big deal to us to observe for an entire solar cycle."
The group hopes to extend the mission even past 2018. Bailey admits that "things get challenging once the spacecraft has been up there, but we don't see anything that would stop us. Everything is functioning just fine."
The AIM mission is the first satellite mission dedicated to studying polar mesospheric clouds. Instruments observe the cloud visually, and measure temperatures and water vapor. The researchers hope to discover why these clouds form and why they vary so widely. "They've gone from never being observed, to being routinely observed every summer," says Bailey.
In the seven years since the satellite launched, space scientists have already learned much about these clouds. "The clouds look much different than we expected," notes Bailey. "There's a lot of variability. Sometimes the whole polar cap is covered, some days it's spotty. You could never say it's anything approaching a uniform cloud, but nor is it a bunch of individual clouds." Although the data is more complicated than initially anticipated, "the complexity you see is reflecting the complexity of the atmosphere" Bailey says, explaining that the polar mesospheric clouds change based on effects, such as thunderstorms, in areas both far beneath them and even from the pole in the opposite hemisphere. Bailey summarizes the AIM experience, saying "we got a lot more science than we expected, and our whole view has changed."