IpsDst of Dst Storms Applied to Ionosphere‐Thermosphere Storms and Low‐Latitude Aurora

Abstract

Conventionally, the minimum value of Dst (DstMin) and maximum values of Kp and AE (Kp max and AE max ) representing the geomagnetic storm intensities have been used for investigating space weather in Earth's environment. The present paper uses the derived parameters (IpsDst, IpsKp, and IpsAE) giving the mean values of Dst, Kp, and AE during the main phase (MP) of Dst storms for investigating ionosphere-thermosphere storms and low-latitude (630 nm) aurora. The derived parameters (IpsDst, IpsKp, and IpsAE) representing the impulsive strength of geomagnetic storms seem to have more systematic dependence among themselves than among the intensities (DstMin, Kp max , and AE max ). The ionosphere-thermosphere storms observed by the CHAMP (Challenging Minisatellite Payload) satellite and low-latitude auroras observed by optical imagers are much more intense during high impulsive storms than high intensity storms. In a statistical sense, over 175 positive ionospheric storms (△NmF2) observed in 1985-2005 and the intensity of 20 red auroras observed in 1989-2004 at midlatitudes correlate better with the impulsive parameters than the intensity parameters, with the best correlation being with IpsDst. The mechanism of the impulsive action (high-energy input over a short duration) leading to large IpsDst arises from the impact of fast solar storms (interplanetary coronal mass ejections) with large IMF Bz southward at their front (or shock). The impulsive action results in bright low-latitude auroras and strong ionosphere-thermosphere storms.

Diurnal UT Variation of Low Latitude Geomagnetic Storms Using Six Indices

“…The number of storms identified (Table 1) in SymH is 535 in 1981–2017, RC is 258 in 1997–2017, AER is 97 in 2011–2017, and Dcx is 61 in 2013–2017. The storms in Kyoto Dst have been used to develop a scheme for forecasting severe space weather causing electric power outage and telecommunication failure (Balan et al., 2014, Balan, Ebihara, et al., 2017) and investigating the corresponding ionosphere‐thermosphere storms and low latitude aurora (Balan, Zhang, Shiokawa, et al., 2019).…”

Association of the Main Phase of the Geomagnetic Storms in Solar Cycles 23 and 24 With Corresponding Solar Wind‐IMF Parameters

“…The impulsive strength IpsDst in Dst is obtained as IpsDst = −(1/ T MP )ΣꞁDst MP ꞁ where ΣꞁDst MP ꞁ is the sum of the modulus of Dst from MPO to DstMin and T MP = ( N −1). The IpsDst giving the mean value of Dst during MP was used before for identifying severe space weather (SvSW) that caused utility system damages from normal space weather that did not cause such severe effects (Balan, Zhang, Xing, et al., 2019) and for ionosphere‐thermosphere studies (Balan, Zhang, Shiokawa, et al., 2019). Following the definition of IpsDst, the impulsive strengths in SymH, Kp, and AE are obtained as IpsSymH = −(1/ N TMP )Σ|SymH MP ꞁ, IpsKp = (1/N TMP )ΣKp MP , and IpsAE = (1/ N TMP )ΣAE MP .…”

Recent ionospheric investigations in China (2018–2019)

“…Balan et al (2019) investigated ionosphere–thermosphere storms and low‐latitude (630 nm) aurora by using several derived parameters (Ips Dst , Ips Kp , and Ips AE ). The derived parameters representing the impulsive strength of geomagnetic storms seem to have more systematic dependence among themselves than among the intensities ( Dst min , Kp max , and AE max ).…”