STCE Seminar: the impact of multiple eruptions from Active Region 10930 on the Broad Geospace System

Delores Knipp from the University of Colorado Boulder is visiting the STCE and will give a seminar on:

Title: The Impact of Multiple Eruptions from Active Region 10930 on the Broad Geospace System


Late in solar cycle 23, on 5 December 2006, complex Active Region (AR) 10930 appeared on the Sun's east limb with virtually no warning. Over the next 10 days it erupted multiple times, producing more than 100 flares at or above B-class, with four at X-class level. One of the early flares permanently damaged a GOES X-ray Imager. Solar indices rose to a 15-month high. The interval was further punctuated with solar energetic particle (SEP) levels that achieved at least NOAA S1 level for 10 days in a row. Intense flares and SEPs during the first part of the interval hampered dayside and polar communications. Extraordinary radio bursts hampered GPS navigation.  By the time the AR arrived at central meridian, it was classified as a β-γ-δ magnetic region. On 10 December Space Shuttle Discovery launched to the International Space Station (ISS) for a replenish, repair and reconfigure mission. Extravehicular activities (EVAs) were planned to reconfigure the ISS power supply. Sequential solar eruptions on 13 and 14 December produced compounding events. The first produced a SEP burst associated with ground level event #70. Numerous space missions and Earth’s atmosphere were affected. This event registered inside the ISS, with light-ion counts at least 10 times background. Just under two days later a ‘perfect-storm’ scenario developed as the fast coronal mass ejection from the 13 December eruption reached Earth while SEPs from the next eruption arrived in tandem during an EVA. Compounding circumstances and influences caused the ISS to lose ~0.5 km of altitude in about eight hours. Much of the altitude loss was recovered by boosting the ISS with Shuttle Discovery thrusters. This anomaly developed while the STS-116 crew was assisting with one of the most ambitious construction projects of the entire ISS mission. I will discuss the combination of factors that fed into the ISS altitude loss, including a long interval of geomagnetic pre-conditioning.

Where: Nicolet room at BIRA-IASB and on Teams:

When: Thursday May 4


Thursday, May 4, 2023 - 14:00 to 15:00

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