JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM11] [EE] Mesosphere-Thermosphere-Ionosphere Coupling in the Earth's Atmosphere

Wed. May 24, 2017 9:00 AM - 10:30 AM A01 (Tokyo Bay Makuhari Hall)

convener:Loren Chang(Institute of Space Science, National Central University), Huixin Liu(Earth and Planetary Science Division, Kyushu University SERC, Kyushu University), Akinori Saito(Department of Geophysics, Graduate School of Science, Kyoto University), Tzu-Wei Fang, Chairperson:Loren Chang(Institute of Space Science, National Central University)

9:00 AM - 9:20 AM

[PEM11-06] Thermospheric nitric oxide response to shock-led storms

★Invited papers

*Delores Knipp1, Daniel Pette2, Liam Kilcommons2, Tristan Isaacs2, Alfredo Cruz2, Martin Mlynczak3, Linda Hunt4, Cissi Lin5 (1.University of Colorado Boulder and High Altitude Observatory National Center for Atmospheric Research, Boulder CO, USA, 2.University of Colorado Boulder USA, 3.Science Directorate, NASA Langley Research Center, Hampton, Virginia, USA,, 4.Science Systems and Applications, Inc., Hampton, Virginia, USA, 5.Physics Department, University of Texas at Arlington, Arlington, Texas, USA)

Keywords:Thermospheric nitric oxide, Coronal mass ejections, Shock-led storms

We present a multiyear superposed epoch study of the Sounding of the Atmosphere using Broadband Emission Radiometry nitric oxide (NO) emission data. NO is a trace constituent in the thermosphere that acts as cooling agent via infrared (IR) emissions. The NO cooling competes with storm time thermospheric heating resulting in a thermostat effect. Our study of nearly 200 events reveals that shock-led interplanetary coronal mass ejections (ICMEs) are prone to early and excessive thermospheric NO production and IR emissions. Excess NO emissions can arrest thermospheric expansion by cooling the thermosphere during intense storms. The strongest events curtail the interval of neutral density increase and produce a phenomenon known as thermospheric overcooling.We use Defense Meteorological Satellite Program particle precipitation data to show that interplanetary shocks and their ICME drivers can more than double the fluxes of precipitating particles that are known to trigger the production of thermospheric NO. Coincident increases in Joule heating likely amplify the effect. In turn, NO emissions are more than double. For some events, there may be an additional factor of early NO production due to solar flares. Perhaps a more potent combination of solar wind events involves a series of ICMEs, especially if the interplanetary path has been clearedfor the second or subsequent ICME. We discuss the roles and features of shock/sheath structures that allow the thermosphere to temper the effects of extreme storm time energy input. Shock-driven thermospheric NO IR cooling likely plays an important role in satellite drag forecasting challenges during extreme events.