1 Introduction
The Space Physics and Aeronomy section deals with the electrodynamics of
the Sun and different planetary atmospheres. The section describes the
interactions between solar wind, Interplanetary Magnetic Field (IMF) and
planetary magnetospheres including the Earth. Corresponding effects on
planetary ionosphere and thermosphere are also analyzed. For example,
the morphologies of the Earth’s low, mid and high latitude ionospheres
are different from each other. The low latitude or equatorial ionosphere
exhibits steep temporal and spatial electron density gradients and
seasonal variabilities (Rastogi and Klobuchar, 1990) due to the presence
of Equatorial Ionization Anomaly (EIA). High latitude ionization is
susceptible to space weather events originating from solar wind and IMF.
Study of the effects of these space weather events on Total Electron
Density (TEC) of ionosphere is crucial as TEC causes attenuations to any
transionospheric radio signals such as Global Navigation Satellite
Systems (GNSS). Intense space weather events can also affect artificial
satellites. For example, geomagnetic storm and solar flares during
October 29-31, 2003 damaged Solar and Heliospheric Observatory (SOHO)
and Advanced Composition Explorer (ACE) satellites
(www.nasa.gov/topics/solarsystem/features/halloween_storms.html).
The presence of the Earth’s ionosphere was established by Edward V.
Appleton (Appleton and Barnett, 1925; Appleton, 1946). Some of the
outstanding works related to the background physics of Earth’s
ionosphere are Rishbeth (1977), Fejer and Scherliess (1995); Rishbeth
(1997); Fejer et al. (1999) and Borovsky and Denton (2006). Reviews on
magnetospheres and upper atmospheres of other planetary bodies are
available in Brice and Ioannidis (1970), Russell (1993), Shinagawa
(2000) and Haider et al. (2011). Morphologies of solar physics are also
available in the literature (Temmer, 2006; Gopalswamy, 2007; Vidotto,
2021).
The inter-relations between the solar input parameters (solar wind, IMF,
solar activity level) and Earth’s magnetospheric-ionospheric output
parameters are very complex. Efforts have been given to design models to
describe these relations. Some of the standard models are International
Reference Ionosphere (IRI) (Rawer and Bilitza, 1989; Bilitza et al.,
2011), NeQuick (Nava et al., 2008) and Thermosphere Ionosphere
Electrodynamics General Circulation (TIEGCM) (Dickinson et al., 1981;
Richmond et al., 1992). Models are also designed at localized
latitudinal and longitudinal swaths (Sur et al., 2017).
Though the section is enriched with a lot of past research works, still
many unanswered questions remain. The nature of the interactions between
solar wind, IMF, Earth’s magnetosphere and ionosphere are not yet fully
understood during different intensities of the geomagnetic storm. The
day-to-day variabilities of low latitude TEC and the uncertainties
related to post-sunset ionospheric density irregularities are some of
the outstanding issues towards satellite-based navigation and spacecraft
control. Electrodynamics of the Sun and the other planetary
magnetosphere-ionosphere systems are yet to be fully understood and
subject to the newer space missions (Parker, Juno, etc.). The
outstanding questions in this section are challenging to address, and
progress towards answering these questions can be facilitated by greater
use of Integrated, Coordinated, Open, and Networked (ICON) principles.
Doing so can help bring the community together to collectively address
the major challenges. The main objective of ICON science is to enhance
synthesis, increase resource efficiency, and create transferable
knowledge (Goldman et al., 2021). The present article is a commentary
covering Space Physics and Aeronomy on the state and the future of ICON
science.
2.1. Integrated research in Space Physics and Aeronomy
Space Physics and Aeronomy is an excellent example of integrated
research. The section is a blend of elementary physics, chemistry and
mathematics. Some scientists work on the effects of solar wind, IMF on
the Earth’s magnetosphere. Others work on these space-weather effects on
the Auroral Electrojet (AE) and the atmospheric Joule heating. They also
observe the effects on the global neutral wind and the ionizations from
different longitudes. Study of the ionosphere also needs proper
understanding of the effects coming from the lower atmosphere. The
coupled Whole Atmosphere Model (WAM) Ionosphere Plasmasphere
Electrodynamics (IPE) model designed by NOAA CIRES and SWPC is an
example of integrated research of the effects from upper as well as
lower atmosphere to the ionosphere (Akmaev, 2011; Sun et al., 2015).
Scientists involved in working on the equatorial ionization have to
address the sharp ionospheric variabilities mainly due to EIA. The study
of ionospheric density irregularities is also a very challenging
section. Solar physics scientists analyze the morphologies of the Sun
including solar wind, solar magnetic field, Coronal Mass Ejection (CME),
sunspot cycles, etc. Other planetary magnetospheres and ionospheres are
also emerging fields in this domain. In this regard, multi-disciplinary
conferences and workshops are very crucial as they provide excellent
platforms where scientists can learn the advancements of research in
other domains and can interact with each other which may lead to
possible future collaborative research using interoperable data. During
the recent Covid pandemic, most conferences are being conducted
virtually which helps increase participation as no transport and
accommodation charges are required. The registration fees are also
reduced in many conferences. This reduces financial burdens of the
participants and increases possibilities of further integrated research
across the world.
2.2. Coordinated research in Space Physics and Aeronomy
Space Physics and Aeronomy also use a coordinated research approach. The
methodologies followed for any study are almost consistent throughout
the world. For example, the identification of cycle slips due to
ionospheric irregularities and multipath error correction techniques for
TEC are similar. Some of the procedures may not be the same, however.
For example, there are several methodologies present for TEC calibration
(Abe et al., 2017). Efficiencies of different methodologies vary in
different latitude-longitude sectors. In these cases, users must be
aware of these differences and should apply that mechanism that provides
better TEC representation in that region. The scripts/codes of the
ionospheric and magnetospheric prediction models are stored in
institutional websites or Github accounts and shared with global users
with proper acknowledgements to the developers. The Community
Coordinated Modeling Center (CCMC), NASA provides excellent tools to
global users to simulate and visualize the model outputs. These efforts
are examples of both open and coordinated research.
2.3. Open research in Space Physics and Aeronomy
This section also supports open data sharing. The data, models,
methodologies and formulae in any scholarly articles must be provided in
the data or acknowledgement section or as supplementary materials so
that any reader can replicate the experiment. This is in correspondence
with Findable, Accessible, Interoperable, and Reusable (FAIR) data
policies (Wilkinson et al., 2016) used by American Geophysical Union
(AGU). If the readers still face difficulties interpreting the data (for
example: high frequency 50Hz GNSS data), they may contact the authors or
the data providers.
Data sharing is an essential part of global research. The Space Physics
and Aeronomy section is enriched with free data resources from different
space agencies and universities which is the key to the advancement of
research in this domain. For example, geophysical data related to
heliophysics studies can easily be obtained from NASA’s Space Physics
Data Facility (SPDF), at the website omniweb.gsfc.nasa.gov. The data is
obtained from different satellite missions and ground-based
measurements. Some of the examples are solar wind speed, flow pressure,
IMF (from ACE, WIND, IMP 8, Geotail), proton fluxes (NOAA Geostationary
Operational Environmental Satellite (GOES)), AE, Dst (World Data Center
for Geomagnetism (WDC), Kyoto and all its data supplier stations), Polar
Cap North (PCN) from Thule (Technical University of Denmark (DTU),
Denmark). The data can be available in one minute as well as in
hourly/daily resolutions. Geophysical data are also available from the
website of WDC (wdc.kugi.kyoto-u.ac.jp) and NOAA’s National Center for
Environmental Information (NCEI)
(www.ngdc.noaa.gov/stp/GEOMAG/kp_ap.html). Global TEC data are
available from GNSS receivers, ionosondes, etc. These are a few examples
of free data resources to help global independent research. Geophysical
data from other planetary observations and new space missions are also
available from the websites of different space agencies and
universities. This increases the scope of research on emerging topics.
Apart from data sharing, NASA and other space agencies also provide free
study materials to every space enthusiast.
Information on data calibration and corresponding sensing instruments
are also freely available at websites. For example, details of
instruments used in NASA’s Living with a Star (LWS) Parker Solar Probe
(PSP) are available at the website of Johns Hopkins University, Applied
Physics Laboratory
(parkersolarprobe.jhuapl.edu/Spacecraft/index.php#Instruments) and at
www.nasa.gov/content/goddard/parker-solar-probe-instruments). The
details of NASA’s Solar Probe Plus (SPP) mission FIELD instrument is
available in Bale et al. (2016). The same from PSP is available in
Diaz-Aguado et al. (2021a, 2021b).
Workshops are being organized for contributing to decadal surveys, white
papers, etc. through slack channels and Google documents. The author had
a chance to participate in similar workshop (Heliophysics 2050 Workshop
by Lunar and Planetary Institute and Universities Space Research
Association) in 2021 where efforts have been given for international
collaboration to summarize the present understandings in space physics
and enlist necessary future plans. These are some good examples for both
open and networked research.
2.4. Networked research in Space Physics and Aeronomy
Networking is an important aspect towards the growth of any field of
science. Networking helps sharing ideas, creating possible
collaborations and helps young researchers to learn from eminent
scientists around the world. Networking can be conducted in the form of
workshops, conferences, seminars, collaborations with mutual benefits,
etc. The author has participated in the International Reference
Ionosphere workshop conducted by the Committee on Space Research
(COSPAR) at National Central University, Taiwan in 2017 and the Workshop
on Space Weather Effects on GNSS Operations at Low Latitudes at Abdus
Salam International Centre for Theoretical Physics (ICTP), Italy in 2018
with financial supports. Financial support is crucial for young
scientists, especially from developing countries. In those mentioned
workshops, the author had the chance to interact and learn from the
eminent scientists in this field. All young participants were divided
into several groups to work on certain scientific objectives during the
workshops. The works were presented at the end of the workshops when the
eminent scientists provided their valuable feedback. The author also had
a chance to be involved in an International Space Science Institute
(ISSI) project as a young scientist. ISSI provides an excellent platform
for collaborative research by various international teams. The author
also participated in several multidisciplinary conferences and meetings
during the last five years such as AGU fall meeting, European
Geosciences Union (EGU) fall meeting, International Union of Radio
Science (URSI) General Assembly, COSPAR General Assembly and Beacon
Satellite Symposium. These experiences provided him with good platforms
for interactions and possible collaborations. The recent Covid pandemic
definitely slows down the progress of research all over the world. But
even during this uncertain period, collaborative research has been
increased due to numerous virtual meetings. As there is no need to join
physically, no financial burdens are associated which facilitate broader
participation. In these meetings, participants can interact with each
other for further discussions in a more focused manner. Different slack
channels are provided for these focused discussions and possible
collaborative research. The author is currently involved in working in
two focused groups (i) COSPAR International Space Weather Action Team
(ISWAT) and (ii) Center for the Unified Study of Interhemispheric
Asymmetries (CUSIA) under Dr. Daniel T. Welling, University of Texas at
Arlington. In these groups, global scientists can contribute alongside
the team leaders and principal investigators for their mutual benefits.
Science missions by different space agencies have co-investigators from
different universities. Students working under those investigators can
also contribute to these missions as necessary “people-power” to
analyze and interpret data which benefits both sides. SCOSTEP Visiting
Scholar (SVS) program assists young scientists to work in eminent
research institutes to their space program objectives. This is another
example of mutual benefits (for the young scientist and the
corresponding institute). CCMC GEM Modeling Challenge, CEDAR
Electrodynamics Thermosphere Ionosphere (CETI) Challenge were conducted
to simulate certain space weather events and validate the performances
of the existing models. Scientists can submit their model runs which get
published in reputed journals and conferences and provide important
information regarding the efficiencies of existing models in adverse
space-weather conditions. NASA citizen scientist program is an excellent
way to involve any space enthusiasts in space related observations. Some
of the programs related to this section are Junocam
(www.missionjuno.swri.edu/junocam) and Aurorasaurus
(www.aurorasaurus.org). In 2021, the NASA heliophysics division LWS
Architecture Committee (LWSAC) requested the space science community to
provide feedback on the Strategic Science Areas (SSA) Focused Mission
Topics. The author has also provided some feedback. These are excellent
examples of networked research with mutual benefits.