C23

Presentation Title:	How Do We Know When to Launch? Statistical Basis for Sounding Rocket Flare Triggers
Author(s):	Marianne Peterson, Juliana Vievering, Kristopher Cooper, Paolo Massa, Juan Camilo Buitrago-Casas, Philip Chamberlin, Gordon Emslie, Lindsay Glesener, Vicki Herde, Säm Krucker, Ryan O Milligan, Ndiefreke Okon Nyah, Subramania Athiray Panchapakesan, Athanasios Pantazides, Katharine Reeves, Orlando Romeo, Yoshiaki Sato, Sabrina Savage, Genevieve Vigil, Robert Walsh, Amy Winebarger, Yixian Zhang

Abstract:

In April 2024, the Focusing Optics X-Ray Solar Imager (FOXSI)-4 and the High Resolution Coronal Imager Flare Mission (Hi-C Flare) sounding rockets took part in NASA’s first solar flare sounding rocket campaign. The two instruments performed a triggered launch, each having a 4-hour window daily over a two week period to trigger their launches, with the goal of observing the same large solar flare. However, the novel solar flare campaign was met with immediate challenges of performing a triggered launch–how will a solar flare of large magnitude be confidently predicted from its earliest signatures?

We developed an early-onset flare trigger system, based on a statistical study of historical GOES X-ray Sensor (XRS) data, in order to provide actionable realtime trigger values for upcoming flares with a low false-alarm rate. Both long- and short-wavelength GOES XRS flux channels are utilized for such triggers, with parameters of interest including their flux levels and derivatives, as well as temperature and emission measure. Specific combinations of such parameters were tested as triggers and refined on historical data, as well as in trials which simulated the two week launch campaign. We then integrated finalized triggers into an operational tool alongside context GOES XRS and EVE Extreme Ultraviolet Spectrophotometer (ESP) data, which was utilized during the flare campaign. We present results from the historical flare trigger analysis, as well as its successful implementation in the April 2024 launch campaign.

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