Deciphering Solar Magnetic Activity: On Grand Minima in Solar Activity

The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not well understood. There has been tremendous progress in the century since the discovery of solar magnetism - magnetism that ultimately drives the electromagnetic, particulate and eruptive forcing of our planetary system. There is contemporary evidence of a decrease in solar magnetism, perhaps even indicators of a significant downward trend, over recent decades. Are we entering a minimum in solar activity that is deeper and longer than a typical solar minimum, a "grand minimum"? How could we tell if we are? What is a grand minimum and how does the Sun recover? These are very pertinent questions for modern civilization. In this paper we present a hypothetical demonstration of entry and exit from grand minimum conditions based on a recent analysis of solar features over the past 20 years and their possible connection to the origins of the 11(-ish) year solar activity cycle.Comment: 9 pages - submitted to Frontiers in Solar and Stellar Physic

The triple-dip La Niña of 2020–22: updates to the correlation of ENSO with the termination of solar cycles

The Sun provides the energy required to sustain life on Earth and drive our planet’s atmosphere. However, establishing a solid physical connection between solar and tropospheric variability has posed a considerable challenge across the spectrum of Earth-system science. Over the past few years a new picture to describe solar variability has developed, based on observing, understanding and tracing the progression, interaction and intrinsic variability of the magnetized activity bands that belong to the Sun’s 22-year magnetic activity cycle. A solar cycle’s fiducial clock does not run from the canonical min or max, instead resetting when all old cycle polarity magnetic flux is cancelled at the equator, an event dubbed the “termination” of that solar cycle, or terminator. In a recent paper, we demonstrated with high statistical significance, a correlation between the occurrence of termination of the last five solar cycles and the transition from El Niño to La Niña in the Pacific Ocean, and predicted that there would be a transition to La Niña in mid 2020. La Niña did indeed begin in mid-2020, and endured into 2023 as a rare “triple dip” event, but some of the solar predictions made did not occur until late 2021. This work examines what went right, what went wrong, the correlations between El Niño, La Niña and geomagnetic activity indices, and what might be expected for the general trends of large-scale global climate in the next decade

The Heliospheric Meteorology Mission: A Mission to DRIVE our Understanding of Heliospheric Variability

To make transformational scientific progress with the space weather enterprise the Sun, Earth, and heliosphere must be studied as a coupled system, comprehensively. Rapid advances were made in the study, and forecasting, of terrestrial meteorology half a century ago that accompanied the dawn of earth observing satellites. Those assets provided a global perspective on the Earth's weather systems and the ability to look ahead of the observer's local time and to. From a heliospheric, or space, weather perspective we have the same fundamental limitation as the terrestrial meteorologists had—by far the majority of our observing assets are tied to the Sun-Earth line—our planet's “local time” with respect to the Sun. This perspective intrinsically limits our ability to “see what is coming around the solar limb” far less to gain any insight into the global patterns of solar weather and how they guide weather throughout the heliosphere. We propose a mission concept—the Heliospheric Meteorology Mission (HMM)—to sample the complete magnetic and thermodynamic state of the heliosphere inside 1AU using a distributed network of deep space hardened smallsats that encompass the Sun. The observations and in situ plasma measurements made by the fleet of HMM smallsats would be collected, and assimilated into current operational space weather models. Further, the HMM measurements would also being used in an nationally coordinated research effort—at the frontier of understanding the coupled heliospheric system—as a means to develop the next generation models required to provide seamless prediction for the geospace environment to protect vital infrastructure and human/robotic explorers throughout the solar system. The HMM mission concept naturally allows for research-motivated technology development that can improve forecast skill

Deciphering Solar Magnetic Activity: The (Solar) Hale Cycle Terminator of 2021

McIntosh and colleagues identified an event in the solar timeline that appeared to play a role in how Sunspot Cycle 23 (SC23) transitioned into Sunspot Cycle 24 (SC24). The timeframe for this transition was rapid, taking place in as short as time as a solar rotation. M2014 inferred that the transition observed was a critical episode for the Sun's global-scale magnetic field that was being manifest in the spatially and temporally overlapping and magnetic systems belonging to the Sun's 22-year (Hale) magnetic cycle. These events have been dubbed as Hale Cycle terminations, or `terminators' for short. Further exploration revealed a relationship between terminator separation (as a measure of overlap in the Hale Cycles) and the upcoming sunspot cycle amplitude. McIntosh and colleagues extrapolated upon this relationship to identify the termination of the SC24 carrying Hale Cycle band in Mid-2020 and inferred that this would result in a very large Sunspot Cycle 25 (SC25). This paper presents observational analysis of the end of SC24 and the initial months of SC25 growth following a terminator that occurred in mid-December 2021 (approximately 12/13/2021). We use the December 2021 terminator to finalize the forecast of SC25 amplitude 184 ($\pm$17 with 95\% confidence, and $\pm$63 with 68\% confidence). Finally, we use other terminator-related superposed epoch analyses to project the timing of SC25 maxima in late 2023 to mid 2024.Comment: 16 pages, 10 figures - Submitted to Frontier