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The McIntosh Archive consists of four solar cycles (SC20–23) of synoptic maps of solar features (magnetic polarities, coronal holes, filaments, sunspots, plage) that were produced by Patrick McIntosh and his cartographers. In this paper we present the full Archive for the first time and find a hemispheric pattern of coronal hole polarity reflecting the Hale sunspot polarity pattern. In addition, we present a supplemental set of related maps created for the 2019–2020 solar minimum in support of the Whole Heliosphere and Planetary Interactions (WHPI) interval. To facilitate this addition, we cross calibrate EUV and He‐I 10,830 Å coronal holes and study differences between the WHPI solar minimum and the earlier minima in the main Archive. We find, first, that the visibility of coronal holes in EUV introduces a bias toward larger counts of low‐latitude coronal holes near solar minimum. However, the estimated lifetimes (in Carrington Rotations) of coronal hole complexes are unaffected by this fragmentation, and we find the longest‐lived low‐latitude coronal holes occurred during the 2008–2009 solar minimum, with 2019–2020 solar minimum lifetimes not far behind. In this way, we consider the large‐scale organization of solar magnetic fields between solar minima and study each solar minimum in the context of its solar cycle. Key Points: The McIntosh Archive of solar synoptic maps enables long‐term analysis of multiple solar cyclesBy cross calibrating coronal hole observations across wavelengths we extend the archive to the most recent solar minimumWe compare the past four minima and find the 2008–2009 interval had the longest‐lived low‐latitude coronal holes [ABSTRACT FROM AUTHOR]

The Whole Heliosphere and Planetary Interactions initiative was established to leverage relatively quiet intervals during solar minimum to better understand the interconnectedness of the various domains in the heliosphere. This study provides an expansive mosaic of observations spanning from the Sun, through interplanetary space, to the magnetospheric response and subsequent effects on the ionosphere‐thermosphere‐mesosphere (ITM) system. To accomplish this, a diverse set of observational datasets are utilized from 2019 July 26 to October 16 (i.e., over three Carrington rotations, CR2220, CR2221, and CR2222) with connections of these observations to the more focused studies submitted to this special issue. Particularly, this study focuses on two long‐lived coronal holes and their varying impact in sculpting the heliosphere and driving of the magnetospheric system. As a result, the evolution of coronal holes, impacts on the inner heliosphere solar wind, glimpses at mesoscale solar wind variability, magnetospheric response to these evolving solar wind drivers, and resulting ITM phenomena are captured to reveal the interconnectedness of this system‐of‐systems. Plain Language Summary: The field of Heliophysics research spans a large range of plasma regimes and disciplines that are all linked through the complex interactions each system has with one another. To better explore the interconnected nature of the heliosphere, this study combines observations from across the sub‐domains of Heliophysics to construct snapshots of the Sun, solar wind, and the magnetospheric and ionospheric systems at Earth over three revolutions of the Sun. This allows for a unique vantage point to put these systems in perspective of one another and understand how they impact one another. Key Points: The evolution and impacts of two coronal holes are investigated over three Carrington rotationsThe evolution of the coronal hole led to changes in the solar wind throughout the inner solar systemSubsequent geospace response differed with each passage due to both changes in the solar wind and preconditioning within the systems [ABSTRACT FROM AUTHOR]

The Whole Heliosphere and Planetary Interactions (WHPI) is an international initiative to study the most recent solar minimum and its impact on the interconnected solar‐heliospheric‐planetary system by facilitating and encouraging interdisciplinary activities. Particular WHPI science foci include the global connected structure of the heliosphere and planetary space environments/atmospheres, the origins and impacts of high‐speed solar wind streams, coronal mass ejections from Sun‐to‐Heliopause, and comparative solar minima. This is achieved through a series of coordinated observing campaigns, including Parker Solar Probe perihelia, and scientific virtual interactions including a dedicated workshop where observers and modelers gathered to discuss, compare, and combine research results. This introduction sets the scene for the WHPI interval, placing it into the context of prior initiatives and describing the overall evolution of the system between 2018 and 2020. Along with the accompanying articles, it presents a selection of key scientific results on the interconnected solar‐heliospheric‐planetary system at solar minimum. Key Points: The Whole Heliosphere and Planetary Interactions initiative studies the solar‐heliospheric‐planetary system's response to solar minimumSolar minimum time periods provide an opportunity to characterize the baseline system and to trace events from "end to end"By comparing solar minima of multiple solar cycles, we gain insight into how the system changes over decadal times scales [ABSTRACT FROM AUTHOR]

We evaluate energetic electron scattering in pitch angle and energy using realistic magnetic field and density models due to whistler mode chorus waves in Jupiter's magnetosphere and study their dependences on various wave and background parameters. We calculate the bounce‐averaged diffusion coefficients by considering the latitudinal variation of total electron density and ambient magnetic field intensity, using the VIP4 internal magnetic field and CAN current sheet model. The electron phase space density evolution due to chorus waves is simulated at M shell of 10, using the central wave frequency at 0.1fce and wave amplitude of 30 pT. Under the typical values of the ratio between the plasma frequency and electron cyclotron frequency, chorus waves could cause fast pitch angle scattering loss of energetic electrons from tens to several hundred keV in several hours, and gradual acceleration of relativistic electrons at several MeV in several days. The electron pitch angle scattering at ~500 keV and the acceleration at several MeV are both enhanced using the latitudinally varying density and VIP4 + CAN magnetic field model compared to the electron evolution using the constant density and dipole magnetic field model. Our sensitivity study indicates that the electron scattering at higher energy is caused by waves at lower frequencies or in a lower‐density background plasma, and the scattering is faster for waves at smaller wave normal angles. The electron diffusion is mainly caused by waves at lower latitudes, but the waves at higher latitudes (>30°) contribute to the electron loss at higher energies (>2 MeV). Plain Language Summary: Whistler mode chorus waves are capable of causing the flux decay of energetic electrons and acceleration of relativistic electrons in Jupiter's magnetosphere. We evaluate the efficiency of the electron flux decay and acceleration due to chorus waves using more realistic magnetic field and total electron density profiles. The decay of energetic electrons and the acceleration of relativistic electrons are both more significant in our simulation than the results using the constant density and dipolar magnetic field model. The chorus waves at higher wave frequency or in a lower density condition can cause the electron flux acceleration at higher energies, and the waves at lower frequency or in a lower density condition can cause the flux decay at higher energies. The waves propagating closer to the magnetic field line lead to the more efficient electron precipitation than the waves propagating at larger angles with respect to the field line. Although most of the electron flux decay and precipitation into Jupiter's atmosphere is caused by the waves at low latitudes, the waves at higher latitudes can affect the electrons at higher energies than the waves at lower latitudes. Key Points: We calculate the bounce‐averaged diffusion coefficients using realistic magnetic field and density modelsThe scattering at 100 s keV and acceleration at several MeV are enhanced using a realistic magnetic field and density modelsChorus waves at high latitudes can cause relativistic electron precipitation, which can potentially be confirmed by Juno observations [ABSTRACT FROM AUTHOR]

The poleward boundary intensification (PBI) is a common appearance at the poleward boundary of the auroral bulge and auroral oval. The PBI presented here occurred during the expansion phase of a small substorm with an auroral surge power of 6.5 GW. The auroral power of the PBI (1.1 GW) was ~17% of this value. The largest powers above the nominal auroral acceleration region at 5 RE geocentric were carried by Alfvén waves (1.7 GW) and Alfvénic electrons (0.7 GW), sufficient to account for the conjugate PBI auroral power. In contrast, the conjugate quasistatic, field‐aligned current power (<0.3 GW) was not sufficient. Observed correlation between quasiperiodic Alfvénic pulses and auroral modulations strengthens our conclusion that the electromagnetic magnetosphere‐ionosphere coupling of the PBI was dominantly Alfvénic, as opposed to electrostatic, thus causing Alfvénic aurora. Key Points: Quasiperiodic magnetotail Alfvén wave pulses drive correlated PBI luminosity modulationsMagnetosphere‐ionosphere coupling of PBI is dominantly Alfvénic, as opposed to electrostaticPBI power estimates are compared with streamer power estimates [ABSTRACT FROM AUTHOR]

Here we compare the global‐scale morphology of Earth's the Far‐Ultraviolet (FUV) emissions observed by NASA's Global‐scale Observations of Limb and Disk (GOLD) mission to those modeled using the Global Airglow (GLOW) code with atmospheric parameters provided by Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM). The O 5S oxygen (135.6 nm) and N2 Lyman‐Birge‐Hopfield (LBH) emissions are observed over the Western hemisphere every 30 min by the GOLD instrument. The FUV brightness of the thermosphere‐ionosphere is expected to vary in systemic ways with respect to geophysical parameters, solar energy input from above, and terrestrial weather input from below. In this paper we examine the O 5S oxygen emission and the N2 LBH emission brightnesses with local time, latitude, season, tides, geomagnetic activity, and solar activity based on GOLD observations and GLOW modeling. Early GOLD observations indicate that the model effectively reproduces the brightness variations with local time and latitude but is biased low in magnitude. However, the TIEGCM is unable to accurately represent the extraordinary nighttime equatorial ionization anomaly observed by GOLD. It is also expected from these results that the signal from geomagnetic storms may obscure tidal signals. Plain Language Summary: In January 2018, a FUV instrument, the Global‐scale Observations of Limb and Disk (GOLD), was launched as a NASA mission of opportunity aboard a geostationary satellite and scientific operations began in October of 2018. GOLD views the entire disk of the Earth every 30 min, allowing the separation of geophysical variability in both space and time. This allows an unprecedented test of global models. Here, we model the Earth's upper atmosphere using the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM), which produces temperature and the densities of the major chemical components of the neutral atmosphere, ionized plasma densities, and neutral air temperatures. These atmospheric temperatures and densities are used to calculate the Earth's upper atmosphere emissions in the Far‐Ultraviolet (FUV) with the Global Airglow (GLOW) model. The calculated emission rates are then used to compute the expected FUV signals as observed from geostationary orbit. In this paper, we show how the FUV brightness varies with local time, season, atmospheric activity, and solar activity. Of particular interest is that the GLOW model excels at producing FUV brightnesses that match the local time and latitude trends of the daytime observations; however, the model fails to adequately portray the extraordinary nighttime phenomena observed by GOLD. Key Points: The Global‐scale Observations of Limb and Disk (GOLD) instrument observes the Earth in the Far‐Ultraviolet (FUV) from a geostationary orbitGLOW adequately calculates the FUV brightness for various local times, latitudes, solar forcing, and lower atmospheric forcingGLOW calculations indicate the oxygen brightness varies by ±45 R and the effective temperature varies by more than 80 K due to tides [ABSTRACT FROM AUTHOR]

Two sequences of five high‐speed solar wind stream/corotating interaction region (HSS/CIR) events were observed at 1 AU in December 2007–2008. These two HSS/CIR sequences had opposite magnetic polarities, and they originated from two persistent low‐latitude coronal holes with corresponding polarities. Each HSS/CIR event triggered a geomagnetic storm and strong high‐latitude activity. We follow the evolution of the properties and geomagnetic effects of the two sequences and find that the sequence with negative interplanetary magnetic field polarity (toward sector) develops systematically a more negative Bz(GSM) component and becomes relatively more geoeffective when moving from winter solstice in 2007 to spring equinox in 2008. On the other hand, the sequence with positive polarity (away sector) develops systematically a less negative Bz(GSM) component and becomes relatively less geoeffective. These changes allow the first detailed monitoring of the turning on of the Russell‐McPherron effect when moving from solstice to equinox and the development of the related changes in high‐latitude geomagnetic activity and geomagnetic storms. Key Points: We study two sequences of stable high‐speed streams with opposite polarities in 2007–2008, locate their sources and follow their effectsIMF Bz(GSM)‐Bz(GSE) difference decreases (increases) systematically in the negative (positive) polarity sequence from solstice to equinoxWe quantify the effect of this turning on of the Russell‐McPherron mechanism to high‐latitude geomagnetic activity and geomagnetic storms [ABSTRACT FROM AUTHOR]

Previous evidence has suggested that either lower band chorus waves or kinetic Alfven waves scatter equatorial kilovolt electrons that propagate to lower altitudes where they precipitate or undergo further low-altitude scattering to make pulsating auroras. Recently, time domain structures (TDSs) were shown, both theoretically and experimentally, to efficiently scatter equatorial electrons. To assess the relative importance of these three mechanisms for production of pulsating auroras, 11 intervals of equatorial THEMIS data and a 4 h interval of Van Allen Probe measurements have been analyzed. During these events, lower band chorus waves produced only negligible modifications of the equatorial electron distributions. During the several TDS events, the equatorial 0.1-3 keV electrons became magnetic field-aligned. Kinetic Alfven waves may also have had a small electron scattering effect. The conclusion of these studies is that time domain structures caused the most important equatorial scattering of ~1 keV electrons toward the loss cone to provide the main electron contribution to pulsating auroras. Chorus wave scattering may have provided part of the highest energy (>10 keV) electrons in such auroras. [ABSTRACT FROM AUTHOR]