January 4, 2016 – The warm El Niño conditions affecting weather around the Pacific Ocean are also affecting conditions in space, according to University of California, Berkeley scientists.
El Niño is commonly observed as a global change in rainfall due to changes in temperature in the Pacific Ocean. However, UC Berkeley scientists reported in December at the annual meeting of the American Geophysical Union meeting in San Francisco that the processes that lead to increased precipitation are also driving unexpected changes in the ionosphere, the uppermost level of the atmosphere.
The findings (AGU abstract #SA31F-2383) were presented by Dr. Thomas Immel, and were based on calculations by Dr. Astrid Maute of the High Altitude Observatory in Boulder, Colorado.
“We expected that we would see some changes in the ionosphere when we started this study” said Dr. Immel, a Senior Fellow at UC Berkeley’s Space Sciences Laboratory, “but we were shocked at how strong the effect has turned out to be”.
“The connection between the lower and upper atmosphere has been getting more attention lately” said Immel, who also participated on a panel with former Vice President, Al Gore on the future of Earth Observations. “This is largely because we keep discovering new ways in which the lower atmosphere affects the conditions higher up”.
The study is being conducted in advance of a new NASA mission, the Ionospheric Connection Explorer (ICON), which will study this and similar effects, has observed large enhancements in ionospheric density after dusk – a time when the ionosphere generally relaxes and is significantly thinner. Instead, they are finding that the ionosphere is disproportionately thick, even after sunset.
Dr. Katelynn Greer explains the effect: “El Nino is the term used to describe abnormally high temperatures in the Pacific Ocean, which results in temporary changes in global weather patterns. During El Nino, changes in wind and ocean current patterns result in warm waters stretching across the whole Pacific Ocean. This causes more water to vaporize into the atmosphere, which in turn will absorb more solar energy into the atmosphere. This extra heating causes changes in wind patterns, which causes atmosphere to react and change all the way from the ground to the edge of space around Earth.”
Although the evidence for this effect is quite convincing, the evidence currently consists exclusively of theoretical models. This is because there is no way to observe these kinds of changes in the ionosphere at the current time. However, a new satellite mission called the Ionospheric Connection Explorer, or ICON, will directly observe and measure these ionospheric shifts.
“ICON will help us to understand what’s happening in our own atmosphere, during El Nino and during normal conditions” said Dr. Immel, principal investigator for the mission. “This is very exciting for us since ICON will observe El Nino in the ionosphere for the first time ever.”
ICON is currently scheduled for launch in the summer of 2017.