First results from the Penn State Allsky Imager at the Arecibo Observatory

Abstract

The Penn State Allsky imager (PSASI), a user-owned-public-access (UOPA) instrument installed at Arecibo Observatory (AO: 18.3 • N, 66.75 • W; altitude: 350 m a.s.l.; L = 1.43 at 300 km; dip angle: 46• ; geomagnetic coordinates: 29• N, 5.5• E), is a CCD-based high-resolution allsky optical imager that has been collecting ionospheric airglow data at night since May 2003. The computer controlled six-position filter wheel is equipped with three filters at 630 nm (red), 557.7 nm (green), and 777.4 nm (near-IR), respectively, which correspond to ionosphere-related oxygen emissions. The imager data, taken for more than 3.5 years now, is being used to study various ionospheric processes, such as mapped equatorial spread-F plumes, E-region gravity waves, among other, in conjunction with the AO incoherent scatter radar (ISR), mesosphere and lower thermosphere (MLT) metals lidar, and other instruments, including microbarographs. Data availability and quality as well as specific airglow events on both small/large time/spatial scales are examined, categorized, and made freely available at a data-server website. Our goal here is to briefly review the airglow science enabled by allsky imaging at AO, to describe the instrument and the data-collection methodology, and to present some of the significant results, including airglow events that correspond to ISR results.

Tracking F-region plasma depletion bands using GPS-TEC, incoherent scatter radar, and all-sky imaging at Arecibo

“…From that and the correlation between Kp and plumes/depletion bands observed by PSASI (e.g. in Seker et al, 2007), it could be inferred that as the geomagnetic activity becomes more disturbed, it becomes more likely to observe equatorial plumes reaching AO latitudes instead of these MSTID bands. More studies on this need to be done in order to understand the dynamics of these phenomena.…”

“…Recent imaging studies have revealed that the mid-latitude F-region is also active with plasma depletion bands (or so called slabs, MSTIDs), equatorial plumes, the midnight temperature maximum, spread-F, etc. (Mendillo et al, 1997;Garcia et al, 2000;Kelley et al, 2000bKelley et al, , 2002Kelley et al, , 2004Shiokawa et al, 2003a, b;Otsuka et al, 2003;Seker et al, 2007). The use of imager and radar together has been the subject of several recent papers: Pi et al (2000) (imager, ISR, FPI), Kelley et al (2000a) (imager, ISR), Kelley et al (2002) (imager, ISR, GPS), Otsuka et al (2003) (imager, MU radar, FPI).…”

“…The all-sky imager data for more than three years is available online (allsky.ee.psu.edu) and is being used to study various ionospheric phenomena. More details on PSASI and all-sky imaging in general are available in Seker et al (2007).…”

Relation between magnetospheric state parameters and the occurrence of plasma depletion events in the nighttime midlatitudeFregion

“…Finally, and perhaps most importantly, it has been tentatively found that, at midlatitudes, the MSTIDs usually occur during geomagnetically quiet times [Saito et al, 2002;Shiokawa et al, 2003;Kotake et al, 2006;Tsugawa et al, 2007a;Candido et al, 2008;He and Ping, 2008;Seker et al, 2008] whereas the plumes usually occur at midlatitudes when the geomagnetic activity is high [Garcia et al, 2000;Sahai et al, 2000;Seker et al, 2007].…”

Dependence of mesospheric Na and Fe distributions on electron density at Arecibo

“…Since atomic oxygen is one of the major sources of ions and electrons in the lower E-region of the ionosphere, this emission can be used to monitor both neutral phenomena (such as gravity waves) and electrodynamics near this altitude. More details on PSASI, airglow, and ionospheric phenomena revealed by it can be found in Seker et al (2007).…”