A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions

Chisham, G.; Lester, M.; Milan, S. E.; Freeman, M. P.; Bristow, W. A.; Grocott, Adrian; McWilliams, K. A.; Ruohoniemi, J. M.; Yeoman, T. K.; Dyson, P. L.; Greenwald, R. A.; Kikuchi, Takashi; Pinnock, M.; Rash, J. P. S.; Sato, Natsuo; Sofko, G. J.; Villain, J. P.; Walker, A. D. M.

doi:10.1007/s10712-007-9017-8

Cited by 651 publications

(711 citation statements)

References 330 publications

(378 reference statements)

Supporting

Mentioning

679

Contrasting

Unclassified

Order By: Relevance

“…The SuperDARN network of HF radars provides almost continuous measurements of ionospheric convection velocities in the auroral regions of the Northern and Southern Hemispheres (Greenwald et al, 1995;Chisham et al, 2007) and this facilitates the routine production of large scale maps of the high-latitude convection using the "Map Potential" technique (Ruohoniemi and Baker, 1998). This technique involves the mapping of line-of-sight radar velocity measurements onto an equal area polar grid and using them to derive a best-fit solution to an nth-order expansion of the electrostatic potential, expressed in spherical harmonics.…”

Section: Discussionmentioning

confidence: 99%

Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

et al. 2009

Self Cite

View full text Add to dashboard Cite

Abstract. Using data from the Super Dual Auroral Radar Network (SuperDARN) we investigate the ionospheric convection response to magnetospheric substorms. Substorms were identified using the Far Ultraviolet (FUV) instrument on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft, and were then binned according to the magnetic latitude of their onset. A superposed epoch analysis of the ionospheric convection patterns for each onset-latitude bin was then performed using radar data for the interval 60 min before onset to 90 min after. It is found that lower onset-latitude substorms are associated with generally more enhanced convection than the higher latitude substorms, although they suffer from a significant localised reduction of the flow in the midnight sector during the expansion phase. Higher-latitude substorms are associated with a significant and rapid increase in the nightside convection following substorm onset, with all onset-latitude bins showing an enhancement over onset values by ∼60 min into the expansion phase. A rudimentary inspection of the concurrent auroral evolution suggests that the duration of the flow reduction following substorm onset is dependent on the strength and duration of the expansion phase aurora and its associated conductivity enhancement.

show abstract

Section: Discussionmentioning

confidence: 99%

Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this study we make use of structure function analysis to investigate the structure of ionospheric convection measured by the Halley SuperDARN radar (Greenwald et al, 1995;Chisham et al, 2007). Compared to Fourier and many other analysis techniques that require regularly sampled data, structure function analysis can be applied to data that are patchy in time and space, which makes it suitable for analysing SuperDARN data that have many data gaps.…”

Section: Methodsmentioning

confidence: 99%

Investigating turbulent structure of ionospheric plasma velocity using the Halley SuperDARN radar

Abel

Freeman

Chisham

et al. 2007

Nonlin. Processes Geophys.

Self Cite

View full text Add to dashboard Cite

Abstract. We present a detailed analysis of the spatial structure of the ionospheric plasma velocity in the nightside Fregion ionosphere, poleward of the open-closed magnetic field line boundary (OCB), i.e. in regions magnetically connected to the turbulent solar wind. We make use of spatially distributed measurements of the ionospheric plasma velocity made with the Halley Super Dual Auroral Radar Network (SuperDARN) radar between 1996 and 2003. We analyze the spatial structure of the plasma velocity using structure functions and P (0) scaling (where P (0) is the value of the probability density function at 0), which provide simple methods for deriving information about the scaling, intermittency and multi-fractal nature of the fluctuations. The structure functions can also be compared to values predicted by different turbulence models. We find that the limited range of velocity that can be measured by the Halley SuperDARN radar restricts our ability to calculate structure functions. We correct for this by using conditioning (removing velocity fluctuations with magnitudes larger than 3 standard deviations from our calculations). The resultant structure functions suggest that Kraichnan-Iroshnikov versions of P and log-normal models of turbulence best describe the velocity structure seen in the ionosphere.

show abstract

“…The Super Dual Auroral Radar Network (SuperDARN) is an international collaboration operating highfrequency coherent radars in both the Northern and Southern Hemispheres [Greenwald et al, 1995;Chisham et al, 2007]. They enable imaging the large-scale ionospheric convection and thus electric fields with high temporal resolution (about 1 or 2 min).…”

Section: Superdarnmentioning

confidence: 99%

On the generation/decay of the storm‐enhanced density plumes: Role of the convection flow and field‐aligned ion flow

et al. 2014

View full text Add to dashboard Cite

Storm-enhanced density (SED) plumes are prominent ionospheric electron density increases at the dayside middle and high latitudes. The generation and decay mechanisms of the plumes are still not clear. We present observations of SED plumes during six storms between 2010 and 2013 and comprehensively analyze the associated ionospheric parameters within the plumes, including vertical ion flow, field-aligned ion flow and flux, plasma temperature, and field-aligned currents, obtained from multiple instruments, including GPS total electron content (TEC), Poker Flat Incoherent Scatter Radar (PFISR), Super Dual Auroral Radar Network, and Active Magnetosphere and Planetary Electrodynamics Response Experiment. The TEC increase within the SED plumes at the PFISR site can be 1.4-5.5 times their quiet time value. The plumes are usually associated with northwestward E × B flows ranging from a couple of hundred m s À1 to > 1 km s À1. Upward vertical flows due to the projection of these E × B drifts are mainly responsible for lifting the plasma in sunlit regions to higher altitude and thus leading to plume density enhancement. The upward vertical flows near the poleward part of the plumes are more persistent, while those near the equatorward part are more patchy. In addition, the plumes can be collocated with either upward or downward field-aligned currents (FACs) but are usually observed equatorward of the peak of the Region 1 upward FAC, suggesting that the northwestward flows collocated with plumes can be either subauroral or auroral flows. Furthermore, during the decay phase of the plume, large downward ion flows, as large as~200 m s À1, and downward fluxes, as large as 10 14 m À2 s À1, are often observed within the plumes. In our study of six storms, enhanced ambipolar diffusion due to an elevated pressure gradient is able to explain two of the four large downward flow/flux cases, but this mechanism is not sufficient for the other two cases where the flows are of larger magnitude. For the latter two cases, enhanced poleward thermospheric wind is suggested to be another mechanism for pushing the plasma downward along the field line. These downward flows should be an important mechanism for the decay of the SED plumes. IntroductionDuring enhanced geomagnetic activity periods, in particular storms, significant electron density enhancements are often observed in the midlatitude and subauroral region, which are named storm-enhanced densities (SEDs) [Foster, 1993]. Often, SEDs extend northwestward to higher latitudes and form a plume. This plume can occasionally be entrained into the cusp region and then enter the polar cap, where it is termed the tongueof-ionization (TOI) or, if it is not continuous, a polar cap patch, depending on the shape and spatial coverage of the high-density region there [e.g., Foster et al., 2005;Moen et al., 2013]. The SED plume is suggested to be the ionospheric projection of a plasmaspheric plume in the magnetospheric equatorial plane . Within the magnetosphere, plasmaspheric plumes can play...

show abstract

A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions

Cited by 651 publications

References 330 publications

Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

Investigating turbulent structure of ionospheric plasma velocity using the Halley SuperDARN radar

On the generation/decay of the storm‐enhanced density plumes: Role of the convection flow and field‐aligned ion flow

Contact Info

Product

Resources

About