NSF Award
2431689
This proposal takes advantage of an existing Short Wavelength InfraRed (SWIR) all-sky imager and is an example of advances in technology that has enabled measurements in the least studied spectral region spanning 800 – 1700 nm wavelength range. The investigators plan to utilize this instrument to map mesoscale spatial brightness structures to study auroral and airglow emissions. The project aims to investigate the role of Alfvénic waves in generating auroral arcs and to measure metastable Helium (He) and the associated dynamics. Alfvén waves are travelling ion oscillations and magnetic field tension in the plasma, which propagate along geomagnetic field lines, and transport energy. Electrons are accelerated during the Alfvénic wave propagation, which plays a dominant role in magnetosphere-ionosphere (MI) coupling through their interactions with ionospheric ions. To examine the role of the Alfvénic aurora relative to the electron aurora, midnight observations would be considered, since during this time Alfven waves are more dominant. Supplemental observations by the instruments currently operating at Poker Flat, which include meridian scanning photometers, all sky 630.0/557.7/482.1 imagers, and the Poker Flat incoherent scatter radar (PFISR) are also planned. <br/><br/>The proposal seeks funds to address two science questions (SQ): (i) What is the role of Alfvén waves in exciting auroral arcs and forms as compared with monoenergetic particle influx producing auroral emission? and (ii) what is the exospheric density variability in the polar atmosphere over various time scales between minutes and days? To investigate the first SQ, the proposers plan to combine SWIR observations with other instruments as outlined in the first paragraph, while the second SQ will be explored through the observations of metastable He emissions at 1083 nm, which possibly acts as a tracer of exospheric density. Addressing Alfvén precipitation will contribute to (a) thermospheric responses that impact atmospheric drag calculations and (b) enhance magnetosphere-ionosphere interactions. Observations of exospheric metastable He 1083 nm brightness and its comparison with TIEGCM would provide new insights into exospheric dynamics and total atmospheric density variations relevant to Low Earth Orbit (LEO) atmospheric drag and how it responds to changes in geomagnetic activity and solar flux, hence benefitting space weather research. The proposal will involve several undergraduate/graduate students and will provide support to an early career researcher.<br/><br/>This award has been made possible through co-funding from the GEO directorate reserve funds to broaden participation of EPSCoR and ERI institutions.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
