RENU2 UV PMT Observations of the Cusp

Fritz, B.; Lessard, M.; Dymond, K. F.; Kenward, D. R.; Lynch, K. A.; Hecht, J. H.; Clemmons, J. H.; Cook, Timothy A.; Chakrabarti, Supriya; Solomon, Stanley C.

doi:10.1029/2019gl082314

Cited by 3 publications

(3 citation statements)

References 27 publications

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“…Measurements of the neutral thermosphere were obtained by RENU2 in situ with the Ion Gauge instrument and show no significant deviation from the MSIS densities during the flight, although these authors do show the presence of strong neutral winds. Using an ultraviolet photometer (UV PMT) to observe atomic oxygen signatures in sunlight (i.e., above the payload), Fritz et al (2019) uses the PMT/GLOW comparison to demonstrate how precipitation‐driven emissions in the cusp may be used to infer structural variation in the neutral background.…”

Section: Results Overviewmentioning

confidence: 99%

“…To summarize, the UV PMT instrument observed a density enhancement above the payload beginning near 380‐km altitude on the downleg, perhaps providing a measure of horizontal structure based on the sharp dropoff at the highest latitudes (Fritz et al, 2019). On the other hand, the IG instrument provided in situ measurements of the background density and found no significant deviation from the background values (though it may well be the case that a prior density enhancement had moved away from the region).…”

Section: Results Overviewmentioning

confidence: 99%

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Overview of the Rocket Experiment for Neutral Upwelling Sounding Rocket 2 (RENU2)

Lessard

Fritz

Sadler

et al. 2020

Geophysical Research Letters

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The Rocket Experiment for Neutral Upwelling 2 (RENU2) rocket was launched on 13 December 2015 at 07:34 UT. The payload transited the cusp region during a neutral upwelling event, supported by a comprehensive set of onboard and ground-based instrumentation. RENU2 data highlight two important processes. One is that a proper understanding of neutral upwelling by Poleward Moving Auroral Forms (PMAFs) requires a treatment that mimics the quasiperiodic passage of a sequence of PMAFs. As a PMAF reaches a flux tube, its physical consequences must be determined including the residual history of effects from previous passages, implying that understanding such a process requires an accounting of the system hysteresis. Second, RENU2 observations suggest that neutral density enhancements driven by precipitation and/or Joule heating can be highly structured in altitude and latitude. In addition, timescales involving neutral dynamics suggest that the structuring must be slowly changing, for example, over the course of 10 to tens of minutes. 1.1. Altitudinal Structuring Additional modeling constraints have arisen from recent observations, those that show not only density enhancements but also depletions at higher altitudes. For example, the Streak satellite observed relative density depletions near the southern cusp in the altitude range 123-325 km when averaged over all orbits

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Section: Results Overviewmentioning

confidence: 99%

Section: Results Overviewmentioning

confidence: 99%

Overview of the Rocket Experiment for Neutral Upwelling Sounding Rocket 2 (RENU2)

Lessard

Fritz

Sadler

et al. 2020

Geophysical Research Letters

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“…Solar wind control of the low‐altitude cusp has been revealed by data from satellites with lower orbit such as Defense Meteorological Satellite Program (DMSP) or rockets (e.g., Fritz & Fung, 2005; B. A. Fritz et al., 2019; Newell et al., 1989).…”

Section: Introductionmentioning

confidence: 99%

Tangent Directions of the Cusp Boundary Derived From the Simulated Soft X‐Ray Image

Sun

Wang

2021

JGR Space Physics

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The polar cusps of the magnetosphere are funnel-shaped regions, with their high-altitude parts connecting directly to the magnetosheath and low-altitude parts extending down to the ionosphere (Heikkila, 1985). The cusp is narrow at the low-altitude, but encompasses a broad area to the mid-or high-altitude near local noon. Mapping along magnetic field lines, the magnetopause is directly connected to the cusp regions, and thus the physical processes on the magnetopause such as the magnetic reconnection can be by manifested by the plasma or boundary properties in the cusp (Burch, 1973; Escoubet et al., 1992). This makes the cusp a key region to study the dynamics of the solar wind-magnetosphere coupling. Spectral properties in the cusp are close to the original magnetosheath plasma (Newell & Meng, 1988), which indicates that the sheath plasma can directly enter the cusp region and further precipitate into the ionosphere. The cusp is also one of the major source regions of energetic particles (e.g., Fritz & Fung, 2005; Zong et al., 2003). Therefore, it plays an important role in plasma transport and energization. In-situ observations have provided abundant information about the localized cusp features. As the cusp region extends all the way from right above the ground to the high latitude magnetopause, the orbit of each satellite can only cover a certain portion of the cusp. Consequently, in the literature, the studies about cusp are basically divided into three parts according to the altitude: low-, mid-, and high-altitude regions. The high-altitude cusp is usually studied by analyzing data during satellite crossings such as Cluster, Polar,

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