January 27, 2017, 1:00 pm - 2:00 pm
January 27, 2017, 1:00 pm - 2:00 pm, Heliophysics Director's Seminar
New model of the nighttime CO2 infrared emissions in the middle and upper atmosphere
Alex Panka (GMU)
For over a decade, TIMED has been continuously gathering information about the middle and upper atmosphere. Atmospheric parameters such as CO2 densities, which can act as a tracer for dynamical transport processes, are of particular interest. CO2 densities have been obtained for daytime, however, similar nighttime data are still unknown because the dominant physical reactions that generate the atmospheric emissions characteristic to this constituent are not well understood. As a result, little is still known about CO2 diurnal variation and its distribution in polar night. Recently, theoretical and laboratory studies have suggested a new reaction which has allowed models to accurately reproduce TIMED measurements. This is an important step towards developing the algorithm suitable for obtaining CO2 densities in the middle and upper atmosphere.
From Space Climate to Space Weather - Mission concepts to unravel the enigma of ionospheric plasma density structures
Jeff Klenzing (674)
The low- and mid-latitude ionosphere is home to many irregular plasma density structures that wreak havoc on critical radio waves, including GPS, radar, and communication signals. Observations of radio interference in the ionosphere were first reported nearly eighty years ago, but day-to-day prediction remains a significant question in ionospheric physics. We will discuss potential solutions in the context of petitSat, an upcoming mission to separate plasma bubbles from other plasma density structures, and BOWTIE, a proposed constellation to examine the role of large-scale forcing from above and below on plasma bubble formation.
How Earth's Weather Affects Space Weather - the Ionospheric CONnection Explorer (ICON)
Douglas Rowland (674)
While the solar EUV input is the primary energy input into the upper atmosphere, two other major sources of energy drive much of the observed variability in plasma and neutral atmospheric structure above 80 km. At high latitudes, during all but the most geomagnetically quiet times, solar wind energy, processed by the magnetosphere, streams in along magnetic field lines to heat, transport, and modify the upper atmosphere. However, at low and mid latitudes, the atmosphere is mostly shielded from external energy inputs by the structure of the magnetic field. Here, especially during low to moderate geomagnetic activity, the dominant forcing comes from tropospheric and stratospheric atmospheric dynamics. These propagate upwards in the forms of gravity waves, planetary waves, and tides, and create disturbances in the upper atmosphere that are strongly time dependent, and highly variable in latitude, longitude, and altitude. It is only in the last decade or so that the extent to which neutral dynamics in the lower atmosphere modify the plasma dynamics of the upper atmosphere has begun to be appreciated.
The ICON Explorer mission, due to launch in June 2017, will provide the first systematic study of how tropospheric and stratospheric forcing drives variability in the ionosphere and lower thermosphere. With a unique combination of remote sensing and in situ measurements, ICON will provide the first glimpse into the large scale neutral forcing of the plasma populations above 100 km, and provide the first real insight into how this critical neutral-ion interaction region operates. We will present the science objectives, mission concept, instrumentation, and current status of the ICON mission, as well as provide information about the types of data ICON will provide.
