Abstract An interplanetary shock triggered a substorm with a peak intensity SML = −1,781 nT on 24 September 1998. This is called a shock‐substorm here to differentiate it from generic substorms. The shock, with a speed of ∼790 km s−1, caused the release of prestored magnetosphere/magnetotail energy plus additional solar wind input energy, the latter unusual for a shock‐nonsupersubstorm event. The internal magnetospheric shock/wave had a speed of ∼630 km s−1, consistent with arriving at x = −6 RE at the time of substorm onset. The internal shock arrival to x = −10 RE would have been after the substorm onset time, so magnetic reconnection for the substorm triggering can be ruled out. Akasofu (2023, https://doi.org/10.1093/mnras/stac3187) has stated that there are many different types of substorm onsets. We believe that this shock‐substorm is different than generic substorms.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year